Fix for 12312 (Dartium crash when reloading after running tests).

Add framework for Dart_Cleanup which will cleanup stuff on exit.
Ideally the VM isolate should be shutdown in Dart_Terminate but we don't
seem to have a clean thread pool shutdown as a result of which there are
racing isolates.

R=iposva@google.com

Review URL: https://codereview.chromium.org//25674009

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@28248 260f80e4-7a28-3924-810f-c04153c831b5

runtime/bin/main.cc

@@ -630,6 +630,8 @@ static int ErrorExit(int exit_code, const char* format, ...) {
   Dart_ExitScope();
   Dart_ShutdownIsolate();
 
+  Dart_Cleanup();
+
   return exit_code;
 }
 
@@ -799,8 +801,6 @@ int main(int argc, char** argv) {
     result = Dart_CreateScriptSnapshot(&buffer, &size);
     if (Dart_IsError(result)) {
       Log::PrintErr("%s\n", Dart_GetError(result));
-      Dart_ExitScope();
-      Dart_ShutdownIsolate();
       return DartErrorExit(result);
     }
 
@@ -875,6 +875,8 @@ int main(int argc, char** argv) {
   // Terminate process exit-code handler.
   Process::TerminateExitCodeHandler();
 
+  Dart_Cleanup();
+
   // Free copied argument strings if converted.
   if (argv_converted) {
     for (int i = 0; i < argc; i++) free(argv[i]);

runtime/include/dart_api.h

@@ -749,6 +749,13 @@ DART_EXPORT bool Dart_Initialize(
     Dart_FileWriteCallback file_write,
     Dart_FileCloseCallback file_close);
 
+/**
+ * Cleanup state in the VM before process termination.
+ *
+ * \return True if cleanup is successful.
+ */
+DART_EXPORT bool Dart_Cleanup();
+
 /**
  * Sets command line flags. Should be called before Dart_Initialize.
  *

runtime/vm/code_observers.cc

@@ -50,6 +50,8 @@ void CodeObservers::DeleteAll() {
     delete observers_[i];
   }
   free(observers_);
+  observers_length_ = 0;
+  observers_ = NULL;
 }
 
 

runtime/vm/dart.cc

@@ -74,7 +74,6 @@ class ReadOnlyHandles {
 };
 
 
-// TODO(turnidge): We should add a corresponding Dart::Cleanup.
 const char* Dart::InitOnce(Dart_IsolateCreateCallback create,
                            Dart_IsolateInterruptCallback interrupt,
                            Dart_IsolateUnhandledExceptionCallback unhandled,
@@ -144,6 +143,37 @@ const char* Dart::InitOnce(Dart_IsolateCreateCallback create,
 }
 
 
+const char* Dart::Cleanup() {
+#if 0
+  // Ideally we should shutdown the VM isolate here, but the thread pool
+  // shutdown does not seem to ensure that all the threads have stopped
+  // execution before it terminates, this results in racing isolates.
+  if (vm_isolate_ == NULL) {
+    return "VM already terminated.";
+  }
+
+  ASSERT(Isolate::Current() == NULL);
+
+  delete thread_pool_;
+  thread_pool_ = NULL;
+
+  // Set the VM isolate as current isolate.
+  Isolate::SetCurrent(vm_isolate_);
+
+  // There is a planned and known asymmetry here: We exit one scope for the VM
+  // isolate to account for the scope that was entered in Dart_InitOnce.
+  Dart_ExitScope();
+
+  ShutdownIsolate();
+  vm_isolate_ = NULL;
+#endif
+
+  CodeObservers::DeleteAll();
+
+  return NULL;
+}
+
+
 Isolate* Dart::CreateIsolate(const char* name_prefix) {
   // Create a new isolate.
   Isolate* isolate = Isolate::Init(name_prefix);

runtime/vm/dart.h

@@ -28,6 +28,7 @@ class Dart : public AllStatic {
       Dart_FileReadCallback file_read,
       Dart_FileWriteCallback file_write,
       Dart_FileCloseCallback file_close);
+  static const char* Cleanup();
 
   static Isolate* CreateIsolate(const char* name_prefix);
   static RawError* InitializeIsolate(const uint8_t* snapshot, void* data);

runtime/vm/dart_api_impl.cc

@@ -761,10 +761,23 @@ DART_EXPORT bool Dart_Initialize(
   return true;
 }
 
+
+DART_EXPORT bool Dart_Cleanup() {
+  CHECK_NO_ISOLATE(Isolate::Current());
+  const char* err_msg = Dart::Cleanup();
+  if (err_msg != NULL) {
+    OS::PrintErr("Dart_Cleanup: %s\n", err_msg);
+    return false;
+  }
+  return true;
+}
+
+
 DART_EXPORT bool Dart_SetVMFlags(int argc, const char** argv) {
   return Flags::ProcessCommandLineFlags(argc, argv);
 }
 
+
 DART_EXPORT bool Dart_IsVMFlagSet(const char* flag_name) {
   if (Flags::Lookup(flag_name) != NULL) {
     return true;

runtime/vm/isolate.cc

@@ -680,9 +680,6 @@ void Isolate::Shutdown() {
     api_state()->weak_persistent_handles().VisitHandles(&visitor);
 
     CompilerStats::Print();
-    // TODO(asiva): Move this code to Dart::Cleanup when we have that method
-    // as the cleanup for Dart::InitOnce.
-    CodeObservers::DeleteAll();
     if (FLAG_trace_isolates) {
       heap()->PrintSizes();
       megamorphic_cache_table()->PrintSizes();