Merge branch 'maint'

8 files changed, 180 insertions, 46 deletions

diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 53e7af9628..4dcfe997d4 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -4124,48 +4124,52 @@ BIF_RETTYPE erts_debug_lock_counters_1(BIF_ALIST_1)
 	Eterm* tp = tuple_val(BIF_ARG_1);
 
 	switch (arityval(tp[0])) {
-	    case 2:
+	    case 2: {
+		int opt = 0;
+		int val = 0;
 		if (ERTS_IS_ATOM_STR("copy_save", tp[1])) {
-		    erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
-		    erts_smp_thr_progress_block();
-		    if (tp[2] == am_true) {
-
-			res = erts_lcnt_set_rt_opt(ERTS_LCNT_OPT_COPYSAVE) ? am_true : am_false;
-
-		    } else if (tp[2] == am_false) {
-
-			res = erts_lcnt_clear_rt_opt(ERTS_LCNT_OPT_COPYSAVE) ? am_true : am_false;
-
-		    } else {
-			erts_smp_thr_progress_unblock();
-			erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
-			BIF_ERROR(BIF_P, BADARG);
-		    }
-		    erts_smp_thr_progress_unblock();
-		    erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
-		    BIF_RET(res);
-
+		    opt = ERTS_LCNT_OPT_COPYSAVE;
 		} else if (ERTS_IS_ATOM_STR("process_locks", tp[1])) {
-		    erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
-		    erts_smp_thr_progress_block();
-		    if (tp[2] == am_true) {
-
-			res = erts_lcnt_set_rt_opt(ERTS_LCNT_OPT_PROCLOCK) ? am_true : am_false;
-
-		    } else if (tp[2] == am_false) {
-
-			res = erts_lcnt_set_rt_opt(ERTS_LCNT_OPT_PROCLOCK) ? am_true : am_false;
+		    opt = ERTS_LCNT_OPT_PROCLOCK;
+		} else if (ERTS_IS_ATOM_STR("port_locks", tp[1])) {
+		    opt = ERTS_LCNT_OPT_PORTLOCK;
+		} else if (ERTS_IS_ATOM_STR("suspend", tp[1])) {
+		    opt = ERTS_LCNT_OPT_SUSPEND;
+		} else if (ERTS_IS_ATOM_STR("location", tp[1])) {
+		    opt = ERTS_LCNT_OPT_LOCATION;
+		} else {
+		    BIF_ERROR(BIF_P, BADARG);
+		}
+		if (tp[2] == am_true) {
+		    val = 1;
+		} else if (tp[2] == am_false) {
+		    val = 0;
+		} else {
+		    BIF_ERROR(BIF_P, BADARG);
+		}
 
-		    } else {
-			erts_smp_thr_progress_unblock();
-			erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
-			BIF_ERROR(BIF_P, BADARG);
+		erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
+		erts_smp_thr_progress_block();
+		
+		if (val) {
+		    res = erts_lcnt_set_rt_opt(opt) ? am_true : am_false;
+		} else {
+		    res = erts_lcnt_clear_rt_opt(opt) ? am_true : am_false;
+		}
+#ifdef ERTS_SMP
+		if (res != tp[2]) {
+		    if (opt == ERTS_LCNT_OPT_PORTLOCK) {
+			erts_lcnt_enable_io_lock_count(val);
+		    } else if (opt == ERTS_LCNT_OPT_PROCLOCK) {
+			erts_lcnt_enable_proc_lock_count(val);
 		    }
-		    erts_smp_thr_progress_unblock();
-		    erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
-		    BIF_RET(res);
-		 }
-	    break;
+		}
+#endif
+		erts_smp_thr_progress_unblock();
+		erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
+		BIF_RET(res);
+		break;
+	    }
      
 	    default:
 	    break;
diff --git a/erts/emulator/beam/erl_lock_count.c b/erts/emulator/beam/erl_lock_count.c
index a36c53560e..741c0cb08e 100644
--- a/erts/emulator/beam/erl_lock_count.c
+++ b/erts/emulator/beam/erl_lock_count.c
@@ -49,7 +49,7 @@ const char *str_undefined = "undefined";
 
 static ethr_tsd_key lcnt_thr_data_key;
 static int lcnt_n_thr;
-static erts_lcnt_thread_data_t *lcnt_thread_data[1024]; 
+static erts_lcnt_thread_data_t *lcnt_thread_data[4096]; 
 
 /* local functions */
 
@@ -240,7 +240,7 @@ void erts_lcnt_init() {
 
     lcnt_lock();
 
-    erts_lcnt_rt_options = ERTS_LCNT_OPT_PROCLOCK;
+    erts_lcnt_rt_options = ERTS_LCNT_OPT_PROCLOCK | ERTS_LCNT_OPT_LOCATION;
     
     eltd = lcnt_thread_data_alloc();
 
@@ -312,7 +312,7 @@ void erts_lcnt_list_insert(erts_lcnt_lock_list_t *list, erts_lcnt_lock_t *lock)
 }
 
 void erts_lcnt_list_delete(erts_lcnt_lock_list_t *list, erts_lcnt_lock_t *lock) {
-    
+
     if (lock->next) lock->next->prev = lock->prev;
     if (lock->prev) lock->prev->next = lock->next;
     if (list->head == lock) list->head = lock->next;
@@ -334,6 +334,10 @@ void erts_lcnt_init_lock(erts_lcnt_lock_t *lock, char *name, Uint16 flag ) {
 }
 void erts_lcnt_init_lock_x(erts_lcnt_lock_t *lock, char *name, Uint16 flag, Eterm id) { 
     int i;
+    if (!name) {
+	lock->flag = 0;
+	return;
+    }
     lcnt_lock();
     
     lock->next = NULL;
@@ -363,6 +367,8 @@ void erts_lcnt_init_lock_x(erts_lcnt_lock_t *lock, char *name, Uint16 flag, Eter
 void erts_lcnt_destroy_lock(erts_lcnt_lock_t *lock) {
     erts_lcnt_lock_t *deleted_lock;
 
+    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
+
     lcnt_lock();
 
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_COPYSAVE) {
@@ -378,6 +384,7 @@ void erts_lcnt_destroy_lock(erts_lcnt_lock_t *lock) {
     }
     /* delete original */
     erts_lcnt_list_delete(erts_lcnt_data->current_locks, lock);
+    lock->flag = 0;
     
     lcnt_unlock();
 }
@@ -389,6 +396,7 @@ void erts_lcnt_lock_opt(erts_lcnt_lock_t *lock, Uint16 option) {
     erts_lcnt_thread_data_t *eltd;
     
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
+    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
 
     eltd = lcnt_get_thread_data();
 
@@ -422,6 +430,7 @@ void erts_lcnt_lock(erts_lcnt_lock_t *lock) {
     erts_lcnt_thread_data_t *eltd;
     
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
+    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
 
     w_state = ethr_atomic_read(&lock->w_state);
     ethr_atomic_inc( &lock->w_state);
@@ -452,6 +461,7 @@ void erts_lcnt_lock_unaquire(erts_lcnt_lock_t *lock) {
     /* should check if this thread was "waiting" */
     
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
+    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
 
     ethr_atomic_dec( &lock->w_state);
 }
@@ -475,6 +485,7 @@ void erts_lcnt_lock_post_x(erts_lcnt_lock_t *lock, char *file, unsigned int line
 #endif
 
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
+    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
     
 #ifdef DEBUG
     if (!(lock->flag & (ERTS_LCNT_LT_RWMUTEX | ERTS_LCNT_LT_RWSPINLOCK))) {
@@ -489,9 +500,13 @@ void erts_lcnt_lock_post_x(erts_lcnt_lock_t *lock, char *file, unsigned int line
     ASSERT(eltd);
 
     /* if lock was in conflict, time it */
-	
-    stats = lcnt_get_lock_stats(lock, file, line);
     
+    if (erts_lcnt_rt_options & ERTS_LCNT_OPT_LOCATION) {
+	stats = lcnt_get_lock_stats(lock, file, line);
+    } else {
+	stats = &lock->stats[0];
+    }
+
     if (eltd->timer_set) {
 	lcnt_time(&timer);
 	
@@ -510,6 +525,7 @@ void erts_lcnt_lock_post_x(erts_lcnt_lock_t *lock, char *file, unsigned int line
 
 void erts_lcnt_unlock_opt(erts_lcnt_lock_t *lock, Uint16 option) {
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
+    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
     if (option & ERTS_LCNT_LO_WRITE) ethr_atomic_dec(&lock->w_state);
     if (option & ERTS_LCNT_LO_READ ) ethr_atomic_dec(&lock->r_state);
 }
@@ -520,6 +536,7 @@ void erts_lcnt_unlock(erts_lcnt_lock_t *lock) {
     erts_aint_t flowstate;
 #endif
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
+    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
 #ifdef DEBUG
     /* flowstate */
     flowstate = ethr_atomic_read(&lock->flowstate);
@@ -537,6 +554,7 @@ void erts_lcnt_unlock(erts_lcnt_lock_t *lock) {
 
 void erts_lcnt_trylock_opt(erts_lcnt_lock_t *lock, int res, Uint16 option) {
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
+    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
     /* Determine lock_state via res instead of state */
     if (res != EBUSY) {
 	if (option & ERTS_LCNT_LO_WRITE) ethr_atomic_inc(&lock->w_state);
@@ -555,6 +573,7 @@ void erts_lcnt_trylock(erts_lcnt_lock_t *lock, int res) {
     erts_aint_t flowstate;
 #endif 
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_SUSPEND) return;
+    if (!ERTS_LCNT_LOCK_TYPE(lock)) return;
     if (res != EBUSY) {
 	
 #ifdef DEBUG
diff --git a/erts/emulator/beam/erl_lock_count.h b/erts/emulator/beam/erl_lock_count.h
index 6306580ae4..690551c71f 100644
--- a/erts/emulator/beam/erl_lock_count.h
+++ b/erts/emulator/beam/erl_lock_count.h
@@ -89,6 +89,7 @@
 #define ERTS_LCNT_OPT_LOCATION  (((Uint16) 1) << 1)
 #define ERTS_LCNT_OPT_PROCLOCK  (((Uint16) 1) << 2)
 #define ERTS_LCNT_OPT_COPYSAVE  (((Uint16) 1) << 3)
+#define ERTS_LCNT_OPT_PORTLOCK  (((Uint16) 1) << 4)
 
 typedef struct {
     unsigned long s;
@@ -201,5 +202,7 @@ void   erts_lcnt_clear_counters(void);
 char  *erts_lcnt_lock_type(Uint16 type);
 erts_lcnt_data_t *erts_lcnt_get_data(void);
 
+#define ERTS_LCNT_LOCK_TYPE(lockp)	((lockp)->flag & ERTS_LCNT_LT_ALL)
+
 #endif /* ifdef  ERTS_ENABLE_LOCK_COUNT  */
 #endif /* ifndef ERTS_LOCK_COUNT_H__     */
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index 45a96f1e96..707e7abe63 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -1410,10 +1410,14 @@ ERTS_GLB_INLINE Eterm erts_get_current_pid(void);
 ERTS_GLB_INLINE Uint erts_get_scheduler_id(void);
 ERTS_GLB_INLINE ErtsRunQueue *erts_get_runq_proc(Process *p);
 ERTS_GLB_INLINE ErtsRunQueue *erts_get_runq_current(ErtsSchedulerData *esdp);
+#ifndef ERTS_ENABLE_LOCK_COUNT
 ERTS_GLB_INLINE void erts_smp_runq_lock(ErtsRunQueue *rq);
+#endif
 ERTS_GLB_INLINE int erts_smp_runq_trylock(ErtsRunQueue *rq);
 ERTS_GLB_INLINE void erts_smp_runq_unlock(ErtsRunQueue *rq);
+#ifndef ERTS_ENABLE_LOCK_COUNT
 ERTS_GLB_INLINE void erts_smp_xrunq_lock(ErtsRunQueue *rq, ErtsRunQueue *xrq);
+#endif
 ERTS_GLB_INLINE void erts_smp_xrunq_unlock(ErtsRunQueue *rq, ErtsRunQueue *xrq);
 ERTS_GLB_INLINE void erts_smp_runqs_lock(ErtsRunQueue *rq1, ErtsRunQueue *rq2);
 ERTS_GLB_INLINE void erts_smp_runqs_unlock(ErtsRunQueue *rq1, ErtsRunQueue *rq2);
@@ -1502,6 +1506,12 @@ erts_get_runq_current(ErtsSchedulerData *esdp)
 #endif
 }
 
+#ifdef ERTS_ENABLE_LOCK_COUNT
+
+#define erts_smp_runq_lock(rq)	erts_smp_mtx_lock_x(&(rq)->mtx, __FILE__, __LINE__)
+
+#else
+
 ERTS_GLB_INLINE void
 erts_smp_runq_lock(ErtsRunQueue *rq)
 {
@@ -1510,6 +1520,8 @@ erts_smp_runq_lock(ErtsRunQueue *rq)
 #endif
 }
 
+#endif
+
 ERTS_GLB_INLINE int
 erts_smp_runq_trylock(ErtsRunQueue *rq)
 {
@@ -1528,6 +1540,31 @@ erts_smp_runq_unlock(ErtsRunQueue *rq)
 #endif
 }
 
+#ifdef ERTS_ENABLE_LOCK_COUNT
+
+#define erts_smp_xrunq_lock(rq, xrq)	erts_smp_xrunq_lock_x((rq), (xrq), __FILE__, __LINE__)
+
+ERTS_GLB_INLINE void
+erts_smp_xrunq_lock_x(ErtsRunQueue *rq, ErtsRunQueue *xrq, char* file, int line)
+{
+#ifdef ERTS_SMP
+    ERTS_SMP_LC_ASSERT(erts_smp_lc_mtx_is_locked(&rq->mtx));
+    if (xrq != rq) {
+	if (erts_smp_mtx_trylock(&xrq->mtx) == EBUSY) {
+	    if (rq < xrq)
+		erts_smp_mtx_lock_x(&xrq->mtx, file, line);
+	    else {
+		erts_smp_mtx_unlock(&rq->mtx);
+		erts_smp_mtx_lock_x(&xrq->mtx, file, line);
+		erts_smp_mtx_lock_x(&rq->mtx, file, line);
+	    }
+	}
+    }
+#endif
+}
+
+#else
+
 ERTS_GLB_INLINE void
 erts_smp_xrunq_lock(ErtsRunQueue *rq, ErtsRunQueue *xrq)
 {
@@ -1547,6 +1584,8 @@ erts_smp_xrunq_lock(ErtsRunQueue *rq, ErtsRunQueue *xrq)
 #endif
 }
 
+#endif
+
 ERTS_GLB_INLINE void
 erts_smp_xrunq_unlock(ErtsRunQueue *rq, ErtsRunQueue *xrq)
 {
diff --git a/erts/emulator/beam/erl_process_lock.c b/erts/emulator/beam/erl_process_lock.c
index a5a753b798..b3b4601a31 100644
--- a/erts/emulator/beam/erl_process_lock.c
+++ b/erts/emulator/beam/erl_process_lock.c
@@ -1002,7 +1002,7 @@ erts_proc_lock_init(Process *p)
 
 #ifdef ERTS_ENABLE_LOCK_COUNT
 void erts_lcnt_proc_lock_init(Process *p) {
-    
+    if (erts_lcnt_rt_options & ERTS_LCNT_OPT_PROCLOCK) {
     if (p->id != ERTS_INVALID_PID) {
 	erts_lcnt_init_lock_x(&(p->lock.lcnt_main),   "proc_main",   ERTS_LCNT_LT_PROCLOCK, p->id);
 	erts_lcnt_init_lock_x(&(p->lock.lcnt_msgq),   "proc_msgq",   ERTS_LCNT_LT_PROCLOCK, p->id);
@@ -1014,6 +1014,12 @@ void erts_lcnt_proc_lock_init(Process *p) {
 	erts_lcnt_init_lock(&(p->lock.lcnt_link),   "proc_link",   ERTS_LCNT_LT_PROCLOCK);
 	erts_lcnt_init_lock(&(p->lock.lcnt_status), "proc_status", ERTS_LCNT_LT_PROCLOCK);
     }
+    } else {
+	sys_memzero(&(p->lock.lcnt_main), sizeof(p->lock.lcnt_main));
+	sys_memzero(&(p->lock.lcnt_msgq), sizeof(p->lock.lcnt_msgq));
+	sys_memzero(&(p->lock.lcnt_link), sizeof(p->lock.lcnt_link));
+	sys_memzero(&(p->lock.lcnt_status), sizeof(p->lock.lcnt_status));
+    }
 }
 	
 
@@ -1108,6 +1114,26 @@ void erts_lcnt_proc_trylock(erts_proc_lock_t *lock, ErtsProcLocks locks, int res
     }
 }
 
+
+void erts_lcnt_enable_proc_lock_count(int enable) {
+    int i;
+
+    for (i = 0; i < erts_max_processes; ++i) {
+	Process* p = process_tab[i];
+	if (p) {
+	    if (enable) {
+		if (!ERTS_LCNT_LOCK_TYPE(&(p->lock.lcnt_main))) {
+		    erts_lcnt_proc_lock_init(p);
+		}
+	    } else {
+		if (ERTS_LCNT_LOCK_TYPE(&(p->lock.lcnt_main))) {
+		    erts_lcnt_proc_lock_destroy(p);
+		}
+	    }
+	}
+    }
+}
+
 #endif /* ifdef ERTS_ENABLE_LOCK_COUNT */
 
 
diff --git a/erts/emulator/beam/erl_process_lock.h b/erts/emulator/beam/erl_process_lock.h
index 8dbdaccc68..413c45480c 100644
--- a/erts/emulator/beam/erl_process_lock.h
+++ b/erts/emulator/beam/erl_process_lock.h
@@ -215,6 +215,8 @@ void erts_lcnt_proc_lock_unaquire(erts_proc_lock_t *lock, ErtsProcLocks locks);
 void erts_lcnt_proc_unlock(erts_proc_lock_t *lock, ErtsProcLocks locks);
 void erts_lcnt_proc_trylock(erts_proc_lock_t *lock, ErtsProcLocks locks, int res);
 
+void erts_lcnt_enable_proc_lock_count(int enable);
+
 #endif /* ERTS_ENABLE_LOCK_COUNT*/
 
 
diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h
index 12e40288bd..732cc7d45d 100644
--- a/erts/emulator/beam/global.h
+++ b/erts/emulator/beam/global.h
@@ -1200,6 +1200,10 @@ void erts_fire_port_monitor(Port *prt, Eterm ref);
 void erts_smp_xports_unlock(Port *);
 #endif
 
+#if defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_COUNT)
+void erts_lcnt_enable_io_lock_count(int enable);
+#endif
+
 #if defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK)
 int erts_lc_is_port_locked(Port *);
 #endif
diff --git a/erts/emulator/beam/io.c b/erts/emulator/beam/io.c
index 001d8d0362..a685f41c4d 100644
--- a/erts/emulator/beam/io.c
+++ b/erts/emulator/beam/io.c
@@ -626,7 +626,11 @@ erts_open_driver(erts_driver_t* driver,	/* Pointer to driver. */
 	port->lock = erts_alloc(ERTS_ALC_T_PORT_LOCK,
 					      sizeof(erts_smp_mtx_t));
 	erts_smp_mtx_init_x(port->lock,
+#ifdef ERTS_ENABLE_LOCK_COUNT
+			    (erts_lcnt_rt_options & ERTS_LCNT_OPT_PORTLOCK) ? "port_lock" : NULL,
+#else
 			    "port_lock",
+#endif
 			    port->id);
 	xstatus |= ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK;
     }
@@ -784,7 +788,13 @@ driver_create_port(ErlDrvPort creator_port_ix, /* Creating port */
 	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);
+	erts_smp_mtx_init_locked_x(port->lock,
+#ifdef ERTS_ENABLE_LOCK_COUNT
+				   (erts_lcnt_rt_options & ERTS_LCNT_OPT_PORTLOCK) ? "port_lock" : NULL,
+#else
+				   "port_lock",
+#endif
+				   port_id);
 	xstatus |= ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK;
     }
 
@@ -1348,7 +1358,13 @@ void init_io(void)
 	erts_smp_atomic_init_nob(&erts_port[i].refc, 0);
 	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));
+	erts_smp_spinlock_init_x(&erts_port[i].state_lck,
+#ifdef ERTS_ENABLE_LOCK_COUNT
+				 (erts_lcnt_rt_options & ERTS_LCNT_OPT_PORTLOCK) ? "port_state" : NULL,
+#else
+				 "port_state",
+#endif
+				 0);
 #endif
 	erts_port[i].tracer_proc = NIL;
 	erts_port[i].trace_flags = 0;
@@ -1381,6 +1397,27 @@ void init_io(void)
     erts_smp_mtx_unlock(&erts_driver_list_lock);
 }
 
+#if defined(ERTS_ENABLE_LOCK_COUNT) && defined(ERTS_SMP)
+void erts_lcnt_enable_io_lock_count(int enable) {
+    int i;
+
+    for (i = 0; i < erts_max_ports; i++) {
+	Port* p = &erts_port[i];
+	if (enable) {
+	    erts_lcnt_init_lock_x(&p->state_lck.lcnt, "port_state", ERTS_LCNT_LT_SPINLOCK, make_small(i));
+	    if (p->lock) {
+		erts_lcnt_init_lock_x(&p->lock->lcnt, "port_lock", ERTS_LCNT_LT_MUTEX, make_small(i));
+	    }
+	} else {
+	    erts_lcnt_destroy_lock(&p->state_lck.lcnt);
+	    if (p->lock) {
+		erts_lcnt_destroy_lock(&p->lock->lcnt);
+	    }
+	}
+    }
+}
+#endif
+
 /*
  * Buffering of data when using line oriented I/O on ports
  */