Instrument callers of Semaphore::Signal to help with investigation of

src/debug/debug.cc

 // Copyright 2012 the V8 project 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 "src/debug/debug.h"
 
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 2141 matching lines @@
 // by the API client thread.
 void Debug::EnqueueCommandMessage(Vector<const uint16_t> command,
                                   v8::Debug::ClientData* client_data) {
   // Need to cast away const.
   CommandMessage message = CommandMessage::New(
       Vector<uint16_t>(const_cast<uint16_t*>(command.start()),
                        command.length()),
       client_data);
   isolate_->logger()->DebugTag("Put command on command_queue.");
   command_queue_.Put(message);
-  command_received_.Signal();
+  command_received_.Signal("Debug::EnqueueCommandMessage");
 
   // Set the debug command break flag to have the command processed.
   if (!in_debug_scope()) isolate_->stack_guard()->RequestDebugCommand();
 }
 
 
 MaybeHandle<Object> Debug::Call(Handle<Object> fun, Handle<Object> data) {
   DebugScope debug_scope(this);
   if (debug_scope.failed()) return isolate_->factory()->undefined_value();
 
@@ skipping 413 matching lines @@
 }
 
 
 void LockingCommandMessageQueue::Clear() {
   base::LockGuard<base::Mutex> lock_guard(&mutex_);
   queue_.Clear();
 }
 
 }  // namespace internal
 }  // namespace v8