Enable setting thread names on Linux

BUG=107547
TEST=Manual

Review URL: http://codereview.chromium.org/8936015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@114681 0039d316-1c4b-4281-b951-d872f2087c98

base/threading/platform_thread_posix.cc

@@ -166,11 +166,7 @@ void PlatformThread::Sleep(int duration_ms) {
     sleep_time = remaining;
 }
 
-// Linux SetName is currently disabled, as we need to distinguish between
-// helper threads (where it's ok to make this call) and the main thread
-// (where making this call renames our process, causing tools like killall
-// to stop working).
-#if 0 && defined(OS_LINUX)
+#if defined(OS_LINUX)
 // static
 void PlatformThread::SetName(const char* name) {
   // have to cast away const because ThreadLocalPointer does not support const
@@ -178,6 +174,13 @@ void PlatformThread::SetName(const char* name) {
   current_thread_name.Pointer()->Set(const_cast<char*>(name));
   tracked_objects::ThreadData::InitializeThreadContext(name);
 
+  // On linux we can get the thread names to show up in the debugger by setting
+  // the process name for the LWP.  We don't want to do this for the main
+  // thread because that would rename the process, causing tools like killall
+  // to stop working.
+  if (PlatformThread::CurrentId() == getpid())
+    return;
+
   // http://0pointer.de/blog/projects/name-your-threads.html
 
   // glibc recently added support for pthread_setname_np, but it's not