Base: Don't overwrite the thread id when ThreadMain exits. There's

base/threading/thread.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/threading/thread.h"
 
 #include "base/bind.h"
 #include "base/lazy_instance.h"
 #include "base/third_party/dynamic_annotations/dynamic_annotations.h"
 #include "base/threading/thread_local.h"
@@ skipping 29 matching lines @@
   WaitableEvent event;
 
   explicit StartupData(const Options& opt)
       : options(opt),
         event(false, false) {}
 };
 
 Thread::Thread(const char* name)
     : started_(false),
       stopping_(false),
+      running_(false),
       startup_data_(NULL),
       thread_(0),
       message_loop_(NULL),
       thread_id_(kInvalidThreadId),
       name_(name) {
 }
 
 Thread::~Thread() {
   Stop();
 }
@@ skipping 57 matching lines @@
   // with ThreadMain, so we annotate it to stay silent under ThreadSanitizer.
   DCHECK_NE(ANNOTATE_UNPROTECTED_READ(thread_id_), PlatformThread::CurrentId());
 
   if (stopping_ || !message_loop_)
     return;
 
   stopping_ = true;
   message_loop_->PostTask(FROM_HERE, base::Bind(&ThreadQuitHelper));
 }
 
+bool Thread::IsRunning() const {
+  return running_;
+}
+
 void Thread::Run(MessageLoop* message_loop) {
   message_loop->Run();
 }
 
 void Thread::SetThreadWasQuitProperly(bool flag) {
   lazy_tls_bool.Pointer()->Set(flag);
 }
 
 bool Thread::GetThreadWasQuitProperly() {
   bool quit_properly = true;
@@ skipping 16 matching lines @@
     message_loop_ = &message_loop;
 
     // Let the thread do extra initialization.
     // Let's do this before signaling we are started.
     Init();
 
     startup_data_->event.Signal();
     // startup_data_ can't be touched anymore since the starting thread is now
     // unlocked.
 
+    running_ = true;
     Run(message_loop_);
+    running_ = false;
 
     // Let the thread do extra cleanup.
     CleanUp();
 
     // Assert that MessageLoop::Quit was called by ThreadQuitHelper.
     DCHECK(GetThreadWasQuitProperly());
 
     // We can't receive messages anymore.
     message_loop_ = NULL;
   }
-  thread_id_ = kInvalidThreadId;
 }
 
 }  // namespace base