Added initial support for Dreamcast (thanks HERO!)

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%40510

src/thread/dc/SDL_syssem.c

@@ -0,0 +1,180 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002  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
+
+    BERO
+    bero@geocities.co.jp
+
+    based on generic/SDL_syssem.c
+
+    Sam Lantinga
+    slouken@libsdl.org
+*/
+
+#ifdef SAVE_RCSID
+static char rcsid =
+ "@(#) $Id$";
+#endif
+
+/* An implementation of semaphores using mutexes and condition variables */
+
+#include <stdlib.h>
+
+#include "SDL_error.h"
+#include "SDL_timer.h"
+#include "SDL_thread.h"
+#include "SDL_systhread_c.h"
+
+
+#ifdef DISABLE_THREADS
+
+SDL_sem *SDL_CreateSemaphore(Uint32 initial_value)
+{
+	SDL_SetError("SDL not configured with thread support");
+	return (SDL_sem *)0;
+}
+
+void SDL_DestroySemaphore(SDL_sem *sem)
+{
+	return;
+}
+
+int SDL_SemTryWait(SDL_sem *sem)
+{
+	SDL_SetError("SDL not configured with thread support");
+	return -1;
+}
+
+int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
+{
+	SDL_SetError("SDL not configured with thread support");
+	return -1;
+}
+
+int SDL_SemWait(SDL_sem *sem)
+{
+	SDL_SetError("SDL not configured with thread support");
+	return -1;
+}
+
+Uint32 SDL_SemValue(SDL_sem *sem)
+{
+	return 0;
+}
+
+int SDL_SemPost(SDL_sem *sem)
+{
+	SDL_SetError("SDL not configured with thread support");
+	return -1;
+}
+
+#else
+
+#include <kos/sem.h>
+
+struct SDL_semaphore
+{
+	semaphore_t sem;
+};
+
+SDL_sem *SDL_CreateSemaphore(Uint32 initial_value)
+{
+	return (SDL_sem *)sem_create(initial_value);
+}
+
+/* WARNING:
+   You cannot call this function when another thread is using the semaphore.
+*/
+void SDL_DestroySemaphore(SDL_sem *sem)
+{
+	if ( ! sem ) {
+		SDL_SetError("Passed a NULL semaphore");
+		return;
+	}
+
+	sem_destroy(&sem->sem);
+}
+
+int SDL_SemTryWait(SDL_sem *sem)
+{
+	int retval;
+
+	if ( ! sem ) {
+		SDL_SetError("Passed a NULL semaphore");
+		return -1;
+	}
+
+	retval = sem_trywait(&sem->sem);
+	if (retval==0) return 0;
+	else return SDL_MUTEX_TIMEDOUT;
+
+	return retval;
+}
+
+int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
+{
+	int retval;
+
+	if ( ! sem ) {
+		SDL_SetError("Passed a NULL semaphore");
+		return -1;
+	}
+
+	/* A timeout of 0 is an easy case */
+	if ( timeout == 0 ) {
+		return SDL_SemTryWait(sem);
+	}
+
+	retval = sem_wait_timed(&sem->sem,timeout);
+	if (retval==-1) retval= SDL_MUTEX_TIMEDOUT;
+
+	return retval;
+}
+
+int SDL_SemWait(SDL_sem *sem)
+{
+	if ( ! sem ) {
+		SDL_SetError("Passed a NULL semaphore");
+		return -1;
+	}
+
+	sem_wait(&sem->sem);
+	return 0;
+}
+
+Uint32 SDL_SemValue(SDL_sem *sem)
+{
+	if ( ! sem ) {
+		SDL_SetError("Passed a NULL semaphore");
+		return -1;
+	}
+
+	return sem_count(&sem->sem);
+}
+
+int SDL_SemPost(SDL_sem *sem)
+{
+	if ( ! sem ) {
+		SDL_SetError("Passed a NULL semaphore");
+		return -1;
+	}
+
+	sem_signal(&sem->sem);
+	return 0;
+}
+
+#endif /* DISABLE_THREADS */