gecko/tools/profiler/ProfileEntry.h

/* -*- Mode: C++; tab-width: 2; 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 MOZ_PROFILE_ENTRY_H
#define MOZ_PROFILE_ENTRY_H

#include <map>
#include <ostream>
#include "GeckoProfiler.h"
#include "platform.h"
#include "JSStreamWriter.h"
#include "ProfilerBacktrace.h"
#include "nsRefPtr.h"
#include "mozilla/Maybe.h"
#include "mozilla/Mutex.h"
#include "mozilla/Vector.h"
#include "gtest/MozGtestFriend.h"
#include "mozilla/UniquePtr.h"

class ThreadProfile;

#pragma pack(push, 1)

class ProfileEntry
{
public:
  ProfileEntry();

  // aTagData must not need release (i.e. be a string from the text segment)
  ProfileEntry(char aTagName, const char *aTagData);
  ProfileEntry(char aTagName, void *aTagPtr);
  ProfileEntry(char aTagName, ProfilerMarker *aTagMarker);
  ProfileEntry(char aTagName, float aTagFloat);
  ProfileEntry(char aTagName, uintptr_t aTagOffset);
  ProfileEntry(char aTagName, Address aTagAddress);
  ProfileEntry(char aTagName, int aTagLine);
  ProfileEntry(char aTagName, char aTagChar);
  bool is_ent_hint(char hintChar);
  bool is_ent_hint();
  bool is_ent(char tagName);
  void* get_tagPtr();
  const ProfilerMarker* getMarker() {
    MOZ_ASSERT(mTagName == 'm');
    return mTagMarker;
  }

  char getTagName() const { return mTagName; }

private:
  FRIEND_TEST(ThreadProfile, InsertOneTag);
  FRIEND_TEST(ThreadProfile, InsertOneTagWithTinyBuffer);
  FRIEND_TEST(ThreadProfile, InsertTagsNoWrap);
  FRIEND_TEST(ThreadProfile, InsertTagsWrap);
  FRIEND_TEST(ThreadProfile, MemoryMeasure);
  friend class ProfileBuffer;
  union {
    const char* mTagData;
    char        mTagChars[sizeof(void*)];
    void*       mTagPtr;
    ProfilerMarker* mTagMarker;
    float       mTagFloat;
    Address     mTagAddress;
    uintptr_t   mTagOffset;
    int         mTagInt;
    char        mTagChar;
  };
  char mTagName;
};

#pragma pack(pop)

typedef void (*IterateTagsCallback)(const ProfileEntry& entry, const char* tagStringData);

class UniqueJITOptimizations {
 public:
  bool empty() const {
    return mOpts.empty();
  }

  mozilla::Maybe<unsigned> getIndex(void* addr, JSRuntime* rt);
  void stream(JSStreamWriter& b, JSRuntime* rt);

 private:
  struct OptimizationKey {
    void* mEntryAddr;
    uint8_t mIndex;
    bool operator<(const OptimizationKey& other) const;
  };

  mozilla::Vector<OptimizationKey> mOpts;
  std::map<OptimizationKey, unsigned> mOptToIndexMap;
};

class ProfileBuffer {
public:
  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ProfileBuffer)

  explicit ProfileBuffer(int aEntrySize);

  void addTag(const ProfileEntry& aTag);
  void IterateTagsForThread(IterateTagsCallback aCallback, int aThreadId);
  void StreamSamplesToJSObject(JSStreamWriter& b, int aThreadId, JSRuntime* rt,
                               UniqueJITOptimizations& aUniqueOpts);
  void StreamMarkersToJSObject(JSStreamWriter& b, int aThreadId);
  void DuplicateLastSample(int aThreadId);

  void addStoredMarker(ProfilerMarker* aStoredMarker);

  // The following two methods are not signal safe! They delete markers.
  void deleteExpiredStoredMarkers();
  void reset();

protected:
  char* processDynamicTag(int readPos, int* tagsConsumed, char* tagBuff);
  int FindLastSampleOfThread(int aThreadId);

  ~ProfileBuffer();

public:
  // Circular buffer 'Keep One Slot Open' implementation for simplicity
  mozilla::UniquePtr<ProfileEntry[]> mEntries;

  // Points to the next entry we will write to, which is also the one at which
  // we need to stop reading.
  int mWritePos;

  // Points to the entry at which we can start reading.
  int mReadPos;

  // The number of entries in our buffer.
  int mEntrySize;

  // How many times mWritePos has wrapped around.
  uint32_t mGeneration;

  // Markers that marker entries in the buffer might refer to.
  ProfilerMarkerLinkedList mStoredMarkers;
};

class ThreadProfile
{
public:
  ThreadProfile(ThreadInfo* aThreadInfo, ProfileBuffer* aBuffer);
  virtual ~ThreadProfile();
  void addTag(const ProfileEntry& aTag);

  /**
   * Track a marker which has been inserted into the ThreadProfile.
   * This marker can safely be deleted once the generation has
   * expired.
   */
  void addStoredMarker(ProfilerMarker *aStoredMarker);

  void IterateTags(IterateTagsCallback aCallback);
  void ToStreamAsJSON(std::ostream& stream);
  JSObject *ToJSObject(JSContext *aCx);
  PseudoStack* GetPseudoStack();
  mozilla::Mutex* GetMutex();
  void StreamJSObject(JSStreamWriter& b);

  /**
   * Call this method when the JS entries inside the buffer are about to
   * become invalid, i.e., just before JS shutdown.
   */
  void FlushSamplesAndMarkers();

  void BeginUnwind();
  virtual void EndUnwind();
  virtual SyncProfile* AsSyncProfile() { return nullptr; }

  bool IsMainThread() const { return mIsMainThread; }
  const char* Name() const { return mThreadInfo->Name(); }
  int ThreadId() const { return mThreadId; }

  PlatformData* GetPlatformData() const { return mPlatformData; }
  void* GetStackTop() const { return mStackTop; }
  void DuplicateLastSample();

  ThreadInfo* GetThreadInfo() const { return mThreadInfo; }
  ThreadResponsiveness* GetThreadResponsiveness() { return &mRespInfo; }
  void SetPendingDelete()
  {
    mPseudoStack = nullptr;
    mPlatformData = nullptr;
  }

  uint32_t bufferGeneration() const {
    return mBuffer->mGeneration;
  }

private:
  FRIEND_TEST(ThreadProfile, InsertOneTag);
  FRIEND_TEST(ThreadProfile, InsertOneTagWithTinyBuffer);
  FRIEND_TEST(ThreadProfile, InsertTagsNoWrap);
  FRIEND_TEST(ThreadProfile, InsertTagsWrap);
  FRIEND_TEST(ThreadProfile, MemoryMeasure);
  ThreadInfo* mThreadInfo;

  const nsRefPtr<ProfileBuffer> mBuffer;

  // JS frames in the buffer may require a live JSRuntime to stream (e.g.,
  // stringifying JIT frames). In the case of JSRuntime destruction,
  // FlushSamplesAndMarkers should be called to save them. These are spliced
  // into the final stream.
  std::string mSavedStreamedSamples;
  std::string mSavedStreamedMarkers;
  std::string mSavedStreamedOptimizations;

  PseudoStack*   mPseudoStack;
  mozilla::Mutex mMutex;
  int            mThreadId;
  bool           mIsMainThread;
  PlatformData*  mPlatformData;  // Platform specific data.
  void* const    mStackTop;
  ThreadResponsiveness mRespInfo;

  // Linux and OSX use a signal sender, instead of stopping the thread, so we
  // need some space to store the data which cannot be collected in the signal
  // handler code.
#if defined(XP_LINUX) || defined(XP_MACOSX)
public:
  int64_t        mRssMemory;
  int64_t        mUssMemory;
#endif
};

#endif /* ndef MOZ_PROFILE_ENTRY_H */