gecko-dev/xpcom/threads/ThreadStackHelper.h

159 строки
4.5 KiB
C++

/* -*- 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
#include "mozilla/ThreadHangStats.h"
#include "js/ProfilingStack.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 pseudostack on these platforms.
#if defined(XP_LINUX) || defined(XP_WIN) || defined(XP_MACOSX)
# ifdef MOZ_GECKO_PROFILER
# define MOZ_THREADSTACKHELPER_PSEUDO
# endif
#endif
#if defined(MOZ_THREADSTACKHELPER_PSEUDO) && defined(XP_WIN)
# define MOZ_THREADSTACKHELPER_NATIVE
# if defined(__i386__) || defined(_M_IX86)
# define MOZ_THREADSTACKHELPER_X86
# elif defined(__x86_64__) || defined(_M_X64)
# define MOZ_THREADSTACKHELPER_X64
# elif defined(__arm__) || defined(_M_ARM)
# define MOZ_THREADSTACKHELPER_ARM
# else
// Unsupported architecture
# undef MOZ_THREADSTACKHELPER_NATIVE
# endif
#endif
namespace mozilla {
/**
* ThreadStackHelper is used to retrieve the profiler pseudo-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 pseudo-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:
typedef Telemetry::HangStack Stack;
// When a native stack is gathered, this vector holds the raw program counter
// values that FramePointerStackWalk will return to us after it walks the
// stack. When gathering the Telemetry payload, Telemetry will take care of
// mapping these program counters to proper addresses within modules.
typedef Telemetry::NativeHangStack NativeStack;
private:
Stack* mStackToFill;
#ifdef MOZ_THREADSTACKHELPER_PSEUDO
const PseudoStack* const mPseudoStack;
size_t mMaxStackSize;
size_t mMaxBufferSize;
#endif
bool PrepareStackBuffer(Stack& aStack);
void FillStackBuffer();
#ifdef MOZ_THREADSTACKHELPER_PSEUDO
const char* AppendJSEntry(const volatile js::ProfileEntry* aEntry,
intptr_t& aAvailableBufferSize,
const char* aPrevLabel);
#endif
public:
/**
* Initialize ThreadStackHelper. Must be called from main thread.
*/
static void Startup();
/**
* Uninitialize ThreadStackHelper. Must be called from main thread.
*/
static void Shutdown();
/**
* Create a ThreadStackHelper instance targeting the current thread.
*/
ThreadStackHelper();
~ThreadStackHelper();
/**
* Retrieve the current pseudostack of the thread associated
* with this ThreadStackHelper.
*
* @param aStack Stack instance to be filled.
*/
void GetPseudoStack(Stack& aStack);
/**
* Retrieve the current native stack of the thread associated
* with this ThreadStackHelper.
*
* @param aNativeStack NativeStack instance to be filled.
*/
void GetNativeStack(NativeStack& aNativeStack);
/**
* Retrieve the current pseudostack and native stack of the thread associated
* with this ThreadStackHelper. This method only pauses the target thread once
* to get both stacks.
*
* @param aStack Stack instance to be filled with the pseudostack.
* @param aNativeStack NativeStack instance to be filled with the native stack.
*/
void GetPseudoAndNativeStack(Stack& aStack, NativeStack& aNativeStack);
private:
// Fill in the passed aStack and aNativeStack datastructures with backtraces.
// If only aStack needs to be collected, nullptr may be passed for
// aNativeStack, and vice versa.
void GetStacksInternal(Stack* aStack, NativeStack* aNativeStack);
#if defined(XP_LINUX)
private:
static int sInitialized;
static int sFillStackSignum;
static void FillStackHandler(int aSignal, siginfo_t* aInfo, void* aContext);
sem_t mSem;
pid_t mThreadID;
#elif defined(XP_WIN)
private:
bool mInitialized;
HANDLE mThreadID;
void* mStackTop;
#elif defined(XP_MACOSX)
private:
thread_act_t mThreadID;
#endif
};
} // namespace mozilla
#endif // mozilla_ThreadStackHelper_h