michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef mozilla_ThreadStackHelper_h
michael@0: #define mozilla_ThreadStackHelper_h
michael@0: 
michael@0: #include "mozilla/ThreadHangStats.h"
michael@0: 
michael@0: #include "GeckoProfiler.h"
michael@0: 
michael@0: #include <stddef.h>
michael@0: 
michael@0: #if defined(XP_LINUX)
michael@0: #include <signal.h>
michael@0: #include <semaphore.h>
michael@0: #include <sys/types.h>
michael@0: #elif defined(XP_WIN)
michael@0: #include <windows.h>
michael@0: #elif defined(XP_MACOSX)
michael@0: #include <mach/mach.h>
michael@0: #endif
michael@0: 
michael@0: namespace mozilla {
michael@0: 
michael@0: /**
michael@0:  * ThreadStackHelper is used to retrieve the profiler pseudo-stack of a
michael@0:  * thread, as an alternative of using the profiler to take a profile.
michael@0:  * The target thread first declares an ThreadStackHelper instance;
michael@0:  * then another thread can call ThreadStackHelper::GetStack to retrieve
michael@0:  * the pseudo-stack of the target thread at that instant.
michael@0:  *
michael@0:  * Only non-copying labels are included in the stack, which means labels
michael@0:  * with custom text and markers are not included.
michael@0:  */
michael@0: class ThreadStackHelper
michael@0: {
michael@0: public:
michael@0:   typedef Telemetry::HangHistogram::Stack Stack;
michael@0: 
michael@0: private:
michael@0: #ifdef MOZ_ENABLE_PROFILER_SPS
michael@0:   const PseudoStack* const mPseudoStack;
michael@0: #endif
michael@0:   Stack mStackBuffer;
michael@0:   size_t mMaxStackSize;
michael@0: 
michael@0:   bool PrepareStackBuffer(Stack& aStack);
michael@0:   void FillStackBuffer();
michael@0: 
michael@0: public:
michael@0:   /**
michael@0:    * Initialize ThreadStackHelper. Must be called from main thread.
michael@0:    */
michael@0:   static void Startup();
michael@0:   /**
michael@0:    * Uninitialize ThreadStackHelper. Must be called from main thread.
michael@0:    */
michael@0:   static void Shutdown();
michael@0: 
michael@0:   /**
michael@0:    * Create a ThreadStackHelper instance targeting the current thread.
michael@0:    */
michael@0:   ThreadStackHelper();
michael@0: 
michael@0:   ~ThreadStackHelper();
michael@0: 
michael@0:   /**
michael@0:    * Retrieve the current pseudostack of the thread associated
michael@0:    * with this ThreadStackHelper.
michael@0:    *
michael@0:    * @param aStack Stack instance to be filled.
michael@0:    */
michael@0:   void GetStack(Stack& aStack);
michael@0: 
michael@0: #if defined(XP_LINUX)
michael@0: private:
michael@0:   static int sInitialized;
michael@0:   static sem_t sSem;
michael@0:   static struct sigaction sOldSigAction;
michael@0:   static ThreadStackHelper* sCurrent;
michael@0: 
michael@0:   static void SigAction(int aSignal, siginfo_t* aInfo, void* aContext);
michael@0: 
michael@0:   pid_t mThreadID;
michael@0: 
michael@0: #elif defined(XP_WIN)
michael@0: private:
michael@0:   bool mInitialized;
michael@0:   HANDLE mThreadID;
michael@0: 
michael@0: #elif defined(XP_MACOSX)
michael@0: private:
michael@0:   thread_act_t mThreadID;
michael@0: 
michael@0: #endif
michael@0: };
michael@0: 
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif // mozilla_ThreadStackHelper_h