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;
class CompressionHelper;

#undef LOG
#ifdef ENABLE_LOGGING_AND_PROFILING
#define LOG(Call)                           \
  do {                                      \
    if (v8::internal::Logger::is_logging()) \
      v8::internal::Logger::Call;           \
  } while (false)
#else
#define LOG(Call) ((void) 0)
#endif


class VMState BASE_EMBEDDED {
#ifdef ENABLE_LOGGING_AND_PROFILING
 public:
  inline VMState(StateTag state);
  inline ~VMState();

  StateTag state() { return state_; }
  Address external_callback() { return external_callback_; }
  void set_external_callback(Address external_callback) {
    external_callback_ = external_callback;
  }

 private:
  bool disabled_;
  StateTag state_;
  VMState* previous_;
  Address external_callback_;
#else
 public:
  explicit VMState(StateTag state) {}
#endif
};


#define LOG_EVENTS_AND_TAGS_LIST(V) \
  V(CODE_CREATION_EVENT,            "code-creation",          "cc")       \
  V(CODE_MOVE_EVENT,                "code-move",              "cm")       \
  V(CODE_DELETE_EVENT,              "code-delete",            "cd")       \
  V(SNAPSHOT_POSITION_EVENT,        "snapshot-pos",           "sp")       \
  V(TICK_EVENT,                     "tick",                   "t")        \
  V(REPEAT_META_EVENT,              "repeat",                 "r")        \
  V(BUILTIN_TAG,                    "Builtin",                "bi")       \
  V(CALL_DEBUG_BREAK_TAG,           "CallDebugBreak",         "cdb")      \
  V(CALL_DEBUG_PREPARE_STEP_IN_TAG, "CallDebugPrepareStepIn", "cdbsi")    \
  V(CALL_IC_TAG,                    "CallIC",                 "cic")      \
  V(CALL_INITIALIZE_TAG,            "CallInitialize",         "ci")       \
  V(CALL_MEGAMORPHIC_TAG,           "CallMegamorphic",        "cmm")      \
  V(CALL_MISS_TAG,                  "CallMiss",               "cm")       \
  V(CALL_NORMAL_TAG,                "CallNormal",             "cn")       \
  V(CALL_PRE_MONOMORPHIC_TAG,       "CallPreMonomorphic",     "cpm")      \
  V(CALLBACK_TAG,                   "Callback",               "cb")       \
  V(EVAL_TAG,                       "Eval",                   "e")        \
  V(FUNCTION_TAG,                   "Function",               "f")        \
  V(KEYED_LOAD_IC_TAG,              "KeyedLoadIC",            "klic")     \
  V(KEYED_STORE_IC_TAG,             "KeyedStoreIC",           "ksic")     \
  V(LAZY_COMPILE_TAG,               "LazyCompile",            "lc")       \
  V(LOAD_IC_TAG,                    "LoadIC",                 "lic")      \
  V(REG_EXP_TAG,                    "RegExp",                 "re")       \
  V(SCRIPT_TAG,                     "Script",                 "sc")       \
  V(STORE_IC_TAG,                   "StoreIC",                "sic")      \
  V(STUB_TAG,                       "Stub",                   "s")

class Logger {
 public:
#define DECLARE_ENUM(enum_item, ignore1, ignore2) 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.
  static bool Setup();

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

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

  // Write a raw string to the log to be used as a preamble.
  // No check is made that the 'preamble' is actually at the beginning
  // of the log. The preample is used to write code events saved in the
  // snapshot.
  static void Preamble(const char* content);

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

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

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

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

  // Emits an event that an undefined property was read from an
  // object.
  static 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.
  static void DebugTag(const char* call_site_tag);
  static void DebugEvent(const char* event_type, Vector<uint16_t> parameter);


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


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

  static void SnapshotPositionEvent(Address addr, int pos);

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

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

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

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

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

#ifdef ENABLE_LOGGING_AND_PROFILING
  static StateTag state() {
    return current_state_ ? current_state_->state() : OTHER;
  }

  static bool is_logging() {
    return is_logging_;
  }

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

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

  // Logs all compiled functions found in the heap.
  static void LogCompiledFunctions();
  // Logs all accessor callbacks found in the heap.
  static void LogAccessorCallbacks();
  // Used for logging stubs found in the snapshot.
  static void LogCodeObject(Object* code_object);

 private:

  // Profiler's sampling interval (in milliseconds).
  static const int kSamplingIntervalMs = 1;

  // Size of window used for log records compression.
  static const int kCompressionWindowSize = 4;

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

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

  // Emits aliases for compressed messages.
  static void LogAliases();

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

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

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

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

  // Stops logging and profiling in case of insufficient resources.
  static void StopLoggingAndProfiling();

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

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

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

  // A stack of VM states.
  static VMState* current_state_;

  // Singleton bottom or default vm state.
  static VMState bottom_state_;

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

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

  // An instance of helper created if log compression is enabled.
  static CompressionHelper* compression_helper_;

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

  friend class LoggerTestHelper;

  static bool is_logging_;
#else
  static bool is_logging() { return false; }
#endif
};


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


} }  // namespace v8::internal

#endif  // V8_LOG_H_