VM thread shutdown.

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
diff --git a/runtime/vm/isolate.cc b/runtime/vm/isolate.cc
index 10873ae03c37990f98114808b4acab3361a9455b..0056efcdacebafd50577407f41f6b4174d281fd8 100644
--- a/runtime/vm/isolate.cc
+++ b/runtime/vm/isolate.cc
@@ -5,11 +5,13 @@
 #include "vm/isolate.h"
 
 #include "include/dart_api.h"
+#include "include/dart_native_api.h"
 #include "platform/assert.h"
 #include "platform/json.h"
 #include "vm/code_observers.h"
 #include "vm/compiler_stats.h"
 #include "vm/coverage.h"
+#include "vm/dart_api_message.h"
 #include "vm/dart_api_state.h"
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
@@ -165,7 +167,6 @@ class IsolateMessageHandler : public MessageHandler {
   bool IsCurrentIsolate() const;
   virtual Isolate* isolate() const { return isolate_; }
 
- private:
   // Keep both these enums in sync with isolate_patch.dart.
   // The different Isolate API message types.
   enum {
@@ -186,6 +187,7 @@ class IsolateMessageHandler : public MessageHandler {
     kAsEventAction = 2
   };
 
+ private:
   // A result of false indicates that the isolate should terminate the
   // processing of further events.
   bool HandleLibMessage(const Array& message);
@@ -749,6 +751,7 @@ void Isolate::InitOnce() {
   create_callback_ = NULL;
   isolates_list_monitor_ = new Monitor();
   ASSERT(isolates_list_monitor_ != NULL);
+  EnableIsolateCreation();
 }
 
 
@@ -827,8 +830,14 @@ Isolate* Isolate::Init(const char* name_prefix,
     result->compiler_stats_ = new CompilerStats(result);
   }
   ObjectIdRing::Init(result);
-  // Add to isolate list.
-  AddIsolateTolist(result);
+
+  // Add to isolate list. Shutdown and delete the isolate on failure.
+  if (!AddIsolateToList(result)) {
+    result->LowLevelShutdown();
+    Thread::ExitIsolate();
+    delete result;
+    return NULL;
+  }
 
   return result;
 }
@@ -1454,6 +1463,50 @@ class FinalizeWeakPersistentHandlesVisitor : public HandleVisitor {
 };
 
 
+void Isolate::LowLevelShutdown() {
+  // Ensure we have a zone and handle scope so that we can call VM functions,
+  // but we no longer allocate new heap objects.
+  StackZone stack_zone(this);
+  HandleScope handle_scope(this);
+  NoSafepointScope no_safepoint_scope;
+
+  if (compiler_stats_ != NULL) {
+    compiler_stats()->Print();
+  }
+
+  // Notify exit listeners that this isolate is shutting down.
+  if (object_store() != NULL) {
+    NotifyExitListeners();
+  }
+
+  // Clean up debugger resources.
+  debugger()->Shutdown();
+
+  // Close all the ports owned by this isolate.
+  PortMap::ClosePorts(message_handler());
+
+  // Fail fast if anybody tries to post any more messsages to this isolate.
+  delete message_handler();
+  set_message_handler(NULL);
+
+  // Dump all accumulated timer data for the isolate.
+  timer_list_.ReportTimers();
+
+  // Finalize any weak persistent handles with a non-null referent.
+  FinalizeWeakPersistentHandlesVisitor visitor;
+  api_state()->weak_persistent_handles().VisitHandles(&visitor);
+  api_state()->prologue_weak_persistent_handles().VisitHandles(&visitor);
+
+  if (FLAG_trace_isolates) {
+    heap()->PrintSizes();
+    megamorphic_cache_table()->PrintSizes();
+    Symbols::DumpStats();
+    OS::Print("[-] Stopping isolate:\n"
+              "\tisolate:    %s\n", name());
+  }
+}
+
+
 void Isolate::Shutdown() {
   ASSERT(this == Isolate::Current());
   ASSERT(top_resource() == NULL);
@@ -1471,7 +1524,10 @@ void Isolate::Shutdown() {
     HandleScope handle_scope(this);
 
     // Write out the coverage data if collection has been enabled.
-    CodeCoverage::Write(this);
+    if ((this != Dart::vm_isolate()) &&
+        !ServiceIsolate::IsServiceIsolateDescendant(this)) {
+      CodeCoverage::Write(this);
+    }
 
     if ((timeline_event_recorder_ != NULL) &&
         (FLAG_timeline_trace_dir != NULL)) {
@@ -1494,48 +1550,7 @@ void Isolate::Shutdown() {
   }
 
   // Then, proceed with low-level teardown.
-  {
-    // Ensure we have a zone and handle scope so that we can call VM functions,
-    // but we no longer allocate new heap objects.
-    StackZone stack_zone(this);
-    HandleScope handle_scope(this);
-    NoSafepointScope no_safepoint_scope;
-
-    if (compiler_stats_ != NULL) {
-      compiler_stats()->Print();
-    }
-
-    // Notify exit listeners that this isolate is shutting down.
-    if (object_store() != NULL) {
-      NotifyExitListeners();
-    }
-
-    // Clean up debugger resources.
-    debugger()->Shutdown();
-
-    // Close all the ports owned by this isolate.
-    PortMap::ClosePorts(message_handler());
-
-    // Fail fast if anybody tries to post any more messsages to this isolate.
-    delete message_handler();
-    set_message_handler(NULL);
-
-    // Dump all accumulated timer data for the isolate.
-    timer_list_.ReportTimers();
-
-    // Finalize any weak persistent handles with a non-null referent.
-    FinalizeWeakPersistentHandlesVisitor visitor;
-    api_state()->weak_persistent_handles().VisitHandles(&visitor);
-    api_state()->prologue_weak_persistent_handles().VisitHandles(&visitor);
-
-    if (FLAG_trace_isolates) {
-      heap()->PrintSizes();
-      megamorphic_cache_table()->PrintSizes();
-      Symbols::DumpStats();
-      OS::Print("[-] Stopping isolate:\n"
-                "\tisolate:    %s\n", name());
-    }
-  }
+  LowLevelShutdown();
 
 #if defined(DEBUG)
   // No concurrent sweeper tasks should be running at this point.
@@ -1568,7 +1583,7 @@ Dart_EntropySource Isolate::entropy_source_callback_ = NULL;
 
 Monitor* Isolate::isolates_list_monitor_ = NULL;
 Isolate* Isolate::isolates_list_head_ = NULL;
-
+bool Isolate::creation_enabled_ = false;
 
 void Isolate::IterateObjectPointers(ObjectPointerVisitor* visitor,
                                     bool visit_prologue_weak_handles,
@@ -1909,12 +1924,16 @@ intptr_t Isolate::IsolateListLength() {
 }
 
 
-void Isolate::AddIsolateTolist(Isolate* isolate) {
+bool Isolate::AddIsolateToList(Isolate* isolate) {
   MonitorLocker ml(isolates_list_monitor_);
+  if (!creation_enabled_) {
+    return false;
+  }
   ASSERT(isolate != NULL);
   ASSERT(isolate->next_ == NULL);
   isolate->next_ = isolates_list_head_;
   isolates_list_head_ = isolate;
+  return true;
 }
 
 
@@ -1936,7 +1955,8 @@ void Isolate::RemoveIsolateFromList(Isolate* isolate) {
     previous = current;
     current = current->next_;
   }
-  UNREACHABLE();
+  // If we are shutting down the VM, the isolate may not be in the list.
+  ASSERT(!creation_enabled_);
 }
 
 
@@ -1953,6 +1973,18 @@ void Isolate::CheckForDuplicateThreadState(InterruptableThreadState* state) {
 #endif
 
 
+void Isolate::DisableIsolateCreation() {
+  MonitorLocker ml(isolates_list_monitor_);
+  creation_enabled_ = false;
+}
+
+
+void Isolate::EnableIsolateCreation() {
+  MonitorLocker ml(isolates_list_monitor_);
+  creation_enabled_ = true;
+}
+
+
 template<class T>
 T* Isolate::AllocateReusableHandle() {
   T* handle = reinterpret_cast<T*>(reusable_handles_.AllocateScopedHandle());
@@ -1961,6 +1993,73 @@ T* Isolate::AllocateReusableHandle() {
 }
 
 
+void Isolate::KillIsolate(Isolate* isolate) {

[Ivan Posva, 2015/08/17 13:35:51]

Why is this not an instance method?

[zra, 2015/08/18 06:23:14]

Done.

+  Dart_CObject kill_msg;
+  Dart_CObject* list_values[4];
+  kill_msg.type = Dart_CObject_kArray;
+  kill_msg.value.as_array.length = 4;
+  kill_msg.value.as_array.values = list_values;
+
+  Dart_CObject oob;
+  oob.type = Dart_CObject_kInt32;
+  oob.value.as_int32 = Message::kIsolateLibOOBMsg;
+  list_values[0] = &oob;
+
+  Dart_CObject kill;
+  kill.type = Dart_CObject_kInt32;
+  kill.value.as_int32 = IsolateMessageHandler::kKillMsg;
+  list_values[1] = &kill;
+
+  Dart_CObject cap;
+  cap.type = Dart_CObject_kCapability;
+  cap.value.as_capability.id = isolate->terminate_capability();
+  list_values[2] = ∩
+
+  Dart_CObject imm;
+  imm.type = Dart_CObject_kInt32;
+  imm.value.as_int32 = IsolateMessageHandler::kImmediateAction;
+  list_values[3] = &imm;
+
+  isolate->ScheduleInterrupts(Isolate::kMessageInterrupt);

[Ivan Posva, 2015/08/17 13:35:51]

What is this interrupt for? It will likely be handled before the message is
enqueued below.

[zra, 2015/08/18 06:23:14]

I was following the pattern in the implementation of Dart_InterruptIsolate:
Schedule the interrupt, then post the message. If that's wrong, I'll fix the
order there, too.

+  {
+    uint8_t* buffer = NULL;
+    ApiMessageWriter writer(&buffer, allocator);
+    bool success = writer.WriteCMessage(&kill_msg);
+    ASSERT(success);
+
+    // Post the message at the given port.
+    success = PortMap::PostMessage(new Message(isolate->main_port(),
+                                               buffer,
+                                               writer.BytesWritten(),
+                                               Message::kOOBPriority));
+    ASSERT(success);
+  }
+}
+
+
+class IsolateKillerVisitor : public IsolateVisitor {
+ public:
+  IsolateKillerVisitor() {}
+
+  virtual ~IsolateKillerVisitor() {}
+
+  void VisitIsolate(Isolate* isolate) {
+    ASSERT(isolate != NULL);
+    if (ServiceIsolate::IsServiceIsolateDescendant(isolate) ||
+        (isolate == Dart::vm_isolate())) {
+      return;
+    }
+    Isolate::KillIsolate(isolate);

[Ivan Posva, 2015/08/17 13:35:51]

ditto

isolate->Kill();

[zra, 2015/08/18 06:23:14]

Done.

+  }
+};
+
+
+void Isolate::KillAllIsolates() {
+  IsolateKillerVisitor visitor;
+  VisitIsolates(&visitor);
+}
+
+
 static RawInstance* DeserializeObject(Isolate* isolate,
                                       Zone* zone,
                                       uint8_t* obj_data,