Move pthread_barrier_wait logic to __futexwait. NFC.

Author: kleisauke

system/lib/libc/musl/src/internal/pthread_impl.h

@@ -201,7 +201,20 @@ static inline void __wake(volatile void *addr, int cnt, int priv)
 static inline void __futexwait(volatile void *addr, int val, int priv)
 {
 #ifdef __EMSCRIPTEN__
-	__wait(addr, NULL, val, priv);
+	(void)priv;
+	const int is_runtime_thread = emscripten_is_main_runtime_thread();
+	if (is_runtime_thread) {
+		int e;
+		do {
+			// 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(addr, val, 1);
+		} while (e == -ETIMEDOUT);
+	} else {
+		// Can wait in one go.
+		emscripten_futex_wait(addr, val, INFINITY);
+	}
 #else
 	if (priv) priv = FUTEX_PRIVATE;
 	__syscall(SYS_futex, addr, FUTEX_WAIT|priv, val, 0) != -ENOSYS ||

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

@@ -83,28 +83,14 @@ int pthread_barrier_wait(pthread_barrier_t *b)
 		while (spins-- && !inst->finished)
 			a_spin();
 		a_inc(&inst->finished);
-#ifdef __EMSCRIPTEN__
-		int is_runtime_thread = emscripten_is_main_runtime_thread();
 		while (inst->finished == 1) {
-			if (is_runtime_thread) {
-				int e;
-				do {
-					// 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.
-				emscripten_futex_wait(&inst->finished, 1, INFINITY);
-			}
-		}
+#ifdef __EMSCRIPTEN__
+			__futexwait(&inst->finished, 1, 1);
 #else
-		while (inst->finished == 1) {
 			__syscall(SYS_futex,&inst->finished,FUTEX_WAIT|FUTEX_PRIVATE,1,0) != -ENOSYS
 			|| __syscall(SYS_futex,&inst->finished,FUTEX_WAIT,1,0);
-		}
 #endif
+		}
 		return PTHREAD_BARRIER_SERIAL_THREAD;
 	}