/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_ThreadStackHelper_h

#define mozilla_ThreadStackHelper_h

#ifdef MOZ_GECKO_PROFILER

#include "js/ProfilingStack.h"

#include "HangDetails.h"

#include "nsThread.h"

#include <stddef.h>

#if defined(XP_LINUX)

#include <signal.h>

#include <semaphore.h>

#include <sys/types.h>

#elif defined(XP_WIN)

#include <windows.h>

#elif defined(XP_MACOSX)

#include <mach/mach.h>

#endif

// Support profiling stack and native stack on these platforms.

#if defined(XP_LINUX) || defined(XP_WIN) || defined(XP_MACOSX)

#  define MOZ_THREADSTACKHELPER_PROFILING_STACK

#  define MOZ_THREADSTACKHELPER_NATIVE_STACK

#endif

// Android x86 builds consistently crash in the Background Hang Reporter. bug

// 1368520.

#if defined(__ANDROID__)

#  undef MOZ_THREADSTACKHELPER_PROFILING_STACK

#  undef MOZ_THREADSTACKHELPER_NATIVE_STACK

#endif

namespace mozilla {

/**

 * ThreadStackHelper is used to retrieve the profiler's "profiling stack" of a

 * thread, as an alternative of using the profiler to take a profile.

 * The target thread first declares an ThreadStackHelper instance;

 * then another thread can call ThreadStackHelper::GetStack to retrieve

 * the profiling stack of the target thread at that instant.

 *

 * Only non-copying labels are included in the stack, which means labels

 * with custom text and markers are not included.

 */

class ThreadStackHelper : public ProfilerStackCollector

{

private:

  HangStack* mStackToFill;

  Array<char, nsThread::kRunnableNameBufSize>* mRunnableNameBuffer;

  size_t mMaxStackSize;

  size_t mMaxBufferSize;

  size_t mDesiredStackSize;

  size_t mDesiredBufferSize;

  bool PrepareStackBuffer(HangStack& aStack);

public:

  /**

   * Create a ThreadStackHelper instance targeting the current thread.

   */

  ThreadStackHelper();

  /**

   * Retrieve the current interleaved stack of the thread associated with this ThreadStackHelper.

   *

   * @param aStack        HangStack instance to be filled.

   * @param aRunnableName The name of the current runnable on the target thread.

   * @param aStackWalk    If true, native stack frames will be collected

   *                      along with profiling stack frames.

   */

  void GetStack(HangStack& aStack, nsACString& aRunnableName, bool aStackWalk);

  /**

   * Retrieve the thread's profiler thread ID.

   */

  int GetThreadId() const { return mThreadId; }

protected:

  /**

   * ProfilerStackCollector

   */

  virtual void SetIsMainThread() override;

  virtual void CollectNativeLeafAddr(void* aAddr) override;

  virtual void CollectJitReturnAddr(void* aAddr) override;

  virtual void CollectWasmFrame(const char* aLabel) override;

  virtual void CollectProfilingStackFrame(const js::ProfilingStackFrame& aEntry) override;

private:

  void TryAppendFrame(mozilla::HangEntry aFrame);

  // The profiler's unique thread identifier for the target thread.

  int mThreadId;

};

} // namespace mozilla

#endif // MOZ_GECKO_PROFILER

#endif // mozilla_ThreadStackHelper_h