Prepare for use of ptab functionality also for ports

1 files changed, 503 insertions, 0 deletions

diff --git a/erts/emulator/beam/erl_port.h b/erts/emulator/beam/erl_port.h
new file mode 100644
index 0000000000..1a5bc636e2
--- /dev/null
+++ b/erts/emulator/beam/erl_port.h
@@ -0,0 +1,503 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2012. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#ifndef ERL_PORT_H__
+#define ERL_PORT_H__
+
+typedef struct port Port;
+#include "erl_port_task.h"
+#include "erl_ptab.h"
+
+typedef struct erts_driver_t_ erts_driver_t;
+
+#define SMALL_IO_QUEUE 5   /* Number of fixed elements */
+
+typedef struct {
+    ErlDrvSizeT size;       /* total size in bytes */
+
+    SysIOVec* v_start;
+    SysIOVec* v_end;
+    SysIOVec* v_head;
+    SysIOVec* v_tail;
+    SysIOVec  v_small[SMALL_IO_QUEUE];
+
+    ErlDrvBinary** b_start;
+    ErlDrvBinary** b_end;
+    ErlDrvBinary** b_head;
+    ErlDrvBinary** b_tail;
+    ErlDrvBinary*  b_small[SMALL_IO_QUEUE];
+} ErlIOQueue;
+
+typedef struct line_buf {  /* Buffer used in line oriented I/O */
+    ErlDrvSizeT bufsiz;      /* Size of character buffer */
+    ErlDrvSizeT ovlen;       /* Length of overflow data */
+    ErlDrvSizeT ovsiz;       /* Actual size of overflow buffer */
+    char data[1];            /* Starting point of buffer data,
+			      data[0] is a flag indicating an unprocess CR,
+			      The rest is the overflow buffer. */
+} LineBuf;
+
+
+/*
+ * Port Specific Data.
+ *
+ * Only use PrtSD for very rarely used data.
+ */
+
+#define ERTS_PRTSD_SCHED_ID 0
+
+#define ERTS_PRTSD_SIZE 1
+
+typedef struct {
+    void *data[ERTS_PRTSD_SIZE];
+} ErtsPrtSD;
+
+#ifdef ERTS_SMP
+typedef struct ErtsXPortsList_ ErtsXPortsList;
+#endif
+
+/*
+ * Port locking:
+ *
+ * Locking is done either driver specific or port specific. When
+ * driver specific locking is used, all instances of the driver,
+ * i.e. ports running the driver, share the same lock. When port
+ * specific locking is used each instance have its own lock.
+ *
+ * Most fields in the Port structure are protected by the lock
+ * referred to by the 'lock' field. This lock is shared between
+ * all ports running the same driver when driver specific locking
+ * is used.
+ *
+ * The 'sched' field is protected by the run queue lock that the
+ * port currently is assigned to.
+ *
+ */
+
+struct port {
+    ErtsPTabElementCommon common; /* *Need* to be first in struct */
+
+    ErtsPortTaskSched sched;
+    ErtsPortTaskHandle timeout_task;
+#ifdef ERTS_SMP
+    erts_smp_mtx_t *lock;
+    ErtsXPortsList *xports;
+    erts_smp_atomic_t run_queue;
+    erts_smp_spinlock_t state_lck;  /* protects: id, status, snapshot */
+#endif
+    Eterm connected;            /* A connected process */
+    Eterm caller;		/* Current caller. */
+    Eterm data;			/* Data associated with port. */
+    ErlHeapFragment* bp;	/* Heap fragment holding data (NULL if imm data). */
+    Uint bytes_in;		/* Number of bytes read */
+    Uint bytes_out;		/* Number of bytes written */
+
+    ErlIOQueue ioq;              /* driver accessible i/o queue */
+    DistEntry *dist_entry;       /* Dist entry used in DISTRIBUTION */
+    char *name;		         /* String used in the open */
+    erts_driver_t* drv_ptr;
+    UWord drv_data;
+    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 */
+    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 */
+};
+
+
+ERTS_GLB_INLINE ErtsRunQueue *erts_port_runq(Port *prt);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE ErtsRunQueue *
+erts_port_runq(Port *prt)
+{
+#ifdef ERTS_SMP
+    ErtsRunQueue *rq1, *rq2;
+    rq1 = (ErtsRunQueue *) erts_smp_atomic_read_nob(&prt->run_queue);
+    if (!rq1)
+	return NULL;
+    while (1) {
+	erts_smp_runq_lock(rq1);
+	rq2 = (ErtsRunQueue *) erts_smp_atomic_read_nob(&prt->run_queue);
+	if (rq1 == rq2)
+	    return rq1;
+	erts_smp_runq_unlock(rq1);
+	rq1 = rq2;
+	if (!rq1)
+	    return NULL;
+    }
+#else
+    return ERTS_RUNQ_IX(0);
+#endif
+}
+
+#endif
+
+
+ERTS_GLB_INLINE void *erts_prtsd_get(Port *p, int ix);
+ERTS_GLB_INLINE void *erts_prtsd_set(Port *p, int ix, void *new);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE void *
+erts_prtsd_get(Port *prt, int ix)
+{
+    return prt->psd ? prt->psd->data[ix] : NULL;
+}
+
+ERTS_GLB_INLINE void *
+erts_prtsd_set(Port *prt, int ix, void *data)
+{
+    if (prt->psd) {
+	void *old = prt->psd->data[ix];
+	prt->psd->data[ix] = data;
+	return old;
+    }
+    else {
+	prt->psd = erts_alloc(ERTS_ALC_T_PRTSD, sizeof(ErtsPrtSD));
+	prt->psd->data[ix] = data;
+	return NULL;
+    }
+}
+
+#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 */
+
+
+/* port status flags */
+
+#define ERTS_PORT_SFLG_CONNECTED	((Uint32) (1 <<  0))
+/* Port have begun exiting */
+#define ERTS_PORT_SFLG_EXITING		((Uint32) (1 <<  1))
+/* Distribution port */
+#define ERTS_PORT_SFLG_DISTRIBUTION	((Uint32) (1 <<  2))
+#define ERTS_PORT_SFLG_BINARY_IO	((Uint32) (1 <<  3))
+#define ERTS_PORT_SFLG_SOFT_EOF		((Uint32) (1 <<  4))
+/* Flow control */
+#define ERTS_PORT_SFLG_PORT_BUSY	((Uint32) (1 <<  5))
+/* Port is closing (no i/o accepted) */
+#define ERTS_PORT_SFLG_CLOSING		((Uint32) (1 <<  6))
+/* Send a closed message when terminating */
+#define ERTS_PORT_SFLG_SEND_CLOSED	((Uint32) (1 <<  7))
+/* Line orinted io on port */  
+#define ERTS_PORT_SFLG_LINEBUF_IO	((Uint32) (1 <<  8))
+/* Immortal port (only certain system ports) */
+#define ERTS_PORT_SFLG_IMMORTAL		((Uint32) (1 <<  9))
+#define ERTS_PORT_SFLG_FREE		((Uint32) (1 << 10))
+#define ERTS_PORT_SFLG_FREE_SCHEDULED	((Uint32) (1 << 11))
+#define ERTS_PORT_SFLG_INITIALIZING	((Uint32) (1 << 12))
+/* Port uses port specific locking (opposed to driver specific locking) */
+#define ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK ((Uint32) (1 << 13))
+#define ERTS_PORT_SFLG_INVALID		((Uint32) (1 << 14))
+/* Last port to terminate halts the emulator */
+#define ERTS_PORT_SFLG_HALT		((Uint32) (1 << 15))
+#ifdef DEBUG
+/* Only debug: make sure all flags aren't cleared unintentionally */
+#define ERTS_PORT_SFLG_PORT_DEBUG	((Uint32) (1 << 31))
+#endif
+
+/* Combinations of port status flags */ 
+#define ERTS_PORT_SFLGS_DEAD						\
+  (ERTS_PORT_SFLG_FREE							\
+   | ERTS_PORT_SFLG_FREE_SCHEDULED					\
+   | ERTS_PORT_SFLG_INITIALIZING)
+#define ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP				\
+  (ERTS_PORT_SFLGS_DEAD | ERTS_PORT_SFLG_INVALID)
+#define ERTS_PORT_SFLGS_INVALID_LOOKUP					\
+  (ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP				\
+   | ERTS_PORT_SFLG_CLOSING)
+#define ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP				\
+  (ERTS_PORT_SFLGS_INVALID_LOOKUP					\
+   | ERTS_PORT_SFLG_PORT_BUSY						\
+   | ERTS_PORT_SFLG_DISTRIBUTION)
+
+
+void erts_port_cleanup(Port *);
+void erts_fire_port_monitor(Port *prt, Eterm ref);
+#ifdef ERTS_SMP
+void erts_smp_xports_unlock(Port *);
+#endif
+
+#if defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK)
+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 int erts_smp_port_trylock(Port *prt);
+ERTS_GLB_INLINE void erts_smp_port_lock(Port *prt);
+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)
+{
+#ifdef ERTS_SMP
+    erts_smp_spin_lock(&prt->state_lck);
+#endif
+}
+
+ERTS_GLB_INLINE void
+erts_smp_port_minor_unlock(Port *prt)
+{
+#ifdef ERTS_SMP
+    erts_smp_spin_unlock(&prt->state_lck);
+#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);
+    }
+#else
+    res = 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);
+#endif
+}
+
+ERTS_GLB_INLINE void
+erts_smp_port_unlock(Port *prt)
+{
+    erts_aint32_t refc;
+#ifdef ERTS_SMP
+    erts_smp_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 */
+
+
+#define ERTS_INVALID_PORT_OPT(PP, ID, FLGS)			\
+    (!(PP)							\
+     || (erts_smp_atomic32_read_nob(&(PP)->state) & (FLGS))	\
+     || (PP)->common.id != (ID))
+
+/* port lookup */
+
+#define INVALID_PORT(PP, ID) \
+  ERTS_INVALID_PORT_OPT((PP), (ID), ERTS_PORT_SFLGS_INVALID_LOOKUP)
+
+/* Invalidate trace port if anything suspicious, for instance
+ * that the port is a distribution port or it is busy.
+ */
+#define INVALID_TRACER_PORT(PP, ID)					\
+  ERTS_INVALID_PORT_OPT((PP), (ID), ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP)
+
+#define ERTS_PORT_SCHED_ID(P, ID) \
+  ((Uint) (UWord) erts_prtsd_set((P), ERTS_PSD_SCHED_ID, (void *) (UWord) (ID)))
+
+#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 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);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE Port*
+erts_id2port_sflgs(Eterm id, Process *c_p, ErtsProcLocks c_p_locks, Uint32 sflgs)
+{
+#ifdef ERTS_SMP
+    int no_proc_locks = !c_p || !c_p_locks;
+#endif
+    Port *prt;
+
+    if (is_not_internal_port(id))
+	return NULL;
+
+    prt = &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;
+    }
+    else {
+	erts_smp_atomic32_inc_nob(&prt->common.refc);
+	erts_smp_port_minor_unlock(prt);
+
+#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);
+	}
+
+	/* 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... */
+	    prt = NULL;
+	}
+#endif
+
+    }
+
+    return prt;
+}
+
+ERTS_GLB_INLINE void
+erts_port_release(Port *prt)
+{
+    erts_smp_port_unlock(prt);
+}
+
+ERTS_GLB_INLINE Port*
+erts_drvport2port(ErlDrvPort drvport, erts_aint32_t *statep)
+{
+    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);
+    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];
+}
+
+ERTS_GLB_INLINE Port*
+erts_drvportid2port(Eterm id)
+{
+    int ix;
+    erts_aint32_t state;
+    if (is_not_internal_port(id))
+	return NULL;
+    ix = (int) internal_port_index(id);
+    if (erts_max_ports <= ix)
+	return NULL;
+    state = erts_smp_atomic32_read_nob(&erts_port[ix].state);
+    if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
+	return NULL;
+    if (erts_port[ix].common.id != id)
+	return NULL;
+    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(&erts_port[ix]));
+    return &erts_port[ix];
+}
+
+ERTS_GLB_INLINE Uint32
+erts_portid2status(Eterm id)
+{
+    if (is_not_internal_port(id))
+	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
+erts_is_port_alive(Eterm id)
+{
+    return !(erts_portid2status(id) & (ERTS_PORT_SFLG_INVALID
+				       | ERTS_PORT_SFLGS_DEAD));
+}
+
+ERTS_GLB_INLINE int
+erts_is_valid_tracer_port(Eterm id)
+{
+    return !(erts_portid2status(id) & ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP);
+}
+#endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
+#endif