Added unique function names (IOThreadRun, DBThreadRun, etc)

which make it possible to tell the thread name in crash dumps
from the call stack. Added a volatile automatic variable to
avoid global optimizers optimizing the function.

This change would help us to triage ThreadWatcher crashes
for IO thread. It would also help in debugging crashes.

R=sky, jar
Review URL: https://chromiumcodereview.appspot.com/10796079

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@147949 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/browser_thread_impl.cc

@@ -95,6 +95,91 @@ void BrowserThreadImpl::Init() {
     delegate->Init();
 }
 
+// We disable optimizations for this block of functions so the compiler doesn't
+// merge them all together.
+MSVC_DISABLE_OPTIMIZE()
+MSVC_PUSH_DISABLE_WARNING(4748)
+
+void BrowserThreadImpl::UIThreadRun(MessageLoop* message_loop) {
+  volatile int line_number = __LINE__;
+  Thread::Run(message_loop);
+  CHECK_GT(line_number, 0);
+}
+
+void BrowserThreadImpl::DBThreadRun(MessageLoop* message_loop) {
+  volatile int line_number = __LINE__;
+  Thread::Run(message_loop);
+  CHECK_GT(line_number, 0);
+}
+
+void BrowserThreadImpl::WebKitThreadRun(MessageLoop* message_loop) {
+  volatile int line_number = __LINE__;
+  Thread::Run(message_loop);
+  CHECK_GT(line_number, 0);
+}
+
+void BrowserThreadImpl::FileThreadRun(MessageLoop* message_loop) {
+  volatile int line_number = __LINE__;
+  Thread::Run(message_loop);
+  CHECK_GT(line_number, 0);
+}
+
+void BrowserThreadImpl::FileUserBlockingThreadRun(MessageLoop* message_loop) {
+  volatile int line_number = __LINE__;
+  Thread::Run(message_loop);
+  CHECK_GT(line_number, 0);
+}
+
+void BrowserThreadImpl::ProcessLauncherThreadRun(MessageLoop* message_loop) {
+  volatile int line_number = __LINE__;
+  Thread::Run(message_loop);
+  CHECK_GT(line_number, 0);
+}
+
+void BrowserThreadImpl::CacheThreadRun(MessageLoop* message_loop) {
+  volatile int line_number = __LINE__;
+  Thread::Run(message_loop);
+  CHECK_GT(line_number, 0);
+}
+
+void BrowserThreadImpl::IOThreadRun(MessageLoop* message_loop) {
+  volatile int line_number = __LINE__;
+  Thread::Run(message_loop);
+  CHECK_GT(line_number, 0);
+}
+
+MSVC_POP_WARNING()
+MSVC_ENABLE_OPTIMIZE();
+
+void BrowserThreadImpl::Run(MessageLoop* message_loop) {
+  BrowserThread::ID thread_id;
+  if (!GetCurrentThreadIdentifier(&thread_id))
+    return Thread::Run(message_loop);
+
+  switch (thread_id) {
+    case BrowserThread::UI:
+      return UIThreadRun(message_loop);
+    case BrowserThread::DB:
+      return DBThreadRun(message_loop);
+    case BrowserThread::WEBKIT_DEPRECATED:
+      return WebKitThreadRun(message_loop);
+    case BrowserThread::FILE:
+      return FileThreadRun(message_loop);
+    case BrowserThread::FILE_USER_BLOCKING:
+      return FileUserBlockingThreadRun(message_loop);
+    case BrowserThread::PROCESS_LAUNCHER:
+      return ProcessLauncherThreadRun(message_loop);
+    case BrowserThread::CACHE:
+      return CacheThreadRun(message_loop);
+    case BrowserThread::IO:
+      return IOThreadRun(message_loop);
+    case BrowserThread::ID_COUNT:
+      CHECK(false);  // This shouldn't actually be reached!
+      break;
+  }
+  Thread::Run(message_loop);
+}
+
 void BrowserThreadImpl::CleanUp() {
   BrowserThreadGlobals& globals = g_globals.Get();
 

content/browser/browser_thread_impl.h

@@ -27,6 +27,7 @@ class CONTENT_EXPORT BrowserThreadImpl
 
  protected:
   virtual void Init() OVERRIDE;
+  virtual void Run(MessageLoop* message_loop) OVERRIDE;
   virtual void CleanUp() OVERRIDE;
 
  private:
@@ -35,6 +36,17 @@ class CONTENT_EXPORT BrowserThreadImpl
   // the API cleaner. Therefore make BrowserThread a friend class.
   friend class BrowserThread;
 
+  // The following are unique function names that makes it possible to tell
+  // the thread id from the callstack alone in crash dumps.
+  void UIThreadRun(MessageLoop* message_loop);
+  void DBThreadRun(MessageLoop* message_loop);
+  void WebKitThreadRun(MessageLoop* message_loop);
+  void FileThreadRun(MessageLoop* message_loop);
+  void FileUserBlockingThreadRun(MessageLoop* message_loop);
+  void ProcessLauncherThreadRun(MessageLoop* message_loop);
+  void CacheThreadRun(MessageLoop* message_loop);
+  void IOThreadRun(MessageLoop* message_loop);
+
   static bool PostTaskHelper(
       BrowserThread::ID identifier,
       const tracked_objects::Location& from_here,