diff options
Diffstat (limited to 'sem_init.c')
| -rw-r--r-- | sem_init.c | 331 |
1 files changed, 164 insertions, 167 deletions
@@ -1,167 +1,164 @@ -/* - * ------------------------------------------------------------- - * - * Module: sem_init.c - * - * Purpose: - * Semaphores aren't actually part of PThreads. - * They are defined by the POSIX Standard: - * - * POSIX 1003.1-2001 - * - * ------------------------------------------------------------- - * - * 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" - -int -sem_init (sem_t * sem, int pshared, unsigned int value) - /* - * ------------------------------------------------------ - * DOCPUBLIC - * This function initializes a semaphore. The - * initial value of the semaphore is 'value' - * - * PARAMETERS - * sem - * pointer to an instance of sem_t - * - * pshared - * if zero, this semaphore may only be shared between - * threads in the same process. - * if nonzero, the semaphore can be shared between - * processes - * - * value - * initial value of the semaphore counter - * - * DESCRIPTION - * This function initializes a semaphore. The - * initial value of the semaphore is set to 'value'. - * - * RESULTS - * 0 successfully created semaphore, - * -1 failed, error in errno - * ERRNO - * EINVAL 'sem' is not a valid semaphore, - * ENOMEM out of memory, - * ENOSPC a required resource has been exhausted, - * ENOSYS semaphores are not supported, - * EPERM the process lacks appropriate privilege - * - * ------------------------------------------------------ - */ -{ - int result = 0; - sem_t s = NULL; - - if (pshared != 0) - { - /* - * Creating a semaphore that can be shared between - * processes - */ - result = EPERM; - } - else - { - s = (sem_t) calloc (1, sizeof (*s)); - - if (NULL == s) - { - result = ENOMEM; - } - else - { - -#ifdef NEED_SEM - - s->value = value; - s->event = CreateEvent (NULL, PTW32_FALSE, /* manual reset */ - PTW32_FALSE, /* initial state */ - NULL); - - if (0 == s->event) - { - free (s); - result = ENOSPC; - } - else - { - if (value != 0) - { - SetEvent (s->event); - } - - InitializeCriticalSection (&s->sem_lock_cs); - } - -#else /* NEED_SEM */ - - s->value = value; - if (pthread_mutex_init(&s->lock, NULL) == 0) - { - if ((s->sem = CreateSemaphore (NULL, /* Always NULL */ - (long) 0, /* Force threads to wait */ - (long) _POSIX_SEM_VALUE_MAX, /* Maximum value */ - NULL)) == 0) /* Name */ - { - (void) pthread_mutex_destroy(&s->lock); - result = ENOSPC; - } - } - else - { - result = ENOSPC; - } - - if (result != 0) - { - free(s); - } - -#endif /* NEED_SEM */ - - } - } - - if (result != 0) - { - errno = result; - return -1; - } - - *sem = s; - - return 0; - -} /* sem_init */ +/*
+ * -------------------------------------------------------------
+ *
+ * Module: sem_init.c
+ *
+ * Purpose:
+ * Semaphores aren't actually part of PThreads.
+ * They are defined by the POSIX Standard:
+ *
+ * POSIX 1003.1-2001
+ *
+ * -------------------------------------------------------------
+ *
+ * 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"
+
+int
+sem_init (sem_t * sem, int pshared, unsigned int value)
+ /*
+ * ------------------------------------------------------
+ * DOCPUBLIC
+ * This function initializes a semaphore. The
+ * initial value of the semaphore is 'value'
+ *
+ * PARAMETERS
+ * sem
+ * pointer to an instance of sem_t
+ *
+ * pshared
+ * if zero, this semaphore may only be shared between
+ * threads in the same process.
+ * if nonzero, the semaphore can be shared between
+ * processes
+ *
+ * value
+ * initial value of the semaphore counter
+ *
+ * DESCRIPTION
+ * This function initializes a semaphore. The
+ * initial value of the semaphore is set to 'value'.
+ *
+ * RESULTS
+ * 0 successfully created semaphore,
+ * -1 failed, error in errno
+ * ERRNO
+ * EINVAL 'sem' is not a valid semaphore,
+ * ENOMEM out of memory,
+ * ENOSPC a required resource has been exhausted,
+ * ENOSYS semaphores are not supported,
+ * EPERM the process lacks appropriate privilege
+ *
+ * ------------------------------------------------------
+ */
+{
+ int result = 0;
+ sem_t s = NULL;
+
+ if (pshared != 0)
+ {
+ /*
+ * Creating a semaphore that can be shared between
+ * processes
+ */
+ result = EPERM;
+ }
+ else
+ {
+ s = (sem_t) calloc (1, sizeof (*s));
+
+ if (NULL == s)
+ {
+ result = ENOMEM;
+ }
+ else
+ {
+
+ s->value = value;
+ if (pthread_mutex_init(&s->lock, NULL) == 0)
+ {
+
+#ifdef NEED_SEM
+
+ s->sem = CreateEvent (NULL,
+ PTW32_FALSE, /* auto (not manual) reset */
+ PTW32_FALSE, /* initial state is unset */
+ NULL);
+
+ if (0 == s->sem)
+ {
+ free (s);
+ (void) pthread_mutex_destroy(&s->lock);
+ result = ENOSPC;
+ }
+ else
+ {
+ s->leftToUnblock = 0;
+ }
+
+#else /* NEED_SEM */
+
+ if ((s->sem = CreateSemaphore (NULL, /* Always NULL */
+ (long) 0, /* Force threads to wait */
+ (long) _POSIX_SEM_VALUE_MAX, /* Maximum value */
+ NULL)) == 0) /* Name */
+ {
+ (void) pthread_mutex_destroy(&s->lock);
+ result = ENOSPC;
+ }
+
+#endif /* NEED_SEM */
+
+ }
+ else
+ {
+ result = ENOSPC;
+ }
+
+ if (result != 0)
+ {
+ free(s);
+ }
+ }
+ }
+
+ if (result != 0)
+ {
+ errno = result;
+ return -1;
+ }
+
+ *sem = s;
+
+ return 0;
+
+} /* sem_init */
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