Signal thread names in instrumented binaries, even when a debugger is not attached.

base/threading/platform_thread_win.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 "base/threading/platform_thread.h"
 
 #include "base/debug/alias.h"
+#include "base/debug/profiler.h"
 #include "base/logging.h"
 #include "base/threading/thread_local.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/tracked_objects.h"
 
 #include "base/win/windows_version.h"
 
 namespace base {
 
 namespace {
@@ skipping 108 matching lines @@
   // thread, as it exists only in the chrome.exe image, and never spawns or runs
   // tasks (items which could be profiled).  This test avoids the notification,
   // which would also (as a side effect) initialize the profiler in this unused
   // context, including setting up thread local storage, etc.  The performance
   // impact is not terrible, but there is no reason to do initialize it.
   if (0 != strcmp(name, "BrokerEvent"))
     tracked_objects::ThreadData::InitializeThreadContext(name);
 
   // The debugger needs to be around to catch the name in the exception.  If
   // there isn't a debugger, we are just needlessly throwing an exception.
-  if (!::IsDebuggerPresent())
+  // If this image file is instrumented, we raise the exception anyway
+  // to provide the profiler with human-readable thread names.
+  if (!::IsDebuggerPresent() && !base::debug::IsBinaryInstrumented())

[jar (doing other things), 2012/05/30 19:41:23]

FWIW: In the about:profiler world, we depend on a Thread object to provide its
name, rather than the OS (which is really what is getting set here).

Have you considered relying on that instead of the OS setting, which the
debugger relies on (an we can't change the debugger)?

[Sigurður Ásgeirsson, 2012/05/30 20:52:12]

Yups, as per my previous message, this is more useful as it uses an existing
"interface" or convention also used by other windows libraries. It also allows
the profiler and chrome binaries to be loosely coupled.

     return;
 
   SetNameInternal(CurrentId(), name);
 }
 
 // static
 const char* PlatformThread::GetName() {
   return current_thread_name.Get();
 }
 
@@ skipping 53 matching lines @@
     case kThreadPriority_Normal:
       ::SetThreadPriority(handle, THREAD_PRIORITY_NORMAL);
       break;
     case kThreadPriority_RealtimeAudio:
       ::SetThreadPriority(handle, THREAD_PRIORITY_TIME_CRITICAL);
       break;
   }
 }
 
 }  // namespace base