trace_event support for thread names

base/threading/platform_thread_posix.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/platform_thread.h"
 
 #include <errno.h>
 #include <sched.h>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/safe_strerror_posix.h"
+#include "base/threading/thread_local.h"
 #include "base/threading/thread_restrictions.h"
 
 #if defined(OS_MACOSX)
 #include <mach/mach.h>
 #include <sys/resource.h>
 #include <algorithm>
 #endif
 
 #if defined(OS_LINUX)
 #include <dlfcn.h>
@@ skipping 11 matching lines @@
 #endif
 
 namespace base {
 
 #if defined(OS_MACOSX)
 void InitThreading();
 #endif
 
 namespace {
 
+static ThreadLocalPointer<char> current_thread_name;
+
 struct ThreadParams {
   PlatformThread::Delegate* delegate;
   bool joinable;
 };
 
 void* ThreadFunc(void* params) {
   ThreadParams* thread_params = static_cast<ThreadParams*>(params);
   PlatformThread::Delegate* delegate = thread_params->delegate;
   if (!thread_params->joinable)
     base::ThreadRestrictions::SetSingletonAllowed(false);
@@ skipping 107 matching lines @@
     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)
 // static
 void PlatformThread::SetName(const char* name) {
+  // have to cast away const because ThreadLocalPointer does not support const
+  // void*
+  current_thread_name.Set(const_cast<char*>(name));
+
   // http://0pointer.de/blog/projects/name-your-threads.html
 
   // glibc recently added support for pthread_setname_np, but it's not
   // commonly available yet.  So test for it at runtime.
   int (*dynamic_pthread_setname_np)(pthread_t, const char*);
   *reinterpret_cast<void**>(&dynamic_pthread_setname_np) =
       dlsym(RTLD_DEFAULT, "pthread_setname_np");
 
   if (dynamic_pthread_setname_np) {
     // This limit comes from glibc, which gets it from the kernel
@@ skipping 10 matching lines @@
     // truncated by the callee (see TASK_COMM_LEN above).)
     int err = prctl(PR_SET_NAME, name);
     if (err < 0)
       PLOG(ERROR) << "prctl(PR_SET_NAME)";
   }
 }
 #elif defined(OS_MACOSX)
 // Mac is implemented in platform_thread_mac.mm.
 #else
 // static
-void PlatformThread::SetName(const char* /*name*/) {
-  // Leave it unimplemented.
+void PlatformThread::SetName(const char* name) {
+  // have to cast away const because ThreadLocalPointer does not support const
+  // void*
+  current_thread_name.Set(const_cast<char*>(name));
 
   // (This should be relatively simple to implement for the BSDs; I
   // just don't have one handy to test the code on.)
 }
 #endif  // defined(OS_LINUX)
 
+
+#if !defined(OS_MACOSX)
+// Mac is implemented in platform_thread_mac.mm.
+// static
+const char* PlatformThread::GetName() {
+  return current_thread_name.Get();
+}
+#endif
+
 // static
 bool PlatformThread::Create(size_t stack_size, Delegate* delegate,
                             PlatformThreadHandle* thread_handle) {
   return CreateThread(stack_size, true /* joinable thread */,
                       delegate, thread_handle);
 }
 
 // static
 bool PlatformThread::CreateNonJoinable(size_t stack_size, Delegate* delegate) {
   PlatformThreadHandle unused;
@@ skipping 16 matching lines @@
 // Mac OS X uses lower-level mach APIs
 
 // static
 void PlatformThread::SetThreadPriority(PlatformThreadHandle, ThreadPriority) {
   // TODO(crogers): implement
   NOTIMPLEMENTED();
 }
 #endif
 
 }  // namespace base