1 files changed, 150 insertions, 1 deletions

diff --git a/src/gos/posix.c b/src/gos/posix.c
index 19a02560..f48a4caa 100644
--- a/src/gos/posix.c
+++ b/src/gos/posix.c
@@ -13,7 +13,156 @@
 
 #if GFX_USE_OS_POSIX
 
-#error "GOS: POSIX not supported yet"
+#include <stdio.h>
+#include <unistd.h>
+#include <time.h>
+
+static gfxMutex		SystemMutex;
+
+void _gosInit(void) {
+	gfxMutexInit(&SystemMutex);
+}
+
+void gfxSystemLock(void) {
+	gfxMutexEnter(&SystemMutex);
+}
+
+void gfxSystemUnlock(void) {
+	gfxMutexLeave(&SystemMutex);
+}
+
+void gfxHalt(const char *msg) {
+	if (msg)
+		fprintf(stderr, "%s\n", msg);
+	exit(1);
+}
+
+void gfxSleepMilliseconds(delaytime_t ms) {
+	struct timespec	ts;
+
+	switch(ms) {
+	case TIME_IMMEDIATE:	pthread_yield();			return;
+	case TIME_INFINITE:		while(1) sleep(60);			return;
+	default:
+		ts.tv_sec = ms / 1000;
+		ts.tv_nsec = (ms % 1000) * 1000;
+		nanosleep(&ts, 0);
+		return;
+	}
+}
+
+void gfxSleepMicroseconds(delaytime_t ms) {
+	struct timespec	ts;
+
+	switch(ms) {
+	case TIME_IMMEDIATE:	pthread_yield();			return;
+	case TIME_INFINITE:		while(1) sleep(60);			return;
+	default:
+		ts.tv_sec = ms / 1000000;
+		ts.tv_nsec = ms % 1000000;
+		nanosleep(&ts, 0);
+		return;
+	}
+}
+
+systemticks_t gfxSystemTicks(void) {
+	struct timespec	ts;
+
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	return ts.tv_sec * 1000UL + ts.tv_nsec / 1000UL;
+}
+
+gfxThreadHandle gfxThreadCreate(void *stackarea, size_t stacksz, threadpriority_t prio, DECLARE_THREAD_FUNCTION((*fn),p), void *param) {
+	gfxThreadHandle		th;
+
+	// Implementing priority with pthreads is a rats nest that is also pthreads implementation dependent.
+	//	Only some pthreads schedulers support it, some implementations use the operating system process priority mechanisms.
+	//	Even those that do support it can have different ranges of priority and "normal" priority is an undefined concept.
+	//	Across different UNIX style operating systems things can be very different (let alone OS's such as Windows).
+	//	Even just Linux changes the way priority works with different kernel schedulers and across kernel versions.
+	//	For these reasons we ignore the priority.
+
+	if (pthread_create(&th, 0, fn, param))
+		return 0;
+	return th;
+}
+
+threadreturn_t gfxThreadWait(gfxThreadHandle thread) {
+	threadreturn_t	retval;
+
+	if (pthread_join(thread, &retval))
+		return 0;
+	return retval;
+}
+
+void gfxSemInit(gfxSem *psem, semcount_t val, semcount_t limit) {
+	pthread_mutex_init(&psem->mtx, 0);
+	pthread_cond_init(&psem->cond, 0);
+	pthread_mutex_lock(&psem->mtx);
+	psem->cnt = val;
+	psem->max = limit;
+	pthread_mutex_unlock(&psem->mtx);
+}
+
+void gfxSemDestroy(gfxSem *psem) {
+	pthread_mutex_destroy(&psem->mtx);
+	pthread_cond_destroy(&psem->cond);
+}
+
+bool_t gfxSemWait(gfxSem *psem, delaytime_t ms) {
+	pthread_mutex_lock(&psem->mtx);
+	switch (ms) {
+	case TIME_INFINITE:
+		while (!psem->val)
+			pthread_cond_wait(&psem->cond, &psem->mtx);
+		break;
+	case TIME_IMMEDIATE:
+		if (!psem->val) {
+			pthread_mutex_unlock(&psem->mtx);
+			return FALSE;
+		}
+		break;
+	default:
+		{
+			struct timeval now;
+			struct timespec	tm;
+
+			gettimeofday(&now);
+			tm.tv_sec = now.tv_sec + ms / 1000;
+			tm.tv_nsec = (now.tv_usec + ms % 1000) * 1000;
+			while (!psem->val) {
+				if (pthread_cond_timedwait(&psem->cond, &psem->mtx, &tm) == ETIMEDOUT) {
+					pthread_mutex_unlock(&psem->mtx);
+					return FALSE;
+				}
+			}
+		}
+		break;
+	}
+	psem->val--;
+	pthread_mutex_unlock(&psem->mtx);
+	return TRUE;
+}
+
+void gfxSemSignal(gfxSem *psem) {
+	pthread_mutex_lock(&psem->mtx);
+	if (psem->val < psem->limit) {
+		psem->val++;
+		pthread_cond_signal(&psem->cond);
+	}
+	pthread_mutex_unlock(&psem->mtx);
+}
+
+semcount_t gfxSemCounter(gfxSem *pSem) {
+	semcount_t	res;
+
+	// The locking is really only required if obtaining the count is a divisible operation
+	//	which it might be on a 8/16 bit processor with a 32 bit semaphore count.
+	pthread_mutex_lock(&psem->mtx);
+	res = psem->cnt;
+	pthread_mutex_unlock(&psem->mtx);
+	return res;
+}
 
 #endif /* GFX_USE_OS_POSIX */
 /** @} */