Implement tagging of profiler log event blocks.

This change allows to associate integer tags with blocks of profiler
log events, and repeat calls to 'ResumeProfiler' / 'PauseProfiler' in
order to establsh nested (not necessary properly nested) blocks. By
supporting this, we will be able to match WebInspector's CPU profiler
abilities in DevTools.

I also refactored some testing code.

Review URL: http://codereview.chromium.org/619004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3889 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

include/v8.h

@@ -2349,22 +2349,30 @@ class V8EXPORT V8 {
   static bool IsProfilerPaused();
 
   /**
-   * Resumes specified profiler modules.
+   * Resumes specified profiler modules. Can be called several times to
+   * mark the opening of a profiler events block with the given tag.
+   *
    * "ResumeProfiler" is equivalent to "ResumeProfilerEx(PROFILER_MODULE_CPU)".
    * See ProfilerModules enum.
    *
    * \param flags Flags specifying profiler modules.
+   * \param tag Profile tag.
    */
-  static void ResumeProfilerEx(int flags);
+  static void ResumeProfilerEx(int flags, int tag = 0);
 
   /**
-   * Pauses specified profiler modules.
+   * Pauses specified profiler modules. Each call to "PauseProfilerEx" closes
+   * a block of profiler events opened by a call to "ResumeProfilerEx" with the
+   * same tag value. There is no need for blocks to be properly nested.
+   * The profiler is paused when the last opened block is closed.
+   *
    * "PauseProfiler" is equivalent to "PauseProfilerEx(PROFILER_MODULE_CPU)".
    * See ProfilerModules enum.
    *
    * \param flags Flags specifying profiler modules.
+   * \param tag Profile tag.
    */
-  static void PauseProfilerEx(int flags);
+  static void PauseProfilerEx(int flags, int tag = 0);
 
   /**
    * Returns active (resumed) profiler modules.

src/api.cc

@@ -3469,14 +3469,14 @@ void V8::SetGlobalGCEpilogueCallback(GCCallback callback) {
 
 void V8::PauseProfiler() {
 #ifdef ENABLE_LOGGING_AND_PROFILING
-  i::Logger::PauseProfiler(PROFILER_MODULE_CPU);
+  PauseProfilerEx(PROFILER_MODULE_CPU);
 #endif
 }
 
 
 void V8::ResumeProfiler() {
 #ifdef ENABLE_LOGGING_AND_PROFILING
-  i::Logger::ResumeProfiler(PROFILER_MODULE_CPU);
+  ResumeProfilerEx(PROFILER_MODULE_CPU);
 #endif
 }
 
@@ -3490,7 +3490,7 @@ bool V8::IsProfilerPaused() {
 }
 
 
-void V8::ResumeProfilerEx(int flags) {
+void V8::ResumeProfilerEx(int flags, int tag) {
 #ifdef ENABLE_LOGGING_AND_PROFILING
   if (flags & PROFILER_MODULE_HEAP_SNAPSHOT) {
     // Snapshot mode: resume modules, perform GC, then pause only
@@ -3500,19 +3500,19 @@ void V8::ResumeProfilerEx(int flags) {
     // Reset snapshot flag and CPU module flags.
     flags &= ~(PROFILER_MODULE_HEAP_SNAPSHOT | PROFILER_MODULE_CPU);
     const int current_flags = i::Logger::GetActiveProfilerModules();
-    i::Logger::ResumeProfiler(flags);
+    i::Logger::ResumeProfiler(flags, tag);
     i::Heap::CollectAllGarbage(false);
-    i::Logger::PauseProfiler(~current_flags & flags);
+    i::Logger::PauseProfiler(~current_flags & flags, tag);
   } else {
-    i::Logger::ResumeProfiler(flags);
+    i::Logger::ResumeProfiler(flags, tag);
   }
 #endif
 }
 
 
-void V8::PauseProfilerEx(int flags) {
+void V8::PauseProfilerEx(int flags, int tag) {
 #ifdef ENABLE_LOGGING_AND_PROFILING
-  i::Logger::PauseProfiler(flags);
+  i::Logger::PauseProfiler(flags, tag);
 #endif
 }
 

src/checks.h

@@ -125,7 +125,9 @@ static inline void CheckEqualsHelper(const char* file,
                                      const char* expected,
                                      const char* value_source,
                                      const char* value) {
-  if (strcmp(expected, value) != 0) {
+  if ((expected == NULL && value != NULL) ||
+      (expected != NULL && value == NULL) ||
+      (expected != NULL && value != NULL && strcmp(expected, value) != 0)) {
     V8_Fatal(file, line,
              "CHECK_EQ(%s, %s) failed\n#   Expected: %s\n#   Found: %s",
              expected_source, value_source, expected, value);

src/debug-delay.js

@@ -1934,10 +1934,14 @@ DebugCommandProcessor.prototype.profileRequest_ = function(request, response) {
   if (isNaN(modules)) {
     return response.failed('Modules is not an integer');
   }
+  var tag = parseInt(request.arguments.tag);
+  if (isNaN(tag)) {
+    tag = 0;
+  }
   if (request.arguments.command == 'resume') {
-    %ProfilerResume(modules);
+    %ProfilerResume(modules, tag);
   } else if (request.arguments.command == 'pause') {
-    %ProfilerPause(modules);
+    %ProfilerPause(modules, tag);
   } else {
     return response.failed('Unknown command');
   }

src/log.cc

@@ -330,6 +330,8 @@ SlidingStateWindow* Logger::sliding_state_window_ = NULL;
 const char** Logger::log_events_ = NULL;
 CompressionHelper* Logger::compression_helper_ = NULL;
 bool Logger::is_logging_ = false;
+int Logger::cpu_profiler_nesting_ = 0;
+int Logger::heap_profiler_nesting_ = 0;
 
 #define DECLARE_LONG_EVENT(ignore1, long_name, ignore2) long_name,
 const char* kLongLogEventsNames[Logger::NUMBER_OF_LOG_EVENTS] = {
@@ -1164,13 +1166,11 @@ int Logger::GetActiveProfilerModules() {
 }
 
 
-void Logger::PauseProfiler(int flags) {
+void Logger::PauseProfiler(int flags, int tag) {
   if (!Log::IsEnabled()) return;
-  const int active_modules = GetActiveProfilerModules();
-  const int modules_to_disable = active_modules & flags;
-  if (modules_to_disable == PROFILER_MODULE_NONE) return;
-
-  if (modules_to_disable & PROFILER_MODULE_CPU) {
+  if (flags & PROFILER_MODULE_CPU) {
+    // It is OK to have negative nesting.
+    if (--cpu_profiler_nesting_ == 0) {
       profiler_->pause();
       if (FLAG_prof_lazy) {
         if (!FLAG_sliding_state_window) ticker_->Stop();
@@ -1179,24 +1179,30 @@ void Logger::PauseProfiler(int flags) {
         LOG(UncheckedStringEvent("profiler", "pause"));
       }
     }
-  if (modules_to_disable &
+  }
+  if (flags &
       (PROFILER_MODULE_HEAP_STATS | PROFILER_MODULE_JS_CONSTRUCTORS)) {
+    if (--heap_profiler_nesting_ == 0) {
       FLAG_log_gc = false;
     }
-  // Turn off logging if no active modules remain.
-  if ((active_modules & ~flags) == PROFILER_MODULE_NONE) {
+  }
+  if (tag != 0) {
+    IntEvent("close-tag", tag);
+  }
+  if (GetActiveProfilerModules() == PROFILER_MODULE_NONE) {
     is_logging_ = false;
   }
 }
 
 
-void Logger::ResumeProfiler(int flags) {
+void Logger::ResumeProfiler(int flags, int tag) {
   if (!Log::IsEnabled()) return;
-  const int modules_to_enable = ~GetActiveProfilerModules() & flags;
-  if (modules_to_enable != PROFILER_MODULE_NONE) {
-    is_logging_ = true;
+  if (tag != 0) {
+    IntEvent("open-tag", tag);
   }
-  if (modules_to_enable & PROFILER_MODULE_CPU) {
+  if (flags & PROFILER_MODULE_CPU) {
+    if (cpu_profiler_nesting_++ == 0) {
+      is_logging_ = true;
       if (FLAG_prof_lazy) {
         profiler_->Engage();
         LOG(UncheckedStringEvent("profiler", "resume"));
@@ -1208,10 +1214,14 @@ void Logger::ResumeProfiler(int flags) {
       }
       profiler_->resume();
     }
-  if (modules_to_enable &
+  }
+  if (flags &
       (PROFILER_MODULE_HEAP_STATS | PROFILER_MODULE_JS_CONSTRUCTORS)) {
+    if (heap_profiler_nesting_++ == 0) {
+      is_logging_ = true;
       FLAG_log_gc = true;
     }
+  }
 }
 
 
@@ -1219,7 +1229,7 @@ void Logger::ResumeProfiler(int flags) {
 // either from main or Profiler's thread.
 void Logger::StopLoggingAndProfiling() {
   Log::stop();
-  PauseProfiler(PROFILER_MODULE_CPU);
+  PauseProfiler(PROFILER_MODULE_CPU, 0);
 }
 
 

src/log.h

@@ -277,8 +277,8 @@ class Logger {
   // 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 void PauseProfiler(int flags, int tag);
+  static void ResumeProfiler(int flags, int tag);
   static int GetActiveProfilerModules();
 
   // If logging is performed into a memory buffer, allows to
@@ -379,6 +379,8 @@ class Logger {
   friend class LoggerTestHelper;
 
   static bool is_logging_;
+  static int cpu_profiler_nesting_;
+  static int heap_profiler_nesting_;
 #else
   static bool is_logging() { return false; }
 #endif

src/runtime.cc

@@ -7917,20 +7917,22 @@ static Object* Runtime_FunctionGetInferredName(Arguments args) {
 
 static Object* Runtime_ProfilerResume(Arguments args) {
   NoHandleAllocation ha;
-  ASSERT(args.length() == 1);
+  ASSERT(args.length() == 2);
 
   CONVERT_CHECKED(Smi, smi_modules, args[0]);
-  v8::V8::ResumeProfilerEx(smi_modules->value());
+  CONVERT_CHECKED(Smi, smi_tag, args[1]);
+  v8::V8::ResumeProfilerEx(smi_modules->value(), smi_tag->value());
   return Heap::undefined_value();
 }
 
 
 static Object* Runtime_ProfilerPause(Arguments args) {
   NoHandleAllocation ha;
-  ASSERT(args.length() == 1);
+  ASSERT(args.length() == 2);
 
   CONVERT_CHECKED(Smi, smi_modules, args[0]);
-  v8::V8::PauseProfilerEx(smi_modules->value());
+  CONVERT_CHECKED(Smi, smi_tag, args[1]);
+  v8::V8::PauseProfilerEx(smi_modules->value(), smi_tag->value());
   return Heap::undefined_value();
 }
 

src/runtime.h

@@ -328,8 +328,8 @@ namespace internal {
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
 #define RUNTIME_FUNCTION_LIST_PROFILER_SUPPORT(F) \
-  F(ProfilerResume, 1, 1) \
-  F(ProfilerPause, 1, 1)
+  F(ProfilerResume, 2, 1) \
+  F(ProfilerPause, 2, 1)
 #else
 #define RUNTIME_FUNCTION_LIST_PROFILER_SUPPORT(F)
 #endif