diff src/thread/beos/SDL_syssem.c @ 0:74212992fb08

Initial revision
author Sam Lantinga <slouken@lokigames.com>
date Thu, 26 Apr 2001 16:45:43 +0000
parents
children e8157fcb3114
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/thread/beos/SDL_syssem.c	Thu Apr 26 16:45:43 2001 +0000
@@ -0,0 +1,141 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997, 1998, 1999, 2000, 2001  Sam Lantinga
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Library 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
+    Library General Public License for more details.
+
+    You should have received a copy of the GNU Library General Public
+    License along with this library; if not, write to the Free
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+    Sam Lantinga
+    slouken@devolution.com
+*/
+
+#ifdef SAVE_RCSID
+static char rcsid =
+ "@(#) $Id$";
+#endif
+
+/* Semaphores in the BeOS environment */
+
+#include <be/kernel/OS.h>
+
+#include "SDL_error.h"
+#include "SDL_thread.h"
+
+
+struct SDL_semaphore {
+	sem_id id;
+};
+
+/* Create a counting semaphore */
+SDL_sem *SDL_CreateSemaphore(Uint32 initial_value)
+{
+	SDL_sem *sem;
+
+	sem = (SDL_sem *)malloc(sizeof(*sem));
+	if ( sem ) {
+		sem->id = create_sem(initial_value, "SDL semaphore");
+		if ( sem->id < B_NO_ERROR ) {
+			SDL_SetError("create_sem() failed");
+			free(sem);
+			sem = NULL;
+		}
+	} else {
+		SDL_OutOfMemory();
+	}
+	return(sem);
+}
+
+/* Free the semaphore */
+void SDL_DestroySemaphore(SDL_sem *sem)
+{
+	if ( sem ) {
+		if ( sem->id >= B_NO_ERROR ) {
+			delete_sem(sem->id);
+		}
+		free(sem);
+	}
+}
+
+int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
+{
+	int32 val;
+	int retval;
+
+	if ( ! sem ) {
+		SDL_SetError("Passed a NULL semaphore");
+		return -1;
+	}
+
+  tryagain:
+	if ( timeout == SDL_MUTEX_MAXWAIT ) {
+		val = acquire_sem(sem->id);
+	} else {
+		timeout *= 1000; /* BeOS uses a timeout in microseconds */
+		val = acquire_sem_etc(sem->id, 1, B_RELATIVE_TIMEOUT, timeout);
+	}
+	switch (val) {
+	    case B_INTERRUPTED:
+		goto tryagain;
+	    case B_NO_ERROR:
+		retval = 0;
+		break;
+	    default:
+		SDL_SetError("acquire_sem() failed");
+		retval = -1;
+		break;
+	}
+
+	return retval;
+}
+
+int SDL_SemTryWait(SDL_sem *sem)
+{
+	return SDL_SemWaitTimeout(sem, 0);
+}
+
+int SDL_SemWait(SDL_sem *sem)
+{
+	return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT);
+}
+
+/* Returns the current count of the semaphore */
+Uint32 SDL_SemValue(SDL_sem *sem)
+{
+	int32 count;
+	Uint32 value;
+
+	value = 0;
+	if ( sem ) {
+		get_sem_count(sem->id, &count);
+		if ( count > 0 ) {
+			value = (Uint32)count;
+		}
+	}
+	return value;
+}
+
+/* Atomically increases the semaphore's count (not blocking) */
+int SDL_SemPost(SDL_sem *sem)
+{
+	if ( ! sem ) {
+		SDL_SetError("Passed a NULL semaphore");
+		return -1;
+	}
+
+	if ( release_sem(sem->id) != B_NO_ERROR ) {
+		SDL_SetError("release_sem() failed");
+		return -1;
+	}
+	return 0;
+}