Reliably cancel in-progress CryptoResult(Impl) upon shutdown.

Source/modules/crypto/CryptoResultImpl.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 45 matching lines @@
     if (!resolver->executionContext() || resolver->executionContext()->activeDOMObjectsAreStopped())
         return;
 
     ScriptState::Scope scope(resolver->scriptState());
     v8::Isolate* isolate = resolver->scriptState()->isolate();
     resolver->reject(v8::Exception::TypeError(v8String(isolate, errorDetails)));
 }
 
 class CryptoResultImpl::Resolver final : public ScriptPromiseResolver {
 public:
-    static PassRefPtrWillBeRawPtr<ScriptPromiseResolver> create(ScriptState* scriptState, CryptoResultImpl* result)
+    static PassRefPtrWillBeRawPtr<Resolver> create(ScriptState* scriptState, CryptoResultImpl* result)
     {
         RefPtrWillBeRawPtr<Resolver> resolver = adoptRefWillBeNoop(new Resolver(scriptState, result));
         resolver->suspendIfNeeded();
         resolver->keepAliveWhilePending();
         return resolver.release();
     }
 
     void stop() override
     {
         m_result->cancel();
-        m_result->clearResolver();
         m_result = nullptr;
         ScriptPromiseResolver::stop();
     }
 
+    DEFINE_INLINE_VIRTUAL_TRACE()
+    {
+        visitor->trace(m_result);
+        ScriptPromiseResolver::trace(visitor);
+    }
+
 private:
     Resolver(ScriptState* scriptState, CryptoResultImpl* result)
         : ScriptPromiseResolver(scriptState)
         , m_result(result) { }
-    RefPtr<CryptoResultImpl> m_result;
+
+    RefPtrWillBeMember<CryptoResultImpl> m_result;
 };
 
 ExceptionCode webCryptoErrorToExceptionCode(WebCryptoErrorType errorType)
 {
     switch (errorType) {
     case WebCryptoErrorTypeNotSupported:
         return NotSupportedError;
     case WebCryptoErrorTypeSyntax:
         return SyntaxError;
     case WebCryptoErrorTypeInvalidAccess:
         return InvalidAccessError;
     case WebCryptoErrorTypeData:
         return DataError;
     case WebCryptoErrorTypeOperation:
         return OperationError;
     case WebCryptoErrorTypeType:
         return V8TypeError;
     }
 
     ASSERT_NOT_REACHED();
     return 0;
 }
 
+CryptoResultImpl::CryptoResultImpl(ScriptState* scriptState)
+    : m_resultOwner(nullptr)
+{
+    ASSERT(scriptState->contextIsValid());
+    if (scriptState->executionContext()->activeDOMObjectsAreStopped()) {
+        // If active dom objects have been stopped, avoid creating
+        // CryptoResultImpl::Resolver.
+        m_resolver = nullptr;
+    } else {
+        m_resolver = Resolver::create(scriptState, this).get();
+    }
+}
+
 CryptoResultImpl::~CryptoResultImpl()
 {
     ASSERT(!m_resolver);
 }
 
+DEFINE_TRACE(CryptoResultImpl)
+{
+    visitor->trace(m_resolver);
+    CryptoResult::trace(visitor);
+}
+
 void CryptoResultImpl::clearResolver()
 {
     m_resolver = nullptr;
 }
 
 PassRefPtrWillBeRawPtr<CryptoResultImpl> CryptoResultImpl::create(ScriptState* scriptState)
 {
     return adoptRefWillBeNoop(new CryptoResultImpl(scriptState));
 }
 
 void CryptoResultImpl::completeWithError(WebCryptoErrorType errorType, const WebString& errorDetails)
 {
-    if (m_resolver) {
-        ExceptionCode ec = webCryptoErrorToExceptionCode(errorType);
+    if (!m_resolver)
+        return;
 
-        // Handle TypeError separately, as it cannot be created using
-        // DOMException.
-        if (ec == V8TypeError)
-            rejectWithTypeError(errorDetails, m_resolver);
-        else
-            m_resolver->reject(DOMException::create(ec, errorDetails));
-    }
+    ExceptionCode ec = webCryptoErrorToExceptionCode(errorType);
+
+    // Handle TypeError separately, as it cannot be created using
+    // DOMException.
+    if (ec == V8TypeError)
+        rejectWithTypeError(errorDetails, m_resolver);
+    else
+        m_resolver->reject(DOMException::create(ec, errorDetails));
     clearResolver();
 }
 
 void CryptoResultImpl::completeWithBuffer(const void* bytes, unsigned bytesSize)
 {
-    if (m_resolver)
-        m_resolver->resolve(DOMArrayBuffer::create(bytes, bytesSize));
+    if (!m_resolver)
+        return;
+
+    m_resolver->resolve(DOMArrayBuffer::create(bytes, bytesSize));
     clearResolver();
 }
 
 void CryptoResultImpl::completeWithJson(const char* utf8Data, unsigned length)
 {
-    if (m_resolver) {
-        ScriptPromiseResolver* resolver = m_resolver;
-        ScriptState* scriptState = resolver->scriptState();
-        ScriptState::Scope scope(scriptState);
+    if (!m_resolver)
+        return;
 
-        v8::Local<v8::String> jsonString = v8AtomicString(scriptState->isolate(), utf8Data, length);
+    ScriptState* scriptState = m_resolver->scriptState();
+    ScriptState::Scope scope(scriptState);
 
-        v8::TryCatch exceptionCatcher;
-        v8::Local<v8::Value> jsonDictionary;
-        if (v8Call(v8::JSON::Parse(scriptState->isolate(), jsonString), jsonDictionary, exceptionCatcher))
-            resolver->resolve(jsonDictionary);
-        else
-            resolver->reject(exceptionCatcher.Exception());
-    }
+    v8::Local<v8::String> jsonString = v8AtomicString(scriptState->isolate(), utf8Data, length);
+
+    v8::TryCatch exceptionCatcher;
+    v8::Local<v8::Value> jsonDictionary;
+    if (v8Call(v8::JSON::Parse(scriptState->isolate(), jsonString), jsonDictionary, exceptionCatcher))
+        m_resolver->resolve(jsonDictionary);
+    else
+        m_resolver->reject(exceptionCatcher.Exception());
     clearResolver();
 }
 
 void CryptoResultImpl::completeWithBoolean(bool b)
 {
-    if (m_resolver)
-        m_resolver->resolve(b);
+    if (!m_resolver)
+        return;
+
+    m_resolver->resolve(b);
     clearResolver();
 }
 
 void CryptoResultImpl::completeWithKey(const WebCryptoKey& key)
 {
-    if (m_resolver)
-        m_resolver->resolve(CryptoKey::create(key));
+    if (!m_resolver)
+        return;
+
+    m_resolver->resolve(CryptoKey::create(key));
     clearResolver();
 }
 
 void CryptoResultImpl::completeWithKeyPair(const WebCryptoKey& publicKey, const WebCryptoKey& privateKey)
 {
-    if (m_resolver) {
-        ScriptState* scriptState = m_resolver->scriptState();
-        ScriptState::Scope scope(scriptState);
+    if (!m_resolver)
+        return;
 
-        V8ObjectBuilder keyPair(scriptState);
+    ScriptState* scriptState = m_resolver->scriptState();
+    ScriptState::Scope scope(scriptState);
 
-        keyPair.add("publicKey", ScriptValue::from(scriptState, CryptoKey::create(publicKey)));
-        keyPair.add("privateKey", ScriptValue::from(scriptState, CryptoKey::create(privateKey)));
+    V8ObjectBuilder keyPair(scriptState);
 
-        m_resolver->resolve(keyPair.v8Value());
-    }
+    keyPair.add("publicKey", ScriptValue::from(scriptState, CryptoKey::create(publicKey)));
+    keyPair.add("privateKey", ScriptValue::from(scriptState, CryptoKey::create(privateKey)));
+
+    m_resolver->resolve(keyPair.v8Value());
     clearResolver();
 }
 
-bool CryptoResultImpl::cancelled() const
-{
-    return acquireLoad(&m_cancelled);
-}
-
 void CryptoResultImpl::cancel()
 {
-    releaseStore(&m_cancelled, 1);
-}
+    // Hold a lock to prevent m_resultOwner being updated by a webcrypto thread
+    // while cancelling.
+    MutexLocker lock(m_mutex);
 
-CryptoResultImpl::CryptoResultImpl(ScriptState* scriptState)
-    : m_cancelled(0)
-{
-    ASSERT(scriptState->contextIsValid());
-    if (scriptState->executionContext()->activeDOMObjectsAreStopped()) {
-        // If active dom objects have been stopped, avoid creating
-        // CryptoResultResolver.
-        m_resolver = nullptr;
-    } else {
-        m_resolver = Resolver::create(scriptState, this).get();
-    }
+    if (!m_resultOwner)
+        return;
+
+    // Eagerly detach the WebCryptoResult, so as to allow clean shutdowns.
+    m_resultOwner->clear();
+    // Verify that it unregistered.
+    ASSERT(!m_resultOwner);
+
+    clearResolver();
 }
 
 ScriptPromise CryptoResultImpl::promise()
 {
     return m_resolver ? m_resolver->promise() : ScriptPromise();
 }
 
+bool CryptoResultImpl::registerResult(WebCryptoResult* result)
+{
+    MutexLocker lock(m_mutex);
+
+    // Cancelled?
+    if (!m_resolver)
+        return true;
+
+    m_resultOwner = result;
+    return false;
+}
+
+void CryptoResultImpl::unregisterResult(WebCryptoResult* result)
+{
+    MutexLocker lock(m_mutex);
+
+    if (result == m_resultOwner)
+        m_resultOwner = nullptr;
+}
+
 } // namespace blink