Fix race condition in renderer message loop

Ref nwjs/nw.js#7497 Ref nwjs/nw.js#7590
nwjs · Oct 22, 2020 · 17d0a01 · 17d0a01
1 parent 62f83a7
commit 17d0a01
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Showing 2 changed files with 11 additions and 0 deletions.
diff --git a/base/message_loop/message_pump_uv.cc b/base/message_loop/message_pump_uv.cc
@@ -111,6 +111,13 @@ void MessagePumpUV::Run(Delegate* delegate) {
       continue;
     }
 
+    if (event_.IsSignaled()) {
+      //there is a chance that wake_event_ got processed in uv loop
+      //run above. then the next wait is stalled.
+      event_.Reset();
+      g_msg_pump_did_work_fn(&ctx);
+      continue;
+    }
     if (next_work_info.delayed_run_time.is_max()) {
       // (*node::g_nw_uv_run)(loop, UV_RUN_ONCE);
       g_msg_pump_need_work_fn(&ctx);
@@ -123,6 +130,7 @@ void MessagePumpUV::Run(Delegate* delegate) {
         // uv_timer_stop(&delay_timer);
       g_msg_pump_delay_work_fn(&ctx, delay.InMilliseconds());
     }
+    event_.Reset();
     // Since event_ is auto-reset, we don't need to do anything special here
     // other than service each delegate method.
   }
@@ -161,6 +169,7 @@ void MessagePumpUV::ScheduleWork() {
 // #else
 //   uv_async_send(wakeup_event_);
 // #endif
+  event_.Signal();
   g_msg_pump_sched_work_fn(wakeup_event_);
 }
 

diff --git a/base/message_loop/message_pump_uv.h b/base/message_loop/message_pump_uv.h
@@ -9,6 +9,7 @@
 #include "base/message_loop/message_pump.h"
 #include "base/time/time.h"
 #include "content/common/content_export.h"
+#include "base/synchronization/waitable_event.h"
 
 #include <vector>
 
@@ -39,6 +40,7 @@ class BASE_EXPORT MessagePumpUV : public MessagePump {
   // Handle to wake up loop.
   std::vector<void*> wakeup_events_;
   void* wakeup_event_;
+  WaitableEvent event_;
 
   TimeTicks delayed_work_time_;