Make WebMIDI use blink Promise.

Source/modules/webmidi/MIDIAccess.cpp

Index: Source/modules/webmidi/MIDIAccess.cpp
diff --git a/Source/modules/webmidi/MIDIAccess.cpp b/Source/modules/webmidi/MIDIAccess.cpp
index 39a7ad86fb746cd02795d68adf15bb674251c0a2..d513a480249612584b3eadc3a8b2e135e7ded9ae 100644
--- a/Source/modules/webmidi/MIDIAccess.cpp
+++ b/Source/modules/webmidi/MIDIAccess.cpp
@@ -31,36 +31,44 @@
 #include "config.h"
 #include "modules/webmidi/MIDIAccess.h"
 
+#include "bindings/v8/DOMRequestState.h"
+#include "bindings/v8/DOMWrapperWorld.h"
+#include "bindings/v8/ScriptPromise.h"
+#include "bindings/v8/ScriptPromiseResolver.h"
+#include "bindings/v8/V8Binding.h"
 #include "core/dom/DOMError.h"
 #include "core/dom/Document.h"
 #include "core/loader/DocumentLoadTiming.h"
 #include "core/loader/DocumentLoader.h"
-#include "modules/webmidi/MIDIAccessPromise.h"
 #include "modules/webmidi/MIDIConnectionEvent.h"
 #include "modules/webmidi/MIDIController.h"
+#include "modules/webmidi/MIDIOptions.h"
 #include "modules/webmidi/MIDIPort.h"
+#include "modules/webmidi/NavigatorWebMIDI.h"
 
 namespace WebCore {
 
-PassRefPtrWillBeRawPtr<MIDIAccess> MIDIAccess::create(ExecutionContext* context, MIDIAccessPromise* promise)
+PassRefPtrWillBeRawPtr<MIDIAccess> MIDIAccess::create(const MIDIOptions& options, ExecutionContext* context)
 {
-    RefPtrWillBeRawPtr<MIDIAccess> midiAccess(adoptRefCountedWillBeRefCountedGarbageCollected(new MIDIAccess(context, promise)));
+    RefPtrWillBeRawPtr<MIDIAccess> midiAccess(adoptRefCountedWillBeRefCountedGarbageCollected(new MIDIAccess(options, context)));
     midiAccess->suspendIfNeeded();
-    midiAccess->startRequest();
     return midiAccess.release();
 }
 
 MIDIAccess::~MIDIAccess()
 {
-    stop();
+    ASSERT(!m_requesting);
 }
 
-MIDIAccess::MIDIAccess(ExecutionContext* context, MIDIAccessPromise* promise)
+MIDIAccess::MIDIAccess(const MIDIOptions& options, ExecutionContext* context)
     : ActiveDOMObject(context)
-    , m_promise(promise)
+    , m_activeDOMObjectState(Active)
+    , m_promiseState(Pending)
+    , m_options(options)
     , m_hasAccess(false)
     , m_sysExEnabled(false)
     , m_requesting(false)
+    , m_resumeTimer(this, &MIDIAccess::resumeTimerFired)
 {
     ScriptWrappable::init(this);
     m_accessor = MIDIAccessor::create(this);
@@ -68,12 +76,13 @@ MIDIAccess::MIDIAccess(ExecutionContext* context, MIDIAccessPromise* promise)
 
 void MIDIAccess::setSysExEnabled(bool enable)
 {
-    m_requesting = false;
     m_sysExEnabled = enable;
-    if (enable)
+    if (enable) {
         m_accessor->startSession();
-    else
-        permissionDenied();
+    } else {
+        reject(DOMError::create("SecurityError"));
+        // |this| may be deleted here.
+    }
 }
 
 void MIDIAccess::didAddInputPort(const String& id, const String& manufacturer, const String& name, const String& version)
@@ -94,12 +103,13 @@ void MIDIAccess::didAddOutputPort(const String& id, const String& manufacturer,
 void MIDIAccess::didStartSession(bool success)
 {
     ASSERT(isMainThread());
-
-    m_hasAccess = success;
+    if (!m_requesting)
+        return;
     if (success)
-        m_promise->fulfill();
+        resolve();
     else
-        m_promise->reject(DOMError::create("InvalidStateError"));
+        reject(DOMError::create("InvalidStateError"));
+    // |this| may be deleted here.
 }
 
 void MIDIAccess::didReceiveMIDIData(unsigned portIndex, const unsigned char* data, size_t length, double timeStamp)
@@ -141,49 +151,151 @@ void MIDIAccess::sendMIDIData(unsigned portIndex, const unsigned char* data, siz
     }
 }
 
+void MIDIAccess::suspend()
+{
+    ASSERT(m_activeDOMObjectState == Active);
+    m_activeDOMObjectState = Suspended;
+    m_resumeTimer.stop();
+}
+
+void MIDIAccess::resume()
+{
+    ASSERT(m_activeDOMObjectState == Suspended);
+    m_activeDOMObjectState = Active;
+    if (m_promiseState == Resolving || m_promiseState == Rejecting)
+        m_resumeTimer.startOneShot(0);
+}
+
 void MIDIAccess::stop()
 {
+    RefPtrWillBeRawPtr<MIDIAccess> protect(this);
+    m_activeDOMObjectState = Stopped;
     m_hasAccess = false;
+    m_promiseState = ResolvedOrRejected;
+    m_error.clear();
+    m_resumeTimer.stop();
+    m_accessor.clear();
     if (!m_requesting)
         return;
-    m_requesting = false;
     Document* document = toDocument(executionContext());
     ASSERT(document);
     MIDIController* controller = MIDIController::from(document->page());
     ASSERT(controller);
     controller->cancelSysExPermissionRequest(this);
+    setRequesting(false);
+}
+
+void MIDIAccess::permissionDenied()
+{
+    ASSERT(isMainThread());
+    reject(DOMError::create("SecurityError"));
 }
 
-void MIDIAccess::startRequest()
+void MIDIAccess::setRequesting(bool value)
 {
-    if (!m_promise->options()->sysex) {
+    ASSERT(m_requesting != value);
+    if (value) {
+        setPendingActivity(this);
+        m_requesting = true;

[haraken, 2014/02/26 11:30:39]

Could you avoid using setPendingActivity/unsetPendingActivity by overriding
hasPendingActivity?

  bool hasPendingActivity() {
    return m_requesting;
  }

[yhirano, 2014/02/26 11:55:15]

Because MIDIAccess is not exposed to the V8 GC at the creation time, setting
hasPendingActivity don't take effect.

[haraken, 2014/02/26 12:09:52]

Then probably should we use ContextLifecycleObserver instead of ActiveDOMObject?
ActiveDOMObject is designed for managing lifetime of wrappers (but people are
misusing it in a couple of places:-).

[yhirano, 2014/02/26 12:16:37]

MIDIAccess will be exposed to the GC, but it is not at the creation time.
The wrapper will be created when Promise onFulfilled callback is called.

[yhirano, 2014/02/26 12:37:12]

Sorry, I was wrong. The wrapper will be created when the promise is resolved
with this object.

[haraken, 2014/02/26 12:52:40]

Let's discuss this issue offline tomorrow. I think we need to improve an
infrastructure of ActiveDOMObject and ContextLifecycleObserver so that they can
handle cases like MIDIAccess.

[yhirano, 2014/03/04 17:52:59]

Done.

+    } else {
+        m_requesting = false;
+        unsetPendingActivity(this);
+    }
+}
+
+ScriptPromise MIDIAccess::startRequest()
+{
+    ASSERT(!m_requesting);
+    ScriptPromise promise = ScriptPromise::createPending();
+    m_resolver = MIDIAccessResolver::create(ScriptPromiseResolver::create(promise, executionContext()), executionContext());
+    setRequesting(true);
+    if (!m_options.sysex) {
         m_accessor->startSession();
-        return;
+        return promise;
     }
     Document* document = toDocument(executionContext());
     ASSERT(document);
     MIDIController* controller = MIDIController::from(document->page());
     if (controller) {
-        m_requesting = true;
         controller->requestSysExPermission(this);
     } else {
-        permissionDenied();
+        reject(DOMError::create("SecurityError"));
+        // |this| may be deleted here.
     }
+    return promise;
 }
 
-void MIDIAccess::permissionDenied()
+void MIDIAccess::resolve()
 {
-    ASSERT(isMainThread());
+    if (m_promiseState != Pending || m_activeDOMObjectState == Stopped)
+        return;
+    if (m_activeDOMObjectState == Active) {
+        resolveNow();
+        // |this| may be deleted here.
+    } else {
+        ASSERT(m_activeDOMObjectState == Suspended);
+        m_promiseState = Resolving;
+    }
+}
+
+void MIDIAccess::reject(PassRefPtr<DOMError> error)
+{
+    if (m_promiseState != Pending || m_activeDOMObjectState == Stopped)
+        return;
+    if (m_activeDOMObjectState == Active) {
+        rejectNow(error);
+        // |this| may be deleted here.
+    } else {
+        ASSERT(m_activeDOMObjectState == Suspended);
+        m_promiseState = Rejecting;
+        m_error = error;
+    }
+}
+
+void MIDIAccess::resolveNow()
+{
+    if (!m_requesting)
+        return;
+    ASSERT(m_promiseState != ResolvedOrRejected);
+    ASSERT(m_activeDOMObjectState == Active);
+
+    RefPtrWillBeRawPtr<MIDIAccess> protect(this);
+    m_promiseState = ResolvedOrRejected;
+    m_hasAccess = true;
+    setRequesting(false);
+    m_resolver->resolve(this);
+}
 
+void MIDIAccess::rejectNow(PassRefPtr<DOMError> error)
+{
+    if (!m_requesting)
+        return;
+    ASSERT(m_promiseState != ResolvedOrRejected);
+    ASSERT(m_activeDOMObjectState == Active);
+
+    RefPtrWillBeRawPtr<MIDIAccess> protect(this);
+    m_promiseState = ResolvedOrRejected;
     m_hasAccess = false;
-    m_promise->reject(DOMError::create("SecurityError"));
+    setRequesting(false);
+    m_resolver->reject(error);
+}
+
+void MIDIAccess::resumeTimerFired(Timer<MIDIAccess>*)
+{
+    ASSERT(m_activeDOMObjectState == Active);
+    if (m_promiseState == Resolving) {
+        resolveNow();
+    } else {
+        ASSERT(m_promiseState == Rejecting);
+        rejectNow(m_error.release());
+    }
+    // |this| may be deleted here.
 }
 
 void MIDIAccess::trace(Visitor* visitor)
 {
     visitor->trace(m_inputs);
     visitor->trace(m_outputs);
-    visitor->trace(m_promise);
 }
 
 } // namespace WebCore