Move ScriptStreamerThread::shutdown to CoreInitializer::shutdown

third_party/WebKit/Source/web/WebKit.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 164 matching lines @@
 {
 #if defined(LEAK_SANITIZER)
     // If LSan is about to perform leak detection, release all the registered
     // static Persistent<> root references to global caches that Blink keeps,
     // followed by GCs to clear out all they referred to. A full v8 GC cycle
     // is needed to flush out all garbage.
     //
     // This is not needed for caches over non-Oilpan objects, as they're
     // not scanned by LSan due to being held in non-global storage
     // ("static" references inside functions/methods.)
     if (ThreadState* threadState = ThreadState::current()) {

[haraken, 2016/03/09 13:02:36]

Sigbjorn: Not related to this CL, do you think we can move this code to
Heap::shutdownMainThread?

I don't fully understand the part "a full v8 GC cycle is needed to flush out all
garbage" because no V8 GC will be scheduled after this point. V8 is shut down at
line 205.

Anyways, if we call Heap::collectAllGarbage in Heap::shutdownMainThread, it's
called after unregisterTraceDOMWrappers is called. This means that the Oilpan GC
will ignore all references from V8 wrappers, which is a desirable thing for us.

[sof, 2016/03/09 16:53:20]

The comment is just out of date -- getting all the LSan-reported leaks flushed
out needed some attempts to get it right & it used to call
RequestGarbageCollectionForTesting() for some time to trigger a full v8 GC wash.

=> It can plausibly be moved.

         threadState->releaseStaticPersistentNodes();
         Heap::collectAllGarbage();
     }
 #endif
 
     // currentThread() is null if we are running on a thread without a message loop.
     if (Platform::current()->currentThread()) {
         Platform::current()->unregisterMemoryDumpProvider(WebCacheMemoryDumpProvider::instance());
         Platform::current()->unregisterMemoryDumpProvider(FontCacheMemoryDumpProvider::instance());
 
         // We don't need to (cannot) remove s_endOfTaskRunner from the current
         // message loop, because the message loop is already destructed before
         // the shutdown() is called.
         delete s_endOfTaskRunner;
         s_endOfTaskRunner = nullptr;
     }
 
-    // Shutdown V8-related background threads before V8 is ramped down. Note
-    // that this will wait the thread to stop its operations.
-    ScriptStreamerThread::shutdown();
-
     ThreadState::current()->unregisterTraceDOMWrappers();
 
     V8Initializer::shutdownMainThread();
 
     modulesInitializer().shutdown();
 
     shutdownWithoutV8();
 }
 
 void shutdownWithoutV8()
@@ skipping 70 matching lines @@
     ASSERT(!reloadPages);
     Page::refreshPlugins();
 }
 
 void decommitFreeableMemory()
 {
     WTF::Partitions::decommitFreeableMemory();
 }
 
 } // namespace blink