util/c11: Update function u_thread_create to be c11 conformance

Do not assume thrd_t to be a pointer or integer, as the C11 standard tells us:
  thrd_t: implementation-defined complete object type identifying a thread
At https://en.cppreference.com/w/c/thread
So we always return the thread creation return code instead of thrd_t value, and judge the return
code properly.

Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15087>

src/gallium/auxiliary/driver_ddebug/dd_context.c

@@ -959,8 +959,7 @@ dd_context_create(struct dd_screen *dscreen, struct pipe_context *pipe)
    list_inithead(&dctx->records);
    (void) mtx_init(&dctx->mutex, mtx_plain);
    (void) cnd_init(&dctx->cond);
-   dctx->thread = u_thread_create(dd_thread_main, dctx);
-   if (!dctx->thread) {
+   if (thrd_success != u_thread_create(&dctx->thread,dd_thread_main, dctx)) {
       mtx_destroy(&dctx->mutex);
       goto fail;
    }

src/gallium/auxiliary/driver_rbug/rbug_core.c

@@ -841,7 +841,10 @@ rbug_start(struct rbug_screen *rb_screen)
 
    tr_rbug->rb_screen = rb_screen;
    tr_rbug->running = true;
-   tr_rbug->thread = u_thread_create(rbug_thread, tr_rbug);
+   if (thrd_success != u_thread_create(&tr_rbug->thread, rbug_thread, tr_rbug)) {
+      FREE(tr_rbug);
+      return NULL;
+   }
 
    return tr_rbug;
 }

src/gallium/drivers/llvmpipe/lp_cs_tpool.c

@@ -96,9 +96,13 @@ lp_cs_tpool_create(unsigned num_threads)
 
    list_inithead(&pool->workqueue);
    assert (num_threads <= LP_MAX_THREADS);
+   for (unsigned i = 0; i < num_threads; i++) {
+      if (thrd_success != u_thread_create(pool->threads + i, lp_cs_tpool_worker, pool)) {
+         num_threads = i;  /* previous thread is max */
+         break;
+      }
+   }
    pool->num_threads = num_threads;
-   for (unsigned i = 0; i < num_threads; i++)
-      pool->threads[i] = u_thread_create(lp_cs_tpool_worker, pool);
    return pool;
 }
 

src/gallium/drivers/llvmpipe/lp_rast.c

@@ -1238,9 +1238,8 @@ create_rast_threads(struct lp_rasterizer *rast)
    for (unsigned i = 0; i < rast->num_threads; i++) {
       pipe_semaphore_init(&rast->tasks[i].work_ready, 0);
       pipe_semaphore_init(&rast->tasks[i].work_done, 0);
-      rast->threads[i] = u_thread_create(thread_function,
-                                            (void *) &rast->tasks[i]);
-      if (!rast->threads[i]) {
+      if (thrd_success != u_thread_create(rast->threads + i, thread_function,
+                                            (void *) &rast->tasks[i])) {
          rast->num_threads = i; /* previous thread is max */
          break;
       }

src/gallium/drivers/r600/r600_gpu_load.c

@@ -144,24 +144,27 @@ r600_gpu_load_thread(void *param)
 
 void r600_gpu_load_kill_thread(struct r600_common_screen *rscreen)
 {
-	if (!rscreen->gpu_load_thread)
+	if (!rscreen->gpu_load_thread_created)
 		return;
 
 	p_atomic_inc(&rscreen->gpu_load_stop_thread);
 	thrd_join(rscreen->gpu_load_thread, NULL);
-	rscreen->gpu_load_thread = 0;
+	rscreen->gpu_load_thread_created = false;
 }
 
 static uint64_t r600_read_mmio_counter(struct r600_common_screen *rscreen,
 				       unsigned busy_index)
 {
 	/* Start the thread if needed. */
-	if (!rscreen->gpu_load_thread) {
+	if (!rscreen->gpu_load_thread_created) {
 		mtx_lock(&rscreen->gpu_load_mutex);
 		/* Check again inside the mutex. */
-		if (!rscreen->gpu_load_thread)
-			rscreen->gpu_load_thread =
-				u_thread_create(r600_gpu_load_thread, rscreen);
+		if (!rscreen->gpu_load_thread_created) {
+			int ret = u_thread_create(&rscreen->gpu_load_thread, r600_gpu_load_thread, rscreen);
+			if (ret == thrd_success) {
+				rscreen->gpu_load_thread_created = true;
+			}
+		}
 		mtx_unlock(&rscreen->gpu_load_mutex);
 	}
 

src/gallium/drivers/r600/r600_pipe_common.h

@@ -360,6 +360,7 @@ struct r600_common_screen {
 	/* GPU load thread. */
 	mtx_t				gpu_load_mutex;
 	thrd_t				gpu_load_thread;
+	bool				gpu_load_thread_created;
 	union r600_mmio_counters	mmio_counters;
 	volatile unsigned		gpu_load_stop_thread; /* bool */
 

src/gallium/drivers/radeonsi/si_gpu_load.c

@@ -159,22 +159,25 @@ static int si_gpu_load_thread(void *param)
 
 void si_gpu_load_kill_thread(struct si_screen *sscreen)
 {
-   if (!sscreen->gpu_load_thread)
+   if (!sscreen->gpu_load_thread_created)
       return;
 
    p_atomic_inc(&sscreen->gpu_load_stop_thread);
    thrd_join(sscreen->gpu_load_thread, NULL);
-   sscreen->gpu_load_thread = 0;
+   sscreen->gpu_load_thread_created = false;
 }
 
 static uint64_t si_read_mmio_counter(struct si_screen *sscreen, unsigned busy_index)
 {
    /* Start the thread if needed. */
-   if (!sscreen->gpu_load_thread) {
+   if (!sscreen->gpu_load_thread_created) {
       simple_mtx_lock(&sscreen->gpu_load_mutex);
       /* Check again inside the mutex. */
-      if (!sscreen->gpu_load_thread)
-         sscreen->gpu_load_thread = u_thread_create(si_gpu_load_thread, sscreen);
+      if (!sscreen->gpu_load_thread_created) {
+         if (thrd_success == u_thread_create(&sscreen->gpu_load_thread, si_gpu_load_thread, sscreen)) {
+            sscreen->gpu_load_thread_created = true;
+         }
+      }
       simple_mtx_unlock(&sscreen->gpu_load_mutex);
    }
 

src/gallium/drivers/radeonsi/si_pipe.h

@@ -630,6 +630,7 @@ struct si_screen {
    /* GPU load thread. */
    simple_mtx_t gpu_load_mutex;
    thrd_t gpu_load_thread;
+   bool gpu_load_thread_created;
    union si_mmio_counters mmio_counters;
    volatile unsigned gpu_load_stop_thread; /* bool */
 

src/gallium/frontends/nine/nine_state.c

@@ -163,8 +163,7 @@ nine_csmt_create( struct NineDevice9 *This )
 
     ctx->device = This;
 
-    ctx->worker = u_thread_create(nine_csmt_worker, ctx);
-    if (!ctx->worker) {
+    if (thrd_success != u_thread_create(&ctx->worker, nine_csmt_worker, ctx)) {
         nine_queue_delete(ctx->pool);
         FREE(ctx);
         return NULL;

src/gallium/tests/unit/pipe_barrier_test.c

@@ -114,7 +114,7 @@ int main(int argc, char *argv[])
 
    for (i = 0; i < NUM_THREADS; i++) {
       thread_ids[i] = i;
-      threads[i] = u_thread_create(thread_function, (void *) &thread_ids[i]);
+      u_thread_create(threads + i, thread_function, (void *) &thread_ids[i]);
    }
 
    for (i = 0; i < NUM_THREADS; i++ ) {

src/util/u_queue.c

@@ -337,9 +337,7 @@ util_queue_create_thread(struct util_queue *queue, unsigned index)
    input->queue = queue;
    input->thread_index = index;
 
-   queue->threads[index] = u_thread_create(util_queue_thread_func, input);
-
-   if (!queue->threads[index]) {
+   if (thrd_success != u_thread_create(queue->threads + index, util_queue_thread_func, input)) {
       free(input);
       return false;
    }

src/util/u_thread.h

@@ -101,26 +101,22 @@ util_get_current_cpu(void)
 #endif
 }
 
-static inline thrd_t u_thread_create(int (*routine)(void *), void *param)
+static inline int u_thread_create(thrd_t *thrd, int (*routine)(void *), void *param)
 {
-   thrd_t thread;
+   int ret = thrd_error;
 #ifdef HAVE_PTHREAD
    sigset_t saved_set, new_set;
-   int ret;
 
    sigfillset(&new_set);
    sigdelset(&new_set, SIGSYS);
    pthread_sigmask(SIG_BLOCK, &new_set, &saved_set);
-   ret = thrd_create( &thread, routine, param );
+   ret = thrd_create(thrd, routine, param);
    pthread_sigmask(SIG_SETMASK, &saved_set, NULL);
 #else
-   int ret;
-   ret = thrd_create( &thread, routine, param );
+   ret = thrd_create(thrd, routine, param);
 #endif
-   if (ret)
-      return 0;
 
-   return thread;
+   return ret;
 }
 
 static inline void u_thread_setname( const char *name )