Corrected header file documentation comment.

src/thread/pthread/SDL_syssem.c

@@ -0,0 +1,199 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2014 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "../../SDL_internal.h"
+
+#include <errno.h>
+#include <pthread.h>
+#include <semaphore.h>
+#include <sys/time.h>
+
+#include "SDL_thread.h"
+#include "SDL_timer.h"
+
+/* Wrapper around POSIX 1003.1b semaphores */
+
+#if defined(__MACOSX__) || defined(__IPHONEOS__)
+/* Mac OS X doesn't support sem_getvalue() as of version 10.4 */
+#include "../generic/SDL_syssem.c"
+#else
+
+struct SDL_semaphore
+{
+    sem_t sem;
+};
+
+/* Create a semaphore, initialized with value */
+SDL_sem *
+SDL_CreateSemaphore(Uint32 initial_value)
+{
+    SDL_sem *sem = (SDL_sem *) SDL_malloc(sizeof(SDL_sem));
+    if (sem) {
+        if (sem_init(&sem->sem, 0, initial_value) < 0) {
+            SDL_SetError("sem_init() failed");
+            SDL_free(sem);
+            sem = NULL;
+        }
+    } else {
+        SDL_OutOfMemory();
+    }
+    return sem;
+}
+
+void
+SDL_DestroySemaphore(SDL_sem * sem)
+{
+    if (sem) {
+        sem_destroy(&sem->sem);
+        SDL_free(sem);
+    }
+}
+
+int
+SDL_SemTryWait(SDL_sem * sem)
+{
+    int retval;
+
+    if (!sem) {
+        return SDL_SetError("Passed a NULL semaphore");
+    }
+    retval = SDL_MUTEX_TIMEDOUT;
+    if (sem_trywait(&sem->sem) == 0) {
+        retval = 0;
+    }
+    return retval;
+}
+
+int
+SDL_SemWait(SDL_sem * sem)
+{
+    int retval;
+
+    if (!sem) {
+        return SDL_SetError("Passed a NULL semaphore");
+    }
+
+    retval = sem_wait(&sem->sem);
+    if (retval < 0) {
+        retval = SDL_SetError("sem_wait() failed");
+    }
+    return retval;
+}
+
+int
+SDL_SemWaitTimeout(SDL_sem * sem, Uint32 timeout)
+{
+    int retval;
+#ifdef HAVE_SEM_TIMEDWAIT
+    struct timeval now;
+    struct timespec ts_timeout;
+#else
+    Uint32 end;
+#endif
+
+    if (!sem) {
+        return SDL_SetError("Passed a NULL semaphore");
+    }
+
+    /* Try the easy cases first */
+    if (timeout == 0) {
+        return SDL_SemTryWait(sem);
+    }
+    if (timeout == SDL_MUTEX_MAXWAIT) {
+        return SDL_SemWait(sem);
+    }
+
+#ifdef HAVE_SEM_TIMEDWAIT
+    /* Setup the timeout. sem_timedwait doesn't wait for
+    * a lapse of time, but until we reach a certain time.
+    * This time is now plus the timeout.
+    */
+    gettimeofday(&now, NULL);
+
+    /* Add our timeout to current time */
+    now.tv_usec += (timeout % 1000) * 1000;
+    now.tv_sec += timeout / 1000;
+
+    /* Wrap the second if needed */
+    if ( now.tv_usec >= 1000000 ) {
+        now.tv_usec -= 1000000;
+        now.tv_sec ++;
+    }
+
+    /* Convert to timespec */
+    ts_timeout.tv_sec = now.tv_sec;
+    ts_timeout.tv_nsec = now.tv_usec * 1000;
+
+    /* Wait. */
+    do {
+        retval = sem_timedwait(&sem->sem, &ts_timeout);
+    } while (retval < 0 && errno == EINTR);
+
+    if (retval < 0) {
+        if (errno == ETIMEDOUT) {
+            retval = SDL_MUTEX_TIMEDOUT;
+        } else {
+            SDL_SetError("sem_timedwait returned an error: %s", strerror(errno));
+        }
+    }
+#else
+    end = SDL_GetTicks() + timeout;
+    while ((retval = SDL_SemTryWait(sem)) == SDL_MUTEX_TIMEDOUT) {
+        if (SDL_TICKS_PASSED(SDL_GetTicks(), end)) {
+            break;
+        }
+        SDL_Delay(1);
+    }
+#endif /* HAVE_SEM_TIMEDWAIT */
+
+    return retval;
+}
+
+Uint32
+SDL_SemValue(SDL_sem * sem)
+{
+    int ret = 0;
+    if (sem) {
+        sem_getvalue(&sem->sem, &ret);
+        if (ret < 0) {
+            ret = 0;
+        }
+    }
+    return (Uint32) ret;
+}
+
+int
+SDL_SemPost(SDL_sem * sem)
+{
+    int retval;
+
+    if (!sem) {
+        return SDL_SetError("Passed a NULL semaphore");
+    }
+
+    retval = sem_post(&sem->sem);
+    if (retval < 0) {
+        SDL_SetError("sem_post() failed");
+    }
+    return retval;
+}
+
+#endif /* __MACOSX__ */
+/* vi: set ts=4 sw=4 expandtab: */