VM thread shutdown.

runtime/vm/thread_interrupter.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 "vm/thread_interrupter.h"
 
 #include "vm/flags.h"
 #include "vm/lockers.h"
 #include "vm/os.h"
 #include "vm/simulator.h"
@@ skipping 33 matching lines @@
 // thread local storage pointer is set again. This has an important side
 // effect: if the thread is interrupted by a signal handler during a ThreadState
 // update the signal handler will immediately return.
 
 DEFINE_FLAG(bool, trace_thread_interrupter, false,
             "Trace thread interrupter");
 
 bool ThreadInterrupter::initialized_ = false;
 bool ThreadInterrupter::shutdown_ = false;
 bool ThreadInterrupter::thread_running_ = false;
-ThreadId ThreadInterrupter::interrupter_thread_id_ =
-    OSThread::kInvalidThreadId;
+ThreadJoinId ThreadInterrupter::interrupter_thread_id_ =
+    OSThread::kInvalidThreadJoinId;
 Monitor* ThreadInterrupter::monitor_ = NULL;
 intptr_t ThreadInterrupter::interrupt_period_ = 1000;
 intptr_t ThreadInterrupter::current_wait_time_ = Monitor::kNoTimeout;
 
 
 void ThreadInterrupter::InitOnce() {
   ASSERT(!initialized_);
   monitor_ = new Monitor();
   ASSERT(monitor_ != NULL);
   initialized_ = true;
 }
 
 
 void ThreadInterrupter::Startup() {
   ASSERT(initialized_);
   if (FLAG_trace_thread_interrupter) {
     OS::Print("ThreadInterrupter starting up.\n");
   }
-  ASSERT(interrupter_thread_id_ == OSThread::kInvalidThreadId);
+  ASSERT(interrupter_thread_id_ == OSThread::kInvalidThreadJoinId);
   {
     MonitorLocker startup_ml(monitor_);
     OSThread::Start(ThreadMain, 0);
     while (!thread_running_) {
       startup_ml.Wait();
     }
   }
-  ASSERT(interrupter_thread_id_ != OSThread::kInvalidThreadId);
+  ASSERT(interrupter_thread_id_ != OSThread::kInvalidThreadJoinId);
   if (FLAG_trace_thread_interrupter) {
     OS::Print("ThreadInterrupter running.\n");
   }
 }
 
 
 void ThreadInterrupter::Shutdown() {
   {
     MonitorLocker shutdown_ml(monitor_);
     if (shutdown_) {
       // Already shutdown.
       return;
     }
     shutdown_ = true;
     // Notify.
     monitor_->Notify();
     ASSERT(initialized_);
     if (FLAG_trace_thread_interrupter) {
       OS::Print("ThreadInterrupter shutting down.\n");
     }
   }
-#if defined(TARGET_OS_WINDOWS)
-  // On Windows, a thread's exit-code can leak into the process's exit-code,
-  // if exiting 'at same time' as the process ends. By joining with the thread
-  // here, we avoid this race condition.
-  ASSERT(interrupter_thread_id_ != OSThread::kInvalidThreadId);
+
+  // Join the thread.
+  ASSERT(interrupter_thread_id_ != OSThread::kInvalidThreadJoinId);
   OSThread::Join(interrupter_thread_id_);
-  interrupter_thread_id_ = OSThread::kInvalidThreadId;
-#else
-  // On non-Windows platforms, just wait for the thread interrupter to signal
-  // that it has exited the loop.
-  {
-    MonitorLocker shutdown_ml(monitor_);
-    while (thread_running_) {
-      // Wait for thread to exit.
-      shutdown_ml.Wait();
-    }
-  }
-#endif
+  interrupter_thread_id_ = OSThread::kInvalidThreadJoinId;
+
   if (FLAG_trace_thread_interrupter) {
     OS::Print("ThreadInterrupter shut down.\n");
   }
 }
 
 // Delay between interrupts.
 void ThreadInterrupter::SetInterruptPeriod(intptr_t period) {
   if (shutdown_) {
     return;
   }
@@ skipping 48 matching lines @@
 
 void ThreadInterrupter::ThreadMain(uword parameters) {
   ASSERT(initialized_);
   InstallSignalHandler();
   if (FLAG_trace_thread_interrupter) {
     OS::Print("ThreadInterrupter thread running.\n");
   }
   {
     // Signal to main thread we are ready.
     MonitorLocker startup_ml(monitor_);
-    interrupter_thread_id_ = OSThread::GetCurrentThreadId();
+    interrupter_thread_id_ = OSThread::GetCurrentThreadJoinId();
     thread_running_ = true;
     startup_ml.Notify();
   }
   {
     ThreadInterrupterVisitIsolates visitor;
     current_wait_time_ = interrupt_period_;
     MonitorLocker wait_ml(monitor_);
     while (!shutdown_) {
       intptr_t r = wait_ml.WaitMicros(current_wait_time_);
 
+      if ((r == Monitor::kNotified) && shutdown_) {
+        break;
+      }
+
       if ((r == Monitor::kNotified) && InDeepSleep()) {
         // Woken up from deep sleep.
         ASSERT(visitor.profiled_thread_count() == 0);
         // Return to regular interrupts.
         current_wait_time_ = interrupt_period_;
       }
 
       // Reset count before visiting isolates.
       visitor.set_profiled_thread_count(0);
       Isolate::VisitIsolates(&visitor);
@@ skipping 15 matching lines @@
   }
   {
     // Signal to main thread we are exiting.
     MonitorLocker shutdown_ml(monitor_);
     thread_running_ = false;
     shutdown_ml.Notify();
   }
 }
 
 }  // namespace dart