Revert r43217, r43215, r43208, r43207, and r43202.

runtime/vm/service.cc

Index: runtime/vm/service.cc
diff --git a/runtime/vm/service.cc b/runtime/vm/service.cc
index f0d9da89a11ab24394bc27a1fe06f0114b72b43e..1aae8ae64c4d35c927ca989d2e35f6cd5c974a73 100644
--- a/runtime/vm/service.cc
+++ b/runtime/vm/service.cc
@@ -14,7 +14,6 @@
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
 #include "vm/isolate.h"
-#include "vm/lockers.h"
 #include "vm/message.h"
 #include "vm/message_handler.h"
 #include "vm/native_entry.h"
@@ -248,29 +247,6 @@ static void SendRootServiceMessage(Dart_NativeArguments args) {
 }
 
 
-Dart_Port Service::WaitForLoadPort() {
-  MonitorLocker ml(monitor_);
-
-  while (initializing_ && (load_port_ == ILLEGAL_PORT)) {
-    ml.Wait();
-  }
-
-  return load_port_;
-}
-
-
-Dart_Port Service::LoadPort() {
-  MonitorLocker ml(monitor_);
-  return load_port_;
-}
-
-
-void Service::SetLoadPort(Dart_Port port) {
-  MonitorLocker ml(monitor_);
-  load_port_ = port;
-}
-
-
 void Service::SetEventMask(uint32_t mask) {
   event_mask_ = mask;
 }
@@ -348,11 +324,6 @@ class RegisterRunningIsolatesVisitor : public IsolateVisitor {
     args.SetAt(2, name);
     Object& r = Object::Handle(service_isolate_);
     r = DartEntry::InvokeFunction(register_function_, args);
-    if (FLAG_trace_service) {
-      OS::Print("Isolate %s %" Pd64 " registered with service \n",
-                name.ToCString(),
-                port_id);
-    }
     ASSERT(!r.IsError());
   }
 
@@ -377,9 +348,6 @@ static void OnStart(Dart_NativeArguments args) {
   StackZone zone(isolate);
   HANDLESCOPE(isolate);
   {
-    if (FLAG_trace_service) {
-      OS::Print("Booting dart:vmservice library\n");
-    }
     // Boot the dart:vmservice library.
     Dart_EnterScope();
     Dart_Handle url_str =
@@ -394,11 +362,7 @@ static void OnStart(Dart_NativeArguments args) {
     Service::set_port(port);
     Dart_ExitScope();
   }
-
   {
-    if (FLAG_trace_service) {
-      OS::Print("Registering running isolates\n");
-    }
     // Register running isolates with service.
     RegisterRunningIsolatesVisitor register_isolates(isolate);
     Isolate::VisitIsolates(&register_isolates);
@@ -444,20 +408,77 @@ static Dart_NativeFunction VmServiceNativeResolver(Dart_Handle name,
   return NULL;
 }
 
-const char* Service::kServiceIsolateName = "vm-service";
+
 EmbedderServiceHandler* Service::isolate_service_handler_head_ = NULL;
 EmbedderServiceHandler* Service::root_service_handler_head_ = NULL;
 Isolate* Service::service_isolate_ = NULL;
+Dart_LibraryTagHandler Service::embedder_provided_handler_ = NULL;
 Dart_Port Service::port_ = ILLEGAL_PORT;
-Dart_Port Service::load_port_ = ILLEGAL_PORT;
-Monitor* Service::monitor_ = NULL;
-bool Service::initializing_ = true;
 uint32_t Service::event_mask_ = 0;
 
+Isolate* Service::GetServiceIsolate(void* callback_data) {
+  if (service_isolate_ != NULL) {
+    // Already initialized, return service isolate.
+    return service_isolate_;
+  }
+  Dart_ServiceIsolateCreateCalback create_callback =
+    Isolate::ServiceCreateCallback();
+  if (create_callback == NULL) {
+    return NULL;
+  }
+  Isolate::SetCurrent(NULL);
+  char* error = NULL;
+  Isolate* isolate =
+      reinterpret_cast<Isolate*>(create_callback(callback_data, &error));
+  if (isolate == NULL) {
+    return NULL;
+  }
+  StartIsolateScope isolate_scope(isolate);
+  {
+    // Install the dart:vmservice library.
+    StackZone zone(isolate);
+    HANDLESCOPE(isolate);
+    Library& library =
+        Library::Handle(isolate, isolate->object_store()->root_library());
+    // Isolate is empty.
+    ASSERT(library.IsNull());
+    // Grab embedder tag handler.
+    embedder_provided_handler_ = isolate->library_tag_handler();
+    // Temporarily install our own.
+    isolate->set_library_tag_handler(LibraryTagHandler);
+    // Get script resource.
+    const char* resource = NULL;
+    const char* path = "/vmservice.dart";
+    intptr_t r = Resources::ResourceLookup(path, &resource);
+    ASSERT(r != Resources::kNoSuchInstance);
+    ASSERT(resource != NULL);
+    const String& source_str = String::Handle(
+        String::FromUTF8(reinterpret_cast<const uint8_t*>(resource), r));
+    ASSERT(!source_str.IsNull());
+    const String& url_str = String::Handle(Symbols::DartVMService().raw());
+    library ^= Library::LookupLibrary(url_str);
+    ASSERT(library.IsNull());
+    // Setup library.
+    library = Library::New(url_str);
+    library.Register();
+    const Script& script = Script::Handle(
+      isolate, Script::New(url_str, source_str, RawScript::kLibraryTag));
+    library.SetLoadInProgress();
+    Dart_EnterScope();  // Need to enter scope for tag handler.
+    const Error& error = Error::Handle(isolate,
+                                       Compiler::Compile(library, script));
+    ASSERT(error.IsNull());
+    Dart_Handle result = Dart_FinalizeLoading(false);
+    ASSERT(!Dart_IsError(result));
+    Dart_ExitScope();
 
-bool Service::IsServiceIsolateName(const char* name) {
-  ASSERT(name != NULL);
-  return strcmp(name, kServiceIsolateName) == 0;
+    // Install embedder default library tag handler again.
+    isolate->set_library_tag_handler(embedder_provided_handler_);
+    embedder_provided_handler_ = NULL;
+    library.set_native_entry_resolver(VmServiceNativeResolver);
+  }
+  service_isolate_ = reinterpret_cast<Isolate*>(isolate);
+  return service_isolate_;
 }
 
 
@@ -466,9 +487,6 @@ bool Service::SendIsolateStartupMessage() {
     return false;
   }
   Isolate* isolate = Isolate::Current();
-  if (IsServiceIsolate(isolate)) {
-    return false;
-  }
   ASSERT(isolate != NULL);
   HANDLESCOPE(isolate);
   const String& name = String::Handle(String::New(isolate->name()));
@@ -497,9 +515,6 @@ bool Service::SendIsolateShutdownMessage() {
     return false;
   }
   Isolate* isolate = Isolate::Current();
-  if (IsServiceIsolate(isolate)) {
-    return false;
-  }
   ASSERT(isolate != NULL);
   HANDLESCOPE(isolate);
   const String& name = String::Handle(String::New(isolate->name()));
@@ -545,8 +560,7 @@ Dart_Handle Service::GetSource(const char* name) {
 }
 
 
-Dart_Handle Service::LibraryTagHandler(Dart_LibraryTag tag,
-                                       Dart_Handle library,
+Dart_Handle Service::LibraryTagHandler(Dart_LibraryTag tag, Dart_Handle library,
                                        Dart_Handle url) {
   if (!Dart_IsLibrary(library)) {
     return Dart_NewApiError("not a library");
@@ -560,9 +574,12 @@ Dart_Handle Service::LibraryTagHandler(Dart_LibraryTag tag,
     return result;
   }
   if (tag == Dart_kImportTag) {
-    OS::Print("Attempting to import %s\n", url_string);
-    return Dart_NewApiError("Unable to import module as no library tag "
-                            "is available");
+    // Embedder handles all requests for external libraries.
+    if (embedder_provided_handler_ == NULL) {
+      return Dart_NewApiError("Unable to import module as no library tag "
+                              "handler has been provided by embedder");
+    }
+    return embedder_provided_handler_(tag, library, url);
   }
   ASSERT((tag == Dart_kSourceTag) || (tag == Dart_kCanonicalizeUrl));
   if (tag == Dart_kCanonicalizeUrl) {
@@ -577,177 +594,6 @@ Dart_Handle Service::LibraryTagHandler(Dart_LibraryTag tag,
 }
 
 
-void Service::MaybeInjectVMServiceLibrary(Isolate* isolate) {
-  if (service_isolate_ != NULL) {
-    // Service isolate already exists.
-    return;
-  }
-  if (!Service::IsServiceIsolateName(isolate->name())) {
-    // Not service isolate.
-    return;
-  }
-  service_isolate_ = isolate;
-  ASSERT(isolate != NULL);
-  StackZone zone(isolate);
-  HANDLESCOPE(isolate);
-
-  // Verify that isolate has no root library.
-  Library& library =
-      Library::Handle(isolate, isolate->object_store()->root_library());
-  ASSERT(library.IsNull());
-
-  // Verify that isolate doesn't have the dart:vmservice library.
-  const String& url_str = String::Handle(Symbols::DartVMService().raw());
-  library ^= Library::LookupLibrary(url_str);
-  ASSERT(library.IsNull());
-
-  // Register dart:vmservice library.
-  library = Library::New(url_str);
-  library.Register();
-  library.set_native_entry_resolver(VmServiceNativeResolver);
-
-  // Temporarily install our library tag handler.
-  isolate->set_library_tag_handler(LibraryTagHandler);
-
-  // Get script source.
-  const char* resource = NULL;
-  const char* path = "/vmservice.dart";
-  intptr_t r = Resources::ResourceLookup(path, &resource);
-  ASSERT(r != Resources::kNoSuchInstance);
-  ASSERT(resource != NULL);
-  const String& source_str = String::Handle(
-      String::FromUTF8(reinterpret_cast<const uint8_t*>(resource), r));
-  ASSERT(!source_str.IsNull());
-  const Script& script = Script::Handle(
-    isolate, Script::New(url_str, source_str, RawScript::kLibraryTag));
-
-  // Compile script.
-  Dart_EnterScope();  // Need to enter scope for tag handler.
-  library.SetLoadInProgress();
-  const Error& error = Error::Handle(isolate,
-                                     Compiler::Compile(library, script));
-  ASSERT(error.IsNull());
-  Dart_Handle result = Dart_FinalizeLoading(false);
-  ASSERT(!Dart_IsError(result));
-  Dart_ExitScope();
-
-  // Uninstall our library tag handler.
-  isolate->set_library_tag_handler(NULL);
-}
-
-
-void Service::FinishedInitializing() {
-  MonitorLocker ml(monitor_);
-  initializing_ = false;
-  ml.NotifyAll();
-}
-
-
-static void ShutdownIsolate(uword parameter) {
-  Isolate* isolate = reinterpret_cast<Isolate*>(parameter);
-  {
-    // Print the error if there is one.  This may execute dart code to
-    // print the exception object, so we need to use a StartIsolateScope.
-    StartIsolateScope start_scope(isolate);
-    StackZone zone(isolate);
-    HandleScope handle_scope(isolate);
-    Error& error = Error::Handle();
-    error = isolate->object_store()->sticky_error();
-    if (!error.IsNull()) {
-      OS::PrintErr("Service shutting down: %s\n", error.ToErrorCString());
-    }
-    Dart::RunShutdownCallback();
-  }
-  {
-    // Shut the isolate down.
-    SwitchIsolateScope switch_scope(isolate);
-    Dart::ShutdownIsolate();
-  }
-}
-
-
-class RunServiceTask : public ThreadPool::Task {
- public:
-  virtual void Run() {
-    ASSERT(Isolate::Current() == NULL);
-
-    Dart_IsolateCreateCallback create_callback = Isolate::CreateCallback();
-    if (create_callback == NULL) {
-      Service::FinishedInitializing();
-      return;
-    }
-
-    char* error = NULL;
-    Isolate* isolate =
-        reinterpret_cast<Isolate*>(create_callback(Service::kServiceIsolateName,
-                                                   NULL,
-                                                   NULL,
-                                                   NULL,
-                                                   &error));
-    Isolate::SetCurrent(NULL);
-
-    if (isolate == NULL) {
-      OS::PrintErr("Service startup error: %s\n", error);
-      Service::FinishedInitializing();
-      return;
-    }
-
-    RunMain(isolate);
-
-    Service::FinishedInitializing();
-
-    isolate->message_handler()->Run(Dart::thread_pool(),
-                                    NULL,
-                                    ShutdownIsolate,
-                                    reinterpret_cast<uword>(isolate));
-  }
-
- protected:
-  void RunMain(Isolate* isolate) {
-    StartIsolateScope iso_scope(isolate);
-    StackZone zone(isolate);
-    HANDLESCOPE(isolate);
-    // Invoke main which will return the loadScriptPort.
-    const Library& root_library =
-        Library::Handle(isolate, isolate->object_store()->root_library());
-    if (root_library.IsNull()) {
-      // Service isolate is not supported by embedder.
-      return;
-    }
-    ASSERT(!root_library.IsNull());
-    const String& entry_name = String::Handle(isolate, String::New("main"));
-    ASSERT(!entry_name.IsNull());
-    const Function& entry =
-        Function::Handle(isolate,
-                         root_library.LookupFunctionAllowPrivate(entry_name));
-    if (entry.IsNull()) {
-      // Service isolate is not supported by embedder.
-      return;
-    }
-    ASSERT(!entry.IsNull());
-    const Object& result =
-        Object::Handle(isolate,
-                       DartEntry::InvokeFunction(entry,
-                                                 Object::empty_array()));
-    ASSERT(!result.IsNull());
-    if (result.IsError()) {
-      // Service isolate did not initialize properly.
-      return;
-    }
-    ASSERT(result.IsReceivePort());
-    const ReceivePort& rp = ReceivePort::Cast(result);
-    Service::SetLoadPort(rp.Id());
-  }
-};
-
-
-void Service::RunService() {
-  ASSERT(monitor_ == NULL);
-  monitor_ = new Monitor();
-  ASSERT(monitor_ != NULL);
-  Dart::thread_pool()->Run(new RunServiceTask());
-}
-
 // A handler for a per-isolate request.
 //
 // If a handler returns true, the reply is complete and ready to be