Remove some of the complexity from __timedwait.c. NFC

This should have been part of #26471.

The breaking up of the wait time for 2 of the 3 cases that are handled
here is now handled one layer own in emscripten_futex_wait:

1. Breaking up the wait because we are the main runtime thread.
2. Breaking up the wait because we are async cancelable.

The third cases here (breaking up the wait because we are cancelable
in the non-async sense) still needs to be handled here at the higher
level.

Author: sbc100

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

@@ -59,20 +59,16 @@ int __timedwait_cp(volatile int *addr, int val,
 
 #ifdef __EMSCRIPTEN__
 	double msecsToSleep = top ? (top->tv_sec * 1000 + 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
 	// 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_t self = pthread_self();
+	if (!self->canceldisable) {
+		double max_ms_slice_to_sleep = 100;
 		double sleepUntilTime = emscripten_get_now() + msecsToSleep;
 		do {
-			if (pthread_self()->cancel) {
+			if (self->cancel) {
 				// The thread was canceled by pthread_cancel().
 				// In the case of cancelasync or PTHREAD_CANCEL_ENABLE we can just call
 				// __pthread_testcancel(), which won't return at all.

system/lib/pthread/emscripten_futex_wait.c

@@ -48,7 +48,8 @@ static int futex_wait_main_browser_thread(volatile void* addr,
 
   while (1) {
 #ifdef __EMSCRIPTEN_PTHREADS__
-    if (cancelable && pthread_self()->cancel) {
+    if (cancelable) {
+      __pthread_testcancel();
       return -ETIMEDOUT;
     }
 #endif
@@ -130,7 +131,8 @@ int emscripten_futex_wait(volatile void *addr, uint32_t val, double max_wait_ms)
   emscripten_conditional_set_current_thread_status(EM_THREAD_STATUS_RUNNING, EM_THREAD_STATUS_WAITFUTEX);
 
 #ifdef __EMSCRIPTEN_PTHREADS__
-  bool cancelable = pthread_self()->cancelasync == PTHREAD_CANCEL_ASYNCHRONOUS;
+  pthread_t self = pthread_self();
+  bool cancelable = self->cancelasync;
 #else
   bool cancelable = false;
 #endif
@@ -211,8 +213,8 @@ int emscripten_futex_wait(volatile void *addr, uint32_t val, double max_wait_ms)
     }
 #endif
 #ifdef __EMSCRIPTEN_PTHREADS__
-    if (cancelable && ret == ATOMICS_WAIT_TIMED_OUT && pthread_self()->cancel) {
-      // Break out of the loop early if we were cancelled
+    if (cancelable && ret == ATOMICS_WAIT_TIMED_OUT) {
+      __pthread_testcancel();
       break;
     }
     // If remainder_ns is negative it means we want wait forever, and we don't

test/codesize/test_codesize_minimal_pthreads.json

@@ -1,10 +1,10 @@
 {
   "a.out.js": 7364,
   "a.out.js.gz": 3607,
-  "a.out.nodebug.wasm": 19265,
-  "a.out.nodebug.wasm.gz": 8934,
-  "total": 26629,
-  "total_gz": 12541,
+  "a.out.nodebug.wasm": 19231,
+  "a.out.nodebug.wasm.gz": 8905,
+  "total": 26595,
+  "total_gz": 12512,
   "sent": [
     "a (memory)",
     "b (emscripten_get_now)",

test/codesize/test_codesize_minimal_pthreads_memgrowth.json

@@ -1,10 +1,10 @@
 {
   "a.out.js": 7766,
   "a.out.js.gz": 3812,
-  "a.out.nodebug.wasm": 19266,
-  "a.out.nodebug.wasm.gz": 8935,
-  "total": 27032,
-  "total_gz": 12747,
+  "a.out.nodebug.wasm": 19234,
+  "a.out.nodebug.wasm.gz": 8919,
+  "total": 27000,
+  "total_gz": 12731,
   "sent": [
     "a (memory)",
     "b (emscripten_get_now)",

test/pthread/test_pthread_cancel_async.c

@@ -11,14 +11,24 @@
 #include <assert.h>
 #include <unistd.h>
 #include <errno.h>
+
+#ifdef __EMSCRIPTEN__
 #include <emscripten/console.h>
+#else
+void emscripten_out(const char* msg) {
+  printf("%s\n", msg);
+}
+
+void emscripten_outf(const char* msg, ...) {
+  printf("%s\n", msg);
+}
+#endif
 
 pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
 _Atomic long res = 43;
 _Atomic int started = false;
 
-static void cleanup_handler(void *arg)
-{
+static void cleanup_handler(void *arg) {
   long a = (long)arg;
   emscripten_outf("Called clean-up handler with arg %ld", a);
   res -= a;