Added unique function names (IOTHreadRun, DBTHreadRun, etc)

content/browser/browser_thread_impl.cc

 // Copyright (c) 2012 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 "content/browser/browser_thread_impl.h"
 
 #include <string>
 
 #include "base/atomicops.h"
 #include "base/bind.h"
@@ skipping 77 matching lines @@
   using base::subtle::AtomicWord;
   AtomicWord* storage =
       reinterpret_cast<AtomicWord*>(&globals.thread_delegates[identifier_]);
   AtomicWord stored_pointer = base::subtle::NoBarrier_Load(storage);
   BrowserThreadDelegate* delegate =
       reinterpret_cast<BrowserThreadDelegate*>(stored_pointer);
   if (delegate)
     delegate->Init();
 }
 
+// We disable optimizations for this block of functions so the compiler doesn't
+// merge them all together.
+// TODO(rtenneti): What is the equivalent for other compilers?
+#if defined(COMPILER_MSVC)

[sky, 2012/07/23 15:49:17]

Use MSVC_PUSH_DISABLE/POP_DISABLE to avoid the ifdefs (in
base/compiler_specific.h).

[ramant (doing other things), 2012/07/23 17:33:04]

Done.

+#pragma optimize("", off)
+MSVC_PUSH_DISABLE_WARNING(4748)
+#endif
+
+void BrowserThreadImpl::UIThreadRun(MessageLoop* message_loop) {
+  volatile int line_number = __LINE__;

[sky, 2012/07/23 15:49:17]

Why do you need the line numbers on all these?

[ramant (doing other things), 2012/07/23 17:33:04]

Compilers could optimize away all *ThreadRun functions away. line_number
provides a way to trick the optimizer (global?) not to fold this code (or keep
the function name in the callstack). jar mentioned secondary optimizations as
the other reason.

+  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);
+}
+
+#if defined(COMPILER_MSVC)
+MSVC_POP_WARNING()
+#pragma optimize("", on)
+#endif
+
+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();
 
   using base::subtle::AtomicWord;
   AtomicWord* storage =
       reinterpret_cast<AtomicWord*>(&globals.thread_delegates[identifier_]);
   AtomicWord stored_pointer = base::subtle::NoBarrier_Load(storage);
   BrowserThreadDelegate* delegate =
       reinterpret_cast<BrowserThreadDelegate*>(stored_pointer);
 
@@ skipping 268 matching lines @@
   AtomicWord* storage = reinterpret_cast<AtomicWord*>(
       &globals.thread_delegates[identifier]);
   AtomicWord old_pointer = base::subtle::NoBarrier_AtomicExchange(
       storage, reinterpret_cast<AtomicWord>(delegate));
 
   // This catches registration when previously registered.
   DCHECK(!delegate || !old_pointer);
 }
 
 }  // namespace content