Handle filling up of memory buffer to make log processing in DevTools Profiler easier.

src/log.cc

 // Copyright 2009 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
@@ skipping 795 matching lines @@
 bool Logger::IsProfilerPaused() {
   return profiler_->paused();
 }
 
 
 void Logger::PauseProfiler() {
   profiler_->pause();
   if (FLAG_prof_lazy) {
     if (!FLAG_sliding_state_window) ticker_->Stop();
     FLAG_log_code = false;
+    // Must be the same message as Log::kDynamicBufferSeal.
     LOG(UncheckedStringEvent("profiler", "pause"));
   }
 }
 
 
 void Logger::ResumeProfiler() {
+  if (!Log::IsEnabled()) return;
   if (FLAG_prof_lazy) {
     LOG(UncheckedStringEvent("profiler", "resume"));
     FLAG_log_code = true;
     LogCompiledFunctions();
     if (!FLAG_sliding_state_window) ticker_->Start();
   }
   profiler_->resume();
 }
 
 
+// This function can be called when Log's mutex is acquired,
+// either from main or Profiler's thread.
+void Logger::StopLoggingAndProfiling() {
+  Log::stop();
+  PauseProfiler();
+}
+
+
 bool Logger::IsProfilerSamplerActive() {
   return ticker_->IsActive();
 }
 
 
 int Logger::GetLogLines(int from_pos, char* dest_buf, int max_size) {
   return Log::GetLogLines(from_pos, dest_buf, max_size);
 }
 
 
@@ skipping 146 matching lines @@
     sliding_state_window_ = new SlidingStateWindow();
   }
 
   if (FLAG_prof) {
     profiler_ = new Profiler();
     if (!FLAG_prof_auto)
       profiler_->pause();
     profiler_->Engage();
   }
 
+  LogMessageBuilder::write_failure_handler = StopLoggingAndProfiling;
+
   return true;
 
 #else
   return false;
 #endif
 }
 
 
 void Logger::TearDown() {
 #ifdef ENABLE_LOGGING_AND_PROFILING
+  LogMessageBuilder::write_failure_handler = NULL;
+
   // Stop the profiler before closing the file.
   if (profiler_ != NULL) {
     profiler_->Disengage();
     delete profiler_;
     profiler_ = NULL;
   }
 
   delete sliding_state_window_;
   sliding_state_window_ = NULL;
 
@@ skipping 99 matching lines @@
     } else if (previous_->state_ == EXTERNAL) {
       // We are leaving V8.
       Heap::Protect();
     }
   }
 #endif
 }
 #endif
 
 } }  // namespace v8::internal