From 150a7a6e99d3cf8fd0b6315e7b184b5cce0f4ce4 Mon Sep 17 00:00:00 2001
From: rpj <rpj>
Date: Mon, 25 Apr 2005 00:45:59 +0000
Subject: Fix timeout bug
---
sem_timedwait.c | 476 ++++++++++++++++++++++++++------------------------------
1 file changed, 220 insertions(+), 256 deletions(-)
diff --git a/sem_timedwait.c b/sem_timedwait.c
index 7fba45f..01bab42 100644
--- a/sem_timedwait.c
+++ b/sem_timedwait.c
@@ -1,256 +1,220 @@
-/*
- * -------------------------------------------------------------
- *
- * Module: sem_timedwait.c
- *
- * Purpose:
- * Semaphores aren't actually part of the PThreads standard.
- * They are defined by the POSIX Standard:
- *
- * POSIX 1003.1b-1993 (POSIX.1b)
- *
- * -------------------------------------------------------------
- *
- * --------------------------------------------------------------------------
- *
- * Pthreads-win32 - POSIX Threads Library for Win32
- * Copyright(C) 1998 John E. Bossom
- * Copyright(C) 1999,2005 Pthreads-win32 contributors
- *
- * Contact Email: rpj@callisto.canberra.edu.au
- *
- * The current list of contributors is contained
- * in the file CONTRIBUTORS included with the source
- * code distribution. The list can also be seen at the
- * following World Wide Web location:
- * http://sources.redhat.com/pthreads-win32/contributors.html
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library in the file COPYING.LIB;
- * if not, write to the Free Software Foundation, Inc.,
- * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- */
-
-#ifndef _UWIN
-//#include <process.h>
-#endif
-#ifndef NEED_FTIME
-#include <sys/timeb.h>
-#endif
-
-#include "pthread.h"
-#include "semaphore.h"
-#include "implement.h"
-
-static void PTW32_CDECL
-ptw32_sem_timedwait_cleanup (void * sem)
-{
- sem_t s = (sem_t) sem;
-
- if (pthread_mutex_lock (&s->lock) == 0)
- {
- ++s->value;
- /*
- * Don't release the W32 sema, it doesn't need adjustment
- * because it doesn't record the number of waiters.
- */
- (void) pthread_mutex_unlock (&s->lock);
- }
-}
-
-int
-sem_timedwait (sem_t * sem, const struct timespec *abstime)
- /*
- * ------------------------------------------------------
- * DOCPUBLIC
- * This function waits on a semaphore possibly until
- * 'abstime' time.
- *
- * PARAMETERS
- * sem
- * pointer to an instance of sem_t
- *
- * abstime
- * pointer to an instance of struct timespec
- *
- * DESCRIPTION
- * This function waits on a semaphore. If the
- * semaphore value is greater than zero, it decreases
- * its value by one. If the semaphore value is zero, then
- * the calling thread (or process) is blocked until it can
- * successfully decrease the value or until interrupted by
- * a signal.
- *
- * If 'abstime' is a NULL pointer then this function will
- * block until it can successfully decrease the value or
- * until interrupted by a signal.
- *
- * RESULTS
- * 0 successfully decreased semaphore,
- * -1 failed, error in errno
- * ERRNO
- * EINVAL 'sem' is not a valid semaphore,
- * ENOSYS semaphores are not supported,
- * EINTR the function was interrupted by a signal,
- * EDEADLK a deadlock condition was detected.
- * ETIMEDOUT abstime elapsed before success.
- *
- * ------------------------------------------------------
- */
-{
- int result = 0;
- sem_t s = *sem;
-
-#ifdef NEED_FTIME
-
- struct timespec currSysTime;
-
-#else /* NEED_FTIME */
-
- struct _timeb currSysTime;
-
-#endif /* NEED_FTIME */
-
- const int64_t NANOSEC_PER_MILLISEC = 1000000;
- const int64_t MILLISEC_PER_SEC = 1000;
- DWORD milliseconds;
- int64_t tmpAbsMilliseconds;
- int64_t tmpCurrMilliseconds;
-
- if (sem == NULL)
- {
- result = EINVAL;
- }
- else
- {
- if (abstime == NULL)
- {
- milliseconds = INFINITE;
- }
- else
- {
- /*
- * Calculate timeout as milliseconds from current system time.
- */
-
- /*
- * subtract current system time from abstime in a way that checks
- * that abstime is never in the past, or is never equivalent to the
- * defined INFINITE value (0xFFFFFFFF).
- *
- * Assume all integers are unsigned, i.e. cannot test if less than 0.
- */
- tmpAbsMilliseconds = (int64_t)abstime->tv_sec * MILLISEC_PER_SEC;
- tmpAbsMilliseconds += ((int64_t)abstime->tv_nsec + (NANOSEC_PER_MILLISEC/2)) / NANOSEC_PER_MILLISEC;
-
- /* get current system time */
-
-#ifdef NEED_FTIME
-
- {
- FILETIME ft;
- SYSTEMTIME st;
-
- GetSystemTime(&st);
- SystemTimeToFileTime(&st, &ft);
- /*
- * GetSystemTimeAsFileTime(&ft); would be faster,
- * but it does not exist on WinCE
- */
-
- ptw32_filetime_to_timespec(&ft, &currSysTime);
- }
-
- tmpCurrMilliseconds = (int64_t)currSysTime.tv_sec * MILLISEC_PER_SEC;
- tmpCurrMilliseconds += ((int64_t)currSysTime.tv_nsec + (NANOSEC_PER_MILLISEC/2)) / NANOSEC_PER_MILLISEC;
-
-#else /* ! NEED_FTIME */
-
- _ftime(&currSysTime);
-
- tmpCurrMilliseconds = (int64_t) currSysTime.time * MILLISEC_PER_SEC;
- tmpCurrMilliseconds += (int64_t) currSysTime.millitm;
-
-#endif /* NEED_FTIME */
-
- if (tmpAbsMilliseconds > tmpCurrMilliseconds)
- {
- milliseconds = (DWORD) (tmpAbsMilliseconds - tmpCurrMilliseconds);
- if (milliseconds == INFINITE)
- {
- /* Timeouts must be finite */
- milliseconds--;
- }
- }
- else
- {
- /* The abstime given is in the past */
- milliseconds = 0;
- }
- }
-
-#ifdef NEED_SEM
-
- result = (pthreadCancelableTimedWait (s->event, milliseconds));
-
-#else /* NEED_SEM */
-
- pthread_testcancel();
-
- if ((result = pthread_mutex_lock (&s->lock)) == 0)
- {
- int v = --s->value;
- (void) pthread_mutex_unlock (&s->lock);
-
- if (v < 0)
- {
- /* Must wait */
-#ifdef _MSC_VER
-#pragma inline_depth(0)
-#endif
- pthread_cleanup_push(ptw32_sem_timedwait_cleanup, (void *) s);
- result = pthreadCancelableTimedWait (s->sem, milliseconds);
- /*
- * Restore the semaphore counter if no longer waiting
- * and not taking the semaphore. This will occur if the
- * thread is cancelled while waiting, or the wake was
- * not the result of a post event given to us, e.g. a timeout.
- */
- pthread_cleanup_pop(result);
-#ifdef _MSC_VER
-#pragma inline_depth()
-#endif
- }
- }
-
-#endif
-
- }
-
- if (result != 0)
- {
-
- errno = result;
- return -1;
-
- }
-
-#ifdef NEED_SEM
-
- ptw32_decrease_semaphore (sem);
-
-#endif /* NEED_SEM */
-
- return 0;
-
-} /* sem_timedwait */
+/*
+ * -------------------------------------------------------------
+ *
+ * Module: sem_timedwait.c
+ *
+ * Purpose:
+ * Semaphores aren't actually part of the PThreads standard.
+ * They are defined by the POSIX Standard:
+ *
+ * POSIX 1003.1b-1993 (POSIX.1b)
+ *
+ * -------------------------------------------------------------
+ *
+ * --------------------------------------------------------------------------
+ *
+ * Pthreads-win32 - POSIX Threads Library for Win32
+ * Copyright(C) 1998 John E. Bossom
+ * Copyright(C) 1999,2005 Pthreads-win32 contributors
+ *
+ * Contact Email: rpj@callisto.canberra.edu.au
+ *
+ * The current list of contributors is contained
+ * in the file CONTRIBUTORS included with the source
+ * code distribution. The list can also be seen at the
+ * following World Wide Web location:
+ * http://sources.redhat.com/pthreads-win32/contributors.html
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library in the file COPYING.LIB;
+ * if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include "pthread.h"
+#include "semaphore.h"
+#include "implement.h"
+
+
+typedef struct {
+ sem_t sem;
+ int * resultPtr;
+} sem_timedwait_cleanup_args_t;
+
+
+static void PTW32_CDECL
+ptw32_sem_timedwait_cleanup (void * args)
+{
+ sem_timedwait_cleanup_args_t * a = (sem_timedwait_cleanup_args_t *)args;
+ sem_t s = a->sem;
+
+ if (pthread_mutex_lock (&s->lock) == 0)
+ {
+ /*
+ * We either timed out or were cancelled.
+ * If someone posted since then we try to take the semaphore.
+ * Otherwise the semaphore count may be wrong after we
+ * return. In the case of a cancellation, it is as if we
+ * were cancelled just before we return (after taking the semaphore)
+ * which is ok.
+ */
+ if (WaitForSingleObject(s->sem, 0) == WAIT_OBJECT_0)
+ {
+ /* We got the semaphore on the second attempt */
+ *(a->resultPtr) = 0;
+ }
+ else
+ {
+ /* Indicate we're no longer waiting */
+ s->value++;
+#ifdef NEED_SEM
+ if (s->value > 0)
+ {
+ s->leftToUnblock = 0;
+ }
+#else
+ /*
+ * Don't release the W32 sema, it doesn't need adjustment
+ * because it doesn't record the number of waiters.
+ */
+#endif
+ }
+ (void) pthread_mutex_unlock (&s->lock);
+ }
+}
+
+
+int
+sem_timedwait (sem_t * sem, const struct timespec *abstime)
+ /*
+ * ------------------------------------------------------
+ * DOCPUBLIC
+ * This function waits on a semaphore possibly until
+ * 'abstime' time.
+ *
+ * PARAMETERS
+ * sem
+ * pointer to an instance of sem_t
+ *
+ * abstime
+ * pointer to an instance of struct timespec
+ *
+ * DESCRIPTION
+ * This function waits on a semaphore. If the
+ * semaphore value is greater than zero, it decreases
+ * its value by one. If the semaphore value is zero, then
+ * the calling thread (or process) is blocked until it can
+ * successfully decrease the value or until interrupted by
+ * a signal.
+ *
+ * If 'abstime' is a NULL pointer then this function will
+ * block until it can successfully decrease the value or
+ * until interrupted by a signal.
+ *
+ * RESULTS
+ * 0 successfully decreased semaphore,
+ * -1 failed, error in errno
+ * ERRNO
+ * EINVAL 'sem' is not a valid semaphore,
+ * ENOSYS semaphores are not supported,
+ * EINTR the function was interrupted by a signal,
+ * EDEADLK a deadlock condition was detected.
+ * ETIMEDOUT abstime elapsed before success.
+ *
+ * ------------------------------------------------------
+ */
+{
+ int result = 0;
+ sem_t s = *sem;
+
+ if (sem == NULL)
+ {
+ result = EINVAL;
+ }
+ else
+ {
+ DWORD milliseconds;
+
+ if (abstime == NULL)
+ {
+ milliseconds = INFINITE;
+ }
+ else
+ {
+ /*
+ * Calculate timeout as milliseconds from current system time.
+ */
+ milliseconds = ptw32_relmillisecs (abstime);
+ }
+
+ pthread_testcancel();
+
+ if ((result = pthread_mutex_lock (&s->lock)) == 0)
+ {
+ int v = --s->value;
+ (void) pthread_mutex_unlock (&s->lock);
+
+ if (v < 0)
+ {
+#ifdef NEED_SEM
+ int timedout;
+#endif
+ sem_timedwait_cleanup_args_t cleanup_args;
+
+ cleanup_args.sem = s;
+ cleanup_args.resultPtr = &result;
+
+#ifdef _MSC_VER
+#pragma inline_depth(0)
+#endif
+ /* Must wait */
+ pthread_cleanup_push(ptw32_sem_timedwait_cleanup, (void *) &cleanup_args);
+#ifdef NEED_SEM
+ timedout =
+#endif
+ result = pthreadCancelableTimedWait (s->sem, milliseconds);
+ pthread_cleanup_pop(result);
+#ifdef _MSC_VER
+#pragma inline_depth()
+#endif
+
+#ifdef NEED_SEM
+
+ if (!timedout && pthread_mutex_lock (&s->lock) == 0)
+ {
+ if (s->leftToUnblock > 0)
+ {
+ --s->leftToUnblock;
+ SetEvent(s->sem);
+ }
+ (void) pthread_mutex_unlock (&s->lock);
+ }
+
+#endif /* NEED_SEM */
+
+ }
+ }
+
+ }
+
+ if (result != 0)
+ {
+
+ errno = result;
+ return -1;
+
+ }
+
+ return 0;
+
+} /* sem_timedwait */
--
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