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-rw-r--r--nsprpub/pr/src/io/prmwait.c1457
1 files changed, 1457 insertions, 0 deletions
diff --git a/nsprpub/pr/src/io/prmwait.c b/nsprpub/pr/src/io/prmwait.c
new file mode 100644
index 000000000..ab32fb5d8
--- /dev/null
+++ b/nsprpub/pr/src/io/prmwait.c
@@ -0,0 +1,1457 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "primpl.h"
+#include "pprmwait.h"
+
+#define _MW_REHASH_MAX 11
+
+static PRLock *mw_lock = NULL;
+static _PRGlobalState *mw_state = NULL;
+
+static PRIntervalTime max_polling_interval;
+
+#ifdef WINNT
+
+typedef struct TimerEvent {
+ PRIntervalTime absolute;
+ void (*func)(void *);
+ void *arg;
+ LONG ref_count;
+ PRCList links;
+} TimerEvent;
+
+#define TIMER_EVENT_PTR(_qp) \
+ ((TimerEvent *) ((char *) (_qp) - offsetof(TimerEvent, links)))
+
+struct {
+ PRLock *ml;
+ PRCondVar *new_timer;
+ PRCondVar *cancel_timer;
+ PRThread *manager_thread;
+ PRCList timer_queue;
+} tm_vars;
+
+static PRStatus TimerInit(void);
+static void TimerManager(void *arg);
+static TimerEvent *CreateTimer(PRIntervalTime timeout,
+ void (*func)(void *), void *arg);
+static PRBool CancelTimer(TimerEvent *timer);
+
+static void TimerManager(void *arg)
+{
+ PRIntervalTime now;
+ PRIntervalTime timeout;
+ PRCList *head;
+ TimerEvent *timer;
+
+ PR_Lock(tm_vars.ml);
+ while (1)
+ {
+ if (PR_CLIST_IS_EMPTY(&tm_vars.timer_queue))
+ {
+ PR_WaitCondVar(tm_vars.new_timer, PR_INTERVAL_NO_TIMEOUT);
+ }
+ else
+ {
+ now = PR_IntervalNow();
+ head = PR_LIST_HEAD(&tm_vars.timer_queue);
+ timer = TIMER_EVENT_PTR(head);
+ if ((PRInt32) (now - timer->absolute) >= 0)
+ {
+ PR_REMOVE_LINK(head);
+ /*
+ * make its prev and next point to itself so that
+ * it's obvious that it's not on the timer_queue.
+ */
+ PR_INIT_CLIST(head);
+ PR_ASSERT(2 == timer->ref_count);
+ PR_Unlock(tm_vars.ml);
+ timer->func(timer->arg);
+ PR_Lock(tm_vars.ml);
+ timer->ref_count -= 1;
+ if (0 == timer->ref_count)
+ {
+ PR_NotifyAllCondVar(tm_vars.cancel_timer);
+ }
+ }
+ else
+ {
+ timeout = (PRIntervalTime)(timer->absolute - now);
+ PR_WaitCondVar(tm_vars.new_timer, timeout);
+ }
+ }
+ }
+ PR_Unlock(tm_vars.ml);
+}
+
+static TimerEvent *CreateTimer(
+ PRIntervalTime timeout,
+ void (*func)(void *),
+ void *arg)
+{
+ TimerEvent *timer;
+ PRCList *links, *tail;
+ TimerEvent *elem;
+
+ timer = PR_NEW(TimerEvent);
+ if (NULL == timer)
+ {
+ PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+ return timer;
+ }
+ timer->absolute = PR_IntervalNow() + timeout;
+ timer->func = func;
+ timer->arg = arg;
+ timer->ref_count = 2;
+ PR_Lock(tm_vars.ml);
+ tail = links = PR_LIST_TAIL(&tm_vars.timer_queue);
+ while (links->prev != tail)
+ {
+ elem = TIMER_EVENT_PTR(links);
+ if ((PRInt32)(timer->absolute - elem->absolute) >= 0)
+ {
+ break;
+ }
+ links = links->prev;
+ }
+ PR_INSERT_AFTER(&timer->links, links);
+ PR_NotifyCondVar(tm_vars.new_timer);
+ PR_Unlock(tm_vars.ml);
+ return timer;
+}
+
+static PRBool CancelTimer(TimerEvent *timer)
+{
+ PRBool canceled = PR_FALSE;
+
+ PR_Lock(tm_vars.ml);
+ timer->ref_count -= 1;
+ if (timer->links.prev == &timer->links)
+ {
+ while (timer->ref_count == 1)
+ {
+ PR_WaitCondVar(tm_vars.cancel_timer, PR_INTERVAL_NO_TIMEOUT);
+ }
+ }
+ else
+ {
+ PR_REMOVE_LINK(&timer->links);
+ canceled = PR_TRUE;
+ }
+ PR_Unlock(tm_vars.ml);
+ PR_DELETE(timer);
+ return canceled;
+}
+
+static PRStatus TimerInit(void)
+{
+ tm_vars.ml = PR_NewLock();
+ if (NULL == tm_vars.ml)
+ {
+ goto failed;
+ }
+ tm_vars.new_timer = PR_NewCondVar(tm_vars.ml);
+ if (NULL == tm_vars.new_timer)
+ {
+ goto failed;
+ }
+ tm_vars.cancel_timer = PR_NewCondVar(tm_vars.ml);
+ if (NULL == tm_vars.cancel_timer)
+ {
+ goto failed;
+ }
+ PR_INIT_CLIST(&tm_vars.timer_queue);
+ tm_vars.manager_thread = PR_CreateThread(
+ PR_SYSTEM_THREAD, TimerManager, NULL, PR_PRIORITY_NORMAL,
+ PR_LOCAL_THREAD, PR_UNJOINABLE_THREAD, 0);
+ if (NULL == tm_vars.manager_thread)
+ {
+ goto failed;
+ }
+ return PR_SUCCESS;
+
+failed:
+ if (NULL != tm_vars.cancel_timer)
+ {
+ PR_DestroyCondVar(tm_vars.cancel_timer);
+ }
+ if (NULL != tm_vars.new_timer)
+ {
+ PR_DestroyCondVar(tm_vars.new_timer);
+ }
+ if (NULL != tm_vars.ml)
+ {
+ PR_DestroyLock(tm_vars.ml);
+ }
+ return PR_FAILURE;
+}
+
+#endif /* WINNT */
+
+/******************************************************************/
+/******************************************************************/
+/************************ The private portion *********************/
+/******************************************************************/
+/******************************************************************/
+void _PR_InitMW(void)
+{
+#ifdef WINNT
+ /*
+ * We use NT 4's InterlockedCompareExchange() to operate
+ * on PRMWStatus variables.
+ */
+ PR_ASSERT(sizeof(LONG) == sizeof(PRMWStatus));
+ TimerInit();
+#endif
+ mw_lock = PR_NewLock();
+ PR_ASSERT(NULL != mw_lock);
+ mw_state = PR_NEWZAP(_PRGlobalState);
+ PR_ASSERT(NULL != mw_state);
+ PR_INIT_CLIST(&mw_state->group_list);
+ max_polling_interval = PR_MillisecondsToInterval(MAX_POLLING_INTERVAL);
+} /* _PR_InitMW */
+
+void _PR_CleanupMW(void)
+{
+ PR_DestroyLock(mw_lock);
+ mw_lock = NULL;
+ if (mw_state->group) {
+ PR_DestroyWaitGroup(mw_state->group);
+ /* mw_state->group is set to NULL as a side effect. */
+ }
+ PR_DELETE(mw_state);
+} /* _PR_CleanupMW */
+
+static PRWaitGroup *MW_Init2(void)
+{
+ PRWaitGroup *group = mw_state->group; /* it's the null group */
+ if (NULL == group) /* there is this special case */
+ {
+ group = PR_CreateWaitGroup(_PR_DEFAULT_HASH_LENGTH);
+ if (NULL == group) goto failed_alloc;
+ PR_Lock(mw_lock);
+ if (NULL == mw_state->group)
+ {
+ mw_state->group = group;
+ group = NULL;
+ }
+ PR_Unlock(mw_lock);
+ if (group != NULL) (void)PR_DestroyWaitGroup(group);
+ group = mw_state->group; /* somebody beat us to it */
+ }
+failed_alloc:
+ return group; /* whatever */
+} /* MW_Init2 */
+
+static _PR_HashStory MW_AddHashInternal(PRRecvWait *desc, _PRWaiterHash *hash)
+{
+ /*
+ ** The entries are put in the table using the fd (PRFileDesc*) of
+ ** the receive descriptor as the key. This allows us to locate
+ ** the appropriate entry aqain when the poll operation finishes.
+ **
+ ** The pointer to the file descriptor object is first divided by
+ ** the natural alignment of a pointer in the belief that object
+ ** will have at least that many zeros in the low order bits.
+ ** This may not be a good assuption.
+ **
+ ** We try to put the entry in by rehashing _MW_REHASH_MAX times. After
+ ** that we declare defeat and force the table to be reconstructed.
+ ** Since some fds might be added more than once, won't that cause
+ ** collisions even in an empty table?
+ */
+ PRIntn rehash = _MW_REHASH_MAX;
+ PRRecvWait **waiter;
+ PRUintn hidx = _MW_HASH(desc->fd, hash->length);
+ PRUintn hoffset = 0;
+
+ while (rehash-- > 0)
+ {
+ waiter = &hash->recv_wait;
+ if (NULL == waiter[hidx])
+ {
+ waiter[hidx] = desc;
+ hash->count += 1;
+#if 0
+ printf("Adding 0x%x->0x%x ", desc, desc->fd);
+ printf(
+ "table[%u:%u:*%u]: 0x%x->0x%x\n",
+ hidx, hash->count, hash->length, waiter[hidx], waiter[hidx]->fd);
+#endif
+ return _prmw_success;
+ }
+ if (desc == waiter[hidx])
+ {
+ PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0); /* desc already in table */
+ return _prmw_error;
+ }
+#if 0
+ printf("Failing 0x%x->0x%x ", desc, desc->fd);
+ printf(
+ "table[*%u:%u:%u]: 0x%x->0x%x\n",
+ hidx, hash->count, hash->length, waiter[hidx], waiter[hidx]->fd);
+#endif
+ if (0 == hoffset)
+ {
+ hoffset = _MW_HASH2(desc->fd, hash->length);
+ PR_ASSERT(0 != hoffset);
+ }
+ hidx = (hidx + hoffset) % (hash->length);
+ }
+ return _prmw_rehash;
+} /* MW_AddHashInternal */
+
+static _PR_HashStory MW_ExpandHashInternal(PRWaitGroup *group)
+{
+ PRRecvWait **desc;
+ PRUint32 pidx, length;
+ _PRWaiterHash *newHash, *oldHash = group->waiter;
+ PRBool retry;
+ _PR_HashStory hrv;
+
+ static const PRInt32 prime_number[] = {
+ _PR_DEFAULT_HASH_LENGTH, 179, 521, 907, 1427,
+ 2711, 3917, 5021, 8219, 11549, 18911, 26711, 33749, 44771};
+ PRUintn primes = (sizeof(prime_number) / sizeof(PRInt32));
+
+ /* look up the next size we'd like to use for the hash table */
+ for (pidx = 0; pidx < primes; ++pidx)
+ {
+ if (prime_number[pidx] == oldHash->length)
+ {
+ break;
+ }
+ }
+ /* table size must be one of the prime numbers */
+ PR_ASSERT(pidx < primes);
+
+ /* if pidx == primes - 1, we can't expand the table any more */
+ while (pidx < primes - 1)
+ {
+ /* next size */
+ ++pidx;
+ length = prime_number[pidx];
+
+ /* allocate the new hash table and fill it in with the old */
+ newHash = (_PRWaiterHash*)PR_CALLOC(
+ sizeof(_PRWaiterHash) + (length * sizeof(PRRecvWait*)));
+ if (NULL == newHash)
+ {
+ PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+ return _prmw_error;
+ }
+
+ newHash->length = length;
+ retry = PR_FALSE;
+ for (desc = &oldHash->recv_wait;
+ newHash->count < oldHash->count; ++desc)
+ {
+ PR_ASSERT(desc < &oldHash->recv_wait + oldHash->length);
+ if (NULL != *desc)
+ {
+ hrv = MW_AddHashInternal(*desc, newHash);
+ PR_ASSERT(_prmw_error != hrv);
+ if (_prmw_success != hrv)
+ {
+ PR_DELETE(newHash);
+ retry = PR_TRUE;
+ break;
+ }
+ }
+ }
+ if (retry) continue;
+
+ PR_DELETE(group->waiter);
+ group->waiter = newHash;
+ group->p_timestamp += 1;
+ return _prmw_success;
+ }
+
+ PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+ return _prmw_error; /* we're hosed */
+} /* MW_ExpandHashInternal */
+
+#ifndef WINNT
+static void _MW_DoneInternal(
+ PRWaitGroup *group, PRRecvWait **waiter, PRMWStatus outcome)
+{
+ /*
+ ** Add this receive wait object to the list of finished I/O
+ ** operations for this particular group. If there are other
+ ** threads waiting on the group, notify one. If not, arrange
+ ** for this thread to return.
+ */
+
+#if 0
+ printf("Removing 0x%x->0x%x\n", *waiter, (*waiter)->fd);
+#endif
+ (*waiter)->outcome = outcome;
+ PR_APPEND_LINK(&((*waiter)->internal), &group->io_ready);
+ PR_NotifyCondVar(group->io_complete);
+ PR_ASSERT(0 != group->waiter->count);
+ group->waiter->count -= 1;
+ *waiter = NULL;
+} /* _MW_DoneInternal */
+#endif /* WINNT */
+
+static PRRecvWait **_MW_LookupInternal(PRWaitGroup *group, PRFileDesc *fd)
+{
+ /*
+ ** Find the receive wait object corresponding to the file descriptor.
+ ** Only search the wait group specified.
+ */
+ PRRecvWait **desc;
+ PRIntn rehash = _MW_REHASH_MAX;
+ _PRWaiterHash *hash = group->waiter;
+ PRUintn hidx = _MW_HASH(fd, hash->length);
+ PRUintn hoffset = 0;
+
+ while (rehash-- > 0)
+ {
+ desc = (&hash->recv_wait) + hidx;
+ if ((*desc != NULL) && ((*desc)->fd == fd)) return desc;
+ if (0 == hoffset)
+ {
+ hoffset = _MW_HASH2(fd, hash->length);
+ PR_ASSERT(0 != hoffset);
+ }
+ hidx = (hidx + hoffset) % (hash->length);
+ }
+ return NULL;
+} /* _MW_LookupInternal */
+
+#ifndef WINNT
+static PRStatus _MW_PollInternal(PRWaitGroup *group)
+{
+ PRRecvWait **waiter;
+ PRStatus rv = PR_FAILURE;
+ PRInt32 count, count_ready;
+ PRIntervalTime polling_interval;
+
+ group->poller = PR_GetCurrentThread();
+
+ while (PR_TRUE)
+ {
+ PRIntervalTime now, since_last_poll;
+ PRPollDesc *poll_list;
+
+ while (0 == group->waiter->count)
+ {
+ PRStatus st;
+ st = PR_WaitCondVar(group->new_business, PR_INTERVAL_NO_TIMEOUT);
+ if (_prmw_running != group->state)
+ {
+ PR_SetError(PR_INVALID_STATE_ERROR, 0);
+ goto aborted;
+ }
+ if (_MW_ABORTED(st)) goto aborted;
+ }
+
+ /*
+ ** There's something to do. See if our existing polling list
+ ** is large enough for what we have to do?
+ */
+
+ while (group->polling_count < group->waiter->count)
+ {
+ PRUint32 old_count = group->waiter->count;
+ PRUint32 new_count = PR_ROUNDUP(old_count, _PR_POLL_COUNT_FUDGE);
+ PRSize new_size = sizeof(PRPollDesc) * new_count;
+ PRPollDesc *old_polling_list = group->polling_list;
+
+ PR_Unlock(group->ml);
+ poll_list = (PRPollDesc*)PR_CALLOC(new_size);
+ if (NULL == poll_list)
+ {
+ PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+ PR_Lock(group->ml);
+ goto failed_alloc;
+ }
+ if (NULL != old_polling_list)
+ PR_DELETE(old_polling_list);
+ PR_Lock(group->ml);
+ if (_prmw_running != group->state)
+ {
+ PR_DELETE(poll_list);
+ PR_SetError(PR_INVALID_STATE_ERROR, 0);
+ goto aborted;
+ }
+ group->polling_list = poll_list;
+ group->polling_count = new_count;
+ }
+
+ now = PR_IntervalNow();
+ polling_interval = max_polling_interval;
+ since_last_poll = now - group->last_poll;
+
+ waiter = &group->waiter->recv_wait;
+ poll_list = group->polling_list;
+ for (count = 0; count < group->waiter->count; ++waiter)
+ {
+ PR_ASSERT(waiter < &group->waiter->recv_wait
+ + group->waiter->length);
+ if (NULL != *waiter) /* a live one! */
+ {
+ if ((PR_INTERVAL_NO_TIMEOUT != (*waiter)->timeout)
+ && (since_last_poll >= (*waiter)->timeout))
+ _MW_DoneInternal(group, waiter, PR_MW_TIMEOUT);
+ else
+ {
+ if (PR_INTERVAL_NO_TIMEOUT != (*waiter)->timeout)
+ {
+ (*waiter)->timeout -= since_last_poll;
+ if ((*waiter)->timeout < polling_interval)
+ polling_interval = (*waiter)->timeout;
+ }
+ PR_ASSERT(poll_list < group->polling_list
+ + group->polling_count);
+ poll_list->fd = (*waiter)->fd;
+ poll_list->in_flags = PR_POLL_READ;
+ poll_list->out_flags = 0;
+#if 0
+ printf(
+ "Polling 0x%x[%d]: [fd: 0x%x, tmo: %u]\n",
+ poll_list, count, poll_list->fd, (*waiter)->timeout);
+#endif
+ poll_list += 1;
+ count += 1;
+ }
+ }
+ }
+
+ PR_ASSERT(count == group->waiter->count);
+
+ /*
+ ** If there are no more threads waiting for completion,
+ ** we need to return.
+ */
+ if ((!PR_CLIST_IS_EMPTY(&group->io_ready))
+ && (1 == group->waiting_threads)) break;
+
+ if (0 == count) continue; /* wait for new business */
+
+ group->last_poll = now;
+
+ PR_Unlock(group->ml);
+
+ count_ready = PR_Poll(group->polling_list, count, polling_interval);
+
+ PR_Lock(group->ml);
+
+ if (_prmw_running != group->state)
+ {
+ PR_SetError(PR_INVALID_STATE_ERROR, 0);
+ goto aborted;
+ }
+ if (-1 == count_ready)
+ {
+ goto failed_poll; /* that's a shame */
+ }
+ else if (0 < count_ready)
+ {
+ for (poll_list = group->polling_list; count > 0;
+ poll_list++, count--)
+ {
+ PR_ASSERT(
+ poll_list < group->polling_list + group->polling_count);
+ if (poll_list->out_flags != 0)
+ {
+ waiter = _MW_LookupInternal(group, poll_list->fd);
+ /*
+ ** If 'waiter' is NULL, that means the wait receive
+ ** descriptor has been canceled.
+ */
+ if (NULL != waiter)
+ _MW_DoneInternal(group, waiter, PR_MW_SUCCESS);
+ }
+ }
+ }
+ /*
+ ** If there are no more threads waiting for completion,
+ ** we need to return.
+ ** This thread was "borrowed" to do the polling, but it really
+ ** belongs to the client.
+ */
+ if ((!PR_CLIST_IS_EMPTY(&group->io_ready))
+ && (1 == group->waiting_threads)) break;
+ }
+
+ rv = PR_SUCCESS;
+
+aborted:
+failed_poll:
+failed_alloc:
+ group->poller = NULL; /* we were that, not we ain't */
+ if ((_prmw_running == group->state) && (group->waiting_threads > 1))
+ {
+ /* Wake up one thread to become the new poller. */
+ PR_NotifyCondVar(group->io_complete);
+ }
+ return rv; /* we return with the lock held */
+} /* _MW_PollInternal */
+#endif /* !WINNT */
+
+static PRMWGroupState MW_TestForShutdownInternal(PRWaitGroup *group)
+{
+ PRMWGroupState rv = group->state;
+ /*
+ ** Looking at the group's fields is safe because
+ ** once the group's state is no longer running, it
+ ** cannot revert and there is a safe check on entry
+ ** to make sure no more threads are made to wait.
+ */
+ if ((_prmw_stopping == rv)
+ && (0 == group->waiting_threads))
+ {
+ rv = group->state = _prmw_stopped;
+ PR_NotifyCondVar(group->mw_manage);
+ }
+ return rv;
+} /* MW_TestForShutdownInternal */
+
+#ifndef WINNT
+static void _MW_InitialRecv(PRCList *io_ready)
+{
+ PRRecvWait *desc = (PRRecvWait*)io_ready;
+ if ((NULL == desc->buffer.start)
+ || (0 == desc->buffer.length))
+ desc->bytesRecv = 0;
+ else
+ {
+ desc->bytesRecv = (desc->fd->methods->recv)(
+ desc->fd, desc->buffer.start,
+ desc->buffer.length, 0, desc->timeout);
+ if (desc->bytesRecv < 0) /* SetError should already be there */
+ desc->outcome = PR_MW_FAILURE;
+ }
+} /* _MW_InitialRecv */
+#endif
+
+#ifdef WINNT
+static void NT_TimeProc(void *arg)
+{
+ _MDOverlapped *overlapped = (_MDOverlapped *)arg;
+ PRRecvWait *desc = overlapped->data.mw.desc;
+ PRFileDesc *bottom;
+
+ if (InterlockedCompareExchange((LONG *)&desc->outcome,
+ (LONG)PR_MW_TIMEOUT, (LONG)PR_MW_PENDING) != (LONG)PR_MW_PENDING)
+ {
+ /* This wait recv descriptor has already completed. */
+ return;
+ }
+
+ /* close the osfd to abort the outstanding async io request */
+ /* $$$$
+ ** Little late to be checking if NSPR's on the bottom of stack,
+ ** but if we don't check, we can't assert that the private data
+ ** is what we think it is.
+ ** $$$$
+ */
+ bottom = PR_GetIdentitiesLayer(desc->fd, PR_NSPR_IO_LAYER);
+ PR_ASSERT(NULL != bottom);
+ if (NULL != bottom) /* now what!?!?! */
+ {
+ bottom->secret->state = _PR_FILEDESC_CLOSED;
+ if (closesocket(bottom->secret->md.osfd) == SOCKET_ERROR)
+ {
+ fprintf(stderr, "closesocket failed: %d\n", WSAGetLastError());
+ PR_NOT_REACHED("What shall I do?");
+ }
+ }
+ return;
+} /* NT_TimeProc */
+
+static PRStatus NT_HashRemove(PRWaitGroup *group, PRFileDesc *fd)
+{
+ PRRecvWait **waiter;
+
+ _PR_MD_LOCK(&group->mdlock);
+ waiter = _MW_LookupInternal(group, fd);
+ if (NULL != waiter)
+ {
+ group->waiter->count -= 1;
+ *waiter = NULL;
+ }
+ _PR_MD_UNLOCK(&group->mdlock);
+ return (NULL != waiter) ? PR_SUCCESS : PR_FAILURE;
+}
+
+PRStatus NT_HashRemoveInternal(PRWaitGroup *group, PRFileDesc *fd)
+{
+ PRRecvWait **waiter;
+
+ waiter = _MW_LookupInternal(group, fd);
+ if (NULL != waiter)
+ {
+ group->waiter->count -= 1;
+ *waiter = NULL;
+ }
+ return (NULL != waiter) ? PR_SUCCESS : PR_FAILURE;
+}
+#endif /* WINNT */
+
+/******************************************************************/
+/******************************************************************/
+/********************** The public API portion ********************/
+/******************************************************************/
+/******************************************************************/
+PR_IMPLEMENT(PRStatus) PR_AddWaitFileDesc(
+ PRWaitGroup *group, PRRecvWait *desc)
+{
+ _PR_HashStory hrv;
+ PRStatus rv = PR_FAILURE;
+#ifdef WINNT
+ _MDOverlapped *overlapped;
+ HANDLE hFile;
+ BOOL bResult;
+ DWORD dwError;
+ PRFileDesc *bottom;
+#endif
+
+ if (!_pr_initialized) _PR_ImplicitInitialization();
+ if ((NULL == group) && (NULL == (group = MW_Init2())))
+ {
+ return rv;
+ }
+
+ PR_ASSERT(NULL != desc->fd);
+
+ desc->outcome = PR_MW_PENDING; /* nice, well known value */
+ desc->bytesRecv = 0; /* likewise, though this value is ambiguious */
+
+ PR_Lock(group->ml);
+
+ if (_prmw_running != group->state)
+ {
+ /* Not allowed to add after cancelling the group */
+ desc->outcome = PR_MW_INTERRUPT;
+ PR_SetError(PR_INVALID_STATE_ERROR, 0);
+ PR_Unlock(group->ml);
+ return rv;
+ }
+
+#ifdef WINNT
+ _PR_MD_LOCK(&group->mdlock);
+#endif
+
+ /*
+ ** If the waiter count is zero at this point, there's no telling
+ ** how long we've been idle. Therefore, initialize the beginning
+ ** of the timing interval. As long as the list doesn't go empty,
+ ** it will maintain itself.
+ */
+ if (0 == group->waiter->count)
+ group->last_poll = PR_IntervalNow();
+
+ do
+ {
+ hrv = MW_AddHashInternal(desc, group->waiter);
+ if (_prmw_rehash != hrv) break;
+ hrv = MW_ExpandHashInternal(group); /* gruesome */
+ if (_prmw_success != hrv) break;
+ } while (PR_TRUE);
+
+#ifdef WINNT
+ _PR_MD_UNLOCK(&group->mdlock);
+#endif
+
+ PR_NotifyCondVar(group->new_business); /* tell the world */
+ rv = (_prmw_success == hrv) ? PR_SUCCESS : PR_FAILURE;
+ PR_Unlock(group->ml);
+
+#ifdef WINNT
+ overlapped = PR_NEWZAP(_MDOverlapped);
+ if (NULL == overlapped)
+ {
+ PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+ NT_HashRemove(group, desc->fd);
+ return rv;
+ }
+ overlapped->ioModel = _MD_MultiWaitIO;
+ overlapped->data.mw.desc = desc;
+ overlapped->data.mw.group = group;
+ if (desc->timeout != PR_INTERVAL_NO_TIMEOUT)
+ {
+ overlapped->data.mw.timer = CreateTimer(
+ desc->timeout,
+ NT_TimeProc,
+ overlapped);
+ if (0 == overlapped->data.mw.timer)
+ {
+ NT_HashRemove(group, desc->fd);
+ PR_DELETE(overlapped);
+ /*
+ * XXX It appears that a maximum of 16 timer events can
+ * be outstanding. GetLastError() returns 0 when I try it.
+ */
+ PR_SetError(PR_INSUFFICIENT_RESOURCES_ERROR, GetLastError());
+ return PR_FAILURE;
+ }
+ }
+
+ /* Reach to the bottom layer to get the OS fd */
+ bottom = PR_GetIdentitiesLayer(desc->fd, PR_NSPR_IO_LAYER);
+ PR_ASSERT(NULL != bottom);
+ if (NULL == bottom)
+ {
+ PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
+ return PR_FAILURE;
+ }
+ hFile = (HANDLE)bottom->secret->md.osfd;
+ if (!bottom->secret->md.io_model_committed)
+ {
+ PRInt32 st;
+ st = _md_Associate(hFile);
+ PR_ASSERT(0 != st);
+ bottom->secret->md.io_model_committed = PR_TRUE;
+ }
+ bResult = ReadFile(hFile,
+ desc->buffer.start,
+ (DWORD)desc->buffer.length,
+ NULL,
+ &overlapped->overlapped);
+ if (FALSE == bResult && (dwError = GetLastError()) != ERROR_IO_PENDING)
+ {
+ if (desc->timeout != PR_INTERVAL_NO_TIMEOUT)
+ {
+ if (InterlockedCompareExchange((LONG *)&desc->outcome,
+ (LONG)PR_MW_FAILURE, (LONG)PR_MW_PENDING)
+ == (LONG)PR_MW_PENDING)
+ {
+ CancelTimer(overlapped->data.mw.timer);
+ }
+ NT_HashRemove(group, desc->fd);
+ PR_DELETE(overlapped);
+ }
+ _PR_MD_MAP_READ_ERROR(dwError);
+ rv = PR_FAILURE;
+ }
+#endif
+
+ return rv;
+} /* PR_AddWaitFileDesc */
+
+PR_IMPLEMENT(PRRecvWait*) PR_WaitRecvReady(PRWaitGroup *group)
+{
+ PRCList *io_ready = NULL;
+#ifdef WINNT
+ PRThread *me = _PR_MD_CURRENT_THREAD();
+ _MDOverlapped *overlapped;
+#endif
+
+ if (!_pr_initialized) _PR_ImplicitInitialization();
+ if ((NULL == group) && (NULL == (group = MW_Init2()))) goto failed_init;
+
+ PR_Lock(group->ml);
+
+ if (_prmw_running != group->state)
+ {
+ PR_SetError(PR_INVALID_STATE_ERROR, 0);
+ goto invalid_state;
+ }
+
+ group->waiting_threads += 1; /* the polling thread is counted */
+
+#ifdef WINNT
+ _PR_MD_LOCK(&group->mdlock);
+ while (PR_CLIST_IS_EMPTY(&group->io_ready))
+ {
+ _PR_THREAD_LOCK(me);
+ me->state = _PR_IO_WAIT;
+ PR_APPEND_LINK(&me->waitQLinks, &group->wait_list);
+ if (!_PR_IS_NATIVE_THREAD(me))
+ {
+ _PR_SLEEPQ_LOCK(me->cpu);
+ _PR_ADD_SLEEPQ(me, PR_INTERVAL_NO_TIMEOUT);
+ _PR_SLEEPQ_UNLOCK(me->cpu);
+ }
+ _PR_THREAD_UNLOCK(me);
+ _PR_MD_UNLOCK(&group->mdlock);
+ PR_Unlock(group->ml);
+ _PR_MD_WAIT(me, PR_INTERVAL_NO_TIMEOUT);
+ me->state = _PR_RUNNING;
+ PR_Lock(group->ml);
+ _PR_MD_LOCK(&group->mdlock);
+ if (_PR_PENDING_INTERRUPT(me)) {
+ PR_REMOVE_LINK(&me->waitQLinks);
+ _PR_MD_UNLOCK(&group->mdlock);
+ me->flags &= ~_PR_INTERRUPT;
+ me->io_suspended = PR_FALSE;
+ PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0);
+ goto aborted;
+ }
+ }
+ io_ready = PR_LIST_HEAD(&group->io_ready);
+ PR_ASSERT(io_ready != NULL);
+ PR_REMOVE_LINK(io_ready);
+ _PR_MD_UNLOCK(&group->mdlock);
+ overlapped = (_MDOverlapped *)
+ ((char *)io_ready - offsetof(_MDOverlapped, data));
+ io_ready = &overlapped->data.mw.desc->internal;
+#else
+ do
+ {
+ /*
+ ** If the I/O ready list isn't empty, have this thread
+ ** return with the first receive wait object that's available.
+ */
+ if (PR_CLIST_IS_EMPTY(&group->io_ready))
+ {
+ /*
+ ** Is there a polling thread yet? If not, grab this thread
+ ** and use it.
+ */
+ if (NULL == group->poller)
+ {
+ /*
+ ** This thread will stay do polling until it becomes the only one
+ ** left to service a completion. Then it will return and there will
+ ** be none left to actually poll or to run completions.
+ **
+ ** The polling function should only return w/ failure or
+ ** with some I/O ready.
+ */
+ if (PR_FAILURE == _MW_PollInternal(group)) goto failed_poll;
+ }
+ else
+ {
+ /*
+ ** There are four reasons a thread can be awakened from
+ ** a wait on the io_complete condition variable.
+ ** 1. Some I/O has completed, i.e., the io_ready list
+ ** is nonempty.
+ ** 2. The wait group is canceled.
+ ** 3. The thread is interrupted.
+ ** 4. The current polling thread has to leave and needs
+ ** a replacement.
+ ** The logic to find a new polling thread is made more
+ ** complicated by all the other possible events.
+ ** I tried my best to write the logic clearly, but
+ ** it is still full of if's with continue and goto.
+ */
+ PRStatus st;
+ do
+ {
+ st = PR_WaitCondVar(group->io_complete, PR_INTERVAL_NO_TIMEOUT);
+ if (_prmw_running != group->state)
+ {
+ PR_SetError(PR_INVALID_STATE_ERROR, 0);
+ goto aborted;
+ }
+ if (_MW_ABORTED(st) || (NULL == group->poller)) break;
+ } while (PR_CLIST_IS_EMPTY(&group->io_ready));
+
+ /*
+ ** The thread is interrupted and has to leave. It might
+ ** have also been awakened to process ready i/o or be the
+ ** new poller. To be safe, if either condition is true,
+ ** we awaken another thread to take its place.
+ */
+ if (_MW_ABORTED(st))
+ {
+ if ((NULL == group->poller
+ || !PR_CLIST_IS_EMPTY(&group->io_ready))
+ && group->waiting_threads > 1)
+ PR_NotifyCondVar(group->io_complete);
+ goto aborted;
+ }
+
+ /*
+ ** A new poller is needed, but can I be the new poller?
+ ** If there is no i/o ready, sure. But if there is any
+ ** i/o ready, it has a higher priority. I want to
+ ** process the ready i/o first and wake up another
+ ** thread to be the new poller.
+ */
+ if (NULL == group->poller)
+ {
+ if (PR_CLIST_IS_EMPTY(&group->io_ready))
+ continue;
+ if (group->waiting_threads > 1)
+ PR_NotifyCondVar(group->io_complete);
+ }
+ }
+ PR_ASSERT(!PR_CLIST_IS_EMPTY(&group->io_ready));
+ }
+ io_ready = PR_LIST_HEAD(&group->io_ready);
+ PR_NotifyCondVar(group->io_taken);
+ PR_ASSERT(io_ready != NULL);
+ PR_REMOVE_LINK(io_ready);
+ } while (NULL == io_ready);
+
+failed_poll:
+
+#endif
+
+aborted:
+
+ group->waiting_threads -= 1;
+invalid_state:
+ (void)MW_TestForShutdownInternal(group);
+ PR_Unlock(group->ml);
+
+failed_init:
+ if (NULL != io_ready)
+ {
+ /* If the operation failed, record the reason why */
+ switch (((PRRecvWait*)io_ready)->outcome)
+ {
+ case PR_MW_PENDING:
+ PR_ASSERT(0);
+ break;
+ case PR_MW_SUCCESS:
+#ifndef WINNT
+ _MW_InitialRecv(io_ready);
+#endif
+ break;
+#ifdef WINNT
+ case PR_MW_FAILURE:
+ _PR_MD_MAP_READ_ERROR(overlapped->data.mw.error);
+ break;
+#endif
+ case PR_MW_TIMEOUT:
+ PR_SetError(PR_IO_TIMEOUT_ERROR, 0);
+ break;
+ case PR_MW_INTERRUPT:
+ PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0);
+ break;
+ default: break;
+ }
+#ifdef WINNT
+ if (NULL != overlapped->data.mw.timer)
+ {
+ PR_ASSERT(PR_INTERVAL_NO_TIMEOUT
+ != overlapped->data.mw.desc->timeout);
+ CancelTimer(overlapped->data.mw.timer);
+ }
+ else
+ {
+ PR_ASSERT(PR_INTERVAL_NO_TIMEOUT
+ == overlapped->data.mw.desc->timeout);
+ }
+ PR_DELETE(overlapped);
+#endif
+ }
+ return (PRRecvWait*)io_ready;
+} /* PR_WaitRecvReady */
+
+PR_IMPLEMENT(PRStatus) PR_CancelWaitFileDesc(PRWaitGroup *group, PRRecvWait *desc)
+{
+#if !defined(WINNT)
+ PRRecvWait **recv_wait;
+#endif
+ PRStatus rv = PR_SUCCESS;
+ if (NULL == group) group = mw_state->group;
+ PR_ASSERT(NULL != group);
+ if (NULL == group)
+ {
+ PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
+ return PR_FAILURE;
+ }
+
+ PR_Lock(group->ml);
+
+ if (_prmw_running != group->state)
+ {
+ PR_SetError(PR_INVALID_STATE_ERROR, 0);
+ rv = PR_FAILURE;
+ goto unlock;
+ }
+
+#ifdef WINNT
+ if (InterlockedCompareExchange((LONG *)&desc->outcome,
+ (LONG)PR_MW_INTERRUPT, (LONG)PR_MW_PENDING) == (LONG)PR_MW_PENDING)
+ {
+ PRFileDesc *bottom = PR_GetIdentitiesLayer(desc->fd, PR_NSPR_IO_LAYER);
+ PR_ASSERT(NULL != bottom);
+ if (NULL == bottom)
+ {
+ PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
+ goto unlock;
+ }
+ bottom->secret->state = _PR_FILEDESC_CLOSED;
+#if 0
+ fprintf(stderr, "cancel wait recv: closing socket\n");
+#endif
+ if (closesocket(bottom->secret->md.osfd) == SOCKET_ERROR)
+ {
+ fprintf(stderr, "closesocket failed: %d\n", WSAGetLastError());
+ exit(1);
+ }
+ }
+#else
+ if (NULL != (recv_wait = _MW_LookupInternal(group, desc->fd)))
+ {
+ /* it was in the wait table */
+ _MW_DoneInternal(group, recv_wait, PR_MW_INTERRUPT);
+ goto unlock;
+ }
+ if (!PR_CLIST_IS_EMPTY(&group->io_ready))
+ {
+ /* is it already complete? */
+ PRCList *head = PR_LIST_HEAD(&group->io_ready);
+ do
+ {
+ PRRecvWait *done = (PRRecvWait*)head;
+ if (done == desc) goto unlock;
+ head = PR_NEXT_LINK(head);
+ } while (head != &group->io_ready);
+ }
+ PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
+ rv = PR_FAILURE;
+
+#endif
+unlock:
+ PR_Unlock(group->ml);
+ return rv;
+} /* PR_CancelWaitFileDesc */
+
+PR_IMPLEMENT(PRRecvWait*) PR_CancelWaitGroup(PRWaitGroup *group)
+{
+ PRRecvWait **desc;
+ PRRecvWait *recv_wait = NULL;
+#ifdef WINNT
+ _MDOverlapped *overlapped;
+ PRRecvWait **end;
+ PRThread *me = _PR_MD_CURRENT_THREAD();
+#endif
+
+ if (NULL == group) group = mw_state->group;
+ PR_ASSERT(NULL != group);
+ if (NULL == group)
+ {
+ PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
+ return NULL;
+ }
+
+ PR_Lock(group->ml);
+ if (_prmw_stopped != group->state)
+ {
+ if (_prmw_running == group->state)
+ group->state = _prmw_stopping; /* so nothing new comes in */
+ if (0 == group->waiting_threads) /* is there anybody else? */
+ group->state = _prmw_stopped; /* we can stop right now */
+ else
+ {
+ PR_NotifyAllCondVar(group->new_business);
+ PR_NotifyAllCondVar(group->io_complete);
+ }
+ while (_prmw_stopped != group->state)
+ (void)PR_WaitCondVar(group->mw_manage, PR_INTERVAL_NO_TIMEOUT);
+ }
+
+#ifdef WINNT
+ _PR_MD_LOCK(&group->mdlock);
+#endif
+ /* make all the existing descriptors look done/interrupted */
+#ifdef WINNT
+ end = &group->waiter->recv_wait + group->waiter->length;
+ for (desc = &group->waiter->recv_wait; desc < end; ++desc)
+ {
+ if (NULL != *desc)
+ {
+ if (InterlockedCompareExchange((LONG *)&(*desc)->outcome,
+ (LONG)PR_MW_INTERRUPT, (LONG)PR_MW_PENDING)
+ == (LONG)PR_MW_PENDING)
+ {
+ PRFileDesc *bottom = PR_GetIdentitiesLayer(
+ (*desc)->fd, PR_NSPR_IO_LAYER);
+ PR_ASSERT(NULL != bottom);
+ if (NULL == bottom)
+ {
+ PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
+ goto invalid_arg;
+ }
+ bottom->secret->state = _PR_FILEDESC_CLOSED;
+#if 0
+ fprintf(stderr, "cancel wait group: closing socket\n");
+#endif
+ if (closesocket(bottom->secret->md.osfd) == SOCKET_ERROR)
+ {
+ fprintf(stderr, "closesocket failed: %d\n",
+ WSAGetLastError());
+ exit(1);
+ }
+ }
+ }
+ }
+ while (group->waiter->count > 0)
+ {
+ _PR_THREAD_LOCK(me);
+ me->state = _PR_IO_WAIT;
+ PR_APPEND_LINK(&me->waitQLinks, &group->wait_list);
+ if (!_PR_IS_NATIVE_THREAD(me))
+ {
+ _PR_SLEEPQ_LOCK(me->cpu);
+ _PR_ADD_SLEEPQ(me, PR_INTERVAL_NO_TIMEOUT);
+ _PR_SLEEPQ_UNLOCK(me->cpu);
+ }
+ _PR_THREAD_UNLOCK(me);
+ _PR_MD_UNLOCK(&group->mdlock);
+ PR_Unlock(group->ml);
+ _PR_MD_WAIT(me, PR_INTERVAL_NO_TIMEOUT);
+ me->state = _PR_RUNNING;
+ PR_Lock(group->ml);
+ _PR_MD_LOCK(&group->mdlock);
+ }
+#else
+ for (desc = &group->waiter->recv_wait; group->waiter->count > 0; ++desc)
+ {
+ PR_ASSERT(desc < &group->waiter->recv_wait + group->waiter->length);
+ if (NULL != *desc)
+ _MW_DoneInternal(group, desc, PR_MW_INTERRUPT);
+ }
+#endif
+
+ /* take first element of finished list and return it or NULL */
+ if (PR_CLIST_IS_EMPTY(&group->io_ready))
+ PR_SetError(PR_GROUP_EMPTY_ERROR, 0);
+ else
+ {
+ PRCList *head = PR_LIST_HEAD(&group->io_ready);
+ PR_REMOVE_AND_INIT_LINK(head);
+#ifdef WINNT
+ overlapped = (_MDOverlapped *)
+ ((char *)head - offsetof(_MDOverlapped, data));
+ head = &overlapped->data.mw.desc->internal;
+ if (NULL != overlapped->data.mw.timer)
+ {
+ PR_ASSERT(PR_INTERVAL_NO_TIMEOUT
+ != overlapped->data.mw.desc->timeout);
+ CancelTimer(overlapped->data.mw.timer);
+ }
+ else
+ {
+ PR_ASSERT(PR_INTERVAL_NO_TIMEOUT
+ == overlapped->data.mw.desc->timeout);
+ }
+ PR_DELETE(overlapped);
+#endif
+ recv_wait = (PRRecvWait*)head;
+ }
+#ifdef WINNT
+invalid_arg:
+ _PR_MD_UNLOCK(&group->mdlock);
+#endif
+ PR_Unlock(group->ml);
+
+ return recv_wait;
+} /* PR_CancelWaitGroup */
+
+PR_IMPLEMENT(PRWaitGroup*) PR_CreateWaitGroup(PRInt32 size /* ignored */)
+{
+ PRWaitGroup *wg;
+
+ if (NULL == (wg = PR_NEWZAP(PRWaitGroup)))
+ {
+ PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+ goto failed;
+ }
+ /* the wait group itself */
+ wg->ml = PR_NewLock();
+ if (NULL == wg->ml) goto failed_lock;
+ wg->io_taken = PR_NewCondVar(wg->ml);
+ if (NULL == wg->io_taken) goto failed_cvar0;
+ wg->io_complete = PR_NewCondVar(wg->ml);
+ if (NULL == wg->io_complete) goto failed_cvar1;
+ wg->new_business = PR_NewCondVar(wg->ml);
+ if (NULL == wg->new_business) goto failed_cvar2;
+ wg->mw_manage = PR_NewCondVar(wg->ml);
+ if (NULL == wg->mw_manage) goto failed_cvar3;
+
+ PR_INIT_CLIST(&wg->group_link);
+ PR_INIT_CLIST(&wg->io_ready);
+
+ /* the waiters sequence */
+ wg->waiter = (_PRWaiterHash*)PR_CALLOC(
+ sizeof(_PRWaiterHash) +
+ (_PR_DEFAULT_HASH_LENGTH * sizeof(PRRecvWait*)));
+ if (NULL == wg->waiter)
+ {
+ PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+ goto failed_waiter;
+ }
+ wg->waiter->count = 0;
+ wg->waiter->length = _PR_DEFAULT_HASH_LENGTH;
+
+#ifdef WINNT
+ _PR_MD_NEW_LOCK(&wg->mdlock);
+ PR_INIT_CLIST(&wg->wait_list);
+#endif /* WINNT */
+
+ PR_Lock(mw_lock);
+ PR_APPEND_LINK(&wg->group_link, &mw_state->group_list);
+ PR_Unlock(mw_lock);
+ return wg;
+
+failed_waiter:
+ PR_DestroyCondVar(wg->mw_manage);
+failed_cvar3:
+ PR_DestroyCondVar(wg->new_business);
+failed_cvar2:
+ PR_DestroyCondVar(wg->io_complete);
+failed_cvar1:
+ PR_DestroyCondVar(wg->io_taken);
+failed_cvar0:
+ PR_DestroyLock(wg->ml);
+failed_lock:
+ PR_DELETE(wg);
+ wg = NULL;
+
+failed:
+ return wg;
+} /* MW_CreateWaitGroup */
+
+PR_IMPLEMENT(PRStatus) PR_DestroyWaitGroup(PRWaitGroup *group)
+{
+ PRStatus rv = PR_SUCCESS;
+ if (NULL == group) group = mw_state->group;
+ PR_ASSERT(NULL != group);
+ if (NULL != group)
+ {
+ PR_Lock(group->ml);
+ if ((group->waiting_threads == 0)
+ && (group->waiter->count == 0)
+ && PR_CLIST_IS_EMPTY(&group->io_ready))
+ {
+ group->state = _prmw_stopped;
+ }
+ else
+ {
+ PR_SetError(PR_INVALID_STATE_ERROR, 0);
+ rv = PR_FAILURE;
+ }
+ PR_Unlock(group->ml);
+ if (PR_FAILURE == rv) return rv;
+
+ PR_Lock(mw_lock);
+ PR_REMOVE_LINK(&group->group_link);
+ PR_Unlock(mw_lock);
+
+#ifdef WINNT
+ /*
+ * XXX make sure wait_list is empty and waiter is empty.
+ * These must be checked while holding mdlock.
+ */
+ _PR_MD_FREE_LOCK(&group->mdlock);
+#endif
+
+ PR_DELETE(group->waiter);
+ PR_DELETE(group->polling_list);
+ PR_DestroyCondVar(group->mw_manage);
+ PR_DestroyCondVar(group->new_business);
+ PR_DestroyCondVar(group->io_complete);
+ PR_DestroyCondVar(group->io_taken);
+ PR_DestroyLock(group->ml);
+ if (group == mw_state->group) mw_state->group = NULL;
+ PR_DELETE(group);
+ }
+ else
+ {
+ /* The default wait group is not created yet. */
+ PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
+ rv = PR_FAILURE;
+ }
+ return rv;
+} /* PR_DestroyWaitGroup */
+
+/**********************************************************************
+***********************************************************************
+******************** Wait group enumerations **************************
+***********************************************************************
+**********************************************************************/
+
+PR_IMPLEMENT(PRMWaitEnumerator*) PR_CreateMWaitEnumerator(PRWaitGroup *group)
+{
+ PRMWaitEnumerator *enumerator = PR_NEWZAP(PRMWaitEnumerator);
+ if (NULL == enumerator) PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+ else
+ {
+ enumerator->group = group;
+ enumerator->seal = _PR_ENUM_SEALED;
+ }
+ return enumerator;
+} /* PR_CreateMWaitEnumerator */
+
+PR_IMPLEMENT(PRStatus) PR_DestroyMWaitEnumerator(PRMWaitEnumerator* enumerator)
+{
+ PR_ASSERT(NULL != enumerator);
+ PR_ASSERT(_PR_ENUM_SEALED == enumerator->seal);
+ if ((NULL == enumerator) || (_PR_ENUM_SEALED != enumerator->seal))
+ {
+ PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
+ return PR_FAILURE;
+ }
+ enumerator->seal = _PR_ENUM_UNSEALED;
+ PR_Free(enumerator);
+ return PR_SUCCESS;
+} /* PR_DestroyMWaitEnumerator */
+
+PR_IMPLEMENT(PRRecvWait*) PR_EnumerateWaitGroup(
+ PRMWaitEnumerator *enumerator, const PRRecvWait *previous)
+{
+ PRRecvWait *result = NULL;
+
+ /* entry point sanity checking */
+ PR_ASSERT(NULL != enumerator);
+ PR_ASSERT(_PR_ENUM_SEALED == enumerator->seal);
+ if ((NULL == enumerator)
+ || (_PR_ENUM_SEALED != enumerator->seal)) goto bad_argument;
+
+ /* beginning of enumeration */
+ if (NULL == previous)
+ {
+ if (NULL == enumerator->group)
+ {
+ enumerator->group = mw_state->group;
+ if (NULL == enumerator->group)
+ {
+ PR_SetError(PR_GROUP_EMPTY_ERROR, 0);
+ return NULL;
+ }
+ }
+ enumerator->waiter = &enumerator->group->waiter->recv_wait;
+ enumerator->p_timestamp = enumerator->group->p_timestamp;
+ enumerator->thread = PR_GetCurrentThread();
+ enumerator->index = 0;
+ }
+ /* continuing an enumeration */
+ else
+ {
+ PRThread *me = PR_GetCurrentThread();
+ PR_ASSERT(me == enumerator->thread);
+ if (me != enumerator->thread) goto bad_argument;
+
+ /* need to restart the enumeration */
+ if (enumerator->p_timestamp != enumerator->group->p_timestamp)
+ return PR_EnumerateWaitGroup(enumerator, NULL);
+ }
+
+ /* actually progress the enumeration */
+#if defined(WINNT)
+ _PR_MD_LOCK(&enumerator->group->mdlock);
+#else
+ PR_Lock(enumerator->group->ml);
+#endif
+ while (enumerator->index++ < enumerator->group->waiter->length)
+ {
+ if (NULL != (result = *(enumerator->waiter)++)) break;
+ }
+#if defined(WINNT)
+ _PR_MD_UNLOCK(&enumerator->group->mdlock);
+#else
+ PR_Unlock(enumerator->group->ml);
+#endif
+
+ return result; /* what we live for */
+
+bad_argument:
+ PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
+ return NULL; /* probably ambiguous */
+} /* PR_EnumerateWaitGroup */
+
+/* prmwait.c */