Use ptab functionality also for ports

39 files changed, 1104 insertions, 1141 deletions

diff --git a/erts/emulator/beam/atom.names b/erts/emulator/beam/atom.names
index 201719507f..d6d8633f6f 100644
--- a/erts/emulator/beam/atom.names
+++ b/erts/emulator/beam/atom.names
@@ -419,6 +419,7 @@ atom pid
 atom port
 atom ports
 atom port_count
+atom port_limit
 atom print
 atom priority
 atom private
diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index 3fb2fbd01c..d8ccbacc26 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -1660,6 +1660,7 @@ void process_main(void)
      reg[0] = r(0);
      result = erl_send(c_p, r(0), x(1));
      PreFetch(0, next);
+     ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
      ERTS_SMP_REQ_PROC_MAIN_LOCK(c_p);
      PROCESS_MAIN_CHK_LOCKS(c_p);
      if (c_p->mbuf || MSO(c_p).overhead >= BIN_VHEAP_SZ(c_p)) {
@@ -2636,6 +2637,7 @@ void process_main(void)
 	reg[0] = r(0);
 	result = (*bf)(c_p, reg, I);
 	ASSERT(!ERTS_PROC_IS_EXITING(c_p) || is_non_value(result));
+	ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
 	ERTS_HOLE_CHECK(c_p);
 	ERTS_SMP_REQ_PROC_MAIN_LOCK(c_p);
 	PROCESS_MAIN_CHK_LOCKS(c_p);
@@ -3370,7 +3372,6 @@ void process_main(void)
 	    PROCESS_MAIN_CHK_LOCKS(c_p);
 	    bif_nif_arity = I[-1];
 	    ERTS_SMP_UNREQ_PROC_MAIN_LOCK(c_p);
-	    ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
 
 	    ASSERT(!ERTS_PROC_IS_EXITING(c_p));
 	    {
@@ -3415,7 +3416,6 @@ void process_main(void)
 	    bif_nif_arity = I[-1];
 	    ASSERT(bif_nif_arity <= 3);
 	    ERTS_SMP_UNREQ_PROC_MAIN_LOCK(c_p);
-	    ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
 	    reg[0] = r(0);
 	    {
 		Eterm (*bf)(Process*, Eterm*, BeamInstr*) = vbf;
@@ -4646,7 +4646,6 @@ void process_main(void)
 	 ERTS_SMP_UNREQ_PROC_MAIN_LOCK(c_p);
 	 flags = erts_call_trace(c_p, ep->code, ep->match_prog_set, reg,
 				 0, &ERTS_TRACER_PROC(c_p));
-	 ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
 	 ERTS_SMP_REQ_PROC_MAIN_LOCK(c_p);
 	 PROCESS_MAIN_CHK_LOCKS(c_p);
 	 ASSERT(!ERTS_PROC_IS_EXITING(c_p));
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index 84513c1b0e..5ea441ad81 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -37,6 +37,8 @@
 #include "erl_db_util.h"
 #include "register.h"
 #include "erl_thr_progress.h"
+#define ERTS_PTAB_WANT_BIF_IMPL__
+#include "erl_ptab.h"
 
 static Export* flush_monitor_message_trap = NULL;
 static Export* set_cpu_topology_trap = NULL;
@@ -155,7 +157,10 @@ BIF_RETTYPE link_1(BIF_ALIST_1)
     }
 
     if (is_internal_port(BIF_ARG_1)) {
-	Port *pt = erts_id2port(BIF_ARG_1, BIF_P, ERTS_PROC_LOCK_MAIN);
+	Port *pt = erts_id2port_sflgs(BIF_ARG_1,
+				      BIF_P,
+				      ERTS_PROC_LOCK_MAIN,
+				      ERTS_PORT_SFLGS_INVALID_LOOKUP);
 	if (!pt) {
 	    goto res_no_proc;
 	}
@@ -167,7 +172,7 @@ BIF_RETTYPE link_1(BIF_ALIST_1)
 	/* else: already linked */
 
 	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK);
-	erts_smp_port_unlock(pt);
+	erts_port_release(pt);
 	BIF_RET(am_true);
     }
     else if (is_external_port(BIF_ARG_1)
@@ -948,7 +953,7 @@ BIF_RETTYPE unlink_1(BIF_ALIST_1)
 #ifdef ERTS_SMP
 	if (ERTS_PROC_PENDING_EXIT(BIF_P)) {
 	    if (pt)
-		erts_smp_port_unlock(pt);
+		erts_port_release(pt);
 	    goto handle_pending_exit;
 	}
 #endif
@@ -959,7 +964,7 @@ BIF_RETTYPE unlink_1(BIF_ALIST_1)
 
 	if (pt) {
 	    rl = erts_remove_link(&ERTS_P_LINKS(pt), BIF_P->common.id);
-	    erts_smp_port_unlock(pt);
+	    erts_port_release(pt);
 	    if (rl)
 		erts_destroy_link(rl);
 	}
@@ -1341,7 +1346,7 @@ BIF_RETTYPE exit_2(BIF_ALIST_2)
      if (is_internal_port(BIF_ARG_1)) {
 	 Port *prt;
 	 erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
-	 prt = erts_id2port(BIF_ARG_1, NULL, 0);
+	 prt = erts_id2port(BIF_ARG_1);
 	 if (prt) {
 	     erts_do_exit_port(prt, BIF_P->common.id, BIF_ARG_2);
 	     erts_port_release(prt);
@@ -1894,7 +1899,10 @@ do_send(Process *p, Eterm to, Eterm msg, int suspend) {
 	if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
 	    profile_runnable_proc(p, am_inactive);
 	}
-	pt = erts_id2port(to, p, ERTS_PROC_LOCK_MAIN);
+	pt = erts_id2port_sflgs(to,
+				p,
+				ERTS_PROC_LOCK_MAIN,
+				ERTS_PORT_SFLGS_INVALID_LOOKUP);
       port_common:
 	ERTS_SMP_LC_ASSERT(!pt || erts_lc_is_port_locked(pt));
         
@@ -1908,7 +1916,7 @@ do_send(Process *p, Eterm to, Eterm msg, int suspend) {
 		profile_runnable_port(pt, am_active);
 	    }
 	
-	    state = erts_smp_atomic32_read_nob(&pt->state);
+	    state = erts_atomic32_read_nob(&pt->state);
 	    /* XXX let port_command handle the busy stuff !!! */
 	    if (state & ERTS_PORT_SFLG_PORT_BUSY) {
 		if (suspend) {
@@ -3510,75 +3518,25 @@ BIF_RETTYPE garbage_collect_message_area_0(BIF_ALIST_0)
 #endif
 }
 
+
 /**********************************************************************/
-/* Return a list of active ports */
+/*
+ * The erlang:processes/0 BIF.
+ */
 
-BIF_RETTYPE ports_0(BIF_ALIST_0)
+BIF_RETTYPE processes_0(BIF_ALIST_0)
 {
-    Eterm res = NIL;
-    Eterm* port_buf = erts_alloc(ERTS_ALC_T_TMP,
-				 sizeof(Eterm)*erts_max_ports);
-    Eterm* pp = port_buf;
-    Eterm* dead_ports;
-    int alive, dead;
-    Uint32 next_ss;
-    int i;
-
-    /* To get a consistent snapshot... 
-     * We add alive ports from start of the buffer
-     * while dying ports are added from the other end by the killing threads.
-     */
-
-    erts_smp_mtx_lock(&ports_snapshot_mtx); /* One snapshot at a time */
-
-    erts_smp_atomic_set_nob(&erts_dead_ports_ptr,
-			    (erts_aint_t) (port_buf + erts_max_ports));
-
-    next_ss = erts_smp_atomic32_inc_read_relb(&erts_ports_snapshot);
-
-    for (i = erts_max_ports-1; i >= 0; i--) {
-	Port* prt = &erts_port[i];
-	erts_aint32_t state = erts_smp_atomic32_read_acqb(&prt->state);
-	if (!(state & ERTS_PORT_SFLGS_DEAD)) {
-	    erts_smp_port_minor_lock(prt);
-	    state = erts_smp_atomic32_read_nob(&prt->state);
-	    if (!(state & ERTS_PORT_SFLGS_DEAD) && prt->snapshot != next_ss) {
-		ASSERT(prt->snapshot == next_ss - 1);
-		*pp++ = prt->common.id;
-		prt->snapshot = next_ss; /* Consumed by this snapshot */
-	    }
-	    erts_smp_port_minor_unlock(prt);
-	}
-    }
-
-    dead_ports = (Eterm*)erts_smp_atomic_xchg_nob(&erts_dead_ports_ptr,
-						  (erts_aint_t) NULL);
-    erts_smp_mtx_unlock(&ports_snapshot_mtx);
-
-    ASSERT(pp <= dead_ports);
-
-    alive = pp - port_buf;
-    dead = port_buf + erts_max_ports - dead_ports;
-
-    ASSERT((alive+dead) <= erts_max_ports);
-
-    if (alive+dead > 0) {
-	erts_aint_t i;
-	Eterm *hp = HAlloc(BIF_P, (alive+dead)*2);
-
-	for (i = 0; i < alive; i++) {
-	    res = CONS(hp, port_buf[i], res);	    
-	    hp += 2;
-	}
-	for (i = 0; i < dead; i++) {
-	    res = CONS(hp, dead_ports[i], res);
-	    hp += 2;
-	}
-    }
+    return erts_ptab_list(BIF_P, &erts_proc);
+}
 
-    erts_free(ERTS_ALC_T_TMP, port_buf);
+/**********************************************************************/
+/*
+ * The erlang:ports/0 BIF.
+ */
 
-    BIF_RET(res);
+BIF_RETTYPE ports_0(BIF_ALIST_0)
+{
+    return erts_ptab_list(BIF_P, &erts_port);
 }
 
 /**********************************************************************/
diff --git a/erts/emulator/beam/break.c b/erts/emulator/beam/break.c
index fba734623a..ad05316b39 100644
--- a/erts/emulator/beam/break.c
+++ b/erts/emulator/beam/break.c
@@ -61,9 +61,12 @@ extern char* erts_system_version[];
 static void
 port_info(int to, void *to_arg)
 {
-    int i;
-    for (i = 0; i < erts_max_ports; i++)
-	print_port_info(to, to_arg, i);
+    int i, max = erts_ptab_max(&erts_port);
+    for (i = 0; i < max; i++) {
+	Port *p = erts_pix2port(i);
+	if (p)
+	    print_port_info(p, to, to_arg);
+    }
 }
 
 void
diff --git a/erts/emulator/beam/dist.c b/erts/emulator/beam/dist.c
index 7aef26aa21..13715034cb 100644
--- a/erts/emulator/beam/dist.c
+++ b/erts/emulator/beam/dist.c
@@ -144,7 +144,7 @@ create_cache(DistEntry *dep)
 
     ERTS_SMP_LC_ASSERT(
 	is_internal_port(dep->cid)
-	&& erts_lc_is_port_locked(&erts_port[internal_port_index(dep->cid)]));
+	&& erts_lc_is_port_locked(erts_port_lookup_raw(dep->cid)));
     ASSERT(!dep->cache);
 
     dep->cache = cp = (ErtsAtomCache*) erts_alloc(ERTS_ALC_T_DCACHE,
@@ -421,9 +421,9 @@ int erts_do_net_exits(DistEntry *dep, Eterm reason)
 	    ASSERT(is_internal_port(prt_id));
 	    erts_smp_rwmtx_rwunlock(&erts_dist_table_rwmtx);
 
-	    prt = erts_id2port(prt_id, NULL, 0);
+	    prt = erts_id2port(prt_id);
 	    if (prt) {
-		ASSERT(erts_smp_atomic32_read_nob(&prt->state)
+		ASSERT(erts_atomic32_read_nob(&prt->state)
 		       & ERTS_PORT_SFLG_DISTRIBUTION);
 		ASSERT(prt->dist_entry);
 		/* will call do_net_exists !!! */
@@ -455,7 +455,7 @@ int erts_do_net_exits(DistEntry *dep, Eterm reason)
 	erts_smp_de_rwlock(dep);
 
 	ERTS_SMP_LC_ASSERT(is_internal_port(dep->cid)
-			   && erts_lc_is_port_locked(&erts_port[internal_port_index(dep->cid)]));
+			   && erts_lc_is_port_locked(erts_port_lookup_raw(dep->cid)));
 
 	if (erts_port_task_is_scheduled(&dep->dist_cmd))
 	    erts_port_task_abort(dep->cid, &dep->dist_cmd);
@@ -1957,7 +1957,7 @@ erts_dist_command(Port *prt, int reds_limit)
     dep->finalized_out_queue.first = NULL;
     dep->finalized_out_queue.last = NULL;
 
-    state = erts_smp_atomic32_read_nob(&prt->state);
+    state = erts_atomic32_read_nob(&prt->state);
 
     if (reds > reds_limit)
 	goto preempted;
@@ -1978,7 +1978,7 @@ erts_dist_command(Port *prt, int reds_limit)
 	    obufsize += size_obuf(fob);
 	    foq.first = foq.first->next;
 	    free_dist_obuf(fob);
-	    state = erts_smp_atomic32_read_nob(&prt->state);
+	    state = erts_atomic32_read_nob(&prt->state);
 	    preempt = reds > reds_limit || (state & ERTS_PORT_SFLGS_DEAD);
 	    if (state & ERTS_PORT_SFLG_PORT_BUSY)
 		break;
@@ -2060,7 +2060,7 @@ erts_dist_command(Port *prt, int reds_limit)
 	    obufsize += size_obuf(fob);
 	    oq.first = oq.first->next;
 	    free_dist_obuf(fob);
-	    state = erts_smp_atomic32_read_nob(&prt->state);
+	    state = erts_atomic32_read_nob(&prt->state);
 	    preempt = reds > reds_limit || (state & ERTS_PORT_SFLGS_DEAD);
 	    if ((state & ERTS_PORT_SFLG_PORT_BUSY) && oq.first && !preempt)
 		goto finalize_only;
@@ -2580,10 +2580,13 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
     else if (!dep)
 	goto system_limit; /* Should never happen!!! */
 
-    pp = erts_id2port(BIF_ARG_2, BIF_P, ERTS_PROC_LOCK_MAIN);
+    pp = erts_id2port_sflgs(BIF_ARG_2,
+			    BIF_P,
+			    ERTS_PROC_LOCK_MAIN,
+			    ERTS_PORT_SFLGS_INVALID_LOOKUP);
     erts_smp_de_rwlock(dep);
 
-    if (!pp || (erts_smp_atomic32_read_nob(&pp->state)
+    if (!pp || (erts_atomic32_read_nob(&pp->state)
 		& ERTS_PORT_SFLG_EXITING))
 	goto badarg;
 
@@ -2613,7 +2616,7 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
     if (pp->dist_entry || is_not_nil(dep->cid))
 	goto badarg;
 
-    erts_smp_atomic32_read_bor_nob(&pp->state, ERTS_PORT_SFLG_DISTRIBUTION);
+    erts_atomic32_read_bor_nob(&pp->state, ERTS_PORT_SFLG_DISTRIBUTION);
 
     pp->dist_entry = dep;
 
@@ -2658,7 +2661,7 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
     }
 
     if (pp)
-	erts_smp_port_unlock(pp);
+	erts_port_release(pp);
 
     return ret;
 
diff --git a/erts/emulator/beam/dist.h b/erts/emulator/beam/dist.h
index 98c069da8a..7de8786c4a 100644
--- a/erts/emulator/beam/dist.h
+++ b/erts/emulator/beam/dist.h
@@ -187,7 +187,7 @@ void erts_schedule_dist_command(Port *prt, DistEntry *dist_entry)
 
     if (prt) {
 	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-	ASSERT((erts_smp_atomic32_read_nob(&prt->state)
+	ASSERT((erts_atomic32_read_nob(&prt->state)
 		& ERTS_PORT_SFLGS_DEAD) == 0);
 	ASSERT(prt->dist_entry);
 
diff --git a/erts/emulator/beam/erl_alloc.c b/erts/emulator/beam/erl_alloc.c
index d0c0a13400..e8a9c11034 100644
--- a/erts/emulator/beam/erl_alloc.c
+++ b/erts/emulator/beam/erl_alloc.c
@@ -2273,6 +2273,7 @@ erts_allocated_areas(int *print_to_p, void *print_to_arg, void *proc)
     int i, length;
     Uint reserved_atom_space, atom_space;
     int max_processes = erts_ptab_max(&erts_proc);
+    int max_ports = erts_ptab_max(&erts_port);
 
     if (proc) {
 	ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN
@@ -2303,8 +2304,8 @@ erts_allocated_areas(int *print_to_p, void *print_to_arg, void *proc)
 
     values[i].arity = 2;
     values[i].name = "static";
-    values[i].ui[0] = 
-	erts_max_ports*sizeof(Port)		/* Port table */
+    values[i].ui[0] =
+	max_ports*sizeof(Port)		/* Port table */
 	+ erts_timer_wheel_memory_size()	/* Timer wheel */
 #ifdef SYS_TMP_BUF_SIZE
 	+ SYS_TMP_BUF_SIZE		/* tmp_buf in sys on vxworks & ose */
diff --git a/erts/emulator/beam/erl_alloc.h b/erts/emulator/beam/erl_alloc.h
index e475f9d8a2..ba5ec9c367 100644
--- a/erts/emulator/beam/erl_alloc.h
+++ b/erts/emulator/beam/erl_alloc.h
@@ -267,6 +267,8 @@ typedef void (*erts_alloc_verify_func_t)(Allctr_t *);
 erts_alloc_verify_func_t
 erts_alloc_get_verify_unused_temp_alloc(Allctr_t **allctr);
 
+#define ERTS_ALC_DATA_ALIGN_SIZE(SZ) \
+  (((((SZ) - 1) / 8) + 1) * 8)
 
 #define ERTS_ALC_CACHE_LINE_ALIGN_SIZE(SZ) \
   (((((SZ) - 1) / ERTS_CACHE_LINE_SIZE) + 1) * ERTS_CACHE_LINE_SIZE)
diff --git a/erts/emulator/beam/erl_alloc.types b/erts/emulator/beam/erl_alloc.types
index 4ad0c41b50..92ba15214e 100644
--- a/erts/emulator/beam/erl_alloc.types
+++ b/erts/emulator/beam/erl_alloc.types
@@ -146,6 +146,7 @@ class	SYSTEM		system_data
 
 type	SBMBC		SBMBC		SYSTEM		small_block_mbc
 type	PROC		FIXED_SIZE	PROCESSES	proc
+type	PORT		DRIVER		SYSTEM		port
 type	ATOM		LONG_LIVED	ATOM		atom_entry
 type	MODULE		LONG_LIVED	CODE		module_entry
 type	REG_PROC	STANDARD	PROCESSES	reg_proc
@@ -188,7 +189,7 @@ type	PORT_TABLE	LONG_LIVED	SYSTEM		port_tab
 type	TIMER_WHEEL	LONG_LIVED	SYSTEM		timer_wheel
 type	DRV		DRIVER		SYSTEM		drv_internal
 type	DRV_BINARY	BINARY		BINARIES	drv_binary
-type	DRIVER		STANDARD	SYSTEM		driver
+type	DRIVER		DRIVER		SYSTEM		driver
 type	NIF		DRIVER		SYSTEM		nif_internal
 type	BINARY		BINARY		BINARIES	binary
 type	NBIF_TABLE	SYSTEM		SYSTEM		nbif_tab
@@ -196,7 +197,6 @@ type	ARG_REG		STANDARD	PROCESSES	arg_reg
 type	PROC_DICT	STANDARD	PROCESSES	proc_dict
 type	CALLS_BUF	STANDARD	PROCESSES	calls_buf
 type	BPD		STANDARD	SYSTEM		bpd
-type	PORT_NAME	STANDARD	SYSTEM		port_name
 type	LINEBUF		STANDARD	SYSTEM		line_buf
 type	IOQ		STANDARD	SYSTEM		io_queue
 type	BITS_BUF	STANDARD	SYSTEM		bits_buf
@@ -236,7 +236,7 @@ type	PORT_TASK	SHORT_LIVED	SYSTEM		port_task
 type	PORT_TASKQ	SHORT_LIVED	SYSTEM		port_task_queue
 type	MISC_OP_LIST	SHORT_LIVED	SYSTEM		misc_op_list
 type	PORT_NAMES	SHORT_LIVED	SYSTEM		port_names
-type	PORT_DATA_LOCK	STANDARD	SYSTEM		port_data_lock
+type	PORT_DATA_LOCK	DRIVER		SYSTEM		port_data_lock
 type	NODES_MON	STANDARD	PROCESSES	nodes_monitor
 type	PTAB_LIST_DEL	SHORT_LIVED	PROCESSES	ptab_list_deleted_el
 type	PTAB_LIST_CNKI	SHORT_LIVED	PROCESSES	ptab_list_chunk_info
diff --git a/erts/emulator/beam/erl_async.c b/erts/emulator/beam/erl_async.c
index 8d3bea82c1..d8adaedc91 100644
--- a/erts/emulator/beam/erl_async.c
+++ b/erts/emulator/beam/erl_async.c
@@ -375,10 +375,15 @@ static ERTS_INLINE ErtsAsync *async_get(ErtsThrQ_t *q,
 
 static ERTS_INLINE void call_async_ready(ErtsAsync *a)
 {
+#if ERTS_USE_ASYNC_READY_Q
     Port *p = erts_id2port_sflgs(a->port,
 				 NULL,
 				 0,
 				 ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP);
+#else
+    Port *p = erts_thr_id2port_sflgs(a->port,
+				     ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP);
+#endif
     if (!p) {
 	if (a->async_free)
 	    a->async_free(a->async_data);
@@ -388,7 +393,11 @@ static ERTS_INLINE void call_async_ready(ErtsAsync *a)
 	    if (a->async_free)
 		a->async_free(a->async_data);
 	}
+#if ERTS_USE_ASYNC_READY_Q
 	erts_port_release(p);
+#else
+	erts_thr_port_release(p);
+#endif
     }
     if (a->hndl)
 	erts_ddll_dereference_driver(a->hndl);
diff --git a/erts/emulator/beam/erl_bif_ddll.c b/erts/emulator/beam/erl_bif_ddll.c
index a120a3e5f2..e18b1f0159 100644
--- a/erts/emulator/beam/erl_bif_ddll.c
+++ b/erts/emulator/beam/erl_bif_ddll.c
@@ -117,48 +117,27 @@ static void ddll_no_more_references(void *vdh);
 static void
 kill_ports_driver_unloaded(DE_Handle *dh)
 {
-    int ix;
+    int ix, max = erts_ptab_max(&erts_port);
 
-    for (ix = 0; ix < erts_max_ports; ix++) {
-	Port* prt = &erts_port[ix];
+    for (ix = 0; ix < max; ix++) {
 	erts_aint32_t state;
-	state = erts_smp_atomic32_read_acqb(&prt->state);
-	if (state & FREE_PORT_FLAGS)
+	Port* prt = erts_pix2port(ix);
+	if (!prt)
 	    continue;
 
-	erts_smp_port_minor_lock(prt);
+	ERTS_SMP_DATA_DEPENDENCY_READ_MEMORY_BARRIER;
 
-	if (prt->drv_ptr->handle != dh) {
-	    erts_smp_port_minor_unlock(prt);
+	state = erts_atomic32_read_nob(&prt->state);
+	if (state & FREE_PORT_FLAGS)
 	    continue;
-	}
 
-	erts_smp_atomic32_inc_nob(&prt->common.refc);
-	erts_smp_port_minor_unlock(prt);
-
-	state = erts_smp_atomic32_read_acqb(&prt->state);
-	if (!(state & FREE_PORT_FLAGS)) {
-#if DDLL_SMP
-	    if (state & ERTS_PORT_SFLG_INITIALIZING) {
-		/* Extremely rare busy wait */
-		do {
-		    ERTS_SPIN_BODY;
-		    state = erts_smp_atomic32_read_acqb(&prt->state);
-		} while (state & ERTS_PORT_SFLG_INITIALIZING);
-	    }
+	erts_smp_port_lock(prt);
 
-	    erts_smp_mtx_lock(prt->lock);
+	state = erts_atomic32_read_nob(&prt->state);
+	if (!(state & ERTS_PORT_SFLGS_DEAD) && prt->drv_ptr->handle == dh)
+	    driver_failure_atom((ErlDrvPort) prt, "driver_unloaded");
 
-	    if (prt->drv_ptr->handle == dh) {
-		state = erts_smp_atomic32_read_acqb(&prt->state);
-		if (!(state & ERTS_PORT_SFLGS_DEAD))
-		    driver_failure_atom(ix, "driver_unloaded");
-	    }
-#else
-	    driver_failure_atom(ix, "driver_unloaded");
-#endif
-	    erts_port_release(prt);
-	}
+	erts_port_release(prt);
     }
 }
 
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 847a0c33e9..0586a89041 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -2189,6 +2189,10 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 	BIF_RET(make_small(erts_ptab_count(&erts_proc)));
     } else if (BIF_ARG_1 == am_process_limit) {
 	BIF_RET(make_small(erts_ptab_max(&erts_proc)));
+    } else if (BIF_ARG_1 == am_port_count) {
+	BIF_RET(make_small(erts_ptab_count(&erts_port)));
+    } else if (BIF_ARG_1 == am_port_limit) {
+	BIF_RET(make_small(erts_ptab_max(&erts_port)));
     } else if (BIF_ARG_1 == am_info
 	       || BIF_ARG_1 == am_procs
 	       || BIF_ARG_1 == am_loaded
@@ -2840,7 +2844,10 @@ static BIF_RETTYPE port_info(Process* p, Eterm portid, Eterm item)
     int count;
 
     if (is_internal_port(portid))
-	prt = erts_id2port(portid, p, ERTS_PROC_LOCK_MAIN);
+	prt = erts_id2port_sflgs(portid,
+				 p,
+				 ERTS_PROC_LOCK_MAIN,
+				 ERTS_PORT_SFLGS_INVALID_LOOKUP);
     else if (is_atom(portid))
 	erts_whereis_name(p, ERTS_PROC_LOCK_MAIN,
 			  portid, NULL, 0, 0, &prt);
@@ -2975,7 +2982,7 @@ static BIF_RETTYPE port_info(Process* p, Eterm portid, Eterm item)
 #ifndef ERTS_SMP
 	res = am_false;
 #else
-	if (erts_smp_atomic32_read_nob(&prt->state)
+	if (erts_atomic32_read_nob(&prt->state)
 	    & ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK) {
 	    DECL_AM(port_level);
 	    ASSERT(prt->drv_ptr->flags
@@ -2999,7 +3006,7 @@ static BIF_RETTYPE port_info(Process* p, Eterm portid, Eterm item)
 
  done:
 
-    erts_smp_port_unlock(prt);
+    erts_port_release(prt);
 
     return ret;
 }
@@ -3357,9 +3364,8 @@ BIF_RETTYPE erts_debug_get_internal_state_1(BIF_ALIST_1)
 	    Eterm res;
 	    if (ERTS_IS_ATOM_STR("next_pid", BIF_ARG_1))
 		res = erts_ptab_test_next_id(&erts_proc, 0, 0);
-	    else {
-		res = erts_test_next_port(0, 0);
-	    }
+	    else
+		res = erts_ptab_test_next_id(&erts_port, 0, 0);
 	    if (res < 0)
 		BIF_RET(am_false);
 	    BIF_RET(erts_make_integer(res, BIF_P));
@@ -3466,11 +3472,14 @@ BIF_RETTYPE erts_debug_get_internal_state_1(BIF_ALIST_1)
 		}
 		else if(is_internal_port(tp[2])) {
 		    Eterm res;
-		    Port *p = erts_id2port(tp[2], BIF_P, ERTS_PROC_LOCK_MAIN);
+		    Port *p = erts_id2port_sflgs(tp[2],
+						 BIF_P,
+						 ERTS_PROC_LOCK_MAIN,
+						 ERTS_PORT_SFLGS_INVALID_LOOKUP);
 		    if(!p)
 			BIF_RET(am_undefined);
 		    res = make_link_list(BIF_P, ERTS_P_LINKS(p), NIL);
-		    erts_smp_port_unlock(p);
+		    erts_port_release(p);
 		    BIF_RET(res);
 		}
 		else if(is_node_name_atom(tp[2])) {
@@ -3714,9 +3723,8 @@ BIF_RETTYPE erts_debug_set_internal_state_2(BIF_ALIST_2)
 
 		if (ERTS_IS_ATOM_STR("next_pid", BIF_ARG_1))
 		    res = erts_ptab_test_next_id(&erts_proc, 1, next);
-		else {
-		    res = erts_test_next_port(1, next);
-		}
+		else
+		    res = erts_ptab_test_next_id(&erts_port, 1, next);
 		if (res < 0)
 		    BIF_RET(am_false);
 		BIF_RET(erts_make_integer(res, BIF_P));
diff --git a/erts/emulator/beam/erl_bif_port.c b/erts/emulator/beam/erl_bif_port.c
index 2b7760f556..31151dc9f5 100644
--- a/erts/emulator/beam/erl_bif_port.c
+++ b/erts/emulator/beam/erl_bif_port.c
@@ -42,7 +42,7 @@
 #include "erl_bits.h"
 #include "dtrace-wrapper.h"
 
-static int open_port(Process* p, Eterm name, Eterm settings, int *err_nump);
+static Port *open_port(Process* p, Eterm name, Eterm settings, int *err_typep, int *err_nump);
 static byte* convert_environment(Process* p, Eterm env);
 static char **convert_args(Eterm);
 static void free_args(char **);
@@ -54,16 +54,17 @@ port_call(Process* p, Eterm arg1, Eterm arg2, Eterm arg3);
 
 BIF_RETTYPE open_port_2(BIF_ALIST_2)
 {
-    int port_num;
-    Eterm port_val;
+    Port *port;
+    Eterm port_id;
     char *str;
-    int err_num;
+    int err_type, err_num;
 
-    if ((port_num = open_port(BIF_P, BIF_ARG_1, BIF_ARG_2, &err_num)) < 0) {
-	if (port_num == -3) {
+    port = open_port(BIF_P, BIF_ARG_1, BIF_ARG_2, &err_type, &err_num);
+    if (!port) {
+	if (err_type == -3) {
 	    ASSERT(err_num == BADARG || err_num == SYSTEM_LIMIT);
 	    BIF_ERROR(BIF_P, err_num);
-	} else if (port_num == -2) {
+	} else if (err_type == -2) {
 	    str = erl_errno_id(err_num);
 	} else {
 	    str = "einval";
@@ -74,15 +75,15 @@ BIF_RETTYPE open_port_2(BIF_ALIST_2)
 
     erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_LINK);
 
-    port_val = erts_port[port_num].common.id;
-    erts_add_link(&ERTS_P_LINKS(&erts_port[port_num]), LINK_PID, BIF_P->common.id);
-    erts_add_link(&ERTS_P_LINKS(BIF_P), LINK_PID, port_val);
+    port_id = port->common.id;
+    erts_add_link(&ERTS_P_LINKS(port), LINK_PID, BIF_P->common.id);
+    erts_add_link(&ERTS_P_LINKS(BIF_P), LINK_PID, port_id);
 
     erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK);
 
-    erts_port_release(&erts_port[port_num]);
+    erts_port_release(port);
 
-    BIF_RET(port_val);
+    BIF_RET(port_id);
 }
 
 /****************************************************************************
@@ -112,7 +113,10 @@ id_or_name2port(Process *c_p, Eterm id)
 {
     Port *port;
     if (is_not_atom(id))
-	port = erts_id2port(id, c_p, ERTS_PROC_LOCK_MAIN);
+	port = erts_id2port_sflgs(id,
+				  c_p,
+				  ERTS_PROC_LOCK_MAIN,
+				  ERTS_PORT_SFLGS_INVALID_LOOKUP);
     else
 	erts_whereis_name(c_p, ERTS_PROC_LOCK_MAIN, id, NULL, 0, 0, &port);
     return port;
@@ -164,7 +168,7 @@ do_port_command(Process *BIF_P, Eterm arg1, Eterm arg2, Eterm arg3,
 	ERTS_BIF_PREP_ERROR(res, BIF_P, EXC_NOTSUP);
     }
     else if (!(flags & ERTS_PORT_COMMAND_FLAG_FORCE)
-	     && (erts_smp_atomic32_read_nob(&p->state) & ERTS_PORT_SFLG_PORT_BUSY)) {
+	     && (erts_atomic32_read_nob(&p->state) & ERTS_PORT_SFLG_PORT_BUSY)) {
 	if (flags & ERTS_PORT_COMMAND_FLAG_NOSUSPEND) {
 	    ERTS_BIF_PREP_RET(res, am_false);
 	}
@@ -538,7 +542,7 @@ BIF_RETTYPE port_connect_2(BIF_ALIST_2)
     rp = erts_pid2proc(BIF_P, ERTS_PROC_LOCK_MAIN,
 		       pid, ERTS_PROC_LOCK_LINK);
     if (!rp) {
-	erts_smp_port_unlock(prt);
+	erts_port_release(prt);
 	ERTS_SMP_ASSERT_IS_NOT_EXITING(BIF_P);
 	goto error;
     }
@@ -549,7 +553,7 @@ BIF_RETTYPE port_connect_2(BIF_ALIST_2)
     erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
 
     prt->connected = pid; /* internal pid */
-    erts_smp_port_unlock(prt);
+    erts_port_release(prt);
 #ifdef USE_VM_PROBES
     if (DTRACE_ENABLED(port_connect)) {
         DTRACE_CHARBUF(process_str, DTRACE_TERM_BUF_SIZE);
@@ -591,7 +595,7 @@ BIF_RETTYPE port_set_data_2(BIF_ALIST_2)
 	hp = bp->mem;
 	prt->data = copy_struct(data, size, &hp, &bp->off_heap);
     }
-    erts_smp_port_unlock(prt);
+    erts_port_release(prt);
     BIF_RET(am_true);
 }
 
@@ -612,7 +616,7 @@ BIF_RETTYPE port_get_data_1(BIF_ALIST_1)
 	Eterm* hp = HAlloc(BIF_P, prt->bp->used_size);
 	res = copy_struct(prt->data, prt->bp->used_size, &hp, &MSO(BIF_P));
     }
-    erts_smp_port_unlock(prt);
+    erts_port_release(prt);
     BIF_RET(res);
 }
 
@@ -625,11 +629,10 @@ BIF_RETTYPE port_get_data_1(BIF_ALIST_1)
  * either BADARG or SYSTEM_LIMIT).
  */
 
-static int
-open_port(Process* p, Eterm name, Eterm settings, int *err_nump)
+static Port *
+open_port(Process* p, Eterm name, Eterm settings, int *err_typep, int *err_nump)
 {
-#define OPEN_PORT_ERROR(VAL) do { port_num = (VAL); goto do_return; } while (0)
-    int i, port_num;
+    int i;
     Eterm option;
     Uint arity;
     Eterm* tp;
@@ -641,6 +644,7 @@ open_port(Process* p, Eterm name, Eterm settings, int *err_nump)
     Eterm edir = NIL;
     byte dir[MAXPATHLEN];
     erts_aint32_t sflgs = 0;
+    Port *port;
 
     /* These are the defaults */
     opts.packet_bytes = 0;
@@ -923,38 +927,40 @@ open_port(Process* p, Eterm name, Eterm settings, int *err_nump)
 
     erts_smp_proc_unlock(p, ERTS_PROC_LOCK_MAIN);
 
-    port_num = erts_open_driver(driver, p->common.id, name_buf, &opts, err_nump);
+    port = erts_open_driver(driver, p->common.id, name_buf, &opts, err_typep, err_nump);
 #ifdef USE_VM_PROBES
-    if (port_num >= 0 && DTRACE_ENABLED(port_open)) {
+    if (port && DTRACE_ENABLED(port_open)) {
         DTRACE_CHARBUF(process_str, DTRACE_TERM_BUF_SIZE);
         DTRACE_CHARBUF(port_str, DTRACE_TERM_BUF_SIZE);
 
         dtrace_proc_str(p, process_str);
-        erts_snprintf(port_str, sizeof(port_str), "%T", erts_port[port_num].id);
+        erts_snprintf(port_str, sizeof(port_str), "%T", port->common.id);
         DTRACE3(port_open, process_str, name_buf, port_str);
     }
 #endif
     erts_smp_proc_lock(p, ERTS_PROC_LOCK_MAIN);
 
-    if (port_num < 0) {
-	DEBUGF(("open_driver returned %d(%d)\n", port_num, *err_nump));
+    if (!port) {
+	DEBUGF(("open_driver returned (%d:%d)\n",
+		err_typep ? *err_typep : 4711,
+		err_nump ? *err_nump : 4711));
     	if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
             trace_virtual_sched(p, am_in);
     	}
-	OPEN_PORT_ERROR(port_num);
+	goto do_return;
     }
     
     if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
         trace_virtual_sched(p, am_in);
     }
 
-    if (linebuf && erts_port[port_num].linebuf == NULL){
-	erts_port[port_num].linebuf = allocate_linebuf(linebuf);
+    if (linebuf && port->linebuf == NULL){
+	port->linebuf = allocate_linebuf(linebuf);
 	sflgs |= ERTS_PORT_SFLG_LINEBUF_IO;
     }
 
     if (sflgs)
-	erts_smp_atomic32_read_bor_relb(&erts_port[port_num].state, sflgs);
+	erts_atomic32_read_bor_relb(&port->state, sflgs);
  
  do_return:
     if (name_buf)
@@ -965,13 +971,15 @@ open_port(Process* p, Eterm name, Eterm settings, int *err_nump)
     if (opts.wd && opts.wd != ((char *)dir)) {
 	erts_free(ERTS_ALC_T_TMP, (void *) opts.wd);
     }
-    return port_num;
+    return port;
     
  badarg:
-    *err_nump = BADARG;
-    OPEN_PORT_ERROR(-3);
+    if (err_typep)
+	*err_typep = -3;
+    if (err_nump)
+	*err_nump = BADARG;
+    port = NULL;
     goto do_return;
-#undef OPEN_PORT_ERROR
 }
 
 /* Arguments can be given i unicode and as raw binaries, convert filename is used to convert */
diff --git a/erts/emulator/beam/erl_bif_trace.c b/erts/emulator/beam/erl_bif_trace.c
index d94b05fc25..60d5d039ed 100644
--- a/erts/emulator/beam/erl_bif_trace.c
+++ b/erts/emulator/beam/erl_bif_trace.c
@@ -151,14 +151,12 @@ trace_pattern(Process* p, Eterm MFA, Eterm Pattern, Eterm flaglist)
 		}
 	    } else if (is_internal_port(meta_tracer_pid)) {
 		Port *meta_tracer_port;
-		meta_tracer_proc = NULL;		
-		if (internal_port_index(meta_tracer_pid) >= erts_max_ports)
+		meta_tracer_proc = NULL;
+		meta_tracer_port = (erts_port_lookup(
+					meta_tracer_pid,
+					ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP));
+		if (!meta_tracer_port)
 		    goto error;
-		meta_tracer_port = 
-		    &erts_port[internal_port_index(meta_tracer_pid)];
-		if (INVALID_TRACER_PORT(meta_tracer_port, meta_tracer_pid)) {
-		    goto error;
-		}
 	    } else {
 		goto error;
 	    }
@@ -479,14 +477,14 @@ Eterm trace_3(BIF_ALIST_3)
 			      ? ERTS_PROC_LOCKS_ALL_MINOR
 			      : ERTS_PROC_LOCKS_ALL));
     } else if (is_internal_port(tracer)) {
-	Port *tracer_port = erts_id2port(tracer, p, ERTS_PROC_LOCK_MAIN);
-	if (!erts_is_valid_tracer_port(tracer)) {
-	    if (tracer_port)
-		erts_smp_port_unlock(tracer_port);
+	Port *tracer_port = erts_id2port_sflgs(tracer,
+					       p,
+					       ERTS_PROC_LOCK_MAIN,
+					       ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP);
+	if (!tracer_port)
 	    goto error;
-	}
 	ERTS_TRACE_FLAGS(tracer_port) |= F_TRACER;
-	erts_smp_port_unlock(tracer_port);
+	erts_port_release(tracer_port);
     } else
 	goto error;
 
@@ -519,12 +517,15 @@ Eterm trace_3(BIF_ALIST_3)
 	if (pid_spec == tracer)
 	    goto error;
 
-	tracee_port = erts_id2port(pid_spec, p, ERTS_PROC_LOCK_MAIN);
+	tracee_port = erts_id2port_sflgs(pid_spec,
+					 p,
+					 ERTS_PROC_LOCK_MAIN,
+					 ERTS_PORT_SFLGS_INVALID_LOOKUP);
 	if (!tracee_port)
 	    goto error;
 	
 	if (tracer != NIL && port_already_traced(p, tracee_port, tracer)) {
-	    erts_smp_port_unlock(tracee_port);
+	    erts_port_release(tracee_port);
 	    goto already_traced;
 	}
 
@@ -538,7 +539,7 @@ Eterm trace_3(BIF_ALIST_3)
 	else if (tracer != NIL)
 	    ERTS_TRACER_PROC(tracee_port) = tracer;
 
-	erts_smp_port_unlock(tracee_port);
+	erts_port_release(tracee_port);
 
 	matches = 1;
     } else if (is_pid(pid_spec)) {
@@ -677,15 +678,21 @@ Eterm trace_3(BIF_ALIST_3)
 		}
 	    }
 	    if (ports || mods) {
+		int max = erts_ptab_max(&erts_port);
 		/* tracing of ports */
-		for (i = 0; i < erts_max_ports; i++) {
-		    Port *tracee_port = &erts_port[i];
+		for (i = 0; i < max; i++) {
 		    erts_aint32_t state;
-		    state = erts_smp_atomic32_read_nob(&tracee_port->state);
-		    if (state & ERTS_PORT_SFLGS_DEAD) continue;
+		    Port *tracee_port = erts_pix2port(i);
+		    if (!tracee_port)
+			continue;
+		    state = erts_atomic32_read_nob(&tracee_port->state);
+		    if (state & ERTS_PORT_SFLGS_DEAD)
+			continue;
 		    if (tracer != NIL) {
-			if (tracee_port->common.id == tracer) continue;
-			if (port_already_traced(NULL, tracee_port, tracer)) continue;
+			if (tracee_port->common.id == tracer)
+			    continue;
+			if (port_already_traced(NULL, tracee_port, tracer))
+			    continue;
 		    }
 
 		    if (on) ERTS_TRACE_FLAGS(tracee_port) |= mask;
@@ -2147,9 +2154,11 @@ BIF_RETTYPE system_profile_2(BIF_ALIST_2)
 	    if (!profiler_p)
 		goto error;
 	} else if (is_internal_port(profiler)) {
-	    if (internal_port_index(profiler) >= erts_max_ports) goto error;
-	    profiler_port = &erts_port[internal_port_index(profiler)];
-	    if (INVALID_TRACER_PORT(profiler_port, profiler)) goto error;
+	    profiler_port = (erts_port_lookup(
+				 profiler,
+				 ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP));
+	    if (!profiler_port)
+		goto error;
 	} else {
 	    goto error;
 	}
diff --git a/erts/emulator/beam/erl_db_util.c b/erts/emulator/beam/erl_db_util.c
index d89190e3c1..67c2d0eb7f 100644
--- a/erts/emulator/beam/erl_db_util.c
+++ b/erts/emulator/beam/erl_db_util.c
@@ -182,12 +182,13 @@ set_match_trace(Process *tracee_p, Eterm fail_term, Eterm tracer,
 	}
     } else if (is_internal_port(tracer)) {
 	Port *tracer_port = 
-	    erts_id2port(tracer, tracee_p, ERTS_PROC_LOCKS_ALL);
+	    erts_id2port_sflgs(tracer,
+			       tracee_p,
+			       ERTS_PROC_LOCKS_ALL,
+			       ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP);
 	if (tracer_port) {
-	    if (! INVALID_TRACER_PORT(tracer_port, tracer)) {
-		ret = set_tracee_flags(tracee_p, tracer, d_flags, e_flags);
-	    }
-	    erts_smp_port_unlock(tracer_port);
+	    ret = set_tracee_flags(tracee_p, tracer, d_flags, e_flags);
+	    erts_port_release(tracer_port);
 	}
     } else {
 	ASSERT(is_nil(tracer));
diff --git a/erts/emulator/beam/erl_driver.h b/erts/emulator/beam/erl_driver.h
index 1ae9a211d7..1dc43419fe 100644
--- a/erts/emulator/beam/erl_driver.h
+++ b/erts/emulator/beam/erl_driver.h
@@ -210,8 +210,8 @@ typedef struct erl_drv_binary {
 typedef struct _erl_drv_data* ErlDrvData; /* Data to be used by the driver itself. */
 #ifndef ERL_SYS_DRV
 typedef struct _erl_drv_event* ErlDrvEvent; /* An event to be selected on. */
-typedef struct _erl_drv_port* ErlDrvPort; /* A port descriptor. */
 #endif
+typedef struct _erl_drv_port* ErlDrvPort; /* A port descriptor. */
 typedef struct _erl_drv_port* ErlDrvThreadData; /* Thread data. */
 
 #if !defined(__WIN32__) && !defined(_WIN32) && !defined(_WIN32_) && !defined(USE_SELECT)
diff --git a/erts/emulator/beam/erl_lock_check.c b/erts/emulator/beam/erl_lock_check.c
index 1db7b27412..06203a706d 100644
--- a/erts/emulator/beam/erl_lock_check.c
+++ b/erts/emulator/beam/erl_lock_check.c
@@ -112,9 +112,6 @@ static erts_lc_lock_order_t erts_lock_order[] = {
 #if defined(ENABLE_CHILD_WAITER_THREAD) || defined(ERTS_SMP)
     {	"child_status",				NULL			},
 #endif
-#ifdef __WIN32__
-    {	"sys_driver_data_lock",			NULL 			},
-#endif
     {	"drv_ev_state_grow",			NULL,   		},
     {	"drv_ev_state",				"address"		},
     {	"safe_hash",				"address"		},
@@ -159,7 +156,7 @@ static erts_lc_lock_order_t erts_lock_order[] = {
     {	"port_taskq_pre_alloc_lock",		"address"		},
     {	"proclist_pre_alloc_lock",		"address"		},
     {	"port_tasks_lock",			NULL			},
-    {   "get_free_port",                        NULL                    },
+    {   "port_table",                           NULL                    },
     {	"port_state",			        "address"		},
     {	"xports_list_pre_alloc_lock",		"address"		},
     {	"inet_buffer_stack_lock",		NULL			},
@@ -248,6 +245,7 @@ typedef struct {
 typedef struct erts_lc_locked_locks_t_ erts_lc_locked_locks_t;
 struct erts_lc_locked_locks_t_ {
     char *thread_name;
+    int emu_thread;
     erts_tid_t tid;
     erts_lc_locked_locks_t *next;
     erts_lc_locked_locks_t *prev;
@@ -365,6 +363,7 @@ create_locked_locks(char *thread_name)
     if (!l_lcks->thread_name)
 	lc_abort();
 
+    l_lcks->emu_thread = 0;
     l_lcks->tid = erts_thr_self();
     l_lcks->required.first = NULL;
     l_lcks->required.last = NULL;
@@ -672,7 +671,7 @@ erts_lc_set_thread_name(char *thread_name)
 {
     erts_lc_locked_locks_t *l_lcks = get_my_locked_locks();
     if (!l_lcks)
-	(void) create_locked_locks(thread_name);
+	l_lcks = create_locked_locks(thread_name);
     else {
 	ASSERT(l_lcks->thread_name);
 	free((void *) l_lcks->thread_name);
@@ -680,6 +679,14 @@ erts_lc_set_thread_name(char *thread_name)
 	if (!l_lcks->thread_name)
 	    lc_abort();
     }
+    l_lcks->emu_thread = 1;
+}
+
+int
+erts_lc_is_emu_thr(void)
+{
+    erts_lc_locked_locks_t *l_lcks = get_my_locked_locks();
+    return l_lcks->emu_thread;
 }
 
 int
diff --git a/erts/emulator/beam/erl_lock_check.h b/erts/emulator/beam/erl_lock_check.h
index b67f36fa06..e76bcf556e 100644
--- a/erts/emulator/beam/erl_lock_check.h
+++ b/erts/emulator/beam/erl_lock_check.h
@@ -102,6 +102,7 @@ void erts_lc_unrequire_lock_flg(erts_lc_lock_t *lck, Uint16 op_flags);
 void erts_lc_require_lock(erts_lc_lock_t *lck);
 void erts_lc_unrequire_lock(erts_lc_lock_t *lck);
 
+int erts_lc_is_emu_thr(void);
 
 #define ERTS_LC_ASSERT(A) \
   ((void) ((A) ? 1 : erts_lc_assert_failed(__FILE__, __LINE__, #A)))
diff --git a/erts/emulator/beam/erl_monitors.c b/erts/emulator/beam/erl_monitors.c
index 450aad975d..63175c44d6 100644
--- a/erts/emulator/beam/erl_monitors.c
+++ b/erts/emulator/beam/erl_monitors.c
@@ -985,12 +985,15 @@ Eterm erts_debug_dump_links_1(BIF_ALIST_1)
     Process *rp;
     DistEntry *dep;
     if (is_internal_port(pid)) {
-	Port *rport = erts_id2port(pid, p, ERTS_PROC_LOCK_MAIN);
+	Port *rport = erts_id2port_sflgs(pid,
+					 p,
+					 ERTS_PROC_LOCK_MAIN,
+					 ERTS_PORT_SFLGS_INVALID_LOOKUP);
 	if (rport) {
 	    erts_printf("Dumping port links----------------------\n");
 	    erts_dump_links(ERTS_P_LINKS(rport), 0);
 	    erts_printf("Links dumped----------------------------\n");
-	    erts_smp_port_unlock(rport);
+	    erts_port_release(rport);
 	    BIF_RET(am_true);
 	} else {
 	    BIF_ERROR(p,BADARG);
diff --git a/erts/emulator/beam/erl_node_container_utils.h b/erts/emulator/beam/erl_node_container_utils.h
index 62fb277eef..7796cbfc2b 100644
--- a/erts/emulator/beam/erl_node_container_utils.h
+++ b/erts/emulator/beam/erl_node_container_utils.h
@@ -197,8 +197,10 @@ extern ErtsPTab erts_proc;
  * Ports                                                                   *
 \*                                                                         */
 
-#define internal_port_index(x)		(internal_port_data((x))	\
-					 & erts_port_tab_index_mask)
+extern ErtsPTab erts_port;
+
+#define internal_port_index(x)		erts_ptab_data2ix(&erts_port, \
+							  internal_port_data((x)))
 
 #define internal_port_node_name(x)	(internal_port_node((x))->sysname)
 #define external_port_node_name(x)	(external_port_node((x))->sysname)
@@ -237,7 +239,7 @@ extern ErtsPTab erts_proc;
 #define is_not_port(x)			(!is_port(x))
 
 /* Highest port-ID part in a term of type Port 
-   Not necessarily the same as the variable erts_max_ports
+   Not necessarily the same as current maximum port table size
    which defines the maximum number of simultaneous Ports
    in the Erlang node. ERTS_MAX_PORTS is a hard upper limit.
 */
@@ -249,6 +251,9 @@ extern ErtsPTab erts_proc;
 
 #define ERTS_R9_PORTS_BITS		(_PORT_R9_NUM_SIZE)
 #define ERTS_PORTS_BITS			(_PORT_NUM_SIZE)
+
+#define ERTS_INVALID_PORT		make_internal_port(ERTS_MAX_PORT_DATA)
+
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
  * Refs                                                                    *
 \*                                                                         */
diff --git a/erts/emulator/beam/erl_node_tables.c b/erts/emulator/beam/erl_node_tables.c
index 3b400ce0de..67f413ef28 100644
--- a/erts/emulator/beam/erl_node_tables.c
+++ b/erts/emulator/beam/erl_node_tables.c
@@ -1274,7 +1274,7 @@ setup_reference_table(void)
     ErlHeapFragment *hfp;
     DistEntry *dep;
     HashInfo hi;
-    int i, max_processes;
+    int i, max;
     DeclareTmpHeapNoproc(heap,3);
 
     inserted_bins = NULL;
@@ -1309,9 +1309,9 @@ setup_reference_table(void)
 #endif
     UnUseTmpHeapNoproc(3);
 
-    max_processes = erts_ptab_max(&erts_proc);
+    max = erts_ptab_max(&erts_proc);
     /* Insert all processes */
-    for (i = 0; i < max_processes; i++) {
+    for (i = 0; i < max; i++) {
 	Process *proc = erts_pix2proc(i);
 	if (proc) {
 	    ErlMessage *msg;
@@ -1383,25 +1383,33 @@ setup_reference_table(void)
 #endif
 
     /* Insert all ports */
-    for (i = 0; i < erts_max_ports; i++) {
-	erts_aint32_t state = erts_smp_atomic32_read_nob(&erts_port[i].state);
+    max = erts_ptab_max(&erts_port);
+    for (i = 0; i < max; i++) {
+	erts_aint32_t state;
+	Port *prt;
+
+	prt = erts_pix2port(i);
+	if (!prt)
+	    continue;
+
+	state = erts_atomic32_read_nob(&prt->state);
 	if (state & ERTS_PORT_SFLGS_DEAD)
 	    continue;
 
 	/* Insert links */
-	if (ERTS_P_LINKS(&erts_port[i]))
-	    insert_links(ERTS_P_LINKS(&erts_port[i]), erts_port[i].common.id);
+	if (ERTS_P_LINKS(prt))
+	    insert_links(ERTS_P_LINKS(prt), prt->common.id);
 	/* Insert monitors */
-	if (ERTS_P_MONITORS(&erts_port[i]))
-	    insert_monitors(ERTS_P_MONITORS(&erts_port[i]), erts_port[i].common.id);
+	if (ERTS_P_MONITORS(prt))
+	    insert_monitors(ERTS_P_MONITORS(prt), prt->common.id);
 	/* Insert port data */
-	for(hfp = erts_port[i].bp; hfp; hfp = hfp->next)
-	    insert_offheap(&(hfp->off_heap), HEAP_REF, erts_port[i].common.id);
+	for(hfp = prt->bp; hfp; hfp = hfp->next)
+	    insert_offheap(&(hfp->off_heap), HEAP_REF, prt->common.id);
 	/* Insert controller */
-	if (erts_port[i].dist_entry)
-	    insert_dist_entry(erts_port[i].dist_entry,
+	if (prt->dist_entry)
+	    insert_dist_entry(prt->dist_entry,
 			      CTRL_REF,
-			      erts_port[i].common.id,
+			      prt->common.id,
 			      0);
     }
 
diff --git a/erts/emulator/beam/erl_node_tables.h b/erts/emulator/beam/erl_node_tables.h
index 4a015bdef9..3a74888522 100644
--- a/erts/emulator/beam/erl_node_tables.h
+++ b/erts/emulator/beam/erl_node_tables.h
@@ -100,7 +100,6 @@ typedef struct {
  */
 
 struct erl_link;
-struct port;
 
 typedef struct dist_entry_ {
     HashBucket hash_bucket;     /* Hash bucket */
@@ -141,7 +140,7 @@ typedef struct dist_entry_ {
     erts_smp_atomic_t dist_cmd_scheduled;
     ErtsPortTaskHandle dist_cmd;
 
-    Uint (*send)(struct port *prt, ErtsDistOutputBuf *obuf);
+    Uint (*send)(Port *prt, ErtsDistOutputBuf *obuf);
 
     struct cache* cache;	/* The atom cache */
 } DistEntry;
diff --git a/erts/emulator/beam/erl_port.h b/erts/emulator/beam/erl_port.h
index 1a5bc636e2..fb34a6da2d 100644
--- a/erts/emulator/beam/erl_port.h
+++ b/erts/emulator/beam/erl_port.h
@@ -17,15 +17,21 @@
  * %CopyrightEnd%
  */
 
-#ifndef ERL_PORT_H__
+#ifndef ERL_PORT_TYPE__
+#define ERL_PORT_TYPE__
+typedef struct _erl_drv_port Port;
+#endif
+
+#if !defined(ERL_PORT_H__) && !defined(ERL_PORT_GET_PORT_TYPE_ONLY__)
 #define ERL_PORT_H__
 
-typedef struct port Port;
 #include "erl_port_task.h"
 #include "erl_ptab.h"
+#include "erl_thr_progress.h"
 
 typedef struct erts_driver_t_ erts_driver_t;
 
+#define ERTS_INVALID_ERL_DRV_PORT ((ErlDrvPort) (SWord) -1)
 #define SMALL_IO_QUEUE 5   /* Number of fixed elements */
 
 typedef struct {
@@ -90,16 +96,18 @@ typedef struct ErtsXPortsList_ ErtsXPortsList;
  *
  */
 
-struct port {
+struct _erl_drv_port {
     ErtsPTabElementCommon common; /* *Need* to be first in struct */
 
     ErtsPortTaskSched sched;
     ErtsPortTaskHandle timeout_task;
 #ifdef ERTS_SMP
-    erts_smp_mtx_t *lock;
+    erts_mtx_t *lock;
     ErtsXPortsList *xports;
     erts_smp_atomic_t run_queue;
-    erts_smp_spinlock_t state_lck;  /* protects: id, status, snapshot */
+#else
+    erts_atomic32_t refc;
+    int cleanup;
 #endif
     Eterm connected;            /* A connected process */
     Eterm caller;		/* Current caller. */
@@ -116,15 +124,20 @@ struct port {
     ErtsProcList *suspended;	 /* List of suspended processes. */
     LineBuf *linebuf;            /* Buffer to hold data not ready for
 				    process to get (line oriented I/O)*/
-    erts_smp_atomic32_t state;	 /* Status and type flags */
+    erts_atomic32_t state;	 /* Status and type flags */
     int control_flags;		 /* Flags for port_control()  */
-    erts_aint32_t snapshot;      /* Next snapshot that port should be part of */
     ErlDrvPDL port_data_lock;
 
     ErtsPrtSD *psd;		 /* Port specific data */
 };
 
 
+struct erl_drv_port_data_lock {
+    erts_mtx_t mtx;
+    erts_atomic_t refc;
+    Port *prt;
+};
+
 ERTS_GLB_INLINE ErtsRunQueue *erts_port_runq(Port *prt);
 
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
@@ -183,35 +196,6 @@ erts_prtsd_set(Port *prt, int ix, void *data)
 
 #endif
 
-/* arrays that get malloced at startup */
-extern Port* erts_port;
-
-extern Uint erts_max_ports;
-extern Uint erts_port_tab_index_mask;
-extern erts_smp_atomic32_t erts_ports_snapshot;
-extern erts_smp_atomic_t erts_dead_ports_ptr;
-
-ERTS_GLB_INLINE void erts_may_save_closed_port(Port *prt);
-
-#if ERTS_GLB_INLINE_INCL_FUNC_DEF
-
-ERTS_GLB_INLINE void erts_may_save_closed_port(Port *prt)
-{
-    ERTS_SMP_LC_ASSERT(erts_smp_lc_spinlock_is_locked(&prt->state_lck));
-    if (prt->snapshot != erts_smp_atomic32_read_acqb(&erts_ports_snapshot)) {
-	/* Dead ports are added from the end of the snapshot buffer */
-	Eterm* tombstone;
-	tombstone = (Eterm*) erts_smp_atomic_add_read_nob(&erts_dead_ports_ptr,
-							  -(erts_aint_t)sizeof(Eterm));
-	ASSERT(tombstone+1 != NULL);
-	ASSERT(prt->snapshot == erts_smp_atomic32_read_nob(&erts_ports_snapshot) - 1);
-	*tombstone = prt->common.id;
-    }
-    /*else no ongoing snapshot or port was already included or created after snapshot */
-}
-
-#endif
-
 extern erts_smp_atomic_t erts_bytes_out;	/* no bytes written out */
 extern erts_smp_atomic_t erts_bytes_in;		/* no bytes sent into the system */
 
@@ -263,8 +247,11 @@ extern erts_smp_atomic_t erts_bytes_in;		/* no bytes sent into the system */
    | ERTS_PORT_SFLG_PORT_BUSY						\
    | ERTS_PORT_SFLG_DISTRIBUTION)
 
-
+void print_port_info(Port *, int, void *);
+void erts_port_free(Port *);
+#ifndef ERTS_SMP
 void erts_port_cleanup(Port *);
+#endif
 void erts_fire_port_monitor(Port *prt, Eterm ref);
 #ifdef ERTS_SMP
 void erts_smp_xports_unlock(Port *);
@@ -274,8 +261,9 @@ void erts_smp_xports_unlock(Port *);
 int erts_lc_is_port_locked(Port *);
 #endif
 
-ERTS_GLB_INLINE void erts_smp_port_minor_lock(Port*);
-ERTS_GLB_INLINE void erts_smp_port_minor_unlock(Port*);
+ERTS_GLB_INLINE void erts_port_inc_refc(Port *prt);
+ERTS_GLB_INLINE void erts_port_dec_refc(Port *prt);
+ERTS_GLB_INLINE void erts_port_add_refc(Port *prt, Sint32 add_refc);
 
 ERTS_GLB_INLINE int erts_smp_port_trylock(Port *prt);
 ERTS_GLB_INLINE void erts_smp_port_lock(Port *prt);
@@ -283,64 +271,71 @@ ERTS_GLB_INLINE void erts_smp_port_unlock(Port *prt);
 
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
 
-ERTS_GLB_INLINE void
-erts_smp_port_minor_lock(Port* prt)
+ERTS_GLB_INLINE void erts_port_inc_refc(Port *prt)
 {
 #ifdef ERTS_SMP
-    erts_smp_spin_lock(&prt->state_lck);
+    erts_ptab_inc_refc(&prt->common);
+#else
+    erts_atomic32_inc_nob(&prt->refc);
 #endif
 }
 
-ERTS_GLB_INLINE void
-erts_smp_port_minor_unlock(Port *prt)
+ERTS_GLB_INLINE void erts_port_dec_refc(Port *prt)
 {
 #ifdef ERTS_SMP
-    erts_smp_spin_unlock(&prt->state_lck);
+    int referred = erts_ptab_dec_test_refc(&prt->common);
+    if (!referred)
+	erts_port_free(prt);
+#else
+    int refc = erts_atomic32_dec_read_nob(&prt->refc);
+    if (refc == 0)
+	erts_port_free(prt);	
 #endif
 }
 
+ERTS_GLB_INLINE void erts_port_add_refc(Port *prt, Sint32 add_refc)
+{
+#ifdef ERTS_SMP
+    int referred = erts_ptab_add_test_refc(&prt->common, add_refc);
+    if (!referred)
+	erts_port_free(prt);
+#else
+    int refc = erts_atomic32_add_read_nob(&prt->refc, add_refc);
+    if (refc == 0)
+	erts_port_free(prt);	
+#endif
+}
 
 ERTS_GLB_INLINE int
 erts_smp_port_trylock(Port *prt)
 {
-    int res;
-
-    ASSERT(erts_smp_atomic32_read_nob(&prt->common.refc) > 0);
-    erts_smp_atomic32_inc_nob(&prt->common.refc);
-
 #ifdef ERTS_SMP
-    res = erts_smp_mtx_trylock(prt->lock);
-    if (res == EBUSY) {
-	erts_smp_atomic32_dec_nob(&prt->common.refc);
-    }
+    /* *Need* to be a managed thread */
+    ERTS_SMP_LC_ASSERT(erts_thr_progress_is_managed_thread());
+    return erts_mtx_trylock(prt->lock);
 #else
-    res = 0;
+    return 0;
 #endif
-
-    return res;
 }
 
 ERTS_GLB_INLINE void
 erts_smp_port_lock(Port *prt)
 {
-    ASSERT(erts_smp_atomic32_read_nob(&prt->common.refc) > 0);
-    erts_smp_atomic32_inc_nob(&prt->common.refc);
 #ifdef ERTS_SMP
-    erts_smp_mtx_lock(prt->lock);
+    /* *Need* to be a managed thread */
+    ERTS_SMP_LC_ASSERT(erts_thr_progress_is_managed_thread());
+    erts_mtx_lock(prt->lock);
 #endif
 }
 
 ERTS_GLB_INLINE void
 erts_smp_port_unlock(Port *prt)
 {
-    erts_aint32_t refc;
 #ifdef ERTS_SMP
-    erts_smp_mtx_unlock(prt->lock);
+    /* *Need* to be a managed thread */
+    ERTS_SMP_LC_ASSERT(erts_thr_progress_is_managed_thread());
+    erts_mtx_unlock(prt->lock);
 #endif
-    refc = erts_smp_atomic32_dec_read_nob(&prt->common.refc);
-    ASSERT(refc >= 0);
-    if (refc == 0)
-	erts_port_cleanup(prt);
 }
 
 #endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */
@@ -348,7 +343,7 @@ erts_smp_port_unlock(Port *prt)
 
 #define ERTS_INVALID_PORT_OPT(PP, ID, FLGS)			\
     (!(PP)							\
-     || (erts_smp_atomic32_read_nob(&(PP)->state) & (FLGS))	\
+     || (erts_atomic32_read_nob(&(PP)->state) & (FLGS))	\
      || (PP)->common.id != (ID))
 
 /* port lookup */
@@ -365,125 +360,301 @@ erts_smp_port_unlock(Port *prt)
 #define ERTS_PORT_SCHED_ID(P, ID) \
   ((Uint) (UWord) erts_prtsd_set((P), ERTS_PSD_SCHED_ID, (void *) (UWord) (ID)))
 
+extern const Port erts_invalid_port;
+#define ERTS_PORT_LOCK_BUSY ((Port *) &erts_invalid_port)
+
 #ifdef ERTS_SMP
 Port *erts_de2port(DistEntry *, Process *, ErtsProcLocks);
 #endif
 
-#define erts_id2port(ID, P, PL) \
-  erts_id2port_sflgs((ID), (P), (PL), ERTS_PORT_SFLGS_INVALID_LOOKUP)
-
-ERTS_GLB_INLINE Port*erts_id2port_sflgs(Eterm, Process *, ErtsProcLocks, Uint32);
+ERTS_GLB_INLINE Port *erts_pix2port(int);
+ERTS_GLB_INLINE Port *erts_port_lookup_raw(Eterm);
+ERTS_GLB_INLINE Port *erts_port_lookup(Eterm, Uint32);
+ERTS_GLB_INLINE Port*erts_id2port(Eterm id);
+ERTS_GLB_INLINE Port *erts_id2port_sflgs(Eterm, Process *, ErtsProcLocks, Uint32);
 ERTS_GLB_INLINE void erts_port_release(Port *);
-ERTS_GLB_INLINE Port*erts_drvport2port(ErlDrvPort, erts_aint32_t *);
-ERTS_GLB_INLINE Port*erts_drvportid2port(Eterm);
-ERTS_GLB_INLINE Uint32 erts_portid2status(Eterm id);
-ERTS_GLB_INLINE int erts_is_port_alive(Eterm id);
-ERTS_GLB_INLINE int erts_is_valid_tracer_port(Eterm id);
+#ifdef ERTS_SMP
+ERTS_GLB_INLINE Port *erts_thr_id2port_sflgs(Eterm id, Uint32 invalid_sflgs);
+ERTS_GLB_INLINE void erts_thr_port_release(Port *prt);
+#endif
+ERTS_GLB_INLINE Port *erts_thr_drvport2port_raw(ErlDrvPort);
+ERTS_GLB_INLINE Port *erts_drvport2port_raw(ErlDrvPort drvport);
+ERTS_GLB_INLINE Port *erts_drvport2port(ErlDrvPort, erts_aint32_t *);
+ERTS_GLB_INLINE Port *erts_drvportid2port(Eterm);
+ERTS_GLB_INLINE Eterm erts_drvport2id(ErlDrvPort);
+ERTS_GLB_INLINE Uint32 erts_portid2status(Eterm);
+ERTS_GLB_INLINE int erts_is_port_alive(Eterm);
+ERTS_GLB_INLINE int erts_is_valid_tracer_port(Eterm);
 
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
 
+ERTS_GLB_INLINE Port *erts_pix2port(int ix)
+{
+    Port *prt;
+    ASSERT(0 <= ix && ix < erts_ptab_max(&erts_port));
+    prt = (Port *) erts_ptab_pix2intptr_nob(&erts_port, ix);
+    return prt == ERTS_PORT_LOCK_BUSY ? NULL : prt;
+}
+
+ERTS_GLB_INLINE Port *
+erts_port_lookup_raw(Eterm id)
+{
+    Port *prt;
+
+    ERTS_SMP_LC_ASSERT(erts_thr_progress_lc_is_delaying());
+
+    if (is_not_internal_port(id))
+	return NULL;
+
+    prt = (Port *) erts_ptab_pix2intptr_ddrb(&erts_port,
+					     internal_port_index(id));
+    return prt && prt->common.id == id ? prt : NULL;
+}
+
+ERTS_GLB_INLINE Port *
+erts_port_lookup(Eterm id, Uint32 invalid_sflgs)
+{
+    Port *prt = erts_port_lookup_raw(id);
+    erts_aint32_t state = erts_atomic32_read_nob(&prt->state);
+    return (state & invalid_sflgs) ? NULL : prt;
+}
+
+
 ERTS_GLB_INLINE Port*
-erts_id2port_sflgs(Eterm id, Process *c_p, ErtsProcLocks c_p_locks, Uint32 sflgs)
+erts_id2port(Eterm id)
+{
+    erts_aint32_t state;
+    Port *prt;
+
+    /* Only allowed to be called from managed threads */
+    ERTS_SMP_LC_ASSERT(erts_thr_progress_is_managed_thread());
+
+    if (is_not_internal_port(id))
+	return NULL;
+
+    prt = (Port *) erts_ptab_pix2intptr_ddrb(&erts_port,
+					     internal_port_index(id));
+
+    if (!prt || prt->common.id != id)
+	return NULL;
+
+    erts_smp_port_lock(prt);
+    state = erts_atomic32_read_nob(&prt->state);
+    if (state & ERTS_PORT_SFLGS_INVALID_LOOKUP) {
+	erts_smp_port_unlock(prt);
+	return NULL;
+    }
+
+    return prt;
+}
+
+
+ERTS_GLB_INLINE Port*
+erts_id2port_sflgs(Eterm id,
+		   Process *c_p, ErtsProcLocks c_p_locks,
+		   Uint32 invalid_sflgs)
 {
 #ifdef ERTS_SMP
     int no_proc_locks = !c_p || !c_p_locks;
 #endif
+    erts_aint32_t state;
     Port *prt;
 
+    /* Only allowed to be called from managed threads */
+    ERTS_SMP_LC_ASSERT(erts_thr_progress_is_managed_thread());
+
     if (is_not_internal_port(id))
 	return NULL;
 
-    prt = &erts_port[internal_port_index(id)];
+    prt = (Port *) erts_ptab_pix2intptr_ddrb(&erts_port,
+					     internal_port_index(id));
 
-    erts_smp_port_minor_lock(prt);
-    if (ERTS_INVALID_PORT_OPT(prt, id, sflgs)) {
-	erts_smp_port_minor_unlock(prt);
-	prt = NULL;
+    if (!prt || prt->common.id != id)
+	return NULL;
+
+#ifdef ERTS_SMP
+    if (no_proc_locks)
+	erts_smp_port_lock(prt);
+    else if (erts_smp_port_trylock(prt) == EBUSY) {
+	/* Unlock process locks, and acquire locks in lock order... */
+	erts_smp_proc_unlock(c_p, c_p_locks);
+	erts_smp_port_lock(prt);
+	erts_smp_proc_lock(c_p, c_p_locks);
+    }
+#endif
+    state = erts_atomic32_read_nob(&prt->state);
+    if (state & invalid_sflgs) {
+#ifdef ERTS_SMP
+	erts_smp_port_unlock(prt);
+#endif
+	return NULL;
     }
-    else {
-	erts_smp_atomic32_inc_nob(&prt->common.refc);
-	erts_smp_port_minor_unlock(prt);
 
+    return prt;
+}
+
+ERTS_GLB_INLINE void
+erts_port_release(Port *prt)
+{
+    /* Only allowed to be called from managed threads */
+    ERTS_SMP_LC_ASSERT(erts_thr_progress_is_managed_thread());
 #ifdef ERTS_SMP
- 	if (no_proc_locks)
-	    erts_smp_mtx_lock(prt->lock);
-	else if (erts_smp_mtx_trylock(prt->lock) == EBUSY) {
-	    /* Unlock process locks, and acquire locks in lock order... */
-	    erts_smp_proc_unlock(c_p, c_p_locks);
-	    erts_smp_mtx_lock(prt->lock);
-	    erts_smp_proc_lock(c_p, c_p_locks);
+    erts_smp_port_unlock(prt);
+#else
+    if (prt->cleanup) {
+	prt->cleanup = 0;
+	erts_port_cleanup(prt);
+    }
+#endif
+}
+
+#ifdef ERTS_SMP
+
+/*
+ * erts_thr_id2port_sflgs() and erts_thr_port_release() can
+ * be used by unmanaged threads in the SMP case.
+ */
+ERTS_GLB_INLINE Port *
+erts_thr_id2port_sflgs(Eterm id, Uint32 invalid_sflgs)
+{
+    Port *prt;
+    ErtsThrPrgrDelayHandle dhndl;
+
+    if (is_not_internal_port(id))
+	return NULL;
+
+    dhndl = erts_thr_progress_unmanaged_delay();
+
+    prt = (Port *) erts_ptab_pix2intptr_ddrb(&erts_port,
+					     internal_port_index(id));
+
+    if (!prt || prt->common.id != id) {
+	erts_thr_progress_unmanaged_continue(dhndl);
+	prt = NULL;
+    }
+    else {
+	erts_aint32_t state;
+	if (dhndl != ERTS_THR_PRGR_DHANDLE_MANAGED) {
+	    erts_port_inc_refc(prt);
+	    erts_thr_progress_unmanaged_continue(dhndl);
 	}
 
-	/* The id may not have changed... */
-	ERTS_SMP_LC_ASSERT(prt->common.id == id);
-	/* ... but state may have... */
-	if (erts_smp_atomic32_read_nob(&prt->state) & sflgs) {
-	    erts_smp_port_unlock(prt); /* Also decrements common.refc... */
+	erts_mtx_lock(prt->lock);
+	state = erts_atomic32_read_nob(&prt->state);
+	if (state & invalid_sflgs) {
+	    erts_mtx_unlock(prt->lock);
+	    if (dhndl != ERTS_THR_PRGR_DHANDLE_MANAGED)
+		erts_port_dec_refc(prt);
 	    prt = NULL;
 	}
-#endif
-
     }
 
     return prt;
 }
 
 ERTS_GLB_INLINE void
-erts_port_release(Port *prt)
+erts_thr_port_release(Port *prt)
 {
-    erts_smp_port_unlock(prt);
+    erts_mtx_unlock(prt->lock);
+#ifdef ERTS_SMP
+    if (!erts_thr_progress_is_managed_thread())
+	erts_port_dec_refc(prt);
+#endif
+}
+
+#endif
+
+ERTS_GLB_INLINE Port*
+erts_thr_drvport2port_raw(ErlDrvPort drvport)
+{
+#if ERTS_ENABLE_LOCK_CHECK
+    int emu_thread = erts_lc_is_emu_thr();
+#endif
+    if (drvport == ERTS_INVALID_ERL_DRV_PORT)
+	return NULL;
+    else {
+	Port *prt = (Port *) drvport;
+#if ERTS_ENABLE_LOCK_CHECK
+	if (emu_thread) {
+	    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
+	    ERTS_LC_ASSERT(!prt->port_data_lock
+			   || erts_lc_mtx_is_locked(&prt->port_data_lock->mtx));
+	}
+	else {
+	    ERTS_LC_ASSERT(prt->port_data_lock);
+	    ERTS_LC_ASSERT(erts_lc_mtx_is_locked(&prt->port_data_lock->mtx));
+	}
+#endif
+	return prt;
+    }
+}
+
+ERTS_GLB_INLINE Port*
+erts_drvport2port_raw(ErlDrvPort drvport)
+{
+    ERTS_LC_ASSERT(erts_lc_is_emu_thr());
+    if (drvport == ERTS_INVALID_ERL_DRV_PORT)
+	return NULL;
+    else {
+	Port *prt = (Port *) drvport;
+	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
+	return prt;
+    }
 }
 
 ERTS_GLB_INLINE Port*
 erts_drvport2port(ErlDrvPort drvport, erts_aint32_t *statep)
 {
-    int ix = (int) drvport;
+    Port *prt = erts_drvport2port_raw(drvport);
     erts_aint32_t state;
-    if (ix < 0 || erts_max_ports <= ix)
+    if (!prt)
 	return NULL;
-    state = erts_smp_atomic32_read_nob(&erts_port[ix].state);
+    state = erts_atomic32_read_nob(&prt->state);
     if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
 	return NULL;
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(&erts_port[ix]));
     if (statep)
 	*statep = state;
-    return &erts_port[ix];
+    return prt;
 }
 
 ERTS_GLB_INLINE Port*
 erts_drvportid2port(Eterm id)
 {
-    int ix;
+    Port *prt;
     erts_aint32_t state;
     if (is_not_internal_port(id))
 	return NULL;
-    ix = (int) internal_port_index(id);
-    if (erts_max_ports <= ix)
+    prt = (Port *) erts_ptab_pix2intptr_nob(&erts_port,
+					    internal_port_index(id));
+    if (!prt)
 	return NULL;
-    state = erts_smp_atomic32_read_nob(&erts_port[ix].state);
-    if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
+    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
+    if (prt->common.id != id)
 	return NULL;
-    if (erts_port[ix].common.id != id)
+    state = erts_atomic32_read_nob(&prt->state);
+    if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
 	return NULL;
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(&erts_port[ix]));
-    return &erts_port[ix];
+    return prt;
+}
+
+ERTS_GLB_INLINE Eterm
+erts_drvport2id(ErlDrvPort drvport)
+{
+    Port *prt = erts_drvport2port_raw(drvport);
+    if (!prt)
+	return am_undefined;
+    else
+	return prt->common.id;
 }
 
 ERTS_GLB_INLINE Uint32
 erts_portid2status(Eterm id)
 {
-    if (is_not_internal_port(id))
+    Port *prt = erts_port_lookup_raw(id);
+    if (prt)
+	return (Uint32) erts_atomic32_read_acqb(&prt->state);
+    else
 	return ERTS_PORT_SFLG_INVALID;
-    else {
-	erts_aint32_t state;
-	int ix = internal_port_index(id);
-	if (erts_max_ports <= ix)
-	    return ERTS_PORT_SFLG_INVALID;
-	state = erts_smp_atomic32_read_ddrb(&erts_port[ix].state);
-	if (erts_port[ix].common.id != id)
-	    return ERTS_PORT_SFLG_INVALID;
-	return state;
-    }
 }
 
 ERTS_GLB_INLINE int
diff --git a/erts/emulator/beam/erl_port_task.c b/erts/emulator/beam/erl_port_task.c
index 6eb8c4869c..112d27c94e 100644
--- a/erts/emulator/beam/erl_port_task.c
+++ b/erts/emulator/beam/erl_port_task.c
@@ -51,12 +51,9 @@
 
 
 #define ERTS_PORT_TASK_INVALID_PORT(P, ID) \
-  ((erts_smp_atomic32_read_acqb(&(P)->state) & ERTS_PORT_SFLGS_DEAD) \
+  ((erts_atomic32_read_acqb(&(P)->state) & ERTS_PORT_SFLGS_DEAD) \
    || (P)->common.id != (ID))
 
-#define ERTS_PORT_IS_IN_RUNQ(RQ, P) \
-  ((P)->sched.next || (P)->sched.prev || (RQ)->ports.start == (P))
-
 #ifdef USE_VM_PROBES
 #define DTRACE_DRIVER(PROBE_NAME, PP)                              \
     if (DTRACE_ENABLED(driver_ready_input)) {                      \
@@ -76,7 +73,6 @@ erts_smp_atomic_t erts_port_task_outstanding_io_tasks;
 struct ErtsPortTaskQueue_ {
     ErtsPortTask *first;
     ErtsPortTask *last;
-    Port *port;
 };
 
 struct ErtsPortTask_ {
@@ -275,7 +271,6 @@ port_taskq_init(ErtsPortTaskQueue *ptqp, Port *pp)
     if (ptqp) {
 	ptqp->first = NULL;
 	ptqp->last = NULL;
-	ptqp->port = pp;
     }
     return ptqp;
 }
@@ -429,7 +424,10 @@ erts_port_task_abort(Eterm id, ErtsPortTaskHandle *pthp)
     ErtsPortTask *ptp;
     Port *pp;
 
-    pp = &erts_port[internal_port_index(id)];
+    pp = erts_port_lookup_raw(id);
+    if (!pp)
+	return 1;
+
     runq = erts_port_runq(pp);
     if (!runq)
 	return 1;
@@ -512,7 +510,10 @@ erts_port_task_schedule(Eterm id,
     ptp = port_task_alloc();
 
     ASSERT(is_internal_port(id));
-    pp = &erts_port[internal_port_index(id)];
+    pp = erts_port_lookup_raw(id);
+    if (!pp)
+	return -1;
+
     runq = erts_port_runq(pp);
 
     if (!runq || ERTS_PORT_TASK_INVALID_PORT(pp, id)) {
@@ -616,7 +617,7 @@ erts_port_task_free_port(Port *pp)
     ErtsPortTaskQueue *ptqp;
 
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(pp));
-    ASSERT(!(erts_smp_atomic32_read_nob(&pp->state) & ERTS_PORT_SFLGS_DEAD));
+    ASSERT(!(erts_atomic32_read_nob(&pp->state) & ERTS_PORT_SFLGS_DEAD));
     runq = erts_port_runq(pp);
     ASSERT(runq);
     ERTS_PT_CHK_PRES_PORTQ(runq, pp);
@@ -627,14 +628,10 @@ erts_port_task_free_port(Port *pp)
 	ErtsPortTask *ptp;
     enqueue_free:
 	ptp = port_task_alloc();
-	erts_smp_port_minor_lock(pp);
-	erts_smp_atomic32_read_bset_relb(&pp->state,
-					 (ERTS_PORT_SFLG_CLOSING
-					  | ERTS_PORT_SFLG_FREE_SCHEDULED),
-					 ERTS_PORT_SFLG_FREE_SCHEDULED);
-	erts_may_save_closed_port(pp);
-	erts_smp_port_minor_unlock(pp);
-	ERTS_LC_ASSERT(erts_smp_atomic32_read_nob(&pp->common.refc) > 1);
+ 	erts_atomic32_read_bset_relb(&pp->state,
+				     (ERTS_PORT_SFLG_CLOSING
+				      | ERTS_PORT_SFLG_FREE_SCHEDULED),
+				     ERTS_PORT_SFLG_FREE_SCHEDULED);
 	ptp->type = ERTS_PORT_TASK_FREE;
 	ptp->event = (ErlDrvEvent) -1;
 	ptp->event_data = NULL;
@@ -651,20 +648,18 @@ erts_port_task_free_port(Port *pp)
 	    goto enqueue_free;
 	}
 	ASSERT(!pp->sched.taskq);
-	erts_smp_port_minor_lock(pp);
-	erts_smp_atomic32_read_bset_relb(&pp->state,
-					 (ERTS_PORT_SFLG_CLOSING
-					  | ERTS_PORT_SFLG_FREE_SCHEDULED),
-					 ERTS_PORT_SFLG_FREE_SCHEDULED);
-	erts_may_save_closed_port(pp);
-	erts_smp_port_minor_unlock(pp);
-	erts_smp_atomic32_dec_nob(&pp->common.refc); /* Not alive */
-	ERTS_LC_ASSERT(erts_smp_atomic32_read_nob(&pp->common.refc) > 0); /* Lock */
+	erts_atomic32_read_bset_relb(&pp->state,
+				     (ERTS_PORT_SFLG_CLOSING
+				      | ERTS_PORT_SFLG_FREE_SCHEDULED),
+				     ERTS_PORT_SFLG_FREE_SCHEDULED);
 	handle_remaining_tasks(runq, pp); /* May release runq lock */
 	ASSERT(!pp->sched.exe_taskq && (!ptqp || !ptqp->first));
 	pp->sched.taskq = NULL;
 	ERTS_PT_CHK_PRES_PORTQ(runq, pp);
 	erts_smp_runq_unlock(runq);
+#ifndef ERTS_SMP
+	pp->cleanup = 1;
+#endif
     }
 }
 
@@ -703,14 +698,21 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
 	goto done;
     }
 
+    if (erts_smp_port_trylock(pp) == EBUSY) {
+	erts_smp_runq_unlock(runq);
+	erts_smp_port_lock(pp);
+	erts_smp_runq_lock(runq);
+    }
+
     ASSERT(pp->sched.in_runq);
     pp->sched.in_runq = 0;
+
     if (!pp->sched.taskq) {
 	if (erts_system_profile_flags.runnable_ports)
 	    profile_runnable_port(pp, am_inactive);
 	res = (erts_smp_atomic_read_nob(&erts_port_task_outstanding_io_tasks)
 	       != (erts_aint_t) 0);
-	goto done;
+	goto release_port_done;
     }
 
     *curr_port_pp = pp;
@@ -721,12 +723,6 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
 
     ASSERT(!pp->sched.exe_taskq);
     pp->sched.exe_taskq = ptqp;
-
-    if (erts_smp_port_trylock(pp) == EBUSY) {
-	erts_smp_runq_unlock(runq);
-	erts_smp_port_lock(pp);
-	erts_smp_runq_lock(runq);
-    }
     
     if (erts_sched_stat.enabled) {
 	ErtsSchedulerData *esdp = erts_get_scheduler_data();
@@ -771,31 +767,31 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
 	    erts_smp_runq_lock(runq);
 
 	    erts_unblock_fpe(fpe_was_unmasked);
-	    ASSERT(erts_smp_atomic32_read_nob(&pp->state)
+	    ASSERT(erts_atomic32_read_nob(&pp->state)
 		   & ERTS_PORT_SFLG_FREE_SCHEDULED);
 	    if (ptqp->first || (pp->sched.taskq && pp->sched.taskq->first))
 		handle_remaining_tasks(runq, pp);
 	    ASSERT(!ptqp->first
 		   && (!pp->sched.taskq || !pp->sched.taskq->first));
-	    erts_smp_atomic32_dec_nob(&pp->common.refc); /* Not alive */
-	    ERTS_LC_ASSERT(erts_smp_atomic32_read_nob(&pp->common.refc) > 0); /* Lock */
 
 	    port_task_free(ptp);
 	    if (pp->sched.taskq)
 		port_taskq_free(pp->sched.taskq);
 	    pp->sched.taskq = NULL;
-
+#ifndef ERTS_SMP
+	    pp->cleanup = 1;
+#endif
 	    goto tasks_done;
 	case ERTS_PORT_TASK_TIMEOUT:
 	    reds += ERTS_PORT_REDS_TIMEOUT;
-	    if (!(erts_smp_atomic32_read_nob(&pp->state) & ERTS_PORT_SFLGS_DEAD)) {
+	    if (!(erts_atomic32_read_nob(&pp->state) & ERTS_PORT_SFLGS_DEAD)) {
                 DTRACE_DRIVER(driver_timeout, pp);
 		(*pp->drv_ptr->timeout)((ErlDrvData) pp->drv_data);
             }
 	    break;
 	case ERTS_PORT_TASK_INPUT:
 	    reds += ERTS_PORT_REDS_INPUT;
-	    ASSERT((erts_smp_atomic32_read_nob(&pp->state)
+	    ASSERT((erts_atomic32_read_nob(&pp->state)
 		    & ERTS_PORT_SFLGS_DEAD) == 0);
             DTRACE_DRIVER(driver_ready_input, pp);
 	    /* NOTE some windows drivers use ->ready_input for input and output */
@@ -804,7 +800,7 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
 	    break;
 	case ERTS_PORT_TASK_OUTPUT:
 	    reds += ERTS_PORT_REDS_OUTPUT;
-	    ASSERT((erts_smp_atomic32_read_nob(&pp->state)
+	    ASSERT((erts_atomic32_read_nob(&pp->state)
 		    & ERTS_PORT_SFLGS_DEAD) == 0);
             DTRACE_DRIVER(driver_ready_output, pp);
 	    (*pp->drv_ptr->ready_output)((ErlDrvData) pp->drv_data, ptp->event);
@@ -812,7 +808,7 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
 	    break;
 	case ERTS_PORT_TASK_EVENT:
 	    reds += ERTS_PORT_REDS_EVENT;
-	    ASSERT((erts_smp_atomic32_read_nob(&pp->state)
+	    ASSERT((erts_atomic32_read_nob(&pp->state)
 		    & ERTS_PORT_SFLGS_DEAD) == 0);
             DTRACE_DRIVER(driver_event, pp);
 	    (*pp->drv_ptr->event)((ErlDrvData) pp->drv_data, ptp->event, ptp->event_data);
@@ -828,7 +824,7 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
 	    break;
 	}
 
-	if ((erts_smp_atomic32_read_nob(&pp->state) & ERTS_PORT_SFLG_CLOSING)
+	if ((erts_atomic32_read_nob(&pp->state) & ERTS_PORT_SFLG_CLOSING)
 	    && erts_is_port_ioq_empty(pp)) {
 	    reds += ERTS_PORT_REDS_TERMINATE;
 	    erts_terminate_port(pp);
@@ -879,7 +875,7 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
 	ErtsRunQueue *xrunq;
 #endif
 
-	ASSERT(!(erts_smp_atomic32_read_nob(&pp->state) & ERTS_PORT_SFLGS_DEAD));
+	ASSERT(!(erts_atomic32_read_nob(&pp->state) & ERTS_PORT_SFLGS_DEAD));
 	ASSERT(pp->sched.taskq->first);
 
 #ifdef ERTS_SMP
@@ -922,23 +918,9 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
     if (IS_TRACED_FL(pp, F_TRACE_SCHED_PORTS)) {
     	trace_sched_ports(pp, am_out);
     }
-#ifndef ERTS_SMP
+
+release_port_done:
     erts_port_release(pp);
-#else
-    {
-	erts_aint32_t refc;
-	erts_smp_mtx_unlock(pp->lock);
-	refc = erts_smp_atomic32_dec_read_nob(&pp->common.refc);
-	ASSERT(refc >= 0);
-	if (refc == 0) {
-	    erts_smp_runq_unlock(runq);
-	    erts_port_cleanup(pp); /* Might aquire runq lock */
-	    erts_smp_runq_lock(runq);
-	    res = (erts_smp_atomic_read_nob(&erts_port_task_outstanding_io_tasks)
-		   != (erts_aint_t) 0);
-	}
-    }
-#endif
 
  done:
     ERTS_SMP_LC_ASSERT(erts_smp_lc_runq_is_locked(runq));
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index f9ff3c4bd5..e6fe4ccdc1 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -43,7 +43,6 @@
 #include "erl_thr_queue.h"
 #include "erl_async.h"
 #include "dtrace-wrapper.h"
-#define ERTS_PTAB_WANT_BIF_IMPL__
 #include "erl_ptab.h"
 
 #define ERTS_RUNQ_CHECK_BALANCE_REDS_PER_SCHED (2000*CONTEXT_REDS)
@@ -1482,37 +1481,32 @@ handle_reap_ports(ErtsAuxWorkData *awdp, erts_aint32_t aux_work)
     unset_aux_work_flags(awdp->ssi, ERTS_SSI_AUX_WORK_REAP_PORTS);
     awdp->esdp->run_queue->halt_in_progress = 1;
     if (erts_smp_atomic32_dec_read_acqb(&erts_halt_progress) == 0) {
-	int i;
+	int i, max = erts_ptab_max(&erts_port);
 	erts_smp_atomic32_set_nob(&erts_halt_progress, 1);
-	for (i = 0; i < erts_max_ports; i++) {
-	    Port *prt = &erts_port[i];
-	    erts_aint32_t state = erts_smp_atomic32_read_acqb(&prt->state);
+	for (i = 0; i < max; i++) {
+	    erts_aint32_t state;
+	    Port *prt = erts_pix2port(i);
+	    if (!prt)
+		continue;
+	    state = erts_atomic32_read_acqb(&prt->state);
 	    if (state & (ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP
 			 | ERTS_PORT_SFLG_HALT))
 		continue;
-	    erts_smp_port_minor_lock(prt);
+
 	    /* We need to set the halt flag - get the port lock */
-#ifdef ERTS_SMP
-	    erts_smp_atomic32_inc_nob(&prt->common.refc);
-#endif
-	    erts_smp_port_minor_unlock(prt);
-#ifdef ERTS_SMP
-	    erts_smp_mtx_lock(prt->lock);
-#endif
-	    state = erts_smp_atomic32_read_acqb(&prt->state);
-	    if (state & (ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP
-			 | ERTS_PORT_SFLG_HALT)) {
-		erts_port_release(prt);
-		continue;
-	    }
-	    state = erts_smp_atomic32_read_bor_relb(&prt->state,
+
+	    erts_smp_port_lock(prt);
+
+	    state = erts_atomic32_read_nob(&prt->state);
+	    if (!(state & (ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP
+			   | ERTS_PORT_SFLG_HALT))) {
+		state = erts_atomic32_read_bor_relb(&prt->state,
 						    ERTS_PORT_SFLG_HALT);
-	    erts_smp_atomic32_inc_nob(&erts_halt_progress);
-	    if (state & (ERTS_PORT_SFLG_EXITING|ERTS_PORT_SFLG_CLOSING)) {
-		erts_port_release(prt);
-		continue;
+		erts_smp_atomic32_inc_nob(&erts_halt_progress);
+		if (!(state & (ERTS_PORT_SFLG_EXITING|ERTS_PORT_SFLG_CLOSING)))
+		    erts_do_exit_port(prt, prt->common.id, am_killed);
 	    }
-	    erts_do_exit_port(prt, prt->common.id, am_killed);
+
 	    erts_port_release(prt);
 	}
 	if (erts_smp_atomic32_dec_read_nob(&erts_halt_progress) == 0) {
@@ -4304,6 +4298,11 @@ erts_init_scheduling(int no_schedulers, int no_schedulers_online)
 
     erts_smp_atomic32_init_relb(&erts_halt_progress, -1);
     erts_halt_code = 0;
+
+#if !defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK)
+    erts_lc_set_thread_name("scheduler 1");
+#endif
+
 }
 
 ErtsRunQueue *
@@ -8112,7 +8111,7 @@ static void doit_exit_monitor(ErtsMonitor *mon, void *vpcontext)
 	ASSERT(mon->type == MON_TARGET);
 	ASSERT(is_pid(mon->pid) || is_internal_port(mon->pid));
 	if (is_internal_port(mon->pid)) {
-	    Port *prt = erts_id2port(mon->pid, NULL, 0);
+	    Port *prt = erts_id2port(mon->pid);
 	    if (prt == NULL) {
 		goto done;
 	    }
@@ -8199,7 +8198,7 @@ static void doit_exit_link(ErtsLink *lnk, void *vpcontext)
     switch(lnk->type) {
     case LINK_PID:
 	if(is_internal_port(item)) {
-	    Port *prt = erts_id2port(item, NULL, 0);
+	    Port *prt = erts_id2port(item);
 	    if (prt) {
 		rlnk = erts_remove_link(&ERTS_P_LINKS(prt), p->common.id);
 		if (rlnk)
@@ -8758,14 +8757,6 @@ stack_element_dump(int to, void *to_arg, Process* p, Eterm* sp, int yreg)
 }
 
 /*
- * The processes/0 BIF.
- */
-BIF_RETTYPE processes_0(BIF_ALIST_0)
-{
-    return erts_ptab_list(BIF_P, &erts_proc);
-}
-
-/*
  * A nice system halt closing all open port goes as follows:
  * 1) This function schedules the aux work ERTS_SSI_AUX_WORK_REAP_PORTS
  *    on all schedulers, then schedules itself out.
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index 6f882c5e57..f5b7921820 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -42,6 +42,9 @@ typedef struct process Process;
 #include "erl_process_lock.h" /* Only pull out important types... */
 #undef ERTS_PROCESS_LOCK_ONLY_PROC_LOCK_TYPE__
 
+#define ERL_PORT_GET_PORT_TYPE_ONLY__
+#include "erl_port.h"
+#undef ERL_PORT_GET_PORT_TYPE_ONLY__
 #include "erl_vm.h"
 #include "erl_smp.h"
 #include "erl_message.h"
@@ -66,7 +69,6 @@ typedef struct process Process;
 #undef ERL_THR_PROGRESS_TSD_TYPE_ONLY
 
 struct ErtsNodesMonitor_;
-struct port;
 
 #define ERTS_MAX_NO_OF_SCHEDULERS 1024
 
@@ -378,8 +380,8 @@ struct ErtsRunQueue_ {
 
     struct {
 	ErtsRunQueueInfo info;
-	struct port *start;
-	struct port *end;
+	Port *start;
+	Port *end;
     } ports;
 };
 
@@ -476,7 +478,7 @@ struct ErtsSchedulerData_ {
     ErtsSchedulerSleepInfo *ssi;
     Process *current_process;
     Uint no;			/* Scheduler number */
-    struct port *current_port;
+    Port *current_port;
     ErtsRunQueue *run_queue;
     int virtual_reds;
     int cpu_id;			/* >= 0 when bound */
@@ -1219,7 +1221,7 @@ Eterm erts_sched_stat_term(Process *p, int total);
 
 void erts_free_proc(Process *);
 
-void erts_suspend(Process*, ErtsProcLocks, struct port*);
+void erts_suspend(Process*, ErtsProcLocks, Port*);
 void erts_resume(Process*, ErtsProcLocks);
 int erts_resume_processes(ErtsProcList *);
 
diff --git a/erts/emulator/beam/erl_ptab.c b/erts/emulator/beam/erl_ptab.c
index 8195a350fb..8cab1de9da 100644
--- a/erts/emulator/beam/erl_ptab.c
+++ b/erts/emulator/beam/erl_ptab.c
@@ -660,11 +660,9 @@ erts_ptab_delete_element(ErtsPTab *ptab,
 	erts_ptab_rwunlock(ptab);
     }
 
-#ifdef ERTS_SMP
     erts_schedule_thr_prgr_later_op(ptab->r.o.release_element,
 				    (void *) ptab_el,
 				    &ptab_el->u.release);
-#endif
 }
 
 /*
@@ -1151,16 +1149,18 @@ ptab_list_bif_engine(Process *c_p, Eterm *res_accp, Binary *mbp)
 		conses = ptlbdp->pid_ix;
 	    }
 
-	    hp = HAlloc(c_p, conses*2);
-	    ERTS_PTAB_LIST_DBG_SAVE_HEAP_ALLOC(ptlbdp, hp, conses*2);
+	    if (conses) {
+		hp = HAlloc(c_p, conses*2);
+		ERTS_PTAB_LIST_DBG_SAVE_HEAP_ALLOC(ptlbdp, hp, conses*2);
 
-	    for (ix = ptlbdp->pid_ix - 1; ix >= min_ix; ix--) {
-		ERTS_PTAB_LIST_ASSERT(erts_ptab_is_valid_id(ptlbdp->pid[ix]));
-		res = CONS(hp, ptlbdp->pid[ix], res);
-		hp += 2;
-	    }
+		for (ix = ptlbdp->pid_ix - 1; ix >= min_ix; ix--) {
+		    ERTS_PTAB_LIST_ASSERT(erts_ptab_is_valid_id(ptlbdp->pid[ix]));
+		    res = CONS(hp, ptlbdp->pid[ix], res);
+		    hp += 2;
+		}
 
-	    ERTS_PTAB_LIST_DBG_VERIFY_HEAP_ALLOC_USED(ptlbdp, hp);
+		ERTS_PTAB_LIST_DBG_VERIFY_HEAP_ALLOC_USED(ptlbdp, hp);
+	    }
 
 	    ptlbdp->pid_ix = min_ix;
 	    if (min_ix == 0)
diff --git a/erts/emulator/beam/erl_ptab.h b/erts/emulator/beam/erl_ptab.h
index b65db330e5..b2ae829d62 100644
--- a/erts/emulator/beam/erl_ptab.h
+++ b/erts/emulator/beam/erl_ptab.h
@@ -53,8 +53,6 @@ typedef struct {
     Eterm id;
 #ifdef ERTS_SMP
     erts_atomic32_t refc;
-#else
-    erts_smp_atomic32_t refc; /* Temporary solution during dev; to be removed! */
 #endif
     Eterm tracer_proc;
     Uint trace_flags;
@@ -73,9 +71,7 @@ typedef struct {
 	} alive;
 
 	/* --- While being released --- */
-#ifdef ERTS_SMP
 	ErtsThrPrgrLaterOp release;
-#endif
     } u;
 } ErtsPTabElementCommon;
 
diff --git a/erts/emulator/beam/erl_sys_driver.h b/erts/emulator/beam/erl_sys_driver.h
index d429d0ce96..b991a2840c 100644
--- a/erts/emulator/beam/erl_sys_driver.h
+++ b/erts/emulator/beam/erl_sys_driver.h
@@ -31,7 +31,6 @@
 #define ERL_SYS_DRV
 
 typedef long ErlDrvEvent; /* An event to be selected on. */
-typedef long ErlDrvPort; /* A port descriptor. */
 
 /* typedef struct _SysDriverOpts SysDriverOpts; defined in sys.h */
 
diff --git a/erts/emulator/beam/erl_trace.c b/erts/emulator/beam/erl_trace.c
index dd2a121165..991e573c14 100644
--- a/erts/emulator/beam/erl_trace.c
+++ b/erts/emulator/beam/erl_trace.c
@@ -3442,10 +3442,8 @@ sys_msg_dispatcher_func(void *unused)
 		    goto queue_proc_msg;
 	    }
 	    else if (is_internal_port(receiver)) {
-		port = erts_id2port_sflgs(receiver,
-					  NULL,
-					  0,
-					  ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP);
+		port = erts_thr_id2port_sflgs(receiver,
+					      ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP);
 		if (!port)
 		    goto failure;
 		else {
@@ -3459,7 +3457,7 @@ sys_msg_dispatcher_func(void *unused)
 #ifdef DEBUG_PRINTOUTS
 		    erts_fprintf(stderr, "delivered\n");
 #endif
-		    erts_port_release(port);
+		    erts_thr_port_release(port);
 		    if (smqp->bp)
 			free_message_buffer(smqp->bp);
 		}
diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h
index d93ac723a4..ae31ab54b5 100644
--- a/erts/emulator/beam/global.h
+++ b/erts/emulator/beam/global.h
@@ -884,11 +884,6 @@ int erts_global_garbage_collect(Process*, int, Eterm*, int);
 
 /* io.c */
 
-struct erl_drv_port_data_lock {
-    erts_mtx_t mtx;
-    erts_atomic_t refc;
-};
-
 typedef struct {
     char *name;
     char *driver_name;
@@ -901,22 +896,18 @@ typedef struct {
 int erts_add_driver_entry(ErlDrvEntry *drv, DE_Handle *handle, int driver_list_locked);
 void erts_destroy_driver(erts_driver_t *drv);
 void erts_wake_process_later(Port*, Process*);
-int erts_open_driver(erts_driver_t*, Eterm, char*, SysDriverOpts*, int *);
+Port *erts_open_driver(erts_driver_t*, Eterm, char*, SysDriverOpts*, int *, int *);
 int erts_is_port_ioq_empty(Port *);
 void erts_terminate_port(Port *);
-void close_port(Eterm);
 void init_io(void);
-void cleanup_io(void);
 void erts_do_exit_port(Port *, Eterm, Eterm);
 void erts_port_command(Process *, Eterm, Port *, Eterm);
 Eterm erts_port_control(Process*, Port*, Uint, Eterm);
 int erts_write_to_port(Eterm caller_id, Port *p, Eterm list);
-void print_port_info(int, void *, int);
 void erts_raw_port_command(Port*, byte*, Uint);
-void driver_report_exit(int, int);
+void driver_report_exit(ErlDrvPort, int);
 LineBuf* allocate_linebuf(int);
 int async_ready(Port *, void*);
-Sint erts_test_next_port(int, Uint);
 ErtsPortNames *erts_get_port_names(Eterm);
 void erts_free_port_names(ErtsPortNames *);
 Uint erts_port_ioq_size(Port *pp);
diff --git a/erts/emulator/beam/io.c b/erts/emulator/beam/io.c
index b772783f64..4dcec356a9 100644
--- a/erts/emulator/beam/io.c
+++ b/erts/emulator/beam/io.c
@@ -57,15 +57,14 @@ static erts_smp_tsd_key_t driver_list_lock_status_key; /*stop recursive locks wh
 static erts_smp_tsd_key_t driver_list_last_error_key;  /* Save last DDLL error on a 
 							  per thread basis (for BC interfaces) */
 
-Port*      erts_port; /* The port table */
+ErtsPTab erts_port erts_align_attribute(ERTS_CACHE_LINE_SIZE); /* The port table */
 erts_smp_atomic_t erts_bytes_out;	/* No bytes sent out of the system */
 erts_smp_atomic_t erts_bytes_in;	/* No bytes gotten into the system */
 
-Uint erts_max_ports;
-Uint erts_port_tab_index_mask;
-
 const ErlDrvTermData driver_term_nil = (ErlDrvTermData)NIL;
 
+const Port erts_invalid_port = {{ERTS_INVALID_PORT}};
+
 erts_driver_t vanilla_driver;
 erts_driver_t spawn_driver;
 erts_driver_t fd_driver;
@@ -89,36 +88,12 @@ static void driver_monitor_unlock_pdl(Port *p);
 static ERTS_INLINE ErlIOQueue*
 drvport2ioq(ErlDrvPort drvport)
 {
-    int ix = (int) drvport;
-    erts_aint32_t state;
-
-    if (ix < 0 || erts_max_ports <= ix)
-	return NULL;
-
-    state = erts_smp_atomic32_read_nob(&erts_port[ix].state);
-
-#ifdef ERTS_ENABLE_LOCK_CHECK
-
-    if (erts_get_scheduler_data()) {
-	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(&erts_port[ix]));
-	ERTS_LC_ASSERT(!erts_port[ix].port_data_lock
-		       || erts_lc_mtx_is_locked(
-			   &erts_port[ix].port_data_lock->mtx));
-    }
-    else {
-	ERTS_LC_ASSERT((state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
-		       || erts_port[ix].port_data_lock);
-	ERTS_LC_ASSERT(!erts_port[ix].port_data_lock
-		       || erts_lc_mtx_is_locked(
-			   &erts_port[ix].port_data_lock->mtx));
-    }
-
-#endif
-
+    Port *prt = erts_thr_drvport2port_raw(drvport);
+    erts_aint32_t state = erts_atomic32_read_nob(&prt->state);
     if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
 	return NULL;
     else
-	return &erts_port[ix].ioq;
+	return &prt->ioq;
 }
 
 static ERTS_INLINE int
@@ -196,27 +171,13 @@ typedef struct line_buf_context {
     dtrace_port_str((PORT), port_str);
 #endif
 
-/* The 'number' field in a port now has two parts: the lowest bits
-   contain the index in the port table, and the higher bits are a counter
-   which is incremented each time we look for a free port and start from
-   the beginning of the table. erts_max_ports is the number of file descriptors,
-   rounded up to a power of 2.
-   To get the index from a port, use the macro 'internal_port_index';
-   'port_number' returns the whole number field.
-*/
-
-static erts_smp_spinlock_t get_free_port_lck;
-static Uint last_port_num;
-static Uint port_num_mask;
-erts_smp_atomic32_t erts_ports_snapshot; /* Identifies the _next_ snapshot (not the ongoing) */
-
-
 static ERTS_INLINE void
 kill_port(Port *pp)
 {
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(pp));
+    erts_ptab_delete_element(&erts_port, &pp->common); /* Time of death */
     erts_port_task_free_port(pp);
-    ASSERT(erts_smp_atomic32_read_nob(&pp->state) & ERTS_PORT_SFLGS_DEAD);
+    /* In non-smp case the port structure may have been deallocated now */
 }
 
 #ifdef ERTS_SMP
@@ -227,149 +188,194 @@ erts_lc_is_port_locked(Port *prt)
 {
     if (!prt)
 	return 0;
+    ERTS_SMP_LC_ASSERT(prt->lock);
     return erts_smp_lc_mtx_is_locked(prt->lock);
 }
 #endif
 
 #endif /* #ifdef ERTS_SMP */
 
-static int
-get_free_port(void)
-{
-    Uint num;
-    Uint tries = erts_max_ports;
-    Port* port;    
-
-    erts_smp_spin_lock(&get_free_port_lck);
-    num = last_port_num + 1;
-    for (;; ++num) {
-	erts_aint32_t act;
-
-	port = &erts_port[num & erts_port_tab_index_mask];
-
-	act = erts_smp_atomic32_read_nob(&port->state);
-
-	while (act & ERTS_PORT_SFLG_FREE) {
-	    erts_aint32_t exp = act;
-	    act = erts_smp_atomic32_cmpxchg_relb(&port->state,
-						 ERTS_PORT_SFLG_INITIALIZING,
-						 exp);
-	    if (act == exp) {
-		last_port_num = num;
-		erts_smp_spin_unlock(&get_free_port_lck);
-		ERTS_LC_ASSERT(erts_smp_atomic32_read_nob(&port->common.refc) == 0);
-		erts_smp_atomic32_set_nob(&port->common.refc, 2); /* Port alive + lock */
-		return num & port_num_mask;
-	    }
-	}
+static void initq(Port* prt);
 
-	if (--tries == 0) {
-	    erts_smp_spin_unlock(&get_free_port_lck);
-	    return -1;
-	}
-    }
+static void insert_port_struct(void *vprt, Eterm data)
+{
+    Port *prt = (Port *) vprt;
+    Eterm id = make_internal_port(data);
+#ifdef ERTS_SMP
+    ASSERT(prt->drv_ptr && prt->lock);
+    /*
+     * We are breaking lock order in the port specific locking
+     * case. This is, however, safe since the lock has not been
+     * published, yet.
+     */
+    if (!prt->drv_ptr->lock)
+	erts_mtx_init_locked_x(prt->lock, "port_lock", id);
+#endif
+    prt->common.id = id;
+    erts_atomic32_init_relb(&prt->state, ERTS_PORT_SFLG_INITIALIZING);
 }
 
-/*
- * erts_test_next_port() is only used for testing.
- */
-Sint
-erts_test_next_port(int set, Uint next)
+static Port *create_port(char *name,
+			 erts_driver_t *driver,
+			 erts_mtx_t *driver_lock,
+			 Eterm pid,
+			 int *enop)
 {
-    Uint i, num;
-    Sint res = -1;
+    Port *prt;
+    char *p;
+    size_t port_size, size;
+    erts_aint32_t state = ERTS_PORT_SFLG_CONNECTED;
+#ifdef DEBUG
+    /* Make sure the debug flags survives until port is freed */
+    state |= ERTS_PORT_SFLG_PORT_DEBUG;
+#endif
 
-    erts_smp_spin_lock(&get_free_port_lck);
-    if (set) {
-	last_port_num = (next - 1) & port_num_mask;
+#ifdef ERTS_SMP
+    if (!driver_lock) {
+	/* Align size for mutex following port struct */
+	port_size = size = ERTS_ALC_DATA_ALIGN_SIZE(sizeof(Port));
+	size += sizeof(erts_mtx_t);
     }
-    num = last_port_num + 1;
-
-    for (i=0; i < erts_max_ports && res<0; ++i, ++num) {	
-	
-	Port* port = &erts_port[num & erts_port_tab_index_mask];
+    else
+#endif
+	port_size = size = sizeof(Port);
 
-	erts_aint32_t state = erts_smp_atomic32_read_nob(&port->state);
+    size += sys_strlen(name) + 1;
 
-	if (state & ERTS_PORT_SFLG_FREE) {	   
-	    last_port_num = num - 1;
-	    res = num & port_num_mask;
-	}
+    p = erts_alloc_fnf(ERTS_ALC_T_PORT, size);
+    if (!p) {
+	if (enop)
+	    *enop = ENOMEM;
+	return NULL;
     }
-    erts_smp_spin_unlock(&get_free_port_lck);
-    return res;
-}
 
-static void port_cleanup(Port *prt);
+    prt = (Port *) p;
+    p += port_size;
 
 #ifdef ERTS_SMP
+    if (driver_lock) {
+	prt->lock = driver_lock;
+	erts_mtx_lock(driver_lock);
+    }
+    else {
+	prt->lock = (erts_mtx_t *) p;
+	p += sizeof(erts_mtx_t);
+	state |= ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK;
+    }
+    erts_smp_atomic_set_nob(&prt->run_queue,
+			    (erts_aint_t) erts_get_runq_current(NULL));
+    prt->xports = NULL;
+#else
+    erts_atomic32_init_nob(&prt->refc, 1);
+    prt->cleanup = 0;
+#endif
+    
+    prt->name = p;
+    sys_strcpy(p, name);
+    prt->drv_ptr = driver;
+    ERTS_P_LINKS(prt) = NULL;
+    ERTS_P_MONITORS(prt) = NULL;
+    prt->linebuf = NULL;
+    prt->bp = NULL;
+    prt->suspended = NULL;
+    prt->data = am_undefined;
+    prt->port_data_lock = NULL;
+    prt->control_flags = 0;
+    prt->bytes_in = 0;
+    prt->bytes_out = 0;
+    prt->dist_entry = NULL;
+    prt->connected = pid;
+    prt->common.u.alive.reg = NULL;
+#ifdef ERTS_SMP
+    prt->common.u.alive.ptimer = NULL;
+#else
+    sys_memset(&prt->common.u.alive.tm, 0, sizeof(ErlTimer));
+#endif
+    erts_port_task_handle_init(&prt->timeout_task);
+    erts_port_task_init_sched(&prt->sched);
+    prt->psd = NULL;
+    prt->drv_data = (SWord) 0;
 
-static void
-sched_port_cleanup(void *vprt)
-{
-    Port *prt = (Port *) vprt;
-    erts_smp_mtx_lock(prt->lock);
-    port_cleanup(prt);
-}
+    /* Set default tracing */
+    erts_get_default_tracing(&ERTS_TRACE_FLAGS(prt), &ERTS_TRACER_PROC(prt));
+
+    ASSERT(((char *) prt) == ((char *) &prt->common));
 
+    if (!erts_ptab_new_element(&erts_port,
+			       &prt->common,
+			       (void *) prt,
+			       insert_port_struct)) {
+#ifdef ERTS_SMP
+	if (driver_lock)
+	    erts_mtx_unlock(driver_lock);
 #endif
+	if (enop)
+	    *enop = 0;
+	return NULL;
+    }
+
+    ASSERT(prt == (Port *) (erts_ptab_pix2intptr_nob(
+				&erts_port,
+				internal_port_index(prt->common.id))));
 
+    initq(prt);
+
+    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
+
+    erts_atomic32_set_relb(&prt->state, state);
+    return prt;
+}
+
+#ifndef ERTS_SMP
 void
 erts_port_cleanup(Port *prt)
 {
-#ifdef ERTS_SMP
-    if (erts_smp_mtx_trylock(prt->lock) == EBUSY)
-	erts_schedule_misc_op(sched_port_cleanup, (void *) prt);
-    else
-#endif
-	port_cleanup(prt);
+    if (prt->drv_ptr && prt->drv_ptr->handle)
+	erts_ddll_dereference_driver(prt->drv_ptr->handle);
+    prt->drv_ptr = NULL;
+    erts_port_dec_refc(prt);
 }
+#endif
 
 void
-port_cleanup(Port *prt)
+erts_port_free(Port *prt)
 {
-#ifdef ERTS_SMP
-    erts_smp_mtx_t *mtx;
-#endif
 #if defined(ERTS_SMP) || defined(ERTS_ENABLE_LOCK_CHECK)
-    erts_aint32_t state = erts_smp_atomic32_read_nob(&prt->state);
+    erts_aint32_t state = erts_atomic32_read_nob(&prt->state);
 #endif
-    erts_driver_t *driver;
-
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-    driver = prt->drv_ptr;
-    prt->drv_ptr = NULL;
-    ASSERT(driver);
-
-    ERTS_LC_ASSERT(state & ERTS_PORT_SFLG_FREE_SCHEDULED);
-    ERTS_LC_ASSERT(state & ERTS_PORT_SFLG_PORT_DEBUG);
+    ERTS_LC_ASSERT(state & (ERTS_PORT_SFLG_FREE_SCHEDULED
+			    | ERTS_PORT_SFLG_INITIALIZING));
+    ASSERT(state & ERTS_PORT_SFLG_PORT_DEBUG);
     ERTS_LC_ASSERT(!(state & ERTS_PORT_SFLG_FREE));
 
-    ERTS_LC_ASSERT(erts_smp_atomic32_read_nob(&prt->common.refc) == 0);
-
 #ifdef ERTS_SMP
-    mtx = prt->lock;
-    ASSERT(mtx);
-
-    prt->lock = NULL;
-
-    erts_smp_mtx_unlock(mtx);
+    ERTS_LC_ASSERT(erts_atomic32_read_nob(&prt->common.refc) == 0);
+#else
+    ERTS_LC_ASSERT(erts_atomic32_read_nob(&prt->refc) == 0);
 #endif
 
-    erts_smp_atomic32_set_relb(&prt->state, ERTS_PORT_SFLG_FREE);
-
 #ifdef ERTS_SMP
-    if (state & ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK) {
-	erts_smp_mtx_destroy(mtx);
-	erts_free(ERTS_ALC_T_PORT_LOCK, mtx);
-    }
-#endif
+    ASSERT(prt->lock);
+    if (state & ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK)
+	erts_mtx_destroy(prt->lock);
 
-    if (driver->handle)
-	erts_ddll_dereference_driver(driver->handle);
+    /*
+     * We cannot dereference a driver using driver
+     * locking until here in smp case. Otherwise,
+     * the driver lock may still be in use by others.
+     *
+     * In the non-smp case we cannot do it here since
+     * this function may be called by non-scheduler
+     * threads. This is done in erts_port_cleanup()
+     * in the non-smp case.
+     */
+    if (prt->drv_ptr->handle)
+	erts_ddll_dereference_driver(prt->drv_ptr->handle);
+#endif
+    erts_atomic32_set_nob(&prt->state, ERTS_PORT_SFLG_FREE);
+    erts_free(ERTS_ALC_T_PORT, prt);
 }
 
-
 /*
 ** Initialize v_start to point to the small fixed vector.
 ** Once (reallocated) we never reset the pointer to the small vector
@@ -416,73 +422,7 @@ static void stopq(Port* prt)
     if (prt->port_data_lock) {
 	driver_pdl_unlock(prt->port_data_lock);
 	driver_pdl_dec_refc(prt->port_data_lock);
-	prt->port_data_lock = NULL;
-    }
-}
-
-
-
-static void
-setup_port(Port* prt, Eterm pid, erts_driver_t *driver, 
-	   ErlDrvData drv_data, char *name, erts_aint32_t xstate)
-{
-    ErtsRunQueue *runq = erts_get_runq_current(NULL);
-    char *new_name, *old_name;
-#ifdef DEBUG
-    /* Make sure the debug flags survives until port is freed */
-    xstate |= ERTS_PORT_SFLG_PORT_DEBUG;
-#endif
-    ASSERT(runq);
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-
-    
-    new_name = (char*) erts_alloc(ERTS_ALC_T_PORT_NAME, sys_strlen(name)+1);
-    sys_strcpy(new_name, name);
-    erts_smp_runq_lock(runq);
-    prt->snapshot = erts_smp_atomic32_read_nob(&erts_ports_snapshot);    
-    old_name = prt->name;
-    prt->name = new_name;
-#ifdef ERTS_SMP
-    erts_smp_atomic_set_nob(&prt->run_queue, (erts_aint_t) runq);
-#endif
-    ASSERT(!prt->drv_ptr);
-    prt->drv_ptr = driver;
-    erts_smp_atomic32_set_relb(&prt->state,
-			       ERTS_PORT_SFLG_CONNECTED | xstate);
-    erts_smp_runq_unlock(runq);
-#ifdef ERTS_SMP
-    ASSERT(!prt->xports);
-#endif
-    if (old_name) {
-	erts_free(ERTS_ALC_T_PORT_NAME, (void *) old_name);
     }
-
-    prt->control_flags = 0;
-    prt->connected = pid;
-    prt->drv_data = (SWord) drv_data;
-    prt->bytes_in = 0;
-    prt->bytes_out = 0;
-    prt->dist_entry = NULL;
-    prt->common.u.alive.reg = NULL;
-#ifdef ERTS_SMP
-    prt->common.u.alive.ptimer = NULL;
-#else
-    sys_memset(&prt->common.u.alive.tm, 0, sizeof(ErlTimer));
-#endif
-    erts_port_task_handle_init(&prt->timeout_task);
-    prt->suspended  = NULL;
-    sys_strcpy(prt->name, name);
-    ERTS_P_LINKS(prt) = NULL;
-    ERTS_P_MONITORS(prt) = NULL;
-    prt->linebuf = NULL;
-    prt->bp = NULL;
-    prt->data = am_undefined;
-    /* Set default tracing */
-    erts_get_default_tracing(&ERTS_TRACE_FLAGS(prt), &ERTS_TRACER_PROC(prt));
-
-    prt->psd = NULL;
-
-    initq(prt);
 }
 
 void
@@ -493,7 +433,7 @@ erts_wake_process_later(Port *prt, Process *process)
 
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
 
-    if (erts_smp_atomic32_read_nob(&prt->state) & ERTS_PORT_SFLGS_DEAD)
+    if (erts_atomic32_read_nob(&prt->state) & ERTS_PORT_SFLGS_DEAD)
 	return;
 
     for (p = &(prt->suspended); *p != NULL; p = &((*p)->next))
@@ -513,36 +453,34 @@ erts_wake_process_later(Port *prt, Process *process)
    (*error_number_ptr must contain either BADARG or SYSTEM_LIMIT).
    The driver start function must obey the same conventions.
 */
-int
+Port *
 erts_open_driver(erts_driver_t* driver,	/* Pointer to driver. */
 		 Eterm pid,		/* Current process. */
 		 char* name,		/* Driver name. */
 		 SysDriverOpts* opts,	/* Options. */
-		 int *error_number_ptr)	/* errno in case -2 is returned */
+		 int *error_type_ptr,	/* error type */
+		 int *error_number_ptr)	/* errno in case of error type -2 */
 {
-    int port_num;
-    int port_ix;
+
+#undef ERTS_OPEN_DRIVER_RET
+#define ERTS_OPEN_DRIVER_RET(Prt, EType, ENo)	\
+    do {					\
+	if (error_type_ptr)			\
+	    *error_type_ptr = (EType);		\
+	if (error_number_ptr)			\
+	    *error_number_ptr = (ENo);		\
+	return (Prt);				\
+    } while (0)
+
     ErlDrvData drv_data = 0;
-    erts_aint32_t xstate = 0;
     Port *port;
     int fpe_was_unmasked;
-
-    if (error_number_ptr)
-	*error_number_ptr = 0;
+    int error_type, error_number;
+    int port_errno = 0;
+    erts_mtx_t *driver_lock = NULL;
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
-    if ((port_num = get_free_port()) < 0) {
-	if (error_number_ptr) {
-	    *error_number_ptr = SYSTEM_LIMIT;
-	}
-	return -3;
-    }
-
-    port_ix = port_num & erts_port_tab_index_mask;
-    port = &erts_port[port_ix];
-    port->common.id = make_internal_port(port_num);
-
     erts_smp_mtx_lock(&erts_driver_list_lock);
     if (!driver) {
 	for (driver = driver_list; driver; driver = driver->next) {
@@ -551,9 +489,7 @@ erts_open_driver(erts_driver_t* driver,	/* Pointer to driver. */
 	}
 	if (!driver) { 
 	    erts_smp_mtx_unlock(&erts_driver_list_lock);
-	    if (error_number_ptr)
-		*error_number_ptr = BADARG;
-	    return -3;
+	    ERTS_OPEN_DRIVER_RET(NULL, -3, BADARG);
 	}
     }
     if (driver == &spawn_driver) {
@@ -598,32 +534,11 @@ erts_open_driver(erts_driver_t* driver,	/* Pointer to driver. */
 
     if (driver == NULL || (driver != &spawn_driver && opts->exit_status)) {
 	erts_smp_mtx_unlock(&erts_driver_list_lock);
-	if (error_number_ptr) {
-	    *error_number_ptr = BADARG;
-	}
-	/* Need to mark the port as free again */
-	ERTS_LC_ASSERT(erts_smp_atomic32_read_nob(&port->common.refc) == 2);
-	erts_smp_atomic32_set_nob(&port->common.refc, 0); 
-	erts_smp_atomic32_set_relb(&port->state, ERTS_PORT_SFLG_FREE);
-	return -3;
+	ERTS_OPEN_DRIVER_RET(NULL, -3, BADARG);
     }
 
-    /*
-     * We'll set up the port before calling the start function,
-     * to allow message sending and setting timers in the start function.
-     */
-
 #ifdef ERTS_SMP
-    ASSERT(!port->lock);
-    port->lock = driver->lock;
-    if (!port->lock) {
-	port->lock = erts_alloc(ERTS_ALC_T_PORT_LOCK,
-					      sizeof(erts_smp_mtx_t));
-	erts_smp_mtx_init_x(port->lock,
-			    "port_lock",
-			    port->common.id);
-	xstate |= ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK;
-    }
+    driver_lock = driver->lock;
 #endif
 
     if (driver->handle != NULL) {
@@ -632,18 +547,32 @@ erts_open_driver(erts_driver_t* driver,	/* Pointer to driver. */
     }
     erts_smp_mtx_unlock(&erts_driver_list_lock);
 
-#ifdef ERTS_SMP
-    erts_smp_mtx_lock(port->lock);
-#endif
+    /*
+     * We'll set up the port before calling the start function,
+     * to allow message sending and setting timers in the start function.
+     */
 
-    setup_port(port, pid, driver, drv_data, name, xstate);
+    port = create_port(name, driver, driver_lock, pid, &port_errno);
+    if (!port) {
+	if (driver->handle) {
+	    erts_smp_mtx_lock(&erts_driver_list_lock);
+	    erts_ddll_decrement_port_count(driver->handle);
+	    erts_smp_mtx_unlock(&erts_driver_list_lock);
+	    erts_ddll_dereference_driver(driver->handle);
+	}
+	if (port_errno)
+	    ERTS_OPEN_DRIVER_RET(NULL, -2, port_errno);
+	else
+	    ERTS_OPEN_DRIVER_RET(NULL, -3, SYSTEM_LIMIT);
+    }
     
     if (IS_TRACED_FL(port, F_TRACE_PORTS)) {
 	trace_port_open(port,
 		pid,		
 		am_atom_put(port->name, strlen(port->name)));
     }
-    
+
+    error_number = error_type = 0;
     if (driver->start) {
 	if (IS_TRACED_FL(port, F_TRACE_SCHED_PORTS)) {
 	    trace_sched_ports_where(port, am_in, am_start);
@@ -656,15 +585,28 @@ erts_open_driver(erts_driver_t* driver,	/* Pointer to driver. */
         }
 #endif
 	fpe_was_unmasked = erts_block_fpe();
-	drv_data = (*driver->start)((ErlDrvPort)(port_ix),
-				    name, opts);
+	drv_data = (*driver->start)((ErlDrvPort) port, name, opts);
+	if (((SWord) drv_data) == -1)
+	    error_type = -1;
+	else if (((SWord) drv_data) == -2) {
+	    /*
+	     * We need to save errno quickly after the
+	     * call to the 'start' callback before
+	     * something else modify it.
+	     */
+	    error_type = -2;
+	    error_number = errno;
+	}
+	else if (((SWord) drv_data) == -3) {
+	    error_type = -3;
+	    error_number = BADARG;
+	}
+
 	erts_unblock_fpe(fpe_was_unmasked);
 	port->caller = NIL;
 	if (IS_TRACED_FL(port, F_TRACE_SCHED_PORTS)) {
 	    trace_sched_ports_where(port, am_out, am_start);
 	}
-	if (error_number_ptr && ((SWord) drv_data) == (SWord) -2)
-	    *error_number_ptr = errno;
 #ifdef ERTS_SMP
 	if (port->xports)
 	    erts_smp_xports_unlock(port);
@@ -672,15 +614,7 @@ erts_open_driver(erts_driver_t* driver,	/* Pointer to driver. */
 #endif
     }
 
-    if (((SWord)drv_data) == -1 || 
-	((SWord)drv_data) == -2 || 
-	((SWord)drv_data) == -3) {
-	int res = (int) ((SWord) drv_data);
-
-	if (res == -3 && error_number_ptr) {
-	    *error_number_ptr = BADARG;
-	}
-
+    if (error_type) {
 	/*
 	 * Must clean up the port.
 	 */
@@ -690,7 +624,6 @@ erts_open_driver(erts_driver_t* driver,	/* Pointer to driver. */
 	erts_cancel_timer(&(port->common.u.alive.tm));
 #endif
 	stopq(port);
-	kill_port(port);
 	if (port->linebuf != NULL) {
 	    erts_free(ERTS_ALC_T_LINEBUF,
 		      (void *) port->linebuf);
@@ -701,11 +634,14 @@ erts_open_driver(erts_driver_t* driver,	/* Pointer to driver. */
 	    erts_ddll_decrement_port_count(driver->handle);
 	    erts_smp_mtx_unlock(&erts_driver_list_lock);
 	}
+	kill_port(port);
 	erts_port_release(port);
-	return res;
+	ERTS_OPEN_DRIVER_RET(NULL, error_type, error_number);
     }
-    port->drv_data = (SWord) drv_data;
-    return port_ix;
+    port->drv_data = (UWord) drv_data;
+    ERTS_OPEN_DRIVER_RET(port, 0, 0);
+
+#undef ERTS_OPEN_DRIVER_RET
 }
 
 #ifdef ERTS_SMP
@@ -734,15 +670,21 @@ driver_create_port(ErlDrvPort creator_port_ix, /* Creating port */
     Port* port;
     erts_driver_t *driver;
     Process *rp;
-    int port_num;
-    Eterm port_id;
-    erts_aint32_t xstate = 0;
+    erts_mtx_t *driver_lock = NULL;
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
+    /* Need to be called from a scheduler thread */
+    if (!erts_get_scheduler_id())
+	return ERTS_INVALID_ERL_DRV_PORT;
+
     creator_port = erts_drvport2port(creator_port_ix, NULL);
     if (!creator_port)
-	return (ErlDrvTermData) -1;
+	return ERTS_INVALID_ERL_DRV_PORT;
+
+    rp = erts_proc_lookup(pid);
+    if (!rp)
+	return ERTS_INVALID_ERL_DRV_PORT;
 
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(creator_port));
 
@@ -750,55 +692,61 @@ driver_create_port(ErlDrvPort creator_port_ix, /* Creating port */
     erts_smp_mtx_lock(&erts_driver_list_lock);
     if (!erts_ddll_driver_ok(driver->handle)) {
 	erts_smp_mtx_unlock(&erts_driver_list_lock);
-	return (ErlDrvTermData) -1;
+	return ERTS_INVALID_ERL_DRV_PORT;
     }
 
-    rp = erts_pid2proc(NULL, 0, pid, ERTS_PROC_LOCK_LINK);
-    if (!rp) {
-	erts_smp_mtx_unlock(&erts_driver_list_lock);
-	return (ErlDrvTermData) -1;   /* pid does not exist */
+    if (driver->handle != NULL) {
+	erts_ddll_increment_port_count(driver->handle);
+	erts_ddll_reference_referenced_driver(driver->handle);
+    }
+
+#ifdef ERTS_SMP
+    driver_lock = driver->lock;
+#endif
+
+    erts_smp_mtx_unlock(&erts_driver_list_lock);
+
+    port = create_port(name, driver, driver_lock, pid, NULL);
+    if (!port) {
+	if (driver->handle) {
+	    erts_smp_mtx_lock(&erts_driver_list_lock);
+	    erts_ddll_decrement_port_count(driver->handle);
+	    erts_smp_mtx_unlock(&erts_driver_list_lock);
+	    erts_ddll_dereference_driver(driver->handle);
+	}
+	return ERTS_INVALID_ERL_DRV_PORT;
     }
-    if ((port_num = get_free_port()) < 0) {
-	errno = SYSTEM_LIMIT;
+    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(port));
+
+    erts_smp_proc_lock(rp, ERTS_PROC_LOCK_LINK);
+    if (ERTS_PROC_IS_EXITING(rp)) {
 	erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
-	erts_smp_mtx_unlock(&erts_driver_list_lock);
-	return (ErlDrvTermData) -1;
+	if (driver->handle) {
+	    erts_smp_mtx_lock(&erts_driver_list_lock);
+	    erts_ddll_decrement_port_count(driver->handle);
+	    erts_smp_mtx_unlock(&erts_driver_list_lock);
+	}
+	kill_port(port);
+	erts_port_release(port);
+	return ERTS_INVALID_ERL_DRV_PORT;
     }
 
-    port_id = make_internal_port(port_num);
-    port = &erts_port[port_num & erts_port_tab_index_mask];
+    erts_add_link(&ERTS_P_LINKS(port), LINK_PID, pid);
+    erts_add_link(&ERTS_P_LINKS(rp), LINK_PID, port->common.id);
+    erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
 
 #ifdef ERTS_SMP
-    ASSERT(!port->lock);
-    port->lock = driver->lock;
-    if (!port->lock) {
+    if (!driver_lock) {
 	ErtsXPortsList *xplp = xports_list_alloc();
 	xplp->port = port;
 	xplp->next = creator_port->xports;
 	creator_port->xports = xplp;
-	port->lock = erts_alloc(ERTS_ALC_T_PORT_LOCK,
-					      sizeof(erts_smp_mtx_t));
-	erts_smp_mtx_init_locked_x(port->lock, "port_lock", port_id);
-	xstate |= ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK;
     }
-
 #endif
 
-    if (driver->handle != NULL) {
-	erts_ddll_increment_port_count(driver->handle);
-	erts_ddll_reference_referenced_driver(driver->handle);
-    }
-    erts_smp_mtx_unlock(&erts_driver_list_lock);
+    port->drv_data = (UWord) drv_data;
 
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(port));
-
-    setup_port(port, pid, driver, drv_data, name, xstate);
-    port->common.id = port_id;
-
-    erts_add_link(&ERTS_P_LINKS(port), LINK_PID, pid);
-    erts_add_link(&ERTS_P_LINKS(rp), LINK_PID, port_id);
-    erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
-    return port_num & erts_port_tab_index_mask;
+    return (ErlDrvPort) port;
 }
 
 #ifdef ERTS_SMP
@@ -1282,15 +1230,22 @@ int erts_write_to_port(Eterm caller_id, Port *p, Eterm list)
     }
 }
 
+#ifdef ERTS_SMP
+static void
+release_port(void *vport)
+{
+    erts_port_dec_refc((Port *) vport);
+}
+#endif
+
 /* initialize the port array */
 void init_io(void)
 {
-    int i;
     ErlDrvEntry** dp;
     char maxports[21]; /* enough for any 64-bit integer */
     size_t maxportssize = sizeof(maxports);
     Uint ports_bits = ERTS_PORTS_BITS;
-    Sint port_extra_shift;
+    int port_tab_size;
 
 #ifdef ERTS_SMP
     init_xports_list_alloc();
@@ -1299,66 +1254,39 @@ void init_io(void)
     pdl_init();
 
     if (erts_sys_getenv("ERL_MAX_PORTS", maxports, &maxportssize) == 0) 
-	erts_max_ports = atoi(maxports);
+	port_tab_size = atoi(maxports);
     else
-	erts_max_ports = sys_max_files();
+	port_tab_size = sys_max_files();
 
-    if (erts_max_ports > ERTS_MAX_PORTS)
-	erts_max_ports = ERTS_MAX_PORTS;
-    if (erts_max_ports < 1024)
-	erts_max_ports = 1024;
+    if (port_tab_size > ERTS_MAX_PORTS)
+	port_tab_size = ERTS_MAX_PORTS;
+    if (port_tab_size < 1024)
+	port_tab_size = 1024;
 
     if (erts_use_r9_pids_ports) {
 	ports_bits = ERTS_R9_PORTS_BITS;
-	if (erts_max_ports > ERTS_MAX_R9_PORTS)
-	    erts_max_ports = ERTS_MAX_R9_PORTS;
+	if (port_tab_size > ERTS_MAX_R9_PORTS)
+	    port_tab_size = ERTS_MAX_R9_PORTS;
     }
 
-    port_extra_shift = erts_fit_in_bits_int32(erts_max_ports - 1);
-    port_num_mask = (1 << ports_bits) - 1;
-
-    erts_port_tab_index_mask = ~(~((Uint) 0) << port_extra_shift);
-    erts_max_ports = 1 << port_extra_shift;
-
     erts_smp_mtx_init(&erts_driver_list_lock,"driver_list");
     driver_list = NULL;
     erts_smp_tsd_key_create(&driver_list_lock_status_key);
     erts_smp_tsd_key_create(&driver_list_last_error_key);
 
-    if (erts_max_ports * sizeof(Port) <= erts_max_ports) {
-	/* More memory needed than the whole address space. */
-	erts_alloc_enomem(ERTS_ALC_T_PORT_TABLE, ~((Uint) 0));
-    }
-
-    erts_port = (Port *) erts_alloc(ERTS_ALC_T_PORT_TABLE,
-				    erts_max_ports * sizeof(Port));
-
-    erts_smp_atomic_init_nob(&erts_bytes_out, 0);
-    erts_smp_atomic_init_nob(&erts_bytes_in, 0);
-
-    for (i = 0; i < erts_max_ports; i++) {
-	erts_port_task_init_sched(&erts_port[i].sched);
-	erts_smp_atomic32_init_nob(&erts_port[i].common.refc, 0);
+    erts_ptab_init_table(&erts_port,
+			 ERTS_ALC_T_PORT_TABLE,
 #ifdef ERTS_SMP
-	erts_port[i].lock = NULL;
-	erts_port[i].xports = NULL;
-	erts_smp_spinlock_init_x(&erts_port[i].state_lck, "port_state", make_small(i));
+			 release_port,
+#else
+			 NULL,
 #endif
-	ERTS_TRACER_PROC(&erts_port[i]) = NIL;
-	ERTS_TRACE_FLAGS(&erts_port[i]) = 0;
-
-	erts_port[i].drv_ptr = NULL;
-	erts_smp_atomic32_init_nob(&erts_port[i].state, ERTS_PORT_SFLG_FREE);
-	erts_port[i].name = NULL;
-	ERTS_P_LINKS(&erts_port[i]) = NULL;
-	ERTS_P_MONITORS(&erts_port[i]) = NULL;
-	erts_port[i].linebuf = NULL;
-	erts_port[i].port_data_lock = NULL;
-    }
+			 (ErtsPTabElementCommon *) &erts_invalid_port.common,
+			 port_tab_size,
+			 "port_table");
 
-    erts_smp_atomic32_init_nob(&erts_ports_snapshot, (erts_aint32_t) 0);
-    last_port_num = 0;
-    erts_smp_spinlock_init(&get_free_port_lck, "get_free_port");
+    erts_smp_atomic_init_nob(&erts_bytes_out, 0);
+    erts_smp_atomic_init_nob(&erts_bytes_in, 0);
 
     sys_init_io();
 
@@ -1769,7 +1697,7 @@ deliver_vec_message(Port* prt,			/* Port */
     if (!rp)
 	return;
 
-    state = erts_smp_atomic32_read_nob(&prt->state);
+    state = erts_atomic32_read_nob(&prt->state);
     /*
      * Calculate the exact number of heap words needed.
      */
@@ -1907,7 +1835,7 @@ static void flush_port(Port *p)
 	ASSERT(!p->xports);
 #endif
     }
-    if ((erts_smp_atomic32_read_nob(&p->state) & ERTS_PORT_SFLGS_DEAD) == 0
+    if ((erts_atomic32_read_nob(&p->state) & ERTS_PORT_SFLGS_DEAD) == 0
 	&& is_port_ioq_empty(p)) {
 	terminate_port(p);
     }
@@ -1929,8 +1857,8 @@ terminate_port(Port *prt)
     ASSERT(!ERTS_P_MONITORS(prt));
 
     /* state may be altered by kill_port() below */
-    state = erts_smp_atomic32_read_band_nob(&prt->state,
-					    ~ERTS_PORT_SFLG_SEND_CLOSED);
+    state = erts_atomic32_read_band_nob(&prt->state,
+					~ERTS_PORT_SFLG_SEND_CLOSED);
     if (state & ERTS_PORT_SFLG_SEND_CLOSED) {
 	send_closed_port_id = prt->common.id;
 	connected_id = prt->connected;
@@ -1981,6 +1909,8 @@ terminate_port(Port *prt)
     if (prt->psd)
 	erts_free(ERTS_ALC_T_PRTSD, prt->psd);
 
+    ASSERT(prt->dist_entry == NULL);
+
     kill_port(prt);
 
     /*
@@ -1989,13 +1919,11 @@ terminate_port(Port *prt)
      */
     if ((state & ERTS_PORT_SFLG_HALT)
 	&& (erts_smp_atomic32_dec_read_nob(&erts_halt_progress) == 0)) {
-	erts_smp_port_unlock(prt); /* We will exit and never return */
+	erts_port_release(prt); /* We will exit and never return */
 	erl_exit_flush_async(erts_halt_code, "");
     }
     if (is_internal_port(send_closed_port_id))
 	deliver_result(send_closed_port_id, connected_id, am_closed);
-
-    ASSERT(prt->dist_entry == NULL);
 }
 
 void
@@ -2130,7 +2058,7 @@ erts_do_exit_port(Port *p, Eterm from, Eterm reason)
    }
 #endif
 
-   state = erts_smp_atomic32_read_nob(&p->state);
+   state = erts_atomic32_read_nob(&p->state);
    if ((state & (ERTS_PORT_SFLGS_DEAD
 		 | ERTS_PORT_SFLG_EXITING
 		 | ERTS_PORT_SFLG_IMMORTAL))
@@ -2149,12 +2077,12 @@ erts_do_exit_port(Port *p, Eterm from, Eterm reason)
     * Setting the port to not busy here, frees the list of pending
     * processes and makes them runnable.
     */
-   set_busy_port((ErlDrvPort)internal_port_index(p->common.id), 0);
+   set_busy_port((ErlDrvPort) p, 0);
 
    if (p->common.u.alive.reg != NULL)
        (void) erts_unregister_name(NULL, 0, p, p->common.u.alive.reg->name);
 
-   state = erts_smp_atomic32_read_bor_relb(&p->state, ERTS_PORT_SFLG_EXITING);
+   state = erts_atomic32_read_bor_relb(&p->state, ERTS_PORT_SFLG_EXITING);
 
    {
        SweepContext sc = {p->common.id, rreason};
@@ -2174,16 +2102,16 @@ erts_do_exit_port(Port *p, Eterm from, Eterm reason)
        erts_do_net_exits(p->dist_entry, rreason);
        erts_deref_dist_entry(p->dist_entry); 
        p->dist_entry = NULL;
-       erts_smp_atomic32_read_band_relb(&p->state,
-					~ERTS_PORT_SFLG_DISTRIBUTION);
+       erts_atomic32_read_band_relb(&p->state,
+				    ~ERTS_PORT_SFLG_DISTRIBUTION);
    }
        
    if ((reason != am_kill) && !is_port_ioq_empty(p)) {
        /* must turn exiting flag off */
-       erts_smp_atomic32_read_bset_relb(&p->state,
-					(ERTS_PORT_SFLG_EXITING
-					 | ERTS_PORT_SFLG_CLOSING),
-					ERTS_PORT_SFLG_CLOSING);
+       erts_atomic32_read_bset_relb(&p->state,
+				    (ERTS_PORT_SFLG_EXITING
+				     | ERTS_PORT_SFLG_CLOSING),
+				    ERTS_PORT_SFLG_CLOSING);
       flush_port(p);
    }
    else {
@@ -2232,8 +2160,8 @@ void erts_port_command(Process *proc,
 	if ((pid = port->connected) == tp[1]) {
 	    /* PID must be connected */
 	    if (tp[2] == am_close) {
-		erts_smp_atomic32_read_bor_relb(&port->state,
-						ERTS_PORT_SFLG_SEND_CLOSED);
+		erts_atomic32_read_bor_relb(&port->state,
+					    ERTS_PORT_SFLG_SEND_CLOSED);
 		erts_do_exit_port(port, pid, am_normal);
 
 #ifdef USE_VM_PROBES
@@ -2456,16 +2384,15 @@ static void prt_one_lnk(ErtsLink *lnk, void *vprtd)
 }
 
 void
-print_port_info(int to, void *arg, int i)
+print_port_info(Port *p, int to, void *arg)
 {
-    Port* p = &erts_port[i];
-    erts_aint32_t state = erts_smp_atomic32_read_nob(&p->state);
+    erts_aint32_t state = erts_atomic32_read_nob(&p->state);
 
     if (state & ERTS_PORT_SFLGS_DEAD)
 	return;
 
     erts_print(to, arg, "=port:%T\n", p->common.id);
-    erts_print(to, arg, "Slot: %d\n", i);
+    erts_print(to, arg, "Slot: %d\n", internal_port_index(p->common.id));
     if (state & ERTS_PORT_SFLG_CONNECTED) {
 	erts_print(to, arg, "Connected: %T", p->connected);
 	erts_print(to, arg, "\n");
@@ -2505,43 +2432,46 @@ print_port_info(int to, void *arg, int i)
 void
 set_busy_port(ErlDrvPort port_num, int on)
 {
+    Port *prt;
 #ifdef USE_VM_PROBES
     DTRACE_CHARBUF(port_str, 16);
 #endif
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(&erts_port[port_num]));
+    prt = erts_drvport2port_raw(port_num);
+    if (!prt)
+	return;
 
     if (on) {
-	erts_smp_atomic32_read_bor_relb(&erts_port[port_num].state,
-					ERTS_PORT_SFLG_PORT_BUSY);
+	erts_atomic32_read_bor_relb(&prt->state,
+				    ERTS_PORT_SFLG_PORT_BUSY);
 #ifdef USE_VM_PROBES
         if (DTRACE_ENABLED(port_busy)) {
             erts_snprintf(port_str, sizeof(port_str),
-                          "%T", erts_port[port_num].id);
+                          "%T", prt->id);
             DTRACE1(port_busy, port_str);
         }
 #endif
     } else {
-        ErtsProcList* plp = erts_port[port_num].suspended;
-	erts_smp_atomic32_read_band_relb(&erts_port[port_num].state,
-					 ~ERTS_PORT_SFLG_PORT_BUSY);
-        erts_port[port_num].suspended = NULL;
+        ErtsProcList* plp = prt->suspended;
+	erts_atomic32_read_band_relb(&prt->state,
+				     ~ERTS_PORT_SFLG_PORT_BUSY);
+        prt->suspended = NULL;
 
 #ifdef USE_VM_PROBES
         if (DTRACE_ENABLED(port_not_busy)) {
             erts_snprintf(port_str, sizeof(port_str),
-                          "%T", erts_port[port_num].id);
+                          "%T", prt->id);
             DTRACE1(port_not_busy, port_str);
         }
 #endif
-	if (erts_port[port_num].dist_entry) {
+	if (prt->dist_entry) {
 	    /*
 	     * Processes suspended on distribution ports are
 	     * normally queued on the dist entry.
 	     */
-	    erts_dist_port_not_busy(&erts_port[port_num]);
+	    erts_dist_port_not_busy(prt);
 	}
 
 	/*
@@ -2587,10 +2517,9 @@ set_busy_port(ErlDrvPort port_num, int on)
 
 void set_port_control_flags(ErlDrvPort port_num, int flags)
 {
-
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(&erts_port[port_num]));
-
-    erts_port[port_num].control_flags = flags;
+    Port *prt = erts_drvport2port_raw(port_num);
+    if (prt)
+	prt->control_flags = flags;
 }
 
 int get_port_flags(ErlDrvPort ix)
@@ -2649,7 +2578,7 @@ int async_ready(Port *p, void* data)
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
     if (p) {
-	erts_aint32_t state = erts_smp_atomic32_read_nob(&p->state);
+	erts_aint32_t state = erts_atomic32_read_nob(&p->state);
 	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(p));
 	ASSERT(!(state & ERTS_PORT_SFLGS_DEAD));
 	if (p->drv_ptr->ready_async != NULL) {
@@ -2697,7 +2626,7 @@ erts_stale_drv_select(Eterm port,
 		      int deselect)
 {
     char *type;
-    ErlDrvPort drv_port = internal_port_index(port);
+    ErlDrvPort drv_port = (ErlDrvPort) erts_port_lookup_raw(port);
     ErtsPortNames *pnp = erts_get_port_names(port);
     erts_dsprintf_buf_t *dsbufp;
 
@@ -2737,16 +2666,16 @@ erts_stale_drv_select(Eterm port,
 ErtsPortNames *
 erts_get_port_names(Eterm id)
 {
+    Port *prt = erts_port_lookup_raw(id);
     ErtsPortNames *pnp;
     ASSERT(is_nil(id) || is_internal_port(id));
-    
-    if (is_not_internal_port(id)) {
+
+    if (!prt) {
 	pnp = erts_alloc(ERTS_ALC_T_PORT_NAMES, sizeof(ErtsPortNames));
 	pnp->name = NULL;
 	pnp->driver_name = NULL;
     }
     else {
-	Port* prt = &erts_port[internal_port_index(id)];
 	int do_realloc = 1;
 	int len = -1;
 	size_t pnp_len = sizeof(ErtsPortNames);
@@ -2762,17 +2691,10 @@ erts_get_port_names(Eterm id)
 		pnp_len = sizeof(ErtsPortNames) + len;
 		pnp = erts_alloc(ERTS_ALC_T_PORT_NAMES, pnp_len);
 	    }
-	    erts_smp_port_minor_lock(prt);
-	    if (id != prt->common.id) {
-		len = nlen = 0;
-		name = driver_name = NULL;
-	    }
-	    else {
-		name = prt->name;
-		len = nlen = name ? sys_strlen(name) + 1 : 0;
-		driver_name = (prt->drv_ptr ? prt->drv_ptr->name : NULL);
-		len += driver_name ? sys_strlen(driver_name) + 1 : 0;
-	    }
+	    name = prt->name;
+	    len = nlen = name ? sys_strlen(name) + 1 : 0;
+	    driver_name = (prt->drv_ptr ? prt->drv_ptr->name : NULL);
+	    len += driver_name ? sys_strlen(driver_name) + 1 : 0;
 	    if (len <= pnp_len - sizeof(ErtsPortNames)) {
 		if (!name)
 		    pnp->name = NULL;
@@ -2790,7 +2712,6 @@ erts_get_port_names(Eterm id)
 		}
 		do_realloc = 0;
 	    }
-	    erts_smp_port_minor_unlock(prt);
 	} while (do_realloc);
     }
     return pnp;
@@ -2827,7 +2748,7 @@ ErlDrvTermData driver_mk_term_nil(void)
     return driver_term_nil;
 }
 
-void driver_report_exit(int ix, int status)
+void driver_report_exit(ErlDrvPort ix, int status)
 {
     Port* prt = erts_drvport2port(ix, NULL);
    Eterm* hp;
@@ -2868,27 +2789,6 @@ void driver_report_exit(int ix, int status)
        erts_smp_proc_dec_refc(rp);
 }
 
-
-static ERTS_INLINE int
-deliver_term_check_port(ErlDrvPort drvport)
-{
-    int res;
-    int ix = (int) drvport;
-    if (ix < 0 || erts_max_ports <= ix)
-	res = -1; /* invalid */
-    else {
-	Port* prt = &erts_port[ix];
-	erts_aint32_t state = erts_smp_atomic32_read_nob(&prt->state);
-	if (!(state & ERTS_PORT_SFLGS_INVALID_LOOKUP))
-	    res = 1; /* ok */
-	else if (state & ERTS_PORT_SFLG_CLOSING)
-	    res = 0; /* closing */
-	else
-	    res = -1; /* invalid (dead) */
-    }
-    return res;
-}
-
 #define ERTS_B2T_STATES_DEF_STATES_SZ 5
 #define ERTS_B2T_STATES_DEF_STATES_INC 100
 
@@ -2976,10 +2876,7 @@ cleanup_b2t_states(struct b2t_states__ *b2tsp)
  */
 
 static int
-driver_deliver_term(ErlDrvPort port,
-		    Eterm to,
-		    ErlDrvTermData* data,
-		    int len)
+driver_deliver_term(Eterm to, ErlDrvTermData* data, int len)
 {
 #define ERTS_DDT_FAIL do { res = -1; goto done; } while (0)
     Uint need = 0;
@@ -3181,11 +3078,8 @@ driver_deliver_term(ErlDrvPort port,
     b2t.ix = 0;
 
     /*
-     * The term is OK. Go ahead and validate the port and process.
+     * The term is OK. Go ahead and validate the process.
      */
-    res = deliver_term_check_port(port);
-    if (res <= 0)
-	goto done;
 
     /*
      * Increase refc on proc if done from a non-scheduler thread.
@@ -3449,25 +3343,29 @@ driver_deliver_term(ErlDrvPort port,
 #undef ERTS_DDT_FAIL
 }
 
-
 int 
-driver_output_term(ErlDrvPort ix, ErlDrvTermData* data, int len)
+driver_output_term(ErlDrvPort drvport, ErlDrvTermData* data, int len)
 {
-    Port* prt = erts_drvport2port(ix, NULL);
-
+    erts_aint32_t state;
+    Port* prt = erts_drvport2port(drvport, &state);
+    if (!prt)
+	return -1; /* invalid (dead) */
     ERTS_SMP_CHK_NO_PROC_LOCKS;
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-
-    if (prt == NULL)
-	return -1;
-    return driver_deliver_term(ix, prt->connected, data, len);
+    if (!(state & ERTS_PORT_SFLGS_INVALID_LOOKUP))
+	return driver_deliver_term(prt->connected, data, len);
+    else if (state & ERTS_PORT_SFLG_CLOSING)
+	return 0; /* closing */
+    else
+	return -1; /* invalid (dead) */
 }
 
 
 int
 driver_send_term(ErlDrvPort ix, ErlDrvTermData to, ErlDrvTermData* data, int len)
 {
-    return driver_deliver_term(ix, to, data, len);
+    /* driver_send_term() assume port is ok... */
+    return driver_deliver_term(to, data, len);
 }
 
 
@@ -3817,6 +3715,7 @@ static ERTS_INLINE void pdl_destroy(ErlDrvPDL pdl)
 {
     ERTS_LC_ASSERT(driver_pdl_get_refc(pdl) == 0);
     erts_mtx_destroy(&pdl->mtx);
+    erts_port_dec_refc(pdl->prt);
     erts_free(ERTS_ALC_T_PORT_DATA_LOCK, pdl);
 }
 
@@ -3861,6 +3760,8 @@ driver_pdl_create(ErlDrvPort dp)
 		     sizeof(struct erl_drv_port_data_lock));
     erts_mtx_init(&pdl->mtx, "port_data_lock");
     pdl_init_refc(pdl);
+    erts_port_inc_refc(pp);
+    pdl->prt = pp;
     pp->port_data_lock = pdl;
 #ifdef HARDDEBUG
     erts_fprintf(stderr, "driver_pdl_create(%T) -> 0x%08X\r\n",pp->common.id,(unsigned) pdl);
@@ -4317,7 +4218,7 @@ int driver_set_timer(ErlDrvPort ix, unsigned long t)
 
     if (prt == NULL)
 	return -1;
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
+
     if (prt->drv_ptr->timeout == NULL)
 	return -1;
     drv_cancel_timer(prt);
@@ -4424,7 +4325,7 @@ static int do_driver_monitor_process(Port *prt,
 /*
  * This can be called from a non scheduler thread iff a port_data_lock exists
  */
-int driver_monitor_process(ErlDrvPort port,
+int driver_monitor_process(ErlDrvPort drvport,
 			   ErlDrvTermData process,
 			   ErlDrvMonitor *monitor)
 {
@@ -4434,15 +4335,12 @@ int driver_monitor_process(ErlDrvPort port,
 #if !HEAP_ON_C_STACK || (defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK))
     ErtsSchedulerData *sched = erts_get_scheduler_data();
 #endif
-    int ix = (int) port;
-    if (ix < 0 || erts_max_ports <= ix) {
-	return -1;
-    }
-    prt = &erts_port[ix];
+
+    prt = erts_thr_drvport2port_raw(drvport);
 
     DRV_MONITOR_LOCK_PDL(prt);
 
-    state = erts_smp_atomic32_read_nob(&erts_port[ix].state);
+    state = erts_atomic32_read_nob(&prt->state);
 
     if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP) {
 	DRV_MONITOR_UNLOCK_PDL(prt);
@@ -4509,7 +4407,7 @@ static int do_driver_demonitor_process(Port *prt, Eterm *buf,
     return 0;
 }
 
-int driver_demonitor_process(ErlDrvPort port,
+int driver_demonitor_process(ErlDrvPort drvport,
 			     const ErlDrvMonitor *monitor)
 {
     Port *prt;
@@ -4518,15 +4416,12 @@ int driver_demonitor_process(ErlDrvPort port,
 #if !HEAP_ON_C_STACK || (defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK))
     ErtsSchedulerData *sched = erts_get_scheduler_data();
 #endif
-    int ix = (int) port;
-    if (ix < 0 || erts_max_ports <= ix) {
-	return -1;
-    }
-    prt = &erts_port[ix];
+
+    prt = erts_thr_drvport2port_raw(drvport);
 
     DRV_MONITOR_LOCK_PDL(prt);
 
-    state = erts_smp_atomic32_read_nob(&erts_port[ix].state);
+    state = erts_atomic32_read_nob(&prt->state);
 
     if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP) {
 	DRV_MONITOR_UNLOCK_PDL(prt);
@@ -4575,7 +4470,7 @@ static ErlDrvTermData do_driver_get_monitored_process(Port *prt, Eterm *buf,
 }
 
 
-ErlDrvTermData driver_get_monitored_process(ErlDrvPort port,
+ErlDrvTermData driver_get_monitored_process(ErlDrvPort drvport,
 					    const ErlDrvMonitor *monitor)
 {
     Port *prt;
@@ -4584,15 +4479,12 @@ ErlDrvTermData driver_get_monitored_process(ErlDrvPort port,
 #if !HEAP_ON_C_STACK || (defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK))
     ErtsSchedulerData *sched = erts_get_scheduler_data();
 #endif
-    int ix = (int) port;
-    if (ix < 0 || erts_max_ports <= ix) {
-	return driver_term_nil;
-    }
-    prt = &erts_port[ix];
+
+    prt = erts_thr_drvport2port_raw(drvport);
 
     DRV_MONITOR_LOCK_PDL(prt);
 
-    state = erts_smp_atomic32_read_nob(&erts_port[ix].state);
+    state = erts_atomic32_read_nob(&prt->state);
     if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP) {
 	DRV_MONITOR_UNLOCK_PDL(prt);
 	return driver_term_nil;
@@ -4711,8 +4603,6 @@ int driver_exit(ErlDrvPort ix, int err)
     if (prt == NULL)
         return -1;
 
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-
     rp = erts_pid2proc(NULL, 0, prt->connected, ERTS_PROC_LOCK_LINK);
     if (rp) {
 	rlnk = erts_remove_link(&ERTS_P_LINKS(rp),prt->common.id);
@@ -5007,7 +4897,7 @@ no_event_callback(ErlDrvData drv_data, ErlDrvEvent event, ErlDrvEventData event_
 {
     Port *prt = get_current_port();
     report_missing_drv_callback(prt, "Event", "event()");
-    driver_event((ErlDrvPort) internal_port_index(prt->common.id), event, NULL);
+    driver_event((ErlDrvPort) prt, event, NULL);
 }
 
 static void
@@ -5015,7 +4905,7 @@ no_ready_input_callback(ErlDrvData drv_data, ErlDrvEvent event)
 {
     Port *prt = get_current_port();
     report_missing_drv_callback(prt, "Input", "ready_input()");
-    driver_select((ErlDrvPort) internal_port_index(prt->common.id), event, 
+    driver_select((ErlDrvPort) prt, event, 
 		  (ERL_DRV_READ | ERL_DRV_USE_NO_CALLBACK), 0);
 }
 
@@ -5024,7 +4914,7 @@ no_ready_output_callback(ErlDrvData drv_data, ErlDrvEvent event)
 {
     Port *prt = get_current_port();
     report_missing_drv_callback(prt, "Output", "ready_output()");
-    driver_select((ErlDrvPort) internal_port_index(prt->common.id), event,
+    driver_select((ErlDrvPort) prt, event,
 		  (ERL_DRV_WRITE | ERL_DRV_USE_NO_CALLBACK), 0);
 }
 
@@ -5059,13 +4949,13 @@ init_driver(erts_driver_t *drv, ErlDrvEntry *de, DE_Handle *handle)
 	drv->lock = NULL;
     else {
 	drv->lock = erts_alloc(ERTS_ALC_T_DRIVER_LOCK,
-			       sizeof(erts_smp_mtx_t));
-	erts_smp_mtx_init_x(drv->lock,
-			    "driver_lock",
+			       sizeof(erts_mtx_t));
+	erts_mtx_init_x(drv->lock,
+			"driver_lock",
 #if defined(ERTS_ENABLE_LOCK_CHECK) || defined(ERTS_ENABLE_LOCK_COUNT)
-			    am_atom_put(drv->name, sys_strlen(drv->name))
+			am_atom_put(drv->name, sys_strlen(drv->name))
 #else
-			    NIL
+			NIL
 #endif
 	    );
     }
diff --git a/erts/emulator/beam/register.c b/erts/emulator/beam/register.c
index feae745749..757e2800e6 100644
--- a/erts/emulator/beam/register.c
+++ b/erts/emulator/beam/register.c
@@ -182,7 +182,7 @@ int erts_register_name(Process *c_p, Eterm name, Eterm id)
 	    return res;
 	erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_MAIN);
 	if (is_internal_port(id)) {
-	    port = erts_id2port(id, NULL, 0);
+	    port = erts_id2port(id);
 	    if (!port)
 		goto done;
 	}
@@ -241,7 +241,7 @@ int erts_register_name(Process *c_p, Eterm name, Eterm id)
  done:
     reg_write_unlock();
     if (port)
-	erts_smp_port_unlock(port);
+	erts_port_release(port);
     if (c_p != proc) {
 	if (proc)
 	    erts_smp_proc_unlock(proc, ERTS_PROC_LOCK_MAIN);
@@ -397,16 +397,14 @@ erts_whereis_name(Process *c_p,
 	if (!rp || !rp->pt)
 	    *port = NULL;
 	else {
-#ifndef ERTS_SMP
-	    erts_smp_atomic32_inc_nob(&rp->pt->common.refc);
-#else
+#ifdef ERTS_SMP
 	    if (pending_port == rp->pt)
 		pending_port = NULL;
 	    else {
 		if (pending_port) {
 		    /* Ahh! Registered port changed while reg lock
 		       was unlocked... */
-		    erts_smp_port_unlock(pending_port);
+		    erts_port_release(pending_port);
 		    pending_port = NULL;
 		}
 		    
@@ -418,7 +416,7 @@ erts_whereis_name(Process *c_p,
 			current_c_p_locks = 0;
 		    }
 		    reg_read_unlock();
-		    pending_port = erts_id2port(id, NULL, 0);
+		    pending_port = erts_id2port(id);
 		    goto restart;
 		}
 	    }
@@ -432,7 +430,7 @@ erts_whereis_name(Process *c_p,
     if (c_p && !current_c_p_locks)
 	erts_smp_proc_lock(c_p, c_p_locks);
     if (pending_port)
-	erts_smp_port_unlock(pending_port);
+	erts_port_release(pending_port);
 #endif
 
     reg_read_unlock();
@@ -506,12 +504,10 @@ int erts_unregister_name(Process *c_p,
     if ((rp = (RegProc*) hash_get(&process_reg, (void*) &r)) != NULL) {
 	if (rp->pt) {
 	    if (port != rp->pt) {
-#ifndef ERTS_SMP
-		erts_smp_atomic32_inc_nob(&rp->pt->common.refc);
-#else
+#ifdef ERTS_SMP
 		if (port) {
 		    ASSERT(port != c_prt);
-		    erts_smp_port_unlock(port);
+		    erts_port_release(port);
 		    port = NULL;
 		}
 
@@ -523,7 +519,7 @@ int erts_unregister_name(Process *c_p,
 			current_c_p_locks = 0;
 		    }
 		    reg_write_unlock();
-		    port = erts_id2port(id, NULL, 0);
+		    port = erts_id2port(id);
 		    goto restart;
 		}
 #endif
@@ -569,7 +565,7 @@ int erts_unregister_name(Process *c_p,
     reg_write_unlock();
     if (c_prt != port) {
 	if (port) {
-	    erts_smp_port_unlock(port);
+	    erts_port_release(port);
 	}
 	if (c_prt) {
 	    erts_smp_port_lock(c_prt);
diff --git a/erts/emulator/beam/register.h b/erts/emulator/beam/register.h
index 38e8cfbf28..7170463375 100644
--- a/erts/emulator/beam/register.h
+++ b/erts/emulator/beam/register.h
@@ -24,26 +24,19 @@
 #ifndef __REGPROC_H__
 #define __REGPROC_H__
 
-#ifndef __SYS_H__
 #include "sys.h"
-#endif
-
-#ifndef __HASH_H__
 #include "hash.h"
-#endif
-
-#ifndef __PROCESS_H__
 #include "erl_process.h"
-#endif
-
-struct port;
+#define ERL_PORT_GET_PORT_TYPE_ONLY__
+#include "erl_port.h"
+#undef ERL_PORT_GET_PORT_TYPE_ONLY__
 
 typedef struct reg_proc
 {
     HashBucket bucket;  /* MUST BE LOCATED AT TOP OF STRUCT!!! */
     Process *p;         /* The process registered (only one of this and
 			   'pt' is non-NULL */
-    struct port *pt;    /* The port registered */
+    Port *pt;		/* The port registered */
     Eterm name;         /* Atom name */
 } RegProc;
 
@@ -55,12 +48,12 @@ int erts_register_name(Process *, Eterm, Eterm);
 Eterm erts_whereis_name_to_id(Process *, Eterm);
 void erts_whereis_name(Process *, ErtsProcLocks,
 		       Eterm, Process**, ErtsProcLocks, int,
-		       struct port**);
+		       Port**);
 Process *erts_whereis_process(Process *,
 			      ErtsProcLocks,
 			      Eterm,
 			      ErtsProcLocks,
 			      int);
-int erts_unregister_name(Process *, ErtsProcLocks, struct port *, Eterm);
+int erts_unregister_name(Process *, ErtsProcLocks, Port *, Eterm);
 
 #endif
diff --git a/erts/emulator/hipe/hipe_bif_list.m4 b/erts/emulator/hipe/hipe_bif_list.m4
index 942fa0c5cb..8a430bf561 100644
--- a/erts/emulator/hipe/hipe_bif_list.m4
+++ b/erts/emulator/hipe/hipe_bif_list.m4
@@ -145,6 +145,7 @@
  * Zero-arity BIFs that can fail.
  */
 standard_bif_interface_0(nbif_processes_0, processes_0)
+standard_bif_interface_0(nbif_ports_0, ports_0)
 
 /*
  * BIFs and primops that may do a GC (change heap limit and walk the native stack).
diff --git a/erts/emulator/sys/common/erl_check_io.c b/erts/emulator/sys/common/erl_check_io.c
index 5d814e0164..9ef861bfe4 100644
--- a/erts/emulator/sys/common/erl_check_io.c
+++ b/erts/emulator/sys/common/erl_check_io.c
@@ -201,17 +201,6 @@ static void event_large_fd_error(ErlDrvPort, ErtsSysFdType, ErlDrvEventData);
 #endif
 static void steal_pending_stop_select(erts_dsprintf_buf_t*, ErlDrvPort,
 				      ErtsDrvEventState*, int mode, int on);
-static ERTS_INLINE Eterm
-drvport2id(ErlDrvPort dp)
-{
-    Port *pp = erts_drvport2port(dp, NULL);
-    if (pp)
-	return pp->common.id;
-    else {
-	ASSERT(0);
-	return am_undefined;
-    }
-}
 
 #ifdef ERTS_SMP
 ERTS_SCHED_PREF_QUICK_ALLOC_IMPL(removed_fd, struct removed_fd, 64, ERTS_ALC_T_FD_LIST)
@@ -491,7 +480,7 @@ ERTS_CIO_EXPORT(driver_select)(ErlDrvPort ix,
 			       int on)
 {
     void (*stop_select_fn)(ErlDrvEvent, void*) = NULL;
-    Eterm id = drvport2id(ix);
+    Eterm id = erts_drvport2id(ix);
     ErtsSysFdType fd = (ErtsSysFdType) e;
     ErtsPollEvents ctl_events = (ErtsPollEvents) 0;
     ErtsPollEvents new_events, old_events;
@@ -718,7 +707,7 @@ ERTS_CIO_EXPORT(driver_event)(ErlDrvPort ix,
     ErtsPollEvents events;
     ErtsPollEvents add_events;
     ErtsPollEvents remove_events;
-    Eterm id = drvport2id(ix);
+    Eterm id = erts_drvport2id(ix);
     ErtsDrvEventState *state;
     int do_wake = 0;
     int ret;
diff --git a/erts/emulator/sys/unix/sys.c b/erts/emulator/sys/unix/sys.c
index 57ffb9f151..ea98af26bb 100644
--- a/erts/emulator/sys/unix/sys.c
+++ b/erts/emulator/sys/unix/sys.c
@@ -1023,7 +1023,8 @@ void fini_getenv_state(GETENV_STATE *state)
 
 /* This data is shared by these drivers - initialized by spawn_init() */
 static struct driver_data {
-    int port_num, ofd, packet_bytes;
+    ErlDrvPort port_num;
+    int ofd, packet_bytes;
     ErtsSysReportExit *report_exit;
     int pid;
     int alive;
@@ -1137,7 +1138,7 @@ static RETSIGTYPE onchld(int signum)
 #endif
 }
 
-static int set_driver_data(int port_num,
+static int set_driver_data(ErlDrvPort port_num,
 			   int ifd,
 			   int ofd,
 			   int packet_bytes,
@@ -1153,7 +1154,7 @@ static int set_driver_data(int port_num,
 	report_exit = erts_alloc(ERTS_ALC_T_PRT_REP_EXIT,
 				 sizeof(ErtsSysReportExit));
 	report_exit->next = report_exit_list;
-	report_exit->port = erts_port[port_num].common.id;
+	report_exit->port = erts_drvport2id(port_num);
 	report_exit->pid = pid;
 	report_exit->ifd = read_write & DO_READ ? ifd : -1;
 	report_exit->ofd = read_write & DO_WRITE ? ofd : -1;
@@ -1234,7 +1235,7 @@ static void close_pipes(int ifd[2], int ofd[2], int read_write)
     }
 }
 
-static void init_fd_data(int fd, int prt)
+static void init_fd_data(int fd, ErlDrvPort port_num)
 {
     fd_data[fd].buf = NULL;
     fd_data[fd].cpos = NULL;
@@ -1922,7 +1923,7 @@ static void clear_fd_data(int fd)
     fd_data[fd].psz = 0;
 }
 
-static void nbio_stop_fd(int prt, int fd)
+static void nbio_stop_fd(ErlDrvPort prt, int fd)
 {
     driver_select(prt,fd,DO_READ|DO_WRITE,0);
     clear_fd_data(fd);
@@ -1970,7 +1971,8 @@ static ErlDrvData vanilla_start(ErlDrvPort port_num, char* name,
 
 static void stop(ErlDrvData fd)
 {
-    int prt, ofd;
+    ErlDrvPort prt;
+    int ofd;
 
     prt = driver_data[(int)(long)fd].port_num;
     nbio_stop_fd(prt, (int)(long)fd);
@@ -1983,7 +1985,7 @@ static void stop(ErlDrvData fd)
 
     CHLD_STAT_LOCK;
 
-    /* Mark as unused. Maybe resetting the 'port_num' slot is better? */
+    /* Mark as unused. */
     driver_data[(int)(long)fd].pid = -1;
 
     CHLD_STAT_UNLOCK;
@@ -1999,7 +2001,7 @@ static void stop(ErlDrvData fd)
 static void outputv(ErlDrvData e, ErlIOVec* ev)
 {
     int fd = (int)(long)e;
-    int ix = driver_data[fd].port_num;
+    ErlDrvPort ix = driver_data[fd].port_num;
     int pb = driver_data[fd].packet_bytes;
     int ofd = driver_data[fd].ofd;
     ssize_t n;
@@ -2049,7 +2051,7 @@ static void outputv(ErlDrvData e, ErlIOVec* ev)
 static void output(ErlDrvData e, char* buf, ErlDrvSizeT len)
 {
     int fd = (int)(long)e;
-    int ix = driver_data[fd].port_num;
+    ErlDrvPort ix = driver_data[fd].port_num;
     int pb = driver_data[fd].packet_bytes;
     int ofd = driver_data[fd].ofd;
     ssize_t n;
@@ -2100,7 +2102,7 @@ static void output(ErlDrvData e, char* buf, ErlDrvSizeT len)
     return; /* 0; */
 }
 
-static int port_inp_failure(int port_num, int ready_fd, int res)
+static int port_inp_failure(ErlDrvPort port_num, int ready_fd, int res)
 				/* Result: 0 (eof) or -1 (error) */
 {
     int err = errno;
@@ -2150,7 +2152,7 @@ static int port_inp_failure(int port_num, int ready_fd, int res)
 static void ready_input(ErlDrvData e, ErlDrvEvent ready_fd)
 {
     int fd = (int)(long)e;
-    int port_num;
+    ErlDrvPort port_num;
     int packet_bytes;
     int res;
     Uint h;
@@ -2273,7 +2275,7 @@ static void ready_input(ErlDrvData e, ErlDrvEvent ready_fd)
 static void ready_output(ErlDrvData e, ErlDrvEvent ready_fd)
 {
     int fd = (int)(long)e;
-    int ix = driver_data[fd].port_num;
+    ErlDrvPort ix = driver_data[fd].port_num;
     int n;
     struct iovec* iv;
     int vsize;
@@ -2558,19 +2560,20 @@ report_exit_status(ErtsSysReportExit *rep, int status)
     Port *pp;
 #ifdef ERTS_SMP
     CHLD_STAT_UNLOCK;
-#endif
+    pp = erts_thr_id2port_sflgs(rep->port,
+				ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP);
+    CHLD_STAT_LOCK;
+#else
     pp = erts_id2port_sflgs(rep->port,
 			    NULL,
 			    0,
 			    ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP);
-#ifdef ERTS_SMP
-    CHLD_STAT_LOCK;
 #endif
     if (pp) {
 	if (rep->ifd >= 0) {
 	    driver_data[rep->ifd].alive = 0;
 	    driver_data[rep->ifd].status = status;
-	    (void) driver_select((ErlDrvPort) internal_port_index(pp->common.id),
+	    (void) driver_select((ErlDrvPort) pp,
 				 rep->ifd,
 				 (ERL_DRV_READ|ERL_DRV_USE),
 				 1);
@@ -2578,12 +2581,16 @@ report_exit_status(ErtsSysReportExit *rep, int status)
 	if (rep->ofd >= 0) {
 	    driver_data[rep->ofd].alive = 0;
 	    driver_data[rep->ofd].status = status;
-	    (void) driver_select((ErlDrvPort) internal_port_index(pp->common.id),
+	    (void) driver_select((ErlDrvPort) pp,
 				 rep->ofd,
 				 (ERL_DRV_WRITE|ERL_DRV_USE),
 				 1);
 	}
+#ifdef ERTS_SMP
+	erts_thr_port_release(pp);
+#else
 	erts_port_release(pp);
+#endif
     }
     erts_free(ERTS_ALC_T_PRT_REP_EXIT, rep);
 }
diff --git a/erts/emulator/sys/vxworks/sys.c b/erts/emulator/sys/vxworks/sys.c
index 739b026fb1..205c123ffc 100644
--- a/erts/emulator/sys/vxworks/sys.c
+++ b/erts/emulator/sys/vxworks/sys.c
@@ -522,7 +522,8 @@ static Uint tmp_buf_size;
 
 /* This data is shared by these drivers - initialized by spawn_init() */
 static struct driver_data {
-    int port_num, ofd, packet_bytes, report_exit;
+    ErlDrvPort port_num;
+    int ofd, packet_bytes, report_exit;
     int exitcode, exit_reported; /* For returning of exit codes. */
 } *driver_data;			/* indexed by fd */
 
@@ -678,7 +679,7 @@ static int pre_set_driver_data(int ifd, int ofd,
 ** Set up the driver_data structure, it may have been initiated
 ** partly by the function above, but we dont care. 
 */
-static int set_driver_data(int port_num, int ifd, int ofd, 
+static int set_driver_data(ErlDrvPort port_num, int ifd, int ofd, 
 			   int packet_bytes, int read_write,
 			   int report_exit)
 {
@@ -908,7 +909,7 @@ static void close_pipes(int ifd[2], int ofd[2], int read_write)
   }
 }
 
-static void init_fd_data(int fd, int port_unused_argument)
+static void init_fd_data(int fd, ErlDrvPort port_unused_argument)
 {
   SET_NONBLOCKING(fd);
   fd_data[fd].pending = NULL;
@@ -1062,7 +1063,7 @@ static void clear_fd_data(int fd)
   fd_data[fd].cpos = NULL;
 }
 
-static void nbio_stop_fd(int port_num, int fd)
+static void nbio_stop_fd(ErlDrvPort port_num, int fd)
 {
   Pend *p, *p1;
     
@@ -1132,7 +1133,8 @@ vanilla_start(ErlDrvPort port_num, char *name, SysDriverOpts* opts)
 
 static void stop(ErlDrvData drv_data)
 {
-    int port_num, ofd;
+    ErlDrvPort port_num;
+    int ofd;
     int fd = (int) drv_data;
 
     port_num = driver_data[fd].port_num;
@@ -1146,7 +1148,7 @@ static void stop(ErlDrvData drv_data)
     }
 }
 
-static int sched_write(int port_num,int fd, char *buf, int len, int pb)
+static int sched_write(ErlDrvPort port_num,int fd, char *buf, int len, int pb)
 {
   Pend *p, *p2, *p3;
   int p_bytes = len;
@@ -1189,7 +1191,8 @@ static int sched_write(int port_num,int fd, char *buf, int len, int pb)
 /* Fd is the value returned as drv_data by the start func */
 static void output(ErlDrvData drv_data, char *buf, ErlDrvSizeT len)
 {
-    int buf_done, port_num, wval, pb, ofd;
+    ErlDrvPort port_num;
+    int buf_done, wval, pb, ofd;
     byte lb[4];
     struct iovec iv[2];
     int fd = (int) drv_data;
@@ -1271,7 +1274,7 @@ static int ensure_header(int fd,char *buf,int packet_size, int sofar)
   return(res);
 }
 
-static int port_inp_failure(int port_num, int ready_fd, int res)
+static int port_inp_failure(ErlDrvPort port_num, int ready_fd, int res)
 {
     (void) driver_select(port_num, ready_fd, ERL_DRV_READ|ERL_DRV_WRITE, 0); 
     clear_fd_data(ready_fd);
@@ -1302,7 +1305,8 @@ static int port_inp_failure(int port_num, int ready_fd, int res)
 
 static void ready_input(ErlDrvData drv_data, ErlDrvEvent drv_event)
 {
-  int port_num, packet_bytes, res;
+    ErlDrvPort port_num;
+  int packet_bytes, res;
   Uint h = 0;
   char *buf;
   int fd = (int) drv_data;
diff --git a/erts/emulator/sys/win32/sys.c b/erts/emulator/sys/win32/sys.c
index b106f0932d..c4861b92a2 100755
--- a/erts/emulator/sys/win32/sys.c
+++ b/erts/emulator/sys/win32/sys.c
@@ -87,9 +87,6 @@ static erts_smp_tsd_key_t win32_errstr_key;
 
 static erts_smp_atomic_t pipe_creation_counter;
 
-static erts_smp_mtx_t sys_driver_data_lock;
-
-
 /* Results from application_type(_w) is one of */
 #define APPL_NONE 0
 #define APPL_DOS  1
@@ -97,7 +94,6 @@ static erts_smp_mtx_t sys_driver_data_lock;
 #define APPL_WIN32 3
 
 static int driver_write(long, HANDLE, byte*, int);
-static void common_stop(int);
 static int create_file_thread(struct async_io* aio, int mode);
 #ifdef ERTS_SMP
 static void close_active_handle(ErlDrvPort, HANDLE handle);
@@ -115,9 +111,6 @@ BOOL WINAPI ctrl_handler(DWORD dwCtrlType);
 
 #define PORT_BUFSIZ 4096
 
-#define PORT_FREE (-1)
-#define PORT_EXITING (-2)
-
 #define DRV_BUF_ALLOC(SZ) \
   erts_alloc_fnf(ERTS_ALC_T_DRV_DATA_BUF, (SZ))
 #define DRV_BUF_REALLOC(P, SZ) \
@@ -454,7 +447,7 @@ typedef struct driver_data {
     byte *inbuf;		/* Buffer to use for overlapped read. */
     int outBufSize;		/* Size of output buffer. */
     byte *outbuf;		/* Buffer to use for overlapped write. */
-    ErlDrvPort port_num;		/* The port number. */
+    ErlDrvPort port_num;	/* The port handle. */
     int packet_bytes;		/* 0: continous stream, 1, 2, or 4: the number
 				 * of bytes in the packet header.
 				 */
@@ -464,8 +457,6 @@ typedef struct driver_data {
     int report_exit;            /* Do report exit status for the port */
 } DriverData;
 
-static DriverData* driver_data;	/* Pointer to array of driver data. */
-
 /* Driver interfaces */
 static ErlDrvData spawn_start(ErlDrvPort, char*, SysDriverOpts*);
 static ErlDrvData fd_start(ErlDrvPort, char*, SysDriverOpts*);
@@ -577,67 +568,53 @@ struct erl_drv_entry vanilla_driver_entry = {
  */
 
 static DriverData*
-new_driver_data(int port_num, int packet_bytes, int wait_objs_required, int use_threads)
+new_driver_data(ErlDrvPort port_num, int packet_bytes, int wait_objs_required, int use_threads)
 {
     DriverData* dp;
-    
-    erts_smp_mtx_lock(&sys_driver_data_lock);
 
-    DEBUGF(("new_driver_data(port_num %d, pb %d)\n",
-	    port_num, packet_bytes));
+    DEBUGF(("new_driver_data(%p, pb %d)\n", port_num, packet_bytes));
 
+    dp = driver_alloc(sizeof(DriverData));
+    if (!dp)
+	return NULL;
     /*
      * We used to test first at all that there is enough room in the
      * array used by WaitForMultipleObjects(), but that is not necessary
      * any more, since driver_select() can't fail.
      */
 
-    /*
-     * Search for a free slot.
-     */
+    dp->bytesInBuffer = 0;
+    dp->totalNeeded = packet_bytes;
+    dp->inBufSize = PORT_BUFSIZ;
+    dp->inbuf = DRV_BUF_ALLOC(dp->inBufSize);
+    if (dp->inbuf == NULL)
+	goto buf_alloc_error;
+    erts_smp_atomic_add_nob(&sys_misc_mem_sz, dp->inBufSize);
+    dp->outBufSize = 0;
+    dp->outbuf = NULL;
+    dp->port_num = port_num;
+    dp->packet_bytes = packet_bytes;
+    dp->port_pid = INVALID_HANDLE_VALUE;
+    if (init_async_io(&dp->in, use_threads) == -1)
+	goto async_io_error1;
+    if (init_async_io(&dp->out, use_threads) == -1)
+	goto async_io_error2;
 
-    for (dp = driver_data; dp < driver_data+max_files; dp++) {
-	if (dp->port_num == PORT_FREE) {
-	    dp->bytesInBuffer = 0;
-	    dp->totalNeeded = packet_bytes;
-	    dp->inBufSize = PORT_BUFSIZ;
-	    dp->inbuf = DRV_BUF_ALLOC(dp->inBufSize);
-	    if (dp->inbuf == NULL) {
-		erts_smp_mtx_unlock(&sys_driver_data_lock);
-		return NULL;
-	    }
-	    erts_smp_atomic_add_nob(&sys_misc_mem_sz, dp->inBufSize);
-	    dp->outBufSize = 0;
-	    dp->outbuf = NULL;
-	    dp->port_num = port_num;
-	    dp->packet_bytes = packet_bytes;
-	    dp->port_pid = INVALID_HANDLE_VALUE;
-	    if (init_async_io(&dp->in, use_threads) == -1)
-		break;
-	    if (init_async_io(&dp->out, use_threads) == -1)
-		break;
-	    erts_smp_mtx_unlock(&sys_driver_data_lock);
-	    return dp;
-	}
-    }
+    return dp;
 
-    /*
-     * Error or no free driver data.
-     */
+async_io_error2:
+    release_async_io(&dp->in, dp->port_num);
+async_io_error1:
+    release_async_io(&dp->out, dp->port_num);
 
-    if (dp < driver_data+max_files) {
-	release_async_io(&dp->in, dp->port_num);
-	release_async_io(&dp->out, dp->port_num);
-    }
-    erts_smp_mtx_unlock(&sys_driver_data_lock);
+buf_alloc_error:
+    driver_free(dp);
     return NULL;
 }
 
 static void
 release_driver_data(DriverData* dp)
 {
-    erts_smp_mtx_lock(&sys_driver_data_lock);
-
 #ifdef ERTS_SMP
 #ifdef USE_CANCELIOEX
     if (fpCancelIoEx != NULL) {
@@ -721,8 +698,7 @@ release_driver_data(DriverData* dp)
      * the exit thread.
      */
 
-    dp->port_num = PORT_FREE;
-    erts_smp_mtx_unlock(&sys_driver_data_lock);
+    driver_free(dp);
 }
 
 #ifdef ERTS_SMP
@@ -817,7 +793,6 @@ threaded_handle_closer(LPVOID param)
 static ErlDrvData
 set_driver_data(DriverData* dp, HANDLE ifd, HANDLE ofd, int read_write, int report_exit)
 {
-    int index = dp - driver_data;
     int result;
 
     dp->in.fd = ifd;
@@ -836,13 +811,12 @@ set_driver_data(DriverData* dp, HANDLE ifd, HANDLE ofd, int read_write, int repo
 			       ERL_DRV_WRITE|ERL_DRV_USE, 1);
 	ASSERT(result != -1);
     }
-    return (ErlDrvData)index;
+    return (ErlDrvData) dp;
 }
 
 static ErlDrvData
 reuse_driver_data(DriverData *dp, HANDLE ifd, HANDLE ofd, int read_write, ErlDrvPort port_num)
 {
-    int index = dp - driver_data;
     int result;
 
     dp->port_num = port_num;
@@ -861,7 +835,7 @@ reuse_driver_data(DriverData *dp, HANDLE ifd, HANDLE ofd, int read_write, ErlDrv
 			       ERL_DRV_WRITE|ERL_DRV_USE, 1);
 	ASSERT(result != -1);
     }
-    return (ErlDrvData)index;
+    return (ErlDrvData) dp;
 }
 
 /*
@@ -1118,12 +1092,6 @@ spawn_init(void)
 	((module != NULL) ? GetProcAddress(module,"CancelIoEx") : NULL);
     DEBUGF(("fpCancelIoEx = %p\r\n", fpCancelIoEx));
 #endif
-    driver_data = (struct driver_data *)
-	erts_alloc(ERTS_ALC_T_DRV_TAB, max_files * sizeof(struct driver_data));
-    erts_smp_atomic_add_nob(&sys_misc_mem_sz,
-			    max_files*sizeof(struct driver_data));
-    for (i = 0; i < max_files; i++)
-	driver_data[i].port_num = PORT_FREE;
 
     return 0;
 }
@@ -2187,12 +2155,10 @@ fd_start(ErlDrvPort port_num, char* name, SysDriverOpts* opts)
 	    return ERL_DRV_ERROR_GENERAL;
 	
 	if (!create_file_thread(&dp->in, DO_READ)) {
-	    dp->port_num = PORT_FREE;
 	    return ERL_DRV_ERROR_GENERAL;
 	}
 	
 	if (!create_file_thread(&dp->out, DO_WRITE)) {
-	    dp->port_num = PORT_FREE;
 	    return ERL_DRV_ERROR_GENERAL;
 	}
 	
@@ -2212,10 +2178,9 @@ fd_start(ErlDrvPort port_num, char* name, SysDriverOpts* opts)
     }
 }
 
-static void fd_stop(ErlDrvData d)
+static void fd_stop(ErlDrvData data)
 {
-  int fd = (int)d;
-  DriverData* dp = driver_data+fd;
+  DriverData * dp = (DriverData *) data;
   /*
    * There's no way we can terminate an fd port in a consistent way.
    * Instead we let it live until it's opened again (which it is,
@@ -2276,16 +2241,10 @@ vanilla_start(ErlDrvPort port_num, char* name, SysDriverOpts* opts)
 }
 
 static void
-stop(ErlDrvData index)
-{
-    common_stop((int)index);
-}
-
-static void common_stop(int index)
+stop(ErlDrvData data)
 {
-    DriverData* dp = driver_data+index;
-
-    DEBUGF(("common_stop(%d)\n", index));
+    DriverData *dp = (DriverData *) data;
+    DEBUGF(("stop(%p)\n", dp));
 
     if (dp->in.ov.hEvent != NULL) {
 	(void) driver_select(dp->port_num,
@@ -2307,7 +2266,6 @@ static void common_stop(int index)
 	 */
 	HANDLE thread;
 	DWORD tid;
-	dp->port_num = PORT_EXITING;
 	thread = (HANDLE *) _beginthreadex(NULL, 0, threaded_exiter, dp, 0, &tid);
 	CloseHandle(thread);
     }
@@ -2432,22 +2390,17 @@ threaded_exiter(LPVOID param)
 
 static void
 output(ErlDrvData drv_data, char* buf, ErlDrvSizeT len)
-/*     long drv_data;		/* The slot to use in the driver data table.
+/*     ErlDrvData drv_data;	/* The slot to use in the driver data table.
 				 * For Windows NT, this is *NOT* a file handle.
 				 * The handle is found in the driver data.
 				 */
 /*     char *buf;		/* Pointer to data to write to the port program. */
 /*     ErlDrvSizeT len;		/* Number of bytes to write. */
 {
-    DriverData* dp;
+    DriverData* dp = (DriverData *) drv_data;
     int pb;			/* The header size for this port. */
-    int port_num;		/* The actual port number (for diagnostics). */
     char* current;
 
-    dp = driver_data + (int)drv_data;
-    if ((port_num = dp->port_num) == -1)
-	return ; /*-1;*/
-
     pb = dp->packet_bytes;
 
     if ((pb+len) == 0)
@@ -2458,7 +2411,7 @@ output(ErlDrvData drv_data, char* buf, ErlDrvSizeT len)
      */
 
     if ((pb == 2 && len > 65535) || (pb == 1 && len > 255)) {
-	driver_failure_posix(port_num, EINVAL);
+	driver_failure_posix(dp->port_num, EINVAL);
 	return ; /* -1; */
     }
 
@@ -2472,7 +2425,7 @@ output(ErlDrvData drv_data, char* buf, ErlDrvSizeT len)
     ASSERT(!dp->outbuf);
     dp->outbuf = DRV_BUF_ALLOC(pb+len);
     if (!dp->outbuf) {
-	driver_failure_posix(port_num, ENOMEM);
+	driver_failure_posix(dp->port_num, ENOMEM);
 	return ; /* -1; */
     }
 
@@ -2502,7 +2455,7 @@ output(ErlDrvData drv_data, char* buf, ErlDrvSizeT len)
 	memcpy(current, buf, len);
     
     if (!async_write_file(&dp->out, dp->outbuf, pb+len)) {
-	set_busy_port(port_num, 1);
+	set_busy_port(dp->port_num, 1);
     } else {
 	dp->out.ov.Offset += pb+len; /* For vanilla driver. */
 	/* XXX OffsetHigh should be changed too. */
@@ -2537,10 +2490,9 @@ ready_input(ErlDrvData drv_data, ErlDrvEvent ready_event)
 {
     int error = 0;		/* The error code (assume initially no errors). */
     DWORD bytesRead;		/* Number of bytes read. */
-    DriverData* dp;
+    DriverData* dp = (DriverData *) drv_data;
     int pb;
 
-    dp = driver_data+(int)drv_data;
     pb = dp->packet_bytes;
 #ifdef ERTS_SMP
     if(dp->in.thread == (HANDLE) -1) {
@@ -2708,7 +2660,7 @@ static void
 ready_output(ErlDrvData drv_data, ErlDrvEvent ready_event)
 {
     DWORD bytesWritten;
-    DriverData* dp = driver_data + (int)drv_data;
+    DriverData *dp = (DriverData *) drv_data;
     int error;
 
 #ifdef ERTS_SMP
@@ -2716,7 +2668,7 @@ ready_output(ErlDrvData drv_data, ErlDrvEvent ready_event)
 	dp->out.async_io_active = 0;
     }
 #endif
-    DEBUGF(("ready_output(%d, 0x%x)\n", drv_data, ready_event));
+    DEBUGF(("ready_output(%p, 0x%x)\n", drv_data, ready_event));
     set_busy_port(dp->port_num, 0);
     if (!(dp->outbuf)) {
 	/* Happens because event sometimes get signalled during a successful
@@ -2771,7 +2723,7 @@ sys_init_io(void)
        can change our view of the number of open files possible.
        We estimate the number to twice the amount of ports. 
        We really dont know on windows, do we? */
-    max_files = 2*erts_max_ports;
+    max_files = 2*erts_ptab_max(&erts_port);
 }
 
 #ifdef ERTS_SMP
@@ -3225,9 +3177,6 @@ void erl_sys_init(void)
     noinherit_std_handle(STD_INPUT_HANDLE);
     noinherit_std_handle(STD_ERROR_HANDLE);
 
-
-    erts_smp_mtx_init(&sys_driver_data_lock, "sys_driver_data_lock");
-
 #ifdef ERTS_SMP
     erts_smp_tsd_key_create(&win32_errstr_key);
     InitializeCriticalSection(&htbc_lock);