PR_IMPLEMENT(PRStatus) PR_AddWaitFileDesc(
PRWaitGroup *group, PRRecvWait *desc)
{
_PR_HashStory hrv;
PRStatus rv = PR_FAILURE;
if (PR_FAILURE == MW_Init()) goto failed_init;
if ((NULL == group) && (NULL == (group = MW_Init2()))) goto failed_init;
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);
goto invalid_state;
}
/*
** 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);
PR_NotifyCondVar(group->new_business); /* tell the world */
rv = (_prmw_success == hrv) ? PR_SUCCESS : PR_FAILURE;
failed_init:
invalid_state:
PR_Unlock(group->ml);
return rv;
} /* PR_AddWaitFileDesc */
PR_IMPLEMENT(PRRecvWait*) PR_WaitRecvReady(PRWaitGroup *group)
{
PRStatus rv = PR_SUCCESS;
PRCList *io_ready = NULL;
if (PR_FAILURE == MW_Init()) goto failed_init;
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 */
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))
{
while ((NULL == group->waiter) || (0 == group->waiter->count))
{
if (_prmw_running != group->state) goto aborted;
rv = PR_WaitCondVar(group->new_business, PR_INTERVAL_NO_TIMEOUT);
if (_MW_ABORTED(rv)) goto aborted;
}
/*
** 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;
if (PR_CLIST_IS_EMPTY(&group->io_ready)) continue; /* timeout */
}
else
{
while (PR_CLIST_IS_EMPTY(&group->io_ready))
{
rv = PR_WaitCondVar(group->io_complete, PR_INTERVAL_NO_TIMEOUT);
if (_MW_ABORTED(rv)) goto aborted;
}
}
}
io_ready = PR_LIST_HEAD(&group->io_ready);
PR_NotifyCondVar(group->io_taken);
PR_ASSERT(io_ready != NULL);
PR_REMOVE_LINK(io_ready);
/* If the operation failed, record the reason why */
switch (((PRRecvWait*)io_ready)->outcome)
{
case PR_MW_PENDING:
PR_ASSERT(PR_MW_PENDING != ((PRRecvWait*)io_ready)->outcome);
break;
case PR_MW_SUCCESS:
_MW_InitialRecv(io_ready);
break;
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;
}
} while (NULL == io_ready);
aborted:
failed_poll:
group->waiting_threads -= 1;
invalid_state:
(void)MW_TestForShutdownInternal(group);
PR_Unlock(group->ml);
failed_init:
return (PRRecvWait*)io_ready;
} /* PR_WaitRecvReady */
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_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 */
