Enable VM service inside Dartium Renderer processes

Source/bindings/dart/DartService.cpp

+// 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 "config.h"
+
+#include "bindings/dart/DartService.h"
+
+#include "DartApplicationLoader.h"
+#include "DartController.h"
+#include "DartDocument.h"
+#include "DartServiceInternal.h"
+#include "DartUtilities.h"
+#include "DartWindow.h"
+
+
+// These must be kept in sync with vmservice/constants.dart

[Jacob, 2013/12/04 20:39:52]

nit: these could be kept in sync automatically by adding a native getter so
these constants are only defined once on the C++ side. Perhaps add a FIXME for
this

[Cutch, 2013/12/04 21:20:50]

Done.

+#define VM_SERVICE_ISOLATE_STARTUP_MESSAGE_ID 1
+#define VM_SERVICE_ISOLATE_SHUTDOWN_MESSAGE_ID 2
+
+// The following Resources class is used in combination with a generated
+// source file that expects underscores in names. The NOLINT tags are
+// used to suppress the errors.
+namespace dart {

[Jacob, 2013/12/04 20:39:52]

having files with the namespace dart::bin
seems strange. Any way to move this defn to the impl file or keep it with the
standard webcore namespace?

[Cutch, 2013/12/04 21:20:50]

Added TODO. Moving the namespace requires surgery to runtime/bin and some build
scripts. 

+namespace bin {
+class Resources {
+public:
+    static const int kNoSuchInstance = -1;
+
+    static int ResourceLookup(const char* path, const char** resource)
+    {
+        for (int i = 0; i < get_resource_count(); i++) {
+            resource_map_entry* entry = get_resource(i);
+            if (!strcmp(path, entry->path_)) {
+                *resource = entry->resource_;
+                ASSERT(entry->length_ > 0);
+                return entry->length_;
+            }
+        }
+        return kNoSuchInstance;
+    }
+
+    static intptr_t get_resource_count()  // NOLINT.
+    {
+        return builtin_resources_count_;
+    }
+
+    static const char* get_resource_path(intptr_t i) // NOLINT.
+    {
+        return get_resource(i)->path_;
+    }
+
+private:
+    struct resource_map_entry {  // NOLINT.
+      const char* path_;  // NOLINT.
+      const char* resource_;  // NOLINT.
+      intptr_t length_;  // NOLINT.
+    };
+
+    // These fields are generated by resources_gen.cc.
+    static resource_map_entry builtin_resources_[];  // NOLINT.
+    static const intptr_t builtin_resources_count_;  // NOLINT.
+
+    static resource_map_entry* get_resource(int i)  // NOLINT.
+    {
+        ASSERT(i >= 0 && i < builtin_resources_count_);
+        return &builtin_resources_[i];
+    }
+
+    DISALLOW_IMPLICIT_CONSTRUCTORS(Resources);
+};
+
+}
+}
+namespace WebCore {
+
+#define RETURN_ERROR_HANDLE(handle)                               \
+    if (Dart_IsError(handle)) {                                   \
+        return handle;                                            \
+    }
+
+#define SHUTDOWN_ON_ERROR(handle)                                   \
+    if (Dart_IsError(handle)) {                                     \
+        m_errorMsg = strdup(Dart_GetError(handle));                 \
+        Dart_ExitScope();                                           \
+        Dart_ShutdownIsolate();                                     \
+        return false;                                               \
+    }
+
+#define kLibraryResourceNamePrefix "/vmservice"
+static const char* kVMServiceDartiumLibraryScriptResourceName =
+    kLibraryResourceNamePrefix "/vmservice_dartium.dart";
+static const char* kVMServiceLibraryName =
+    kLibraryResourceNamePrefix "/vmservice.dart";
+
+
+Dart_Isolate DartService::m_isolate = 0;
+Dart_Port DartService::m_port = ILLEGAL_PORT;
+Dart_Port DartService::m_requestPort = ILLEGAL_PORT;
+const char* DartService::m_errorMsg = 0;
+
+
+bool DartService::Start(Document* document)
+{
+    ASSERT(!m_isolate);
+    char* error = 0;
+    const char* scriptUri = "vmservice:";

[Jacob, 2013/12/04 20:39:52]

move this constant outside of the method

[Cutch, 2013/12/04 21:20:50]

Done.

+    m_isolate = DartController::createIsolate(scriptUri, "main", document, true, &error);
+    if (!m_isolate) {
+        m_errorMsg = error;
+        return false;
+    }
+
+
+    Dart_EnterScope();
+
+    // Set up the library tag handler for this isolate.
+    Dart_Handle result = Dart_SetLibraryTagHandler(LibraryTagHandler);
+    SHUTDOWN_ON_ERROR(result);

[Jacob, 2013/12/04 20:39:52]

for consistency use the
Scope auto-release helper classes and the goto error pattern used elsewhere in
this directory.

[Cutch, 2013/12/04 21:20:50]

Done.

+
+    {
+        // Load source into service isolate.
+        Dart_Handle library =
+            LoadScript(kVMServiceDartiumLibraryScriptResourceName);
+        SHUTDOWN_ON_ERROR(library);
+    }
+    // Make the isolate runnable so that it is ready to handle messages.
+    Dart_ExitScope();
+    Dart_ExitIsolate();
+
+    bool retval = Dart_IsolateMakeRunnable(m_isolate);
+    if (!retval) {
+        Dart_EnterIsolate(m_isolate);
+        Dart_ShutdownIsolate();
+        m_errorMsg = "Invalid isolate state - Unable to make it runnable.";
+        return false;
+    }
+
+    Dart_EnterIsolate(m_isolate);
+    Dart_EnterScope();
+
+    // Invoke main.
+    Dart_Handle library = Dart_RootLibrary();
+    Dart_Handle entryFunctioName = Dart_NewStringFromCString("main");
+    SHUTDOWN_ON_ERROR(entryFunctioName);
+    result = Dart_Invoke(library, entryFunctioName, 0, 0);
+    SHUTDOWN_ON_ERROR(result);
+
+    // Retrieve the ReceivePort that the service is waiting on. The _receivePort
+    // variable is setup in the call to main.
+    Dart_Handle portFieldName = Dart_NewStringFromCString("_receivePort");
+    SHUTDOWN_ON_ERROR(portFieldName);
+    Dart_Handle receivePort = Dart_GetField(library, portFieldName);
+    SHUTDOWN_ON_ERROR(receivePort);
+
+    m_port = DartServiceInternal::GetPortIdFromPort(receivePort);
+    if (m_port == ILLEGAL_PORT) {
+        Dart_ExitScope();
+        Dart_ShutdownIsolate();
+        m_errorMsg = "Invalid isolate state - Unable to get receivePort";
+        return false;
+    }
+
+    {
+        // Retrieve the ReceivePort that the service is waiting on. The _receivePort
+        // variable is setup in the call to main.
+        Dart_Handle portFieldName = Dart_NewStringFromCString("_requestPort");
+        SHUTDOWN_ON_ERROR(portFieldName);
+        Dart_Handle receivePort = Dart_GetField(library, portFieldName);
+        SHUTDOWN_ON_ERROR(receivePort);
+        m_requestPort = DartServiceInternal::GetPortIdFromPort(receivePort);
+        ASSERT(m_requestPort != ILLEGAL_PORT);
+    }
+
+    Dart_ExitScope();
+    Dart_ExitIsolate();
+    return true;
+}
+
+
+bool DartService::Stop()
+{
+    // TODO: Properly cleanup VM service isolate.
+    m_port = ILLEGAL_PORT;
+    return true;
+}
+
+
+const char* DartService::GetErrorMessage()
+{
+    return m_errorMsg ? m_errorMsg : "No error.";
+}
+
+
+Dart_Port DartService::port()
+{
+    return m_port;
+}
+
+
+bool DartService::IsRunning()
+{
+    return m_port != ILLEGAL_PORT;
+}
+
+
+static Dart_Handle MakeServiceControlMessage(Dart_Port portId, intptr_t code, Dart_Handle name)
+{
+    Dart_Handle result;
+    Dart_Handle list = Dart_NewList(4);
+    ASSERT(!Dart_IsError(list));
+    Dart_Handle codeHandle = Dart_NewInteger(code);
+    ASSERT(!Dart_IsError(codeHandle));
+    result = Dart_ListSetAt(list, 0, codeHandle);
+    ASSERT(!Dart_IsError(result));
+    Dart_Handle portIdHandle = Dart_NewInteger(portId);
+    ASSERT(!Dart_IsError(portIdHandle));
+    result = Dart_ListSetAt(list, 1, portIdHandle);
+    ASSERT(!Dart_IsError(result));
+    Dart_Handle sendPort = Dart_NewSendPort(portId);
+    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 DartService::SendIsolateStartupMessage()
+{
+    if (!IsRunning()) {
+        return false;
+    }
+    Dart_Handle name = Dart_DebugName();
+    ASSERT(!Dart_IsError(name));
+    Dart_Handle list = MakeServiceControlMessage(

[Jacob, 2013/12/04 20:39:52]

there isn't an 80 char line limit in this directory.

[Cutch, 2013/12/04 21:20:50]

Done.

+        Dart_GetMainPortId(),
+        VM_SERVICE_ISOLATE_STARTUP_MESSAGE_ID,
+        name);
+    ASSERT(!Dart_IsError(list));
+    return Dart_Post(m_port, list);
+}
+
+
+bool DartService::SendIsolateShutdownMessage()
+{
+    if (!IsRunning()) {
+        return false;
+    }
+    Dart_Handle list = MakeServiceControlMessage(Dart_GetMainPortId(), VM_SERVICE_ISOLATE_SHUTDOWN_MESSAGE_ID, Dart_Null());
+    ASSERT(!Dart_IsError(list));
+    return Dart_Post(m_port, list);
+}
+
+
+Dart_Handle DartService::GetSource(const char* name)
+{
+    const char* vmserviceSource = 0;
+    int r = dart::bin::Resources::ResourceLookup(name, &vmserviceSource);
+    ASSERT(r != dart::bin::Resources::kNoSuchInstance);
+    return Dart_NewStringFromCString(vmserviceSource);
+}
+
+
+Dart_Handle DartService::LoadScript(const char* name)
+{
+    Dart_Handle url = Dart_NewStringFromCString(name);
+    Dart_Handle source = GetSource(name);
+    return Dart_LoadScript(url, source, 0, 0);
+}
+
+
+Dart_Handle DartService::LoadSource(Dart_Handle library, const char* name)
+{
+    Dart_Handle url = Dart_NewStringFromCString(name);
+    Dart_Handle source = GetSource(name);
+    return Dart_LoadSource(library, url, source);
+}
+
+
+Dart_Handle DartService::LoadSources(Dart_Handle library, const char* names[])
+{
+    Dart_Handle result = Dart_Null();
+    for (int i = 0; names[i]; i++) {
+        result = LoadSource(library, names[i]);
+        if (Dart_IsError(result)) {
+            break;

[Jacob, 2013/12/04 20:39:52]

here and elsewhere, remove { 

} 
for single line if statements.

[Cutch, 2013/12/04 21:20:50]

Done.

+        }
+    }
+    return result;
+}
+
+
+static bool IsVMServiceURL(const char* url)
+{
+    static const intptr_t kLibraryResourceNamePrefixLen = strlen(kLibraryResourceNamePrefix);
+    return !strncmp(kLibraryResourceNamePrefix, url, kLibraryResourceNamePrefixLen);
+}
+
+
+static bool IsVMServiceLibrary(const char* url)
+{
+    return !strcmp(kVMServiceLibraryName, url);
+}
+
+static bool IsDartLibrary(const char* url)

[Jacob, 2013/12/04 20:39:52]

I assume this is probably defined somewhere else as well

[Cutch, 2013/12/04 21:20:50]

It actually is not.

+{
+    static const char* kDartPrefix = "dart:";
+    static const intptr_t kDartPrefixLen = strlen(kDartPrefix);
+    return !strncmp(kDartPrefix, url, kDartPrefixLen);
+}
+
+static Dart_Handle Canonicalize(const char* url)
+{
+    if (IsVMServiceURL(url)) {
+        // Already canonicalized.
+        return Dart_NewStringFromCString(url);
+    }
+    char buffer[1024];

[Jacob, 2013/12/04 20:39:52]

add FIXME to not hardcode 1024 here.

[Cutch, 2013/12/04 21:20:50]

Done.

+    snprintf(&buffer[0], sizeof(buffer), "%s/%s", kLibraryResourceNamePrefix, url);
+    return Dart_NewStringFromCString(buffer);
+}
+
+
+Dart_Handle DartService::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* urlString = 0;
+    Dart_Handle result = Dart_StringToCString(url, &urlString);
+    if (Dart_IsError(result)) {
+        return result;
+    }
+    Dart_Handle libraryUrl = Dart_LibraryUrl(library);
+    const char* libraryUrlString = 0;
+    result = Dart_StringToCString(libraryUrl, &libraryUrlString);
+    if (Dart_IsError(result)) {
+        return result;
+    }
+    if (IsDartLibrary(urlString)) {
+        return DartApplicationLoader::libraryTagHandlerCallback(tag, library, url);
+    }
+    switch (tag) {
+    case Dart_kCanonicalizeUrl:
+        return Canonicalize(urlString);
+        break;
+    case Dart_kImportTag: {
+        Dart_Handle source = GetSource(urlString);
+        if (Dart_IsError(source)) {
+            return source;
+        }
+        Dart_Handle lib = Dart_LoadLibrary(url, source);
+        if (Dart_IsError(lib)) {
+            return lib;
+        }
+        if (IsVMServiceLibrary(urlString)) {
+            // Install native resolver for this library.
+            result = Dart_SetNativeResolver(lib, DartService::NativeResolver);
+            if (Dart_IsError(result)) {
+                return result;
+            }
+        }
+        return lib;
+        }
+        break;
+    case Dart_kSourceTag: {
+        Dart_Handle source = GetSource(urlString);
+        if (Dart_IsError(source)) {
+            return source;
+        }
+        return Dart_LoadSource(library, url, source);
+        }
+        break;
+    default:
+        DART_UNIMPLEMENTED();
+        break;
+    }
+    DART_UNIMPLEMENTED();

[Jacob, 2013/12/04 20:39:52]

DART_UNIMPLEMENTED seems wrong here. this is hitting for a grab bag of error
cases.
Also, DART_UNIMPLEMENTED should only be at the last line of a function and care
needs to be taken that no stack allocated objects exist.

[Cutch, 2013/12/04 21:20:50]

Replaced with ASSERT_NOT_REACHED

+    return result;
+}
+
+
+void DartService::VmServiceShutdownCallback(void* callbackData)
+{
+    ASSERT(Dart_CurrentIsolate());
+    Dart_EnterScope();
+    SendIsolateShutdownMessage();
+    Dart_ExitScope();
+}
+
+static void SendServiceMessage(Dart_NativeArguments args)
+{
+    Dart_Handle sp = Dart_GetNativeArgument(args, 0);
+    Dart_Handle rp = Dart_GetNativeArgument(args, 1);
+    Dart_Handle message = Dart_GetNativeArgument(args, 2);
+    DartServiceInternal::PostOOB(sp, rp, message);
+}
+
+
+struct VmServiceNativeEntry {
+    const char* name;
+    int numArguments;
+    Dart_NativeFunction function;
+};
+
+
+static VmServiceNativeEntry VmServiceNativeEntries[] = {
+    {"SendServiceMessage", 3, SendServiceMessage}
+};
+
+
+Dart_NativeFunction DartService::NativeResolver(Dart_Handle name, int numArguments)
+{
+    const char* functionName = 0;
+    Dart_Handle result = Dart_StringToCString(name, &functionName);
+    ASSERT(!Dart_IsError(result));
+    ASSERT(functionName);
+    intptr_t n = sizeof(VmServiceNativeEntries) / sizeof(VmServiceNativeEntries[0]);
+    for (intptr_t i = 0; i < n; i++) {
+        VmServiceNativeEntry entry = VmServiceNativeEntries[i];
+        if (!strcmp(functionName, entry.name) && (numArguments == entry.numArguments)) {
+            return entry.function;
+        }
+    }
+    return 0;
+}
+
+}