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Diffstat (limited to 'erts/emulator/sys/win32/erl_poll.c')
-rw-r--r--erts/emulator/sys/win32/erl_poll.c382
1 files changed, 191 insertions, 191 deletions
diff --git a/erts/emulator/sys/win32/erl_poll.c b/erts/emulator/sys/win32/erl_poll.c
index d84ae2ede2..1f2877b682 100644
--- a/erts/emulator/sys/win32/erl_poll.c
+++ b/erts/emulator/sys/win32/erl_poll.c
@@ -1,7 +1,7 @@
/*
* %CopyrightBegin%
*
- * Copyright Ericsson AB 2007-2010. All Rights Reserved.
+ * Copyright Ericsson AB 2007-2011. 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
@@ -274,7 +274,6 @@ struct ErtsPollSet_ {
Waiter** waiter;
int allocated_waiters; /* Size ow waiter array */
int num_waiters; /* Number of waiter threads. */
- erts_atomic_t sys_io_ready; /* Tells us there is I/O ready (already). */
int restore_events; /* Tells us to restore waiters events
next time around */
HANDLE event_io_ready; /* To be used when waiting for io */
@@ -282,12 +281,11 @@ struct ErtsPollSet_ {
volatile int standby_wait_counter; /* Number of threads to wait for */
CRITICAL_SECTION standby_crit; /* CS to guard the counter */
HANDLE standby_wait_event; /* Event signalled when counte == 0 */
+ erts_atomic32_t wakeup_state;
#ifdef ERTS_SMP
- erts_smp_atomic_t woken;
erts_smp_mtx_t mtx;
- erts_smp_atomic_t interrupt;
#endif
- erts_smp_atomic_t timeout;
+ erts_smp_atomic32_t timeout;
};
#ifdef ERTS_SMP
@@ -296,126 +294,24 @@ struct ErtsPollSet_ {
erts_smp_mtx_lock(&(PS)->mtx)
#define ERTS_POLLSET_UNLOCK(PS) \
erts_smp_mtx_unlock(&(PS)->mtx)
-#define ERTS_POLLSET_SET_POLLED_CHK(PS) \
- ((int) erts_smp_atomic_xchg(&(PS)->polled, (erts_aint_t) 1))
-#define ERTS_POLLSET_SET_POLLED(PS) \
- erts_smp_atomic_set(&(PS)->polled, (erts_aint_t) 1)
-#define ERTS_POLLSET_UNSET_POLLED(PS) \
- erts_smp_atomic_set(&(PS)->polled, (erts_aint_t) 0)
-#define ERTS_POLLSET_IS_POLLED(PS) \
- ((int) erts_smp_atomic_read(&(PS)->polled))
-
-#define ERTS_POLLSET_SET_POLLER_WOKEN_CHK(PS) set_poller_woken_chk((PS))
-#define ERTS_POLLSET_SET_POLLER_WOKEN(PS) \
-do { \
- ERTS_THR_MEMORY_BARRIER; \
- erts_smp_atomic_set(&(PS)->woken, (erts_aint_t) 1); \
-} while (0)
-#define ERTS_POLLSET_UNSET_POLLER_WOKEN(PS) \
-do { \
- erts_smp_atomic_set(&(PS)->woken, (erts_aint_t) 0); \
- ERTS_THR_MEMORY_BARRIER; \
-} while (0)
-#define ERTS_POLLSET_IS_POLLER_WOKEN(PS) \
- ((int) erts_smp_atomic_read(&(PS)->woken))
-
-#define ERTS_POLLSET_UNSET_INTERRUPTED_CHK(PS) unset_interrupted_chk((PS))
-#define ERTS_POLLSET_UNSET_INTERRUPTED(PS) \
-do { \
- erts_smp_atomic_set(&(PS)->interrupt, (erts_aint_t) 0); \
- ERTS_THR_MEMORY_BARRIER; \
-} while (0)
-#define ERTS_POLLSET_SET_INTERRUPTED(PS) \
-do { \
- ERTS_THR_MEMORY_BARRIER; \
- erts_smp_atomic_set(&(PS)->interrupt, (erts_aint_t) 1); \
-} while (0)
-#define ERTS_POLLSET_IS_INTERRUPTED(PS) \
- ((int) erts_smp_atomic_read(&(PS)->interrupt))
-
-static ERTS_INLINE int
-unset_interrupted_chk(ErtsPollSet ps)
-{
- int res = (int) erts_smp_atomic_xchg(&ps->interrupt, (erts_aint_t) 0);
- ERTS_THR_MEMORY_BARRIER;
- return res;
-
-}
-
-static ERTS_INLINE int
-set_poller_woken_chk(ErtsPollSet ps)
-{
- ERTS_THR_MEMORY_BARRIER;
- return (int) erts_smp_atomic_xchg(&ps->woken, (erts_aint_t) 1);
-}
#else
#define ERTS_POLLSET_LOCK(PS)
#define ERTS_POLLSET_UNLOCK(PS)
-#define ERTS_POLLSET_SET_POLLED_CHK(PS) 0
-#define ERTS_POLLSET_UNSET_POLLED(PS)
-#define ERTS_POLLSET_IS_POLLED(PS) 0
-#define ERTS_POLLSET_SET_POLLER_WOKEN_CHK(PS) 1
-#define ERTS_POLLSET_SET_POLLER_WOKEN(PS)
-#define ERTS_POLLSET_UNSET_POLLER_WOKEN(PS)
-#define ERTS_POLLSET_IS_POLLER_WOKEN(PS) 1
-
#endif
/*
- * While atomics are not yet implemented for windows in the common library...
- *
- * MSDN doc states that SMP machines and old compilers require
- * InterLockedExchange to properly read and write interlocked
- * variables, otherwise the processors might reschedule
- * the access and order of atomics access is destroyed...
- * While they only mention it in white-papers, the problem
- * in VS2003 is due to the IA64 arch, so we can still count
- * on the CPU not rescheduling the access to volatile in X86 arch using
- * even the slightly older compiler...
- *
- * So here's (hopefully) a subset of the generally working atomic
- * variable access...
- */
-
-#if defined(__GNUC__)
-# if defined(__i386__) || defined(__x86_64__)
-# define VOLATILE_IN_SEQUENCE 1
-# else
-# define VOLATILE_IN_SEQUENCE 0
-# endif
-#elif defined(_MSC_VER)
-# if _MSC_VER < 1300
-# define VOLATILE_IN_SEQUENCE 0 /* Dont trust really old compilers */
-# else
-# if defined(_M_IX86)
-# define VOLATILE_IN_SEQUENCE 1
-# else /* I.e. IA64 */
-# if _MSC_VER >= 1400
-# define VOLATILE_IN_SEQUENCE 1
-# else
-# define VOLATILE_IN_SEQUENCE 0
-# endif
-# endif
-# endif
-#else
-# define VOLATILE_IN_SEQUENCE 0
-#endif
-
-
-
-/*
* Communication with sys_interrupt
*/
#ifdef ERTS_SMP
-extern erts_smp_atomic_t erts_break_requested;
+extern erts_smp_atomic32_t erts_break_requested;
#define ERTS_SET_BREAK_REQUESTED \
- erts_smp_atomic_set(&erts_break_requested, (erts_aint_t) 1)
+ erts_smp_atomic32_set(&erts_break_requested, (erts_aint32_t) 1)
#define ERTS_UNSET_BREAK_REQUESTED \
- erts_smp_atomic_set(&erts_break_requested, (erts_aint_t) 0)
+ erts_smp_atomic32_set(&erts_break_requested, (erts_aint32_t) 0)
#else
extern volatile int erts_break_requested;
#define ERTS_SET_BREAK_REQUESTED (erts_break_requested = 1)
@@ -424,7 +320,7 @@ extern volatile int erts_break_requested;
static erts_mtx_t break_waiter_lock;
static HANDLE break_happened_event;
-static erts_atomic_t break_waiter_state;
+static erts_atomic32_t break_waiter_state;
#define BREAK_WAITER_GOT_BREAK 1
#define BREAK_WAITER_GOT_HALT 2
@@ -467,29 +363,168 @@ do { \
wait_standby(PS); \
} while(0)
-#if ERTS_POLL_ASYNC_INTERRUPT_SUPPORT && !defined(ERTS_SMP)
+#define ERTS_POLL_NOT_WOKEN ((erts_aint32_t) 0)
+#define ERTS_POLL_WOKEN_IO_READY ((erts_aint32_t) 1)
+#define ERTS_POLL_WOKEN_INTR ((erts_aint32_t) 2)
+#define ERTS_POLL_WOKEN_TIMEDOUT ((erts_aint32_t) 3)
static ERTS_INLINE int
-unset_interrupted_chk(ErtsPollSet ps)
+is_io_ready(ErtsPollSet ps)
{
- /* This operation isn't atomic, but we have no need at all for an
- atomic operation here... */
- int res = ps->interrupt;
- ps->interrupt = 0;
- return res;
+ return erts_atomic32_read(&ps->wakeup_state) == ERTS_POLL_WOKEN_IO_READY;
}
+static ERTS_INLINE void
+woke_up(ErtsPollSet ps)
+{
+ if (erts_atomic32_read(&ps->wakeup_state) == ERTS_POLL_NOT_WOKEN)
+ erts_atomic32_cmpxchg(&ps->wakeup_state,
+ ERTS_POLL_WOKEN_TIMEDOUT,
+ ERTS_POLL_NOT_WOKEN);
+#ifdef DEBUG
+ {
+ erts_aint32_t wakeup_state = erts_atomic32_read(&ps->wakeup_state);
+ switch (wakeup_state) {
+ case ERTS_POLL_WOKEN_IO_READY:
+ case ERTS_POLL_WOKEN_INTR:
+ case ERTS_POLL_WOKEN_TIMEDOUT:
+ break;
+ default:
+ ASSERT(0);
+ break;
+ }
+ }
#endif
+}
+
+static ERTS_INLINE int
+wakeup_cause(ErtsPollSet ps)
+{
+ int res;
+ erts_aint32_t wakeup_state = erts_atomic32_read(&ps->wakeup_state);
+ switch (wakeup_state) {
+ case ERTS_POLL_WOKEN_IO_READY:
+ res = 0;
+ break;
+ case ERTS_POLL_WOKEN_INTR:
+ res = EINTR;
+ break;
+ case ERTS_POLL_WOKEN_TIMEDOUT:
+ res = ETIMEDOUT;
+ break;
+ default:
+ res = 0;
+ erl_exit(ERTS_ABORT_EXIT,
+ "%s:%d: Internal error: Invalid wakeup_state=%d\n",
+ __FILE__, __LINE__, (int) wakeup_state);
+ }
+ return res;
+}
+
+static ERTS_INLINE DWORD
+poll_wait_timeout(ErtsPollSet ps, SysTimeval *tvp)
+{
+ time_t timeout = tvp->tv_sec * 1000 + tvp->tv_usec / 1000;
+
+ if (timeout <= 0) {
+ woke_up(ps);
+ return (DWORD) 0;
+ }
+
+ ResetEvent(ps->event_io_ready);
+ /*
+ * Since we don't know the internals of ResetEvent() we issue
+ * a memory barrier as a safety precaution ensuring that
+ * the load of wakeup_state wont be reordered with stores made
+ * by ResetEvent().
+ */
+ ERTS_THR_MEMORY_BARRIER;
+ if (erts_atomic32_read(&ps->wakeup_state) != ERTS_POLL_NOT_WOKEN)
+ return (DWORD) 0;
+
+ if (timeout > ERTS_AINT32_T_MAX) /* Also prevents DWORD overflow */
+ timeout = ERTS_AINT32_T_MAX;
+
+ erts_smp_atomic32_set_relb(&ps->timeout, (erts_aint32_t) timeout);
+ return (DWORD) timeout;
+}
-#ifdef ERTS_SMP
static ERTS_INLINE void
-wake_poller(ErtsPollSet ps)
+wake_poller(ErtsPollSet ps, int io_ready)
{
- if (!ERTS_POLLSET_SET_POLLER_WOKEN_CHK(ps)) {
+ erts_aint32_t wakeup_state = erts_atomic32_read(&ps->wakeup_state);
+ if (io_ready) {
+ /* We may set the event multiple times. This is, however, harmless. */
+ erts_atomic32_set(&ps->wakeup_state, ERTS_POLL_WOKEN_IO_READY);
+ }
+ else {
+ while (wakeup_state != ERTS_POLL_WOKEN_IO_READY
+ && wakeup_state != ERTS_POLL_WOKEN_INTR) {
+ erts_aint32_t act = erts_atomic32_cmpxchg(&ps->wakeup_state,
+ ERTS_POLL_WOKEN_INTR,
+ wakeup_state);
+ if (act == wakeup_state) {
+ wakeup_state = act;
+ break;
+ }
+ wakeup_state = act;
+ }
+ }
+ if (wakeup_state == ERTS_POLL_NOT_WOKEN) {
+ /*
+ * Since we don't know the internals of SetEvent() we issue
+ * a memory barrier as a safety precaution ensuring that
+ * the store we just made to wakeup_state wont be reordered
+ * with loads in SetEvent().
+ */
+ ERTS_THR_MEMORY_BARRIER;
SetEvent(ps->event_io_ready);
}
}
-#endif
+
+static ERTS_INLINE void
+reset_io_ready(ErtsPollSet ps)
+{
+ erts_atomic32_set(&ps->wakeup_state, ERTS_POLL_NOT_WOKEN);
+}
+
+static ERTS_INLINE void
+restore_io_ready(ErtsPollSet ps)
+{
+ erts_atomic32_set(&ps->wakeup_state, ERTS_POLL_WOKEN_IO_READY);
+}
+
+/*
+ * notify_io_ready() is used by threads waiting for events, when
+ * notifying a poller thread about I/O ready.
+ */
+static ERTS_INLINE void
+notify_io_ready(ErtsPollSet ps)
+{
+ wake_poller(ps, 1);
+}
+
+static ERTS_INLINE void
+reset_interrupt(ErtsPollSet ps)
+{
+ /* We need to keep io-ready if set */
+ erts_aint32_t wakeup_state = erts_atomic32_read(&ps->wakeup_state);
+ while (wakeup_state != ERTS_POLL_WOKEN_IO_READY
+ && wakeup_state != ERTS_POLL_NOT_WOKEN) {
+ erts_aint32_t act = erts_atomic32_cmpxchg(&ps->wakeup_state,
+ ERTS_POLL_NOT_WOKEN,
+ wakeup_state);
+ if (wakeup_state == act)
+ break;
+ wakeup_state = act;
+ }
+}
+
+static ERTS_INLINE void
+set_interrupt(ErtsPollSet ps)
+{
+ wake_poller(ps, 0);
+}
static void setup_standby_wait(ErtsPollSet ps, int num_threads)
{
@@ -653,14 +688,14 @@ static void *break_waiter(void *param)
case WAIT_OBJECT_0:
ResetEvent(harr[0]);
erts_mtx_lock(&break_waiter_lock);
- erts_atomic_set(&break_waiter_state,BREAK_WAITER_GOT_BREAK);
+ erts_atomic32_set(&break_waiter_state,BREAK_WAITER_GOT_BREAK);
SetEvent(break_happened_event);
erts_mtx_unlock(&break_waiter_lock);
break;
case (WAIT_OBJECT_0+1):
ResetEvent(harr[1]);
erts_mtx_lock(&break_waiter_lock);
- erts_atomic_set(&break_waiter_state,BREAK_WAITER_GOT_HALT);
+ erts_atomic32_set(&break_waiter_state,BREAK_WAITER_GOT_HALT);
SetEvent(break_happened_event);
erts_mtx_unlock(&break_waiter_lock);
break;
@@ -767,12 +802,7 @@ event_happened:
consistency_check(w);
#endif
ASSERT(WAIT_OBJECT_0 < i && i < WAIT_OBJECT_0+w->active_events);
- if (!erts_atomic_xchg(&ps->sys_io_ready,1)) {
- HARDDEBUGF(("SET EventIoReady (%d)",erts_atomic_read(&ps->sys_io_ready)));
- SetEvent(ps->event_io_ready);
- } else {
- HARDDEBUGF(("DONT SET EventIoReady"));
- }
+ notify_io_ready(ps);
/*
* The main thread wont start working on our arrays untill we're
@@ -967,15 +997,10 @@ static int cancel_driver_select(ErtsPollSet ps, HANDLE event)
void erts_poll_interrupt(ErtsPollSet ps, int set /* bool */)
{
HARDTRACEF(("In erts_poll_interrupt(%d)",set));
-#ifdef ERTS_SMP
- if (set) {
- ERTS_POLLSET_SET_INTERRUPTED(ps);
- wake_poller(ps);
- }
- else {
- ERTS_POLLSET_UNSET_INTERRUPTED(ps);
- }
-#endif
+ if (!set)
+ reset_interrupt(ps);
+ else
+ set_interrupt(ps);
HARDTRACEF(("Out erts_poll_interrupt(%d)",set));
}
@@ -984,17 +1009,10 @@ void erts_poll_interrupt_timed(ErtsPollSet ps,
long msec)
{
HARDTRACEF(("In erts_poll_interrupt_timed(%d,%ld)",set,msec));
-#ifdef ERTS_SMP
- if (set) {
- if (erts_smp_atomic_read(&ps->timeout) > (erts_aint_t) msec) {
- ERTS_POLLSET_SET_INTERRUPTED(ps);
- wake_poller(ps);
- }
- }
- else {
- ERTS_POLLSET_UNSET_INTERRUPTED(ps);
- }
-#endif
+ if (!set)
+ reset_interrupt(ps);
+ else if (erts_smp_atomic32_read_acqb(&ps->timeout) > (erts_aint32_t) msec)
+ set_interrupt(ps);
HARDTRACEF(("Out erts_poll_interrupt_timed"));
}
@@ -1068,10 +1086,8 @@ void erts_poll_controlv(ErtsPollSet ps,
int erts_poll_wait(ErtsPollSet ps,
ErtsPollResFd pr[],
int *len,
- SysTimeval *utvp)
+ SysTimeval *tvp)
{
- SysTimeval *tvp = utvp;
- SysTimeval itv;
int no_fds;
DWORD timeout;
EventData* ev;
@@ -1084,7 +1100,7 @@ int erts_poll_wait(ErtsPollSet ps,
HARDTRACEF(("In erts_poll_wait"));
ERTS_POLLSET_LOCK(ps);
- if (!erts_atomic_read(&ps->sys_io_ready) && ps->restore_events) {
+ if (!is_io_ready(ps) && ps->restore_events) {
HARDDEBUGF(("Restore events: %d",ps->num_waiters));
ps->restore_events = 0;
for (i = 0; i < ps->num_waiters; ++i) {
@@ -1102,7 +1118,7 @@ int erts_poll_wait(ErtsPollSet ps,
if (w->highwater != w->active_events) {
HARDDEBUGF(("Oups!"));
/* Oups, got signalled before we took the lock, can't reset */
- if(erts_atomic_read(&ps->sys_io_ready) == 0) {
+ if(!is_io_ready(ps)) {
erl_exit(1,"Internal error: "
"Inconsistent io structures in erl_poll.\n");
}
@@ -1127,39 +1143,27 @@ int erts_poll_wait(ErtsPollSet ps,
no_fds = ERTS_POLL_MAX_RES;
#endif
+ timeout = poll_wait_timeout(ps, tvp);
- ResetEvent(ps->event_io_ready);
- ERTS_POLLSET_UNSET_POLLER_WOKEN(ps);
-
-#ifdef ERTS_SMP
- if (ERTS_POLLSET_IS_INTERRUPTED(ps)) {
- /* Interrupt use zero timeout */
- itv.tv_sec = 0;
- itv.tv_usec = 0;
- tvp = &itv;
- }
-#endif
-
- timeout = tvp->tv_sec * 1000 + tvp->tv_usec / 1000;
/*HARDDEBUGF(("timeout = %ld",(long) timeout));*/
- erts_smp_atomic_set(&ps->timeout, timeout);
- if (timeout > 0 && ! erts_atomic_read(&ps->sys_io_ready) && ! erts_atomic_read(&break_waiter_state)) {
+ if (timeout > 0 && !erts_atomic32_read(&break_waiter_state)) {
HANDLE harr[2] = {ps->event_io_ready, break_happened_event};
int num_h = 2;
- HARDDEBUGF(("Start waiting %d [%d]",num_h, (long) timeout));
+ HARDDEBUGF(("Start waiting %d [%d]",num_h, (int) timeout));
ERTS_POLLSET_UNLOCK(ps);
WaitForMultipleObjects(num_h, harr, FALSE, timeout);
ERTS_POLLSET_LOCK(ps);
- HARDDEBUGF(("Stop waiting %d [%d]",num_h, (long) timeout));
+ HARDDEBUGF(("Stop waiting %d [%d]",num_h, (int) timeout));
+ woke_up(ps);
}
ERTS_UNSET_BREAK_REQUESTED;
- if(erts_atomic_read(&break_waiter_state)) {
+ if(erts_atomic32_read(&break_waiter_state)) {
erts_mtx_lock(&break_waiter_lock);
- break_state = erts_atomic_read(&break_waiter_state);
- erts_atomic_set(&break_waiter_state,0);
+ break_state = erts_atomic32_read(&break_waiter_state);
+ erts_atomic32_set(&break_waiter_state,0);
ResetEvent(break_happened_event);
erts_mtx_unlock(&break_waiter_lock);
switch (break_state) {
@@ -1174,15 +1178,13 @@ int erts_poll_wait(ErtsPollSet ps,
}
}
- ERTS_POLLSET_SET_POLLER_WOKEN(ps);
-
- if (!erts_atomic_read(&ps->sys_io_ready)) {
- res = EINTR;
- HARDDEBUGF(("EINTR!"));
- goto done;
+ res = wakeup_cause(ps);
+ if (res != 0) {
+ HARDDEBUGF(("%s!", res == EINTR ? "EINTR" : "ETIMEDOUT"));
+ goto done;
}
- erts_atomic_set(&ps->sys_io_ready,0);
+ reset_io_ready(ps);
n = ps->num_waiters;
@@ -1204,9 +1206,9 @@ int erts_poll_wait(ErtsPollSet ps,
if (num >= no_fds) {
w->highwater=j+1;
erts_mtx_unlock(&w->mtx);
- /* This might mean we still have data to report, set
- back the global flag! */
- erts_atomic_set(&ps->sys_io_ready,1);
+ /* This might mean we still have data to report,
+ restore flag indicating I/O ready! */
+ restore_io_ready(ps);
HARDDEBUGF(("To many FD's to report!"));
goto done;
}
@@ -1228,7 +1230,7 @@ int erts_poll_wait(ErtsPollSet ps,
erts_mtx_unlock(&w->mtx);
}
done:
- erts_smp_atomic_set(&ps->timeout, ERTS_AINT_T_MAX);
+ erts_smp_atomic32_set(&ps->timeout, ERTS_AINT32_T_MAX);
*len = num;
ERTS_POLLSET_UNLOCK(ps);
HARDTRACEF(("Out erts_poll_wait"));
@@ -1306,15 +1308,13 @@ ErtsPollSet erts_poll_create_pollset(void)
ps->standby_wait_counter = 0;
ps->event_io_ready = CreateManualEvent(FALSE);
ps->standby_wait_event = CreateManualEvent(FALSE);
- erts_atomic_init(&ps->sys_io_ready,0);
ps->restore_events = 0;
+ erts_atomic32_init(&ps->wakeup_state, ERTS_POLL_NOT_WOKEN);
#ifdef ERTS_SMP
- erts_smp_atomic_init(&ps->woken, 0);
erts_smp_mtx_init(&ps->mtx, "pollset");
- erts_smp_atomic_init(&ps->interrupt, 0);
#endif
- erts_smp_atomic_init(&ps->timeout, ERTS_AINT_T_MAX);
+ erts_smp_atomic32_init(&ps->timeout, ERTS_AINT32_T_MAX);
HARDTRACEF(("Out erts_poll_create_pollset"));
return ps;
@@ -1366,7 +1366,7 @@ void erts_poll_init(void)
erts_mtx_init(&break_waiter_lock,"break_waiter_lock");
break_happened_event = CreateManualEvent(FALSE);
- erts_atomic_init(&break_waiter_state, 0);
+ erts_atomic32_init(&break_waiter_state, 0);
erts_thr_create(&thread, &break_waiter, NULL, NULL);
ERTS_UNSET_BREAK_REQUESTED;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-02 21:52:27 +0000