src/log.h

// Copyright 2006-2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#ifndef V8_LOG_H_
#define V8_LOG_H_

#include "platform.h"
#include "log-utils.h"

namespace v8 {
namespace internal {

// Logger is used for collecting logging information from V8 during
// execution. The result is dumped to a file.
//
// Available command line flags:
//
//  --log
// Minimal logging (no API, code, or GC sample events), default is off.
//
// --log-all
// Log all events to the file, default is off.  This is the same as combining
// --log-api, --log-code, --log-gc, and --log-regexp.
//
// --log-api
// Log API events to the logfile, default is off.  --log-api implies --log.
//
// --log-code
// Log code (create, move, and delete) events to the logfile, default is off.
// --log-code implies --log.
//
// --log-gc
// Log GC heap samples after each GC that can be processed by hp2ps, default
// is off.  --log-gc implies --log.
//
// --log-regexp
// Log creation and use of regular expressions, Default is off.
// --log-regexp implies --log.
//
// --logfile <filename>
// Specify the name of the logfile, default is "v8.log".
//
// --prof
// Collect statistical profiling information (ticks), default is off.  The
// tick profiler requires code events, so --prof implies --log-code.

// Forward declarations.
class Ticker;
class Profiler;
class Semaphore;
class SlidingStateWindow;
class LogMessageBuilder;

#undef LOG
#ifdef ENABLE_LOGGING_AND_PROFILING
#define LOG(isolate, Call)                          \
  do {                                              \
    v8::internal::Logger* logger =                  \
        (isolate)->logger();                        \
    if (logger->is_logging())                       \
      logger->Call;                                 \
  } while (false)
#else
#define LOG(isolate, Call) ((void) 0)
#endif

#define LOG_EVENTS_AND_TAGS_LIST(V) \
  V(CODE_CREATION_EVENT,            "code-creation")            \
  V(CODE_MOVE_EVENT,                "code-move")                \
  V(CODE_DELETE_EVENT,              "code-delete")              \
  V(CODE_MOVING_GC,                 "code-moving-gc")           \
  V(SHARED_FUNC_MOVE_EVENT,         "sfi-move")                 \
  V(SNAPSHOT_POSITION_EVENT,        "snapshot-pos")             \
  V(TICK_EVENT,                     "tick")                     \
  V(REPEAT_META_EVENT,              "repeat")                   \
  V(BUILTIN_TAG,                    "Builtin")                  \
  V(CALL_DEBUG_BREAK_TAG,           "CallDebugBreak")           \
  V(CALL_DEBUG_PREPARE_STEP_IN_TAG, "CallDebugPrepareStepIn")   \
  V(CALL_IC_TAG,                    "CallIC")                   \
  V(CALL_INITIALIZE_TAG,            "CallInitialize")           \
  V(CALL_MEGAMORPHIC_TAG,           "CallMegamorphic")          \
  V(CALL_MISS_TAG,                  "CallMiss")                 \
  V(CALL_NORMAL_TAG,                "CallNormal")               \
  V(CALL_PRE_MONOMORPHIC_TAG,       "CallPreMonomorphic")       \
  V(KEYED_CALL_DEBUG_BREAK_TAG,     "KeyedCallDebugBreak")      \
  V(KEYED_CALL_DEBUG_PREPARE_STEP_IN_TAG,                       \
    "KeyedCallDebugPrepareStepIn")                              \
  V(KEYED_CALL_IC_TAG,              "KeyedCallIC")              \
  V(KEYED_CALL_INITIALIZE_TAG,      "KeyedCallInitialize")      \
  V(KEYED_CALL_MEGAMORPHIC_TAG,     "KeyedCallMegamorphic")     \
  V(KEYED_CALL_MISS_TAG,            "KeyedCallMiss")            \
  V(KEYED_CALL_NORMAL_TAG,          "KeyedCallNormal")          \
  V(KEYED_CALL_PRE_MONOMORPHIC_TAG, "KeyedCallPreMonomorphic")  \
  V(CALLBACK_TAG,                   "Callback")                 \
  V(EVAL_TAG,                       "Eval")                     \
  V(FUNCTION_TAG,                   "Function")                 \
  V(KEYED_LOAD_IC_TAG,              "KeyedLoadIC")              \
  V(KEYED_EXTERNAL_ARRAY_LOAD_IC_TAG, "KeyedExternalArrayLoadIC") \
  V(KEYED_STORE_IC_TAG,             "KeyedStoreIC")             \
  V(KEYED_EXTERNAL_ARRAY_STORE_IC_TAG, "KeyedExternalArrayStoreIC")\
  V(LAZY_COMPILE_TAG,               "LazyCompile")              \
  V(LOAD_IC_TAG,                    "LoadIC")                   \
  V(REG_EXP_TAG,                    "RegExp")                   \
  V(SCRIPT_TAG,                     "Script")                   \
  V(STORE_IC_TAG,                   "StoreIC")                  \
  V(STUB_TAG,                       "Stub")                     \
  V(NATIVE_FUNCTION_TAG,            "Function")                 \
  V(NATIVE_LAZY_COMPILE_TAG,        "LazyCompile")              \
  V(NATIVE_SCRIPT_TAG,              "Script")
// Note that 'NATIVE_' cases for functions and scripts are mapped onto
// original tags when writing to the log.


class Sampler;


class Logger {
 public:
#define DECLARE_ENUM(enum_item, ignore) enum_item,
  enum LogEventsAndTags {
    LOG_EVENTS_AND_TAGS_LIST(DECLARE_ENUM)
    NUMBER_OF_LOG_EVENTS
  };
#undef DECLARE_ENUM

  // Acquires resources for logging if the right flags are set.
  bool Setup();

  void EnsureTickerStarted();
  void EnsureTickerStopped();

  Sampler* sampler();

  // Frees resources acquired in Setup.
  void TearDown();

  // Enable the computation of a sliding window of states.
  void EnableSlidingStateWindow();

  // Emits an event with a string value -> (name, value).
  void StringEvent(const char* name, const char* value);

  // Emits an event with an int value -> (name, value).
  void IntEvent(const char* name, int value);
  void IntPtrTEvent(const char* name, intptr_t value);

  // Emits an event with an handle value -> (name, location).
  void HandleEvent(const char* name, Object** location);

  // Emits memory management events for C allocated structures.
  void NewEvent(const char* name, void* object, size_t size);
  void DeleteEvent(const char* name, void* object);

  // Static versions of the above, operate on current isolate's logger.
  // Used in TRACK_MEMORY(TypeName) defined in globals.h
  static void NewEventStatic(const char* name, void* object, size_t size);
  static void DeleteEventStatic(const char* name, void* object);

  // Emits an event with a tag, and some resource usage information.
  // -> (name, tag, <rusage information>).
  // Currently, the resource usage information is a process time stamp
  // and a real time timestamp.
  void ResourceEvent(const char* name, const char* tag);

  // Emits an event that an undefined property was read from an
  // object.
  void SuspectReadEvent(String* name, Object* obj);

  // Emits an event when a message is put on or read from a debugging queue.
  // DebugTag lets us put a call-site specific label on the event.
  void DebugTag(const char* call_site_tag);
  void DebugEvent(const char* event_type, Vector<uint16_t> parameter);


  // ==== Events logged by --log-api. ====
  void ApiNamedSecurityCheck(Object* key);
  void ApiIndexedSecurityCheck(uint32_t index);
  void ApiNamedPropertyAccess(const char* tag, JSObject* holder, Object* name);
  void ApiIndexedPropertyAccess(const char* tag,
                                JSObject* holder,
                                uint32_t index);
  void ApiObjectAccess(const char* tag, JSObject* obj);
  void ApiEntryCall(const char* name);


  // ==== Events logged by --log-code. ====
  // Emits a code event for a callback function.
  void CallbackEvent(String* name, Address entry_point);
  void GetterCallbackEvent(String* name, Address entry_point);
  void SetterCallbackEvent(String* name, Address entry_point);
  // Emits a code create event.
  void CodeCreateEvent(LogEventsAndTags tag,
                       Code* code, const char* source);
  void CodeCreateEvent(LogEventsAndTags tag,
                       Code* code, String* name);
  void CodeCreateEvent(LogEventsAndTags tag,
                       Code* code,
                       SharedFunctionInfo* shared,
                       String* name);
  void CodeCreateEvent(LogEventsAndTags tag,
                       Code* code,
                       SharedFunctionInfo* shared,
                       String* source, int line);
  void CodeCreateEvent(LogEventsAndTags tag, Code* code, int args_count);
  void CodeMovingGCEvent();
  // Emits a code create event for a RegExp.
  void RegExpCodeCreateEvent(Code* code, String* source);
  // Emits a code move event.
  void CodeMoveEvent(Address from, Address to);
  // Emits a code delete event.
  void CodeDeleteEvent(Address from);

  void SharedFunctionInfoMoveEvent(Address from, Address to);

  void SnapshotPositionEvent(Address addr, int pos);

  // ==== Events logged by --log-gc. ====
  // Heap sampling events: start, end, and individual types.
  void HeapSampleBeginEvent(const char* space, const char* kind);
  void HeapSampleEndEvent(const char* space, const char* kind);
  void HeapSampleItemEvent(const char* type, int number, int bytes);
  void HeapSampleJSConstructorEvent(const char* constructor,
                                    int number, int bytes);
  void HeapSampleJSRetainersEvent(const char* constructor,
                                         const char* event);
  void HeapSampleJSProducerEvent(const char* constructor,
                                 Address* stack);
  void HeapSampleStats(const char* space, const char* kind,
                       intptr_t capacity, intptr_t used);

  void SharedLibraryEvent(const char* library_path,
                          uintptr_t start,
                          uintptr_t end);
  void SharedLibraryEvent(const wchar_t* library_path,
                          uintptr_t start,
                          uintptr_t end);

  // ==== Events logged by --log-regexp ====
  // Regexp compilation and execution events.

  void RegExpCompileEvent(Handle<JSRegExp> regexp, bool in_cache);

  // Log an event reported from generated code
  void LogRuntime(Vector<const char> format, JSArray* args);

#ifdef ENABLE_LOGGING_AND_PROFILING
  bool is_logging() {
    return logging_nesting_ > 0;
  }

  // Pause/Resume collection of profiling data.
  // When data collection is paused, CPU Tick events are discarded until
  // data collection is Resumed.
  void PauseProfiler(int flags, int tag);
  void ResumeProfiler(int flags, int tag);
  int GetActiveProfilerModules();

  // If logging is performed into a memory buffer, allows to
  // retrieve previously written messages. See v8.h.
  int GetLogLines(int from_pos, char* dest_buf, int max_size);

  // Logs all compiled functions found in the heap.
  void LogCompiledFunctions();
  // Logs all accessor callbacks found in the heap.
  void LogAccessorCallbacks();
  // Used for logging stubs found in the snapshot.
  void LogCodeObjects();

  // Converts tag to a corresponding NATIVE_... if the script is native.
  INLINE(static LogEventsAndTags ToNativeByScript(LogEventsAndTags, Script*));

  // Profiler's sampling interval (in milliseconds).
#if defined(ANDROID)
  // Phones and tablets have processors that are much slower than desktop
  // and laptop computers for which current heuristics are tuned.
  static const int kSamplingIntervalMs = 5;
#else
  static const int kSamplingIntervalMs = 1;
#endif

  // Callback from Log, stops profiling in case of insufficient resources.
  void LogFailure();

 private:
  Logger();
  ~Logger();

  // Emits the profiler's first message.
  void ProfilerBeginEvent();

  // Emits callback event messages.
  void CallbackEventInternal(const char* prefix,
                             const char* name,
                             Address entry_point);

  // Internal configurable move event.
  void MoveEventInternal(LogEventsAndTags event, Address from, Address to);

  // Internal configurable move event.
  void DeleteEventInternal(LogEventsAndTags event, Address from);

  // Emits the source code of a regexp. Used by regexp events.
  void LogRegExpSource(Handle<JSRegExp> regexp);

  // Used for logging stubs found in the snapshot.
  void LogCodeObject(Object* code_object);

  // Emits general information about generated code.
  void LogCodeInfo();

  // Handles code creation when low-level profiling is active.
  void LowLevelCodeCreateEvent(Code* code, LogMessageBuilder* msg);

  // Emits a profiler tick event. Used by the profiler thread.
  void TickEvent(TickSample* sample, bool overflow);

  void ApiEvent(const char* name, ...);

  // Logs a StringEvent regardless of whether FLAG_log is true.
  void UncheckedStringEvent(const char* name, const char* value);

  // Logs an IntEvent regardless of whether FLAG_log is true.
  void UncheckedIntEvent(const char* name, int value);
  void UncheckedIntPtrTEvent(const char* name, intptr_t value);

  // Returns whether profiler's sampler is active.
  bool IsProfilerSamplerActive();

  // The sampler used by the profiler and the sliding state window.
  Ticker* ticker_;

  // When the statistical profile is active, profiler_
  // points to a Profiler, that handles collection
  // of samples.
  Profiler* profiler_;

  // SlidingStateWindow instance keeping a sliding window of the most
  // recent VM states.
  SlidingStateWindow* sliding_state_window_;

  // An array of log events names.
  const char* const* log_events_;

  // Internal implementation classes with access to
  // private members.
  friend class EventLog;
  friend class Isolate;
  friend class LogMessageBuilder;
  friend class TimeLog;
  friend class Profiler;
  friend class SlidingStateWindow;
  friend class StackTracer;
  friend class VMState;

  friend class LoggerTestHelper;


  int logging_nesting_;
  int cpu_profiler_nesting_;
  int heap_profiler_nesting_;

  Log* log_;

  // Guards against multiple calls to TearDown() that can happen in some tests.
  // 'true' between Setup() and TearDown().
  bool is_initialized_;

  // Support for 'incremental addresses' in compressed logs:
  //  LogMessageBuilder::AppendAddress(Address addr)
  Address last_address_;
  //  Logger::TickEvent(...)
  Address prev_sp_;
  Address prev_function_;
  //  Logger::MoveEventInternal(...)
  Address prev_to_;
  //  Logger::FunctionCreateEvent(...)
  Address prev_code_;

  friend class CpuProfiler;
#else
  bool is_logging() { return false; }
#endif
};


// Process wide registry of samplers.
class SamplerRegistry : public AllStatic {
 public:
  enum State {
    HAS_NO_SAMPLERS,
    HAS_SAMPLERS,
    HAS_CPU_PROFILING_SAMPLERS
  };

  typedef void (*VisitSampler)(Sampler*, void*);

  static State GetState();

  // Iterates over all active samplers keeping the internal lock held.
  // Returns whether there are any active samplers.
  static bool IterateActiveSamplers(VisitSampler func, void* param);

  // Adds/Removes an active sampler.
  static void AddActiveSampler(Sampler* sampler);
  static void RemoveActiveSampler(Sampler* sampler);

 private:
  static bool ActiveSamplersExist() {
    return active_samplers_ != NULL && !active_samplers_->is_empty();
  }

  static Mutex* mutex_;  // Protects the state below.
  static List<Sampler*>* active_samplers_;

  DISALLOW_IMPLICIT_CONSTRUCTORS(SamplerRegistry);
};


// Class that extracts stack trace, used for profiling.
class StackTracer : public AllStatic {
 public:
  static void Trace(Isolate* isolate, TickSample* sample);
};

} }  // namespace v8::internal


#endif  // V8_LOG_H_