Ensure profiler manager thread has shutdown before main thread

runtime/vm/profiler.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <cstdio>
 
 #include "platform/utils.h"
 
 #include "vm/isolate.h"
 #include "vm/json_stream.h"
@@ skipping 55 matching lines @@
 // If the VM is compiled without frame pointers (which is the default on
 // recent GCC versions with optimizing enabled) the stack walking code will
 // fail (sometimes leading to a crash).
 //
 
 DEFINE_FLAG(bool, profile, true, "Enable Sampling Profiler");
 DEFINE_FLAG(bool, trace_profiled_isolates, false, "Trace profiled isolates.");
 
 bool ProfilerManager::initialized_ = false;
 bool ProfilerManager::shutdown_ = false;
+bool ProfilerManager::thread_running_ = false;
 Monitor* ProfilerManager::monitor_ = NULL;
+Monitor* ProfilerManager::start_stop_monitor_ = NULL;
 Isolate** ProfilerManager::isolates_ = NULL;
 intptr_t ProfilerManager::isolates_capacity_ = 0;
 intptr_t ProfilerManager::isolates_size_ = 0;
 
 
 void ProfilerManager::InitOnce() {
 #if defined(USING_SIMULATOR)
   // Force disable of profiling on simulator.
   FLAG_profile = false;
 #endif
   if (!FLAG_profile) {
     return;
   }
   NativeSymbolResolver::InitOnce();
   ASSERT(!initialized_);
   monitor_ = new Monitor();
+  start_stop_monitor_ = new Monitor();
   initialized_ = true;
   ResizeIsolates(16);
-  Thread::Start(ThreadMain, 0);
+  if (FLAG_trace_profiled_isolates) {
+    OS::Print("ProfilerManager starting up.\n");
+  }
+  {
+    ScopedMonitor startup_lock(start_stop_monitor_);
+    Thread::Start(ThreadMain, 0);
+    while (!thread_running_) {
+      // Wait until profiler thread has started up.
+      startup_lock.Wait();
+    }
+  }
+  if (FLAG_trace_profiled_isolates) {
+    OS::Print("ProfilerManager running.\n");
+  }
 }
 
 
 void ProfilerManager::Shutdown() {
   if (!FLAG_profile) {
     return;
   }
   ASSERT(initialized_);
+  if (FLAG_trace_profiled_isolates) {
+    OS::Print("ProfilerManager shutting down.\n");
+  }
+  intptr_t size_at_shutdown = 0;
   {
     ScopedSignalBlocker ssb;
     {
       ScopedMonitor lock(monitor_);
       shutdown_ = true;
+      size_at_shutdown = isolates_size_;
       isolates_size_ = 0;
       free(isolates_);
       isolates_ = NULL;
       lock.Notify();
     }
   }
   NativeSymbolResolver::ShutdownOnce();
+  {
+    ScopedMonitor shutdown_lock(start_stop_monitor_);
+    while (thread_running_) {
+      // Wait until profiler thread has exited.
+      shutdown_lock.Wait();
+    }
+  }
+  initialized_ = false;
+  if (FLAG_trace_profiled_isolates) {
+    OS::Print("ProfilerManager shut down (%" Pd ").\n", size_at_shutdown);
+  }
 }
 
 
 void ProfilerManager::SetupIsolateForProfiling(Isolate* isolate) {
   if (!FLAG_profile) {
     return;
   }
   ASSERT(isolate != NULL);
   {
     ScopedSignalBlocker ssb;
     {
       ScopedMutex profiler_data_lock(isolate->profiler_data_mutex());
       SampleBuffer* sample_buffer = new SampleBuffer();
       ASSERT(sample_buffer != NULL);
       IsolateProfilerData* profiler_data =
           new IsolateProfilerData(isolate, sample_buffer);
       ASSERT(profiler_data != NULL);
       profiler_data->set_sample_interval_micros(1000);
       isolate->set_profiler_data(profiler_data);
       if (FLAG_trace_profiled_isolates) {
-        OS::Print("PROF SETUP %p %s %p\n",
+        OS::Print("ProfilerManager Setup Isolate %p %s %p\n",
             isolate,
             isolate->name(),
             reinterpret_cast<void*>(Thread::GetCurrentThreadId()));
       }
     }
   }
 }
 
 
 void ProfilerManager::FreeIsolateProfilingData(Isolate* isolate) {
   ScopedMutex profiler_data_lock(isolate->profiler_data_mutex());
   IsolateProfilerData* profiler_data = isolate->profiler_data();
   if (profiler_data == NULL) {
     // Already freed.
     return;
   }
   isolate->set_profiler_data(NULL);
   SampleBuffer* sample_buffer = profiler_data->sample_buffer();
   ASSERT(sample_buffer != NULL);
   profiler_data->set_sample_buffer(NULL);
   delete sample_buffer;
   delete profiler_data;
   if (FLAG_trace_profiled_isolates) {
-    OS::Print("PROF SHUTDOWN %p %s %p\n", isolate,
-        isolate->name(), reinterpret_cast<void*>(Thread::GetCurrentThreadId()));
+    OS::Print("ProfilerManager Shutdown Isolate %p %s %p\n",
+        isolate,
+        isolate->name(),
+        reinterpret_cast<void*>(Thread::GetCurrentThreadId()));
   }
 }
 
 
 void ProfilerManager::ShutdownIsolateForProfiling(Isolate* isolate) {
   ASSERT(isolate != NULL);
   if (!FLAG_profile) {
     return;
   }
   {
@@ skipping 481 matching lines @@
     return false;
   }
   uintptr_t cursor = reinterpret_cast<uintptr_t>(fp);
   cursor += sizeof(fp);
   bool r = cursor >= lower_bound_ && cursor < stack_upper_;
   return r;
 }
 
 
 }  // namespace dart