Cherry-pick remainder of PR 15739

Author: kleisauke

system/lib/libc/musl/src/thread/__timedwait.c

@@ -56,21 +56,20 @@ int __timedwait_cp(volatile int *addr, int val,
 		top = &to;
 	}
 #ifdef __EMSCRIPTEN__
-	double msecsToSleep = top ? (top->tv_sec * 1000 + top->tv_nsec / 1000000.0) : INFINITY;
+	pthread_t self = __pthread_self();
+	double msecsToSleep = top ? (top->tv_sec * 1000.0 + top->tv_nsec / 1000000.0) : INFINITY;
 	int is_runtime_thread = emscripten_is_main_runtime_thread();
 
 	// Main runtime thread may need to run proxied calls, so sleep in very small slices to be responsive.
 	double max_ms_slice_to_sleep = is_runtime_thread ? 1 : 100;
 
 	// cp suffix in the function name means "cancellation point", so this wait can be cancelled
-	// by the users unless current threads cancelability is set to PTHREAD_CANCEL_DISABLE
+	// by the users unless current threads cancellability is set to PTHREAD_CANCEL_DISABLE
 	// which may be either done by the user of __timedwait() function.
-	if (is_runtime_thread ||
-	    pthread_self()->canceldisable != PTHREAD_CANCEL_DISABLE ||
-	    pthread_self()->cancelasync == PTHREAD_CANCEL_ASYNCHRONOUS) {
+	if (is_runtime_thread || self->canceldisable != PTHREAD_CANCEL_DISABLE || self->cancelasync) {
 		double sleepUntilTime = emscripten_get_now() + msecsToSleep;
 		do {
-			if (pthread_self()->cancel) {
+			if (self->cancel) {
 				// Emscripten-specific return value: The wait was canceled by user calling
 				// pthread_cancel() for this thread, and the caller needs to cooperatively
 				// cancel execution.

system/lib/libc/musl/src/thread/__wait.c

@@ -15,16 +15,17 @@ void __wait(volatile int *addr, volatile int *waiters, int val, int priv)
 	}
 	if (waiters) a_inc(waiters);
 #ifdef __EMSCRIPTEN__
+	pthread_t self = __pthread_self();
 	int is_runtime_thread = emscripten_is_main_runtime_thread();
 
 	// Main runtime thread may need to run proxied calls, so sleep in very small slices to be responsive.
 	double max_ms_slice_to_sleep = is_runtime_thread ? 1 : 100;
 
 	while (*addr==val) {
-		if (is_runtime_thread || pthread_self()->cancelasync == PTHREAD_CANCEL_ASYNCHRONOUS) {
+		if (is_runtime_thread || self->cancelasync) {
 			int e;
 			do {
-				if (pthread_self()->cancel) {
+				if (self->cancel) {
 					if (waiters) a_dec(waiters);
 					return;
 				}

system/lib/libc/musl/src/thread/pthread_barrier_wait.c

@@ -93,10 +93,10 @@ int pthread_barrier_wait(pthread_barrier_t *b)
 			if (is_runtime_thread) {
 				int e;
 				do {
-					// Main runtime thread may need to run proxied calls, so sleep in very small slices to be responsive.
-					e = emscripten_futex_wait(&inst->finished, 1, 1);
 					// Assist other threads by executing proxied operations that are effectively singlethreaded.
 					emscripten_main_thread_process_queued_calls();
+					// Main runtime thread may need to run proxied calls, so sleep in very small slices to be responsive.
+					e = emscripten_futex_wait(&inst->finished, 1, 1);
 				} while (e == -ETIMEDOUT);
 			} else {
 				// Can wait in one go.

system/lib/pthread/library_pthread.c

@@ -382,25 +382,21 @@ static CallQueue* GetOrAllocateQueue(void* target) {
   return q;
 }
 
+// TODO(kleisauke): All paths call this with timeoutMSecs == INFINITY, perhaps drop this param?
 EMSCRIPTEN_RESULT emscripten_wait_for_call_v(em_queued_call* call, double timeoutMSecs) {
+  emscripten_set_current_thread_status(EM_THREAD_STATUS_WAITPROXY);
+
   int r;
+  double target = emscripten_get_now() + timeoutMSecs;
+  do {
+    r = -emscripten_futex_wait(&call->operationDone, 0, timeoutMSecs);
 
-  int done = atomic_load(&call->operationDone);
-  if (!done) {
-    double now = emscripten_get_now();
-    double waitEndTime = now + timeoutMSecs;
-    emscripten_set_current_thread_status(EM_THREAD_STATUS_WAITPROXY);
-    while (!done && now < waitEndTime) {
-      r = emscripten_futex_wait(&call->operationDone, 0, waitEndTime - now);
-      done = atomic_load(&call->operationDone);
-      now = emscripten_get_now();
-    }
-    emscripten_set_current_thread_status(EM_THREAD_STATUS_RUNNING);
-  }
-  if (done)
-    return EMSCRIPTEN_RESULT_SUCCESS;
-  else
-    return EMSCRIPTEN_RESULT_TIMED_OUT;
+    timeoutMSecs = target - emscripten_get_now();
+  } while (r == ETIMEDOUT && timeoutMSecs > 0);
+
+  emscripten_set_current_thread_status(EM_THREAD_STATUS_RUNNING);
+
+  return r == ETIMEDOUT ? EMSCRIPTEN_RESULT_TIMED_OUT : EMSCRIPTEN_RESULT_SUCCESS;
 }
 
 EMSCRIPTEN_RESULT emscripten_wait_for_call_i(