summaryrefslogtreecommitdiff
path: root/sem_wait.c
diff options
context:
space:
mode:
authorrpj <rpj>2005-04-25 01:21:20 +0000
committerrpj <rpj>2005-04-25 01:21:20 +0000
commit8a78e259203a6edabe53d78b8aa44666e50366e1 (patch)
tree465e02729ed9a64717d581e0327ce20acf258af8 /sem_wait.c
parent2baa511d22be44701a1cc2f5c3d6e6d643cbc6be (diff)
Fix NEED_SEM code (WinCE)
Diffstat (limited to 'sem_wait.c')
-rw-r--r--sem_wait.c316
1 files changed, 162 insertions, 154 deletions
diff --git a/sem_wait.c b/sem_wait.c
index 0b0eba3..d838aa1 100644
--- a/sem_wait.c
+++ b/sem_wait.c
@@ -1,154 +1,162 @@
-/*
- * -------------------------------------------------------------
- *
- * Module: sem_wait.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"
-
-
-static void PTW32_CDECL
-ptw32_sem_wait_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 should always == 0. */
- (void) pthread_mutex_unlock (&s->lock);
- }
-}
-
-int
-sem_wait (sem_t * sem)
- /*
- * ------------------------------------------------------
- * DOCPUBLIC
- * This function waits on a semaphore.
- *
- * PARAMETERS
- * sem
- * pointer to an instance of sem_t
- *
- * 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.
- *
- * 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.
- *
- * ------------------------------------------------------
- */
-{
- int result = 0;
- sem_t s = *sem;
-
- if (s == NULL)
- {
- result = EINVAL;
- }
- else
- {
-
-#ifdef NEED_SEM
-
- result = pthreadCancelableWait (s->event);
-
-#else /* NEED_SEM */
-
- /*
- * sem_wait is a cancelation point and it's easy to test before
- * modifying the sem value
- */
- 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_wait_cleanup, (void *) s);
- result = pthreadCancelableWait (s->sem);
- pthread_cleanup_pop(result != 0);
-#ifdef _MSC_VER
-#pragma inline_depth()
-#endif
- }
- }
-
-#endif /* NEED_SEM */
-
- }
-
- if (result != 0)
- {
- errno = result;
- return -1;
- }
-
-#ifdef NEED_SEM
-
- ptw32_decrease_semaphore (sem);
-
-#endif /* NEED_SEM */
-
- return 0;
-
-} /* sem_wait */
+/*
+ * -------------------------------------------------------------
+ *
+ * Module: sem_wait.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"
+
+
+static void PTW32_CDECL
+ptw32_sem_wait_cleanup(void * sem)
+{
+ sem_t s = (sem_t) sem;
+
+ if (pthread_mutex_lock (&s->lock) == 0)
+ {
+ ++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 /* NEED_SEM */
+ (void) pthread_mutex_unlock (&s->lock);
+ }
+}
+
+int
+sem_wait (sem_t * sem)
+ /*
+ * ------------------------------------------------------
+ * DOCPUBLIC
+ * This function waits on a semaphore.
+ *
+ * PARAMETERS
+ * sem
+ * pointer to an instance of sem_t
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * ------------------------------------------------------
+ */
+{
+ int result = 0;
+ sem_t s = *sem;
+
+ if (s == NULL)
+ {
+ result = EINVAL;
+ }
+ else
+ {
+
+ /* Faster to test before adjusting the count */
+ pthread_testcancel();
+
+ if ((result = pthread_mutex_lock (&s->lock)) == 0)
+ {
+ int v = --s->value;
+
+ (void) pthread_mutex_unlock (&s->lock);
+
+ if (v < 0)
+ {
+#ifdef _MSC_VER
+#pragma inline_depth(0)
+#endif
+ /* Must wait */
+ pthread_cleanup_push(ptw32_sem_wait_cleanup, (void *) s);
+ result = pthreadCancelableWait (s->sem);
+ pthread_cleanup_pop(result);
+#ifdef _MSC_VER
+#pragma inline_depth()
+#endif
+ }
+#ifdef NEED_SEM
+
+ if (!result && 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_wait */