Convert unnecessary EM_ASM() blocks to JS library functions in pthrea…

…ds library. (#10124)
emscripten-core · Jan 3, 2020 · ef45532 · ef45532
1 parent 041988e
commit ef45532
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Showing 2 changed files with 30 additions and 29 deletions.
diff --git a/src/library_pthread.js b/src/library_pthread.js
@@ -1341,6 +1341,29 @@ var LibraryPThread = {
     // Call inside asm.js/wasm module to set up the stack frame for this pthread in asm.js/wasm module scope
     establishStackSpace(stackTop, stackMax);
   },
+
+  // This function is called internally to notify target thread ID that it has messages it needs to
+  // process in its message queue inside the Wasm heap. As a helper, the caller must also pass the
+  // ID of the main browser thread to this function, to avoid needlessly ping-ponging between JS and
+  // Wasm boundaries.
+  _emscripten_notify_thread_queue: function(targetThreadId, mainThreadId) {
+    if (targetThreadId == mainThreadId) {
+      postMessage({cmd : 'processQueuedMainThreadWork'});
+    } else if (ENVIRONMENT_IS_PTHREAD) {
+      postMessage({targetThread: targetThreadId, cmd: 'processThreadQueue'});
+    } else {
+      var pthread = PThread.pthreads[targetThreadId];
+      var worker = pthread && pthread.worker;
+      if (!worker) {
+#if ASSERTIONS
+        err('Cannot send message to thread with ID ' + targetThreadId + ', unknown thread ID!');
+#endif
+        return /*0*/;
+      }
+      worker.postMessage({cmd : 'processThreadQueue'});
+    }
+    return 1;
+  }
 };
 
 autoAddDeps(LibraryPThread, '$PThread');

diff --git a/system/lib/pthread/library_pthread.c b/system/lib/pthread/library_pthread.c
@@ -186,6 +186,7 @@ static void em_queued_call_free(em_queued_call* call) {
 void emscripten_async_waitable_close(em_queued_call* call) { em_queued_call_free(call); }
 
 extern double emscripten_receive_on_main_thread_js(int functionIndex, int numCallArgs, double* args);
+extern int _emscripten_notify_thread_queue(pthread_t targetThreadId, pthread_t mainThreadId);
 
 #if defined(__has_feature)
 #if __has_feature(address_sanitizer)
@@ -513,35 +514,12 @@ static void EMSCRIPTEN_KEEPALIVE emscripten_async_queue_call_on_thread(
   // so send a message to it to ensure that it wakes up to start processing the command we have
   // posted.
   if (head == tail) {
-    if (target_thread == emscripten_main_browser_thread_id()) {
-      EM_ASM(postMessage({cmd : 'processQueuedMainThreadWork'}));
-    } else {
-      int success = EM_ASM_INT(
-        {
-          if (!ENVIRONMENT_IS_PTHREAD) {
-            if (!PThread.pthreads[$0] || !PThread.pthreads[$0].worker) {
-              // #if DEBUG
-              //						Module.printErr('Cannot send message
-              //to thread with ID ' + $0 + ', unknown thread ID!');
-              // #endif
-              return 0;
-            }
-            PThread.pthreads[$0].worker.postMessage({cmd : 'processThreadQueue'});
-          } else {
-            postMessage({targetThread : $0, cmd : 'processThreadQueue'});
-          }
-          return 1;
-        },
-        target_thread);
-
-      // Failed to dispatch the thread, delete the crafted message.
-      if (!success) {
-        em_queued_call_free(call);
-        pthread_mutex_unlock(&call_queue_lock);
-        return;
-      }
-
-      // TODO: Need to postMessage() to a specific target Worker that is hosting target_thread....
+    int success = _emscripten_notify_thread_queue(target_thread, emscripten_main_browser_thread_id());
+    // Failed to dispatch the thread, delete the crafted message.
+    if (!success) {
+      em_queued_call_free(call);
+      pthread_mutex_unlock(&call_queue_lock);
+      return;
     }
   }