PNaCl: Hold subprocess_mu while doing StartSrpcServices.

components/nacl/renderer/plugin/pnacl_translate_thread.h

 // 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.
 
 #ifndef COMPONENTS_NACL_RENDERER_PLUGIN_PNACL_TRANSLATE_THREAD_H_
 #define COMPONENTS_NACL_RENDERER_PLUGIN_PNACL_TRANSLATE_THREAD_H_
 
 #include <deque>
 #include <vector>
 
@@ skipping 95 matching lines @@
   // Used to guard compiler_subprocess, ld_subprocess,
   // compiler_subprocess_active_, and ld_subprocess_active_
   // (touched by the main thread and the translate thread).
   struct NaClMutex subprocess_mu_;
   // The compiler_subprocess and ld_subprocess memory is owned by the
   // coordinator so we do not delete them. However, the main thread delegates
   // shutdown to this thread, since this thread may still be accessing the
   // subprocesses. The *_subprocess_active flags indicate which subprocesses
   // are active to ensure the subprocesses don't get shutdown more than once.
   // The subprocess_mu_ must be held when shutting down the subprocesses
-  // or checking if it's already shut down (via the active flags).
+  // or otherwise accessing the service_runtime component of the subprocess.
   // There are some accesses to the subprocesses without locks held
-  // (invoking SRPC methods client).
+  // (invoking srpc_client methods -- in contrast to using the service_runtime).
   NaClSubprocess* compiler_subprocess_;
   NaClSubprocess* ld_subprocess_;
   bool compiler_subprocess_active_;
   bool ld_subprocess_active_;
 
   // Condition variable to synchronize communication with the SRPC thread.
   // SRPC thread waits on this condvar if data_buffers_ is empty (meaning
   // there is no bitcode to send to the translator), and the main thread
   // appends to data_buffers_ and signals it when it receives bitcode.
   struct NaClCondVar buffer_cond_;
@@ skipping 16 matching lines @@
   ErrorInfo* coordinator_error_info_;
   PP_PNaClOptions* pnacl_options_;
   std::string architecture_attributes_;
   PnaclCoordinator* coordinator_;
  private:
   NACL_DISALLOW_COPY_AND_ASSIGN(PnaclTranslateThread);
 };
 
 }
 #endif // COMPONENTS_NACL_RENDERER_PLUGIN_PNACL_TRANSLATE_THREAD_H_