Initial GOS port for POSIX (Linux). Untested.

include/gos/posix.h

@@ -14,6 +14,83 @@
 #define _GOS_POSIX_H
 
 #if GFX_USE_OS_POSIX
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <pthread.h>
+
+/* Already defined int8_t, uint8_t, int16_t, uint16_t, int32_t, uint32_t, size_t */
+
+typedef int8_t				bool_t;
+typedef unsigned long		systemticks_t;
+typedef void *				threadreturn_t;
+typedef unsigned long		delaytime_t;
+typedef pthread_t 			gfxThreadHandle;
+typedef int					threadpriority_t;
+typedef uint32_t			semcount_t;
+typedef pthread_mutex_t		gfxMutex;
+
+#define DECLARE_THREAD_FUNCTION(fnName, param)	threadreturn_t fnName(void *param)
+#define DECLARE_THREAD_STACK(name, sz)			uint8_t name[0];
+
+#define gfxExit()						exit(0)
+#define gfxAlloc(sz)					malloc(sz)
+#define gfxRealloc(p,osz,nsz)			realloc(p, nsz)
+#define gfxFree(ptr)					free(ptr)
+#define gfxMillisecondsToTicks(ms)		(ms)
+#define gfxYield()						pthread_yield()
+#define gfxThreadMe()					pthread_self()
+#define gfxThreadClose(th)				{}
+#define gfxMutexInit(pmtx)				pthread_mutex_init(pmtx, 0)
+#define gfxMutexDestroy(pmtx)			pthread_mutex_destroy(pmtx)
+#define gfxMutexEnter(pmtx)				pthread_mutex_lock(pmtx)
+#define gfxMutexExit(pmtx)				pthread_mutex_unlock(pmtx)
+#define gfxSemSignalI(psem)				gfxSemSignal(psem)
+#define gfxSemCounterI(pSem)			((pSem)->cnt)
+
+
+#define FALSE						0
+#define TRUE						1
+#define TIME_IMMEDIATE				0
+#define TIME_INFINITE				((delaytime_t)-1)
+#define MAX_SEMAPHORE_COUNT			((semcount_t)-1)
+#define LOW_PRIORITY				10
+#define NORMAL_PRIORITY				0
+#define HIGH_PRIORITY				-10
+
+typedef struct gfxSem {
+	pthread_mutex_t	mtx;
+	pthread_cond_t	cond;
+	semcount_t		cnt;
+	semcount_t		max;
+	} gfxSem;
+
+/*===========================================================================*/
+/* Function declarations.                                                    */
+/*===========================================================================*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void gfxHalt(const char *msg);
+void gfxSleepMilliseconds(delaytime_t ms);
+void gfxSleepMicroseconds(delaytime_t ms);
+systemticks_t gfxSystemTicks(void);
+void gfxSystemLock(void);
+void gfxSystemUnlock(void);
+void gfxSemInit(gfxSem *psem, semcount_t val, semcount_t limit);
+void gfxSemDestroy(gfxSem *psem);
+bool_t gfxSemWait(gfxSem *psem, delaytime_t ms);
+void gfxSemSignal(gfxSem *psem);
+semcount_t gfxSemCounter(gfxSem *pSem);
+gfxThreadHandle gfxThreadCreate(void *stackarea, size_t stacksz, threadpriority_t prio, DECLARE_THREAD_FUNCTION((*fn),p), void *param);
+threadreturn_t gfxThreadWait(gfxThreadHandle thread);
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GFX_USE_OS_POSIX */
 
 #endif /* _GOS_POSIX_H */

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 */
 /** @} */