emscripten_thread_supports_atomics_wait() is now public

Author: cwoffenden

system/include/emscripten/threading.h

@@ -48,6 +48,11 @@ int emscripten_is_main_runtime_thread(void);
 // this returns 1.
 int emscripten_is_main_browser_thread(void);
 
+// Return non-zero if the calling thread supports Atomic.wait (For example if called from
+// the main browser or audio worklet thread, this function will return zero since blocking
+// is not allowed there).
+int emscripten_thread_supports_atomics_wait(void);
+
 // A temporary workaround to issue
 // https://github.com/emscripten-core/emscripten/issues/3495:
 // Call this in the body of all lock-free atomic (cas) loops that the main

system/lib/pthread/emscripten_futex_wait.c

@@ -12,7 +12,6 @@
 #include <stdio.h>
 #include <sys/param.h>
 #include "atomic.h"
-#include "threading_internal.h"
 #include "pthread_impl.h"
 
 extern void* _emscripten_main_thread_futex;
@@ -129,7 +128,7 @@ int emscripten_futex_wait(volatile void *addr, uint32_t val, double max_wait_ms)
 
   // For the main browser thread and audio worklets we can't use
   // __builtin_wasm_memory_atomic_wait32 so we have busy wait instead.
-  if (!_emscripten_thread_supports_atomics_wait()) {
+  if (!emscripten_thread_supports_atomics_wait()) {
     ret = futex_wait_main_browser_thread(addr, val, max_wait_ms);
     emscripten_conditional_set_current_thread_status(EM_THREAD_STATUS_WAITFUTEX, EM_THREAD_STATUS_RUNNING);
     return ret;

system/lib/pthread/emscripten_thread_state.S

@@ -54,8 +54,8 @@ emscripten_is_main_browser_thread:
   end_function
 
 # Semantically the same as testing "!ENVIRONMENT_IS_WEB && !ENVIRONMENT_IS_AUDIO_WORKLET" in JS
-.globl _emscripten_thread_supports_atomics_wait
-_emscripten_thread_supports_atomics_wait:
-  .functype _emscripten_thread_supports_atomics_wait () -> (i32)
+.globl emscripten_thread_supports_atomics_wait
+emscripten_thread_supports_atomics_wait:
+  .functype emscripten_thread_supports_atomics_wait () -> (i32)
   global.get supports_wait
   end_function

system/lib/pthread/threading_internal.h

@@ -97,8 +97,3 @@ int _emscripten_default_pthread_stack_size();
 void __set_thread_state(pthread_t ptr, int is_main, int is_runtime, int can_block);
 
 double _emscripten_receive_on_main_thread_js(int funcIndex, void* emAsmAddr, pthread_t callingThread, int numCallArgs, double* args);
-
-// Return non-zero if the calling thread supports Atomic.wait (For example
-// if called from the main browser thread, this function will return zero
-// since blocking is not allowed there).
-int _emscripten_thread_supports_atomics_wait(void);

test/webaudio/audioworklet_emscripten_locks.cpp

@@ -1,3 +1,4 @@
+#include <emscripten/threading.h>
 #include <emscripten/wasm_worker.h>
 #include <emscripten/webaudio.h>
 #include <stdio.h>
@@ -12,16 +13,11 @@
 // - emscripten_lock_release()
 // - emscripten_get_now() does not crash in a Wasm Audio Worklet.
 
-// Todo: add/find a way to verify atomic wait fails?
-
-// In system/lib/pthread/emscripten_thread_state.S
-extern "C" int _emscripten_thread_supports_atomics_wait(void);
-
 emscripten_lock_t testLock = EMSCRIPTEN_LOCK_T_STATIC_INITIALIZER;
 int testSuccess = 0;
 
 bool ProcessAudio(int numInputs, const AudioSampleFrame *inputs, int numOutputs, AudioSampleFrame *outputs, int numParams, const AudioParamFrame *params, void *userData) {
-  int supportsAtomicWait = _emscripten_thread_supports_atomics_wait();
+  int supportsAtomicWait = emscripten_thread_supports_atomics_wait();
   printf("supportsAtomicWait: %d\n", supportsAtomicWait);
   assert(!supportsAtomicWait);
   //emscripten_futex_wake(&futexLocation, 1);