Move service into VM

runtime/vm/service.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/service.h"
 
+#include "include/dart_api.h"
+
 #include "vm/cpu.h"
+#include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
 #include "vm/heap_histogram.h"
 #include "vm/isolate.h"
 #include "vm/message.h"
+#include "vm/native_entry.h"
+#include "vm/native_arguments.h"
 #include "vm/object.h"
 #include "vm/object_id_ring.h"
 #include "vm/object_store.h"
 #include "vm/port.h"
 #include "vm/profiler.h"
 
+
 namespace dart {
 
-typedef void (*ServiceMessageHandler)(Isolate* isolate, JSONStream* stream);
-
-struct ServiceMessageHandlerEntry {
-  const char* command;
-  ServiceMessageHandler handler;
+struct ResourcesEntry {
+  const char* path_;
+  const char* resource_;
+  int length_;
 };
 
-static ServiceMessageHandler FindServiceMessageHandler(const char* command);
+extern ResourcesEntry __service_resources_[];
+
+class Resources {
+ public:
+  static const int kNoSuchInstance = -1;
+  static int ResourceLookup(const char* path, const char** resource) {
+    ResourcesEntry* table = get_resources_table();
+    for (int i = 0; table[i].path_ != NULL; i++) {
+      const ResourcesEntry& entry = table[i];
+      if (strcmp(path, entry.path_) == 0) {
+        *resource = entry.resource_;
+        ASSERT(entry.length_ > 0);
+        return entry.length_;
+      }
+    }
+    return kNoSuchInstance;
+  }
+
+  static const char* get_resource_path(int idx) {

[siva, 2014/01/10 00:01:54]

ditto comments about the function names as they are not simple accessors.

[Cutch, 2014/01/10 21:01:42]

Done.

+    ASSERT(idx >= 0);
+    ResourcesEntry* entry = get_resource_entry(idx);
+    if (entry == NULL) {
+      return NULL;
+    }
+    return entry->path_;
+  }
+
+  static const char* get_resource_resource(int idx) {
+    ASSERT(idx >= 0);
+    ResourcesEntry* entry = get_resource_entry(idx);
+    if (entry == NULL) {
+      return NULL;
+    }
+    return entry->resource_;
+  }
+
+ private:
+  static ResourcesEntry* get_resource_entry(int idx) {
+    ASSERT(idx >= 0);
+    ResourcesEntry* table = get_resources_table();
+    for (int i = 0; table[i].path_ != NULL; i++) {
+      if (idx == i) {
+        return &table[i];
+      }
+    }
+    return NULL;
+  }
+
+  static ResourcesEntry* get_resources_table() {
+    return &__service_resources_[0];
+  }
+
+  DISALLOW_ALLOCATION();
+  DISALLOW_IMPLICIT_CONSTRUCTORS(Resources);
+};
 
 
 static uint8_t* allocator(uint8_t* ptr, intptr_t old_size, intptr_t new_size) {
   void* new_ptr = realloc(reinterpret_cast<void*>(ptr), new_size);
   return reinterpret_cast<uint8_t*>(new_ptr);
 }
 
 
+static void SendServiceMessage(Dart_NativeArguments args) {
+  NativeArguments* arguments = reinterpret_cast<NativeArguments*>(args);
+  Isolate* isolate = arguments->isolate();
+  StackZone zone(isolate);
+  HANDLESCOPE(isolate);
+  GET_NON_NULL_NATIVE_ARGUMENT(Instance, sp, arguments->NativeArgAt(0));
+  GET_NON_NULL_NATIVE_ARGUMENT(Instance, message, arguments->NativeArgAt(1));
+
+  // Extract SendPort port id.
+  const Object& sp_id_obj = Object::Handle(DartLibraryCalls::PortGetId(sp));
+  if (sp_id_obj.IsError()) {
+    Exceptions::PropagateError(Error::Cast(sp_id_obj));
+  }
+  Integer& id = Integer::Handle();
+  id ^= sp_id_obj.raw();
+  Dart_Port sp_id = static_cast<Dart_Port>(id.AsInt64Value());
+  ASSERT(sp_id != ILLEGAL_PORT);
+
+  // Serialize message.
+  uint8_t* data = NULL;
+  MessageWriter writer(&data, &allocator);
+  writer.WriteMessage(message);
+
+  // TODO(turnidge): Throw an exception when the return value is false?
+  PortMap::PostMessage(new Message(sp_id, data, writer.BytesWritten(),
+                                   Message::kOOBPriority));
+}
+
+
+struct VmServiceNativeEntry {
+  const char* name;
+  int num_arguments;
+  Dart_NativeFunction function;
+};
+
+
+static VmServiceNativeEntry _VmServiceNativeEntries[] = {
+  {"VMService_SendServiceMessage", 2, SendServiceMessage}
+};
+
+
+static Dart_NativeFunction VmServiceNativeResolver(Dart_Handle name,
+                                                   int num_arguments,
+                                                   bool* auto_setup_scope) {
+  const Object& obj = Object::Handle(Api::UnwrapHandle(name));
+  if (!obj.IsString()) {
+    return NULL;
+  }
+  const char* function_name = obj.ToCString();
+  ASSERT(function_name != NULL);
+  ASSERT(auto_setup_scope != NULL);
+  *auto_setup_scope = true;
+  intptr_t n =
+      sizeof(_VmServiceNativeEntries) / sizeof(_VmServiceNativeEntries[0]);
+  for (intptr_t i = 0; i < n; i++) {
+    VmServiceNativeEntry entry = _VmServiceNativeEntries[i];
+    if (!strcmp(function_name, entry.name) &&
+        (num_arguments == entry.num_arguments)) {
+      return entry.function;
+    }
+  }

[siva, 2014/01/10 00:01:54]

There is only one entry in the table does it need to be a loop? Do you think
there will more native entries later.

[Cutch, 2014/01/10 21:01:42]

There will be more natives later. Todd has a CL which adds another one.

+  return NULL;
+}
+
+#define SHUTDOWN(error_msg)                         \
+  printf("Service Isolate Error: %s\n", error_msg); \
+  Dart_ExitScope();                                 \
+  Dart_ShutdownIsolate();                           \
+  return NULL
+
+#define SHUTDOWN_ON_ERROR(handle)                                 \
+  if (Dart_IsError(handle)) {                                     \
+    SHUTDOWN(Dart_GetError(handle));                              \
+  }
+
+Isolate* Service::service_isolate_ = NULL;
+Dart_LibraryTagHandler Service::default_handler_ = NULL;
+Dart_Port Service::port_ = ILLEGAL_PORT;
+
+Isolate* Service::GetServiceIsolate(void* callback_data) {
+  if (service_isolate_ != NULL) {
+    // Already initialized, return service isolate.
+    return service_isolate_;
+  }

[siva, 2014/01/10 00:01:54]

What happens if multiple threads from the embedder call GetServiceIsolate? the
function is not MT safe

[Cutch, 2014/01/10 21:01:42]

Good point. Do we make thread safety guarantees about the API? What's to stop an
embedder from entering an isolate on two separate threads?

+  Dart_ServiceIsolateCreateCallback create_callback =
+    Isolate::ServiceCreateCallback();
+  if (create_callback == NULL) {
+    return NULL;
+  }
+  if (Dart_CurrentIsolate() != NULL) {
+    // Clear current isolate.
+    Dart_ExitIsolate();
+  }
+  char* error = NULL;
+  Dart_Isolate isolate = create_callback(callback_data, &error);
+  if (isolate == NULL) {
+    printf("Service Isolate Error: %s\n", error);
+    return NULL;
+  }
+  Dart_EnterIsolate(isolate);
+  Dart_EnterScope();
+  Dart_Handle result;
+  Dart_Handle root_library = Dart_RootLibrary();
+  SHUTDOWN_ON_ERROR(root_library);
+  ASSERT(root_library == Dart_Null());
+  // Retrieve the embedder default library tag handler.
+  default_handler_ = reinterpret_cast<Isolate*>(isolate)->library_tag_handler();
+  ASSERT(default_handler_ != NULL);
+  // Temporarily install our own.
+  Dart_SetLibraryTagHandler(LibraryTagHandler);
+  // Load VM service library.
+  Dart_Handle library;
+  {
+    const char* resource = NULL;
+    const char* path = "/vmservice.dart";
+    int r = Resources::ResourceLookup(path, &resource);
+    ASSERT(r != Resources::kNoSuchInstance);
+    ASSERT(resource != NULL);
+    Dart_Handle url = Dart_NewStringFromCString("dart:vmservice");
+    SHUTDOWN_ON_ERROR(url);
+    Dart_Handle source = Dart_NewStringFromCString(resource);
+    SHUTDOWN_ON_ERROR(source);
+    library = Dart_LoadLibrary(url, source);
+    SHUTDOWN_ON_ERROR(library);
+    result = Dart_SetNativeResolver(library, VmServiceNativeResolver);
+    SHUTDOWN_ON_ERROR(result);
+  }
+  // Install embedder default library tag handler again.
+  Dart_SetLibraryTagHandler(default_handler_);
+  default_handler_ = NULL;
+  // Boot the service.
+  {
+    result = Dart_Invoke(library, Dart_NewStringFromCString("boot"), 0, NULL);
+    SHUTDOWN_ON_ERROR(result);
+    HANDLESCOPE(Isolate::Current());
+    const Object& unwrapped_rp = Object::Handle(Api::UnwrapHandle(result));
+    const Instance& rp = Instance::Cast(unwrapped_rp);
+    // Extract RawReceivePort port id.
+    const Object& rp_id_obj = Object::Handle(DartLibraryCalls::PortGetId(rp));
+    if (rp_id_obj.IsError()) {
+      const Error& error = Error::Cast(rp_id_obj);
+      SHUTDOWN(error.ToErrorCString());
+    }
+    ASSERT(rp_id_obj.IsSmi() || rp_id_obj.IsMint());
+    Integer& id = Integer::Handle();
+    id ^= rp_id_obj.raw();

[siva, 2014/01/10 00:01:54]

Since you are asserting that rp_id_obj is a Smi or Mint you
could do:
const Integer& id = Integer::Cast(rp_id_obj);

[Cutch, 2014/01/10 21:01:42]

Done.

+    port_ = static_cast<Dart_Port>(id.AsInt64Value());
+  }
+  Dart_ExitScope();
+  Dart_ExitIsolate();
+  service_isolate_ = reinterpret_cast<Isolate*>(isolate);
+  return service_isolate_;
+}
+
+
+// These must be kept in sync with service/constants.dart
+#define VM_SERVICE_ISOLATE_STARTUP_MESSAGE_ID 1
+#define VM_SERVICE_ISOLATE_SHUTDOWN_MESSAGE_ID 2
+
+
+static Dart_Handle MakeServiceControlMessage(Dart_Port port_id, intptr_t code,
+                                             Dart_Handle name) {
+  Dart_Handle result;
+  Dart_Handle list = Dart_NewList(4);
+  ASSERT(!Dart_IsError(list));
+  Dart_Handle code_handle = Dart_NewInteger(code);
+  ASSERT(!Dart_IsError(code_handle));
+  result = Dart_ListSetAt(list, 0, code_handle);
+  ASSERT(!Dart_IsError(result));
+  Dart_Handle port_id_handle = Dart_NewInteger(port_id);
+  ASSERT(!Dart_IsError(port_id_handle));
+  result = Dart_ListSetAt(list, 1, port_id_handle);
+  ASSERT(!Dart_IsError(result));
+  Dart_Handle sendPort = Dart_NewSendPort(port_id);
+  ASSERT(!Dart_IsError(sendPort));
+  result = Dart_ListSetAt(list, 2, sendPort);
+  ASSERT(!Dart_IsError(result));
+  result = Dart_ListSetAt(list, 3, name);
+  ASSERT(!Dart_IsError(result));
+  return list;
+}
+
+
+bool Service::SendIsolateStartupMessage() {
+  if (!IsRunning()) {
+    return false;
+  }
+  Isolate* isolate = Isolate::Current();
+  ASSERT(isolate != NULL);
+  HANDLESCOPE(isolate);
+  Dart_EnterScope();
+  Dart_Handle name = Api::NewHandle(isolate, String::New(isolate->name()));
+  ASSERT(!Dart_IsError(name));
+  Dart_Handle list =
+      MakeServiceControlMessage(Dart_GetMainPortId(),
+                                VM_SERVICE_ISOLATE_STARTUP_MESSAGE_ID,
+                                name);
+  ASSERT(!Dart_IsError(list));
+  bool r = Dart_Post(port_, list);
+  Dart_ExitScope();
+  return r;
+}
+
+
+bool Service::SendIsolateShutdownMessage() {
+  if (!IsRunning()) {
+    return false;
+  }
+  Isolate* isolate = Isolate::Current();
+  ASSERT(isolate != NULL);
+  HANDLESCOPE(isolate);
+  Dart_EnterScope();
+  Dart_Handle list =
+      MakeServiceControlMessage(Dart_GetMainPortId(),
+                                VM_SERVICE_ISOLATE_SHUTDOWN_MESSAGE_ID,
+                                Dart_Null());
+  ASSERT(!Dart_IsError(list));
+  bool r = Dart_Post(port_, list);
+  Dart_ExitScope();
+  return r;
+}
+
+
+bool Service::IsRunning() {
+  return port_ != ILLEGAL_PORT;
+}
+
+
+Dart_Handle Service::GetSource(const char* name) {
+  ASSERT(name != NULL);
+  int i = 0;
+  while (true) {
+    const char* path = Resources::get_resource_path(i);
+    if (path == NULL) {
+      break;
+    }
+    ASSERT(*path != '\0');
+    // Skip the '/'.
+    path++;
+    if (strcmp(name, path) == 0) {
+      return Dart_NewStringFromCString(Resources::get_resource_resource(i));
+    }
+    i++;
+  }
+  return Dart_Null();
+}
+
+
+Dart_Handle Service::LibraryTagHandler(Dart_LibraryTag tag, Dart_Handle library,
+                                       Dart_Handle url) {
+  if (!Dart_IsLibrary(library)) {
+    return Dart_NewApiError("not a library");
+  }
+  if (!Dart_IsString(url)) {
+    return Dart_NewApiError("url is not a string");
+  }
+  const char* url_string = NULL;
+  Dart_Handle result = Dart_StringToCString(url, &url_string);
+  if (Dart_IsError(result)) {
+    return result;
+  }
+  Dart_Handle library_url = Dart_LibraryUrl(library);
+  const char* library_url_string = NULL;
+  result = Dart_StringToCString(library_url, &library_url_string);
+  if (Dart_IsError(result)) {
+    return result;
+  }

[siva, 2014/01/10 00:01:54]

What is the conversion to C string library_url_string for? The variable is not
used anywhere in this tag handler.

library_url is also not used anywhere?

[Cutch, 2014/01/10 21:01:42]

Done.

+  if (tag == Dart_kImportTag) {
+    // Embedder handles all requests for external libraries.
+    ASSERT(default_handler_ != NULL);
+    return default_handler_(tag, library, url);
+  }
+  ASSERT((tag == Dart_kSourceTag) || (tag == Dart_kCanonicalizeUrl));
+  if (tag == Dart_kCanonicalizeUrl) {
+    // url is already canonicalized.
+    return url;
+  }
+  Dart_Handle source = GetSource(url_string);
+  if (Dart_IsError(source)) {
+    return source;
+  }
+  return Dart_LoadSource(library, url, source);
+}
+
+
+typedef void (*ServiceMessageHandler)(Isolate* isolate, JSONStream* stream);
+
+struct ServiceMessageHandlerEntry {
+  const char* command;
+  ServiceMessageHandler handler;
+};
+
+static ServiceMessageHandler FindServiceMessageHandler(const char* command);
+
 static void PostReply(const String& reply, const Instance& reply_port) {
   const Object& id_obj = Object::Handle(
       DartLibraryCalls::PortGetId(reply_port));
   if (id_obj.IsError()) {
     Exceptions::PropagateError(Error::Cast(id_obj));
   }
   const Integer& id = Integer::Cast(id_obj);
   Dart_Port port = static_cast<Dart_Port>(id.AsInt64Value());
   ASSERT(port != ILLEGAL_PORT);
 
@@ skipping 602 matching lines @@
   for (intptr_t i = 0; i < num_message_handlers; i++) {
     const ServiceMessageHandlerEntry& entry = __message_handlers[i];
     if (!strcmp(command, entry.command)) {
       return entry.handler;
     }
   }
   return HandleFallthrough;
 }
 
 }  // namespace dart