diff src/thread/pthread/SDL_syscond.c @ 1361:19418e4422cb

New configure-based build system. Still work in progress, but much improved
author Sam Lantinga <slouken@libsdl.org>
date Thu, 16 Feb 2006 10:11:48 +0000
parents
children d910939febfa
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/thread/pthread/SDL_syscond.c	Thu Feb 16 10:11:48 2006 +0000
@@ -0,0 +1,154 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997-2006 Sam Lantinga
+
+    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 2.1 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; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+    Sam Lantinga
+    slouken@libsdl.org
+*/
+
+#include <sys/time.h>
+#include <unistd.h>
+#include <errno.h>
+#include <pthread.h>
+
+#include "SDL_thread.h"
+#include "SDL_sysmutex_c.h"
+
+struct SDL_cond
+{
+	pthread_cond_t cond;
+};
+
+/* Create a condition variable */
+SDL_cond * SDL_CreateCond(void)
+{
+	SDL_cond *cond;
+
+	cond = (SDL_cond *) SDL_malloc(sizeof(SDL_cond));
+	if ( cond ) {
+		if ( pthread_cond_init(&cond->cond, NULL) < 0 ) {
+			SDL_SetError("pthread_cond_init() failed");
+			SDL_free(cond);
+			cond = NULL;
+		}
+	}
+	return(cond);
+}
+
+/* Destroy a condition variable */
+void SDL_DestroyCond(SDL_cond *cond)
+{
+	if ( cond ) {
+		pthread_cond_destroy(&cond->cond);
+		SDL_free(cond);
+	}
+}
+
+/* Restart one of the threads that are waiting on the condition variable */
+int SDL_CondSignal(SDL_cond *cond)
+{
+	int retval;
+
+	if ( ! cond ) {
+		SDL_SetError("Passed a NULL condition variable");
+		return -1;
+	}
+
+	retval = 0;
+	if ( pthread_cond_signal(&cond->cond) != 0 ) {
+		SDL_SetError("pthread_cond_signal() failed");
+		retval = -1;
+	}
+	return retval;
+}
+
+/* Restart all threads that are waiting on the condition variable */
+int SDL_CondBroadcast(SDL_cond *cond)
+{
+	int retval;
+
+	if ( ! cond ) {
+		SDL_SetError("Passed a NULL condition variable");
+		return -1;
+	}
+
+	retval = 0;
+	if ( pthread_cond_broadcast(&cond->cond) != 0 ) {
+		SDL_SetError("pthread_cond_broadcast() failed");
+		retval = -1;
+	}
+	return retval;
+}
+
+int SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms)
+{
+	int retval;
+	struct timeval delta;
+	struct timespec abstime;
+
+	if ( ! cond ) {
+		SDL_SetError("Passed a NULL condition variable");
+		return -1;
+	}
+
+	gettimeofday(&delta, NULL);
+
+	abstime.tv_sec = delta.tv_sec + (ms/1000);
+	abstime.tv_nsec = (delta.tv_usec + (ms%1000) * 1000) * 1000;
+        if ( abstime.tv_nsec > 1000000000 ) {
+          abstime.tv_sec += 1;
+          abstime.tv_nsec -= 1000000000;
+        }
+
+  tryagain:
+	retval = pthread_cond_timedwait(&cond->cond, &mutex->id, &abstime);
+	switch (retval) {
+	    case EINTR:
+		goto tryagain;
+		break;
+	    case ETIMEDOUT:
+		retval = SDL_MUTEX_TIMEDOUT;
+		break;
+	    case 0:
+		break;
+	    default:
+		SDL_SetError("pthread_cond_timedwait() failed");
+		retval = -1;
+		break;
+	}
+	return retval;
+}
+
+/* Wait on the condition variable, unlocking the provided mutex.
+   The mutex must be locked before entering this function!
+ */
+int SDL_CondWait(SDL_cond *cond, SDL_mutex *mutex)
+{
+	int retval;
+
+	if ( ! cond ) {
+		SDL_SetError("Passed a NULL condition variable");
+		return -1;
+	}
+
+	retval = 0;
+	if ( pthread_cond_wait(&cond->cond, &mutex->id) != 0 ) {
+		SDL_SetError("pthread_cond_wait() failed");
+		retval = -1;
+	}
+	return retval;
+}