Source/WebKit/Shared/API/Cocoa/_WKRemoteObjectRegistry.mm - WebKit - Git at Google

 /*
  * Copyright (C) 2013 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */

 #import "config.h"
 #import "_WKRemoteObjectRegistryInternal.h"

 #import "APIDictionary.h"
 #import "BlockSPI.h"
 #import "Connection.h"
 #import "RemoteObjectInvocation.h"
 #import "RemoteObjectRegistry.h"
 #import "UserData.h"
 #import "WKConnectionRef.h"
 #import "WKRemoteObject.h"
 #import "WKRemoteObjectCoder.h"
 #import "WKSharedAPICast.h"
 #import "WebPage.h"
 #import "_WKRemoteObjectInterface.h"
 #import <objc/runtime.h>

 extern "C" id __NSMakeSpecialForwardingCaptureBlock(const char *signature, void (^handler)(NSInvocation *inv));

 static const void* replyBlockKey = &replyBlockKey;

 @interface NSMethodSignature ()
 - (NSString *)_typeString;
 @end

 NSString * const invocationKey = @"invocation";

 struct PendingReply {
     PendingReply() = default;

     PendingReply(_WKRemoteObjectInterface* interface, SEL selector, id block)
         : interface(interface)
         , selector(selector)
         , block(adoptNS([block copy]))
     {
     }

     RetainPtr<_WKRemoteObjectInterface> interface;
     SEL selector { nullptr };
     RetainPtr<id> block;
 };

 @implementation _WKRemoteObjectRegistry {
     std::unique_ptr<WebKit::RemoteObjectRegistry> _remoteObjectRegistry;

     RetainPtr<NSMapTable> _remoteObjectProxies;
     HashMap<String, std::pair<RetainPtr<id>, RetainPtr<_WKRemoteObjectInterface>>> _exportedObjects;

     HashMap<uint64_t, PendingReply> _pendingReplies;
 }

 - (void)registerExportedObject:(id)object interface:(_WKRemoteObjectInterface *)interface
 {
     ASSERT(!_exportedObjects.contains(interface.identifier));
     _exportedObjects.add(interface.identifier, std::make_pair<RetainPtr<id>, RetainPtr<_WKRemoteObjectInterface>>(object, interface));
 }

 - (void)unregisterExportedObject:(id)object interface:(_WKRemoteObjectInterface *)interface
 {
     ASSERT(_exportedObjects.get(interface.identifier).first == object);
     ASSERT(_exportedObjects.get(interface.identifier).second == interface);

     _exportedObjects.remove(interface.identifier);
 }

 - (id)remoteObjectProxyWithInterface:(_WKRemoteObjectInterface *)interface
 {
     if (!_remoteObjectProxies)
         _remoteObjectProxies = [NSMapTable strongToWeakObjectsMapTable];

     if (id remoteObjectProxy = [_remoteObjectProxies objectForKey:interface.identifier])
         return remoteObjectProxy;

     RetainPtr<NSString> identifier = adoptNS([interface.identifier copy]);
     auto remoteObject = adoptNS([[WKRemoteObject alloc] _initWithObjectRegistry:self interface:interface]);
     [_remoteObjectProxies setObject:remoteObject.get() forKey:identifier.get()];

     return remoteObject.autorelease();
 }

 - (id)_initWithWebPage:(WebKit::WebPage&)page
 {
     if (!(self = [super init]))
         return nil;

     _remoteObjectRegistry = std::make_unique<WebKit::RemoteObjectRegistry>(self, page);

     return self;
 }

 - (id)_initWithWebPageProxy:(WebKit::WebPageProxy&)page
 {
     if (!(self = [super init]))
         return nil;

     _remoteObjectRegistry = std::make_unique<WebKit::RemoteObjectRegistry>(self, page);

     return self;
 }

 - (void)_invalidate
 {
     _remoteObjectRegistry = nullptr;
 }

 static uint64_t generateReplyIdentifier()
 {
     static uint64_t identifier;

     return ++identifier;
 }

 - (void)_sendInvocation:(NSInvocation *)invocation interface:(_WKRemoteObjectInterface *)interface
 {
     std::unique_ptr<WebKit::RemoteObjectInvocation::ReplyInfo> replyInfo;

     NSMethodSignature *methodSignature = invocation.methodSignature;
     for (NSUInteger i = 0, count = methodSignature.numberOfArguments; i < count; ++i) {
         const char *type = [methodSignature getArgumentTypeAtIndex:i];

         if (strcmp(type, "@?"))
             continue;

         if (replyInfo)
             [NSException raise:NSInvalidArgumentException format:@"Only one reply block is allowed per message send. (%s)", sel_getName(invocation.selector)];

         id replyBlock = nullptr;
         [invocation getArgument:&replyBlock atIndex:i];
         if (!replyBlock)
             [NSException raise:NSInvalidArgumentException format:@"A NULL reply block was passed into a message. (%s)", sel_getName(invocation.selector)];

         const char* replyBlockSignature = _Block_signature((__bridge void*)replyBlock);

         if (strcmp([NSMethodSignature signatureWithObjCTypes:replyBlockSignature].methodReturnType, "v"))
             [NSException raise:NSInvalidArgumentException format:@"Return value of block argument must be 'void'. (%s)", sel_getName(invocation.selector)];

         replyInfo = std::make_unique<WebKit::RemoteObjectInvocation::ReplyInfo>(generateReplyIdentifier(), replyBlockSignature);

         // Replace the block object so we won't try to encode it.
         id null = nullptr;
         [invocation setArgument:&null atIndex:i];

         ASSERT(!_pendingReplies.contains(replyInfo->replyID));
         _pendingReplies.add(replyInfo->replyID, PendingReply(interface, invocation.selector, replyBlock));
     }

     RetainPtr<WKRemoteObjectEncoder> encoder = adoptNS([[WKRemoteObjectEncoder alloc] init]);

     [encoder encodeObject:invocation forKey:invocationKey];

     if (!_remoteObjectRegistry)
         return;

     _remoteObjectRegistry->sendInvocation(WebKit::RemoteObjectInvocation(interface.identifier, [encoder rootObjectDictionary], WTFMove(replyInfo)));
 }

 - (WebKit::RemoteObjectRegistry&)remoteObjectRegistry
 {
     return *_remoteObjectRegistry;
 }

 - (void)_invokeMethod:(const WebKit::RemoteObjectInvocation&)remoteObjectInvocation
 {
     auto& interfaceIdentifier = remoteObjectInvocation.interfaceIdentifier();
     auto* encodedInvocation = remoteObjectInvocation.encodedInvocation();

     auto interfaceAndObject = _exportedObjects.get(interfaceIdentifier);
     if (!interfaceAndObject.second) {
         NSLog(@"Did not find a registered object for the interface \"%@\"", (NSString *)interfaceIdentifier);
         return;
     }

     RetainPtr<_WKRemoteObjectInterface> interface = interfaceAndObject.second;

     auto decoder = adoptNS([[WKRemoteObjectDecoder alloc] initWithInterface:interface.get() rootObjectDictionary:encodedInvocation replyToSelector:nullptr]);

     NSInvocation *invocation = nil;

     @try {
         invocation = [decoder decodeObjectOfClass:[NSInvocation class] forKey:invocationKey];
     } @catch (NSException *exception) {
         NSLog(@"Exception caught during decoding of message: %@", exception);
     }

     if (auto* replyInfo = remoteObjectInvocation.replyInfo()) {
         NSMethodSignature *methodSignature = invocation.methodSignature;

         // Look for the block argument.
         for (NSUInteger i = 0, count = methodSignature.numberOfArguments; i < count; ++i) {
             const char *type = [methodSignature getArgumentTypeAtIndex:i];

             if (strcmp(type, "@?"))
                 continue;

             // We found the block.
             // FIXME: Validate the signature.
             NSMethodSignature *wireBlockSignature = [NSMethodSignature signatureWithObjCTypes:replyInfo->blockSignature.utf8().data()];

             RetainPtr<_WKRemoteObjectRegistry> remoteObjectRegistry = self;
             uint64_t replyID = replyInfo->replyID;

             class ReplyBlockCallChecker : public WTF::ThreadSafeRefCounted<ReplyBlockCallChecker> {
             public:
                 static Ref<ReplyBlockCallChecker> create(_WKRemoteObjectRegistry *registry, uint64_t replyID) { return adoptRef(*new ReplyBlockCallChecker(registry, replyID)); }

                 ~ReplyBlockCallChecker()
                 {
                     if (m_didCallReplyBlock)
                         return;

                     // FIXME: Instead of not sending anything when the remote object registry is null, we should
                     // keep track of all reply block checkers and invalidate them (sending the unused reply message) in
                     // -[_WKRemoteObjectRegistry _invalidate].
                     if (!m_remoteObjectRegistry->_remoteObjectRegistry)
                         return;

                     m_remoteObjectRegistry->_remoteObjectRegistry->sendUnusedReply(m_replyID);
                 }

                 void didCallReplyBlock() { m_didCallReplyBlock = true; }

             private:
                 ReplyBlockCallChecker(_WKRemoteObjectRegistry *registry, uint64_t replyID)
                     : m_remoteObjectRegistry(registry)
                     , m_replyID(replyID)
                 {
                 }

                 RetainPtr<_WKRemoteObjectRegistry> m_remoteObjectRegistry;
                 uint64_t m_replyID = 0;
                 bool m_didCallReplyBlock = false;
             };

             RefPtr<ReplyBlockCallChecker> checker = ReplyBlockCallChecker::create(self, replyID);
             id replyBlock = __NSMakeSpecialForwardingCaptureBlock(wireBlockSignature._typeString.UTF8String, [interface, remoteObjectRegistry, replyID, checker](NSInvocation *invocation) {
                 auto encoder = adoptNS([[WKRemoteObjectEncoder alloc] init]);
                 [encoder encodeObject:invocation forKey:invocationKey];

                 remoteObjectRegistry->_remoteObjectRegistry->sendReplyBlock(replyID, WebKit::UserData([encoder rootObjectDictionary]));
                 checker->didCallReplyBlock();
             });

             [invocation setArgument:&replyBlock atIndex:i];

             // Make sure that the block won't be destroyed before the invocation.
             objc_setAssociatedObject(invocation, replyBlockKey, replyBlock, OBJC_ASSOCIATION_RETAIN);
             [replyBlock release];

             break;
         }
     }

     invocation.target = interfaceAndObject.first.get();

     @try {
         [invocation invoke];
     } @catch (NSException *exception) {
         NSLog(@"%@: Warning: Exception caught during invocation of received message, dropping incoming message .\nException: %@", self, exception);
     }
 }

 - (void)_callReplyWithID:(uint64_t)replyID blockInvocation:(const WebKit::UserData&)blockInvocation
 {
     auto encodedInvocation = blockInvocation.object();
     if (!encodedInvocation || encodedInvocation->type() != API::Object::Type::Dictionary)
         return;

     auto it = _pendingReplies.find(replyID);
     if (it == _pendingReplies.end())
         return;

     auto pendingReply = it->value;
     _pendingReplies.remove(it);

     auto decoder = adoptNS([[WKRemoteObjectDecoder alloc] initWithInterface:pendingReply.interface.get() rootObjectDictionary:static_cast<API::Dictionary*>(encodedInvocation) replyToSelector:pendingReply.selector]);

     NSInvocation *replyInvocation = nil;

     @try {
         replyInvocation = [decoder decodeObjectOfClass:[NSInvocation class] forKey:invocationKey];
     } @catch (NSException *exception) {
         NSLog(@"Exception caught during decoding of reply: %@", exception);
         return;
     }

     [replyInvocation setTarget:pendingReply.block.get()];
     [replyInvocation invoke];
 }

 - (void)_releaseReplyWithID:(uint64_t)replyID
 {
     _pendingReplies.remove(replyID);
 }

 @end
	/*
	* Copyright (C) 2013 Apple 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:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
	* THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#import "config.h"
	#import "_WKRemoteObjectRegistryInternal.h"

	#import "APIDictionary.h"
	#import "BlockSPI.h"
	#import "Connection.h"
	#import "RemoteObjectInvocation.h"
	#import "RemoteObjectRegistry.h"
	#import "UserData.h"
	#import "WKConnectionRef.h"
	#import "WKRemoteObject.h"
	#import "WKRemoteObjectCoder.h"
	#import "WKSharedAPICast.h"
	#import "WebPage.h"
	#import "_WKRemoteObjectInterface.h"
	#import <objc/runtime.h>

	extern "C" id __NSMakeSpecialForwardingCaptureBlock(const char signature, void (^handler)(NSInvocation inv));

	static const void* replyBlockKey = &replyBlockKey;

	@interface NSMethodSignature ()
	- (NSString *)_typeString;
	@end

	NSString * const invocationKey = @"invocation";

	struct PendingReply {
	PendingReply() = default;

	PendingReply(_WKRemoteObjectInterface* interface, SEL selector, id block)
	: interface(interface)
	, selector(selector)
	, block(adoptNS([block copy]))
	{
	}

	RetainPtr<_WKRemoteObjectInterface> interface;
	SEL selector { nullptr };
	RetainPtr<id> block;
	};

	@implementation _WKRemoteObjectRegistry {
	std::unique_ptr<WebKit::RemoteObjectRegistry> _remoteObjectRegistry;

	RetainPtr<NSMapTable> _remoteObjectProxies;
	HashMap<String, std::pair<RetainPtr<id>, RetainPtr<_WKRemoteObjectInterface>>> _exportedObjects;

	HashMap<uint64_t, PendingReply> _pendingReplies;
	}

	- (void)registerExportedObject:(id)object interface:(_WKRemoteObjectInterface *)interface
	{
	ASSERT(!_exportedObjects.contains(interface.identifier));
	_exportedObjects.add(interface.identifier, std::make_pair<RetainPtr<id>, RetainPtr<_WKRemoteObjectInterface>>(object, interface));
	}

	- (void)unregisterExportedObject:(id)object interface:(_WKRemoteObjectInterface *)interface
	{
	ASSERT(_exportedObjects.get(interface.identifier).first == object);
	ASSERT(_exportedObjects.get(interface.identifier).second == interface);

	_exportedObjects.remove(interface.identifier);
	}

	- (id)remoteObjectProxyWithInterface:(_WKRemoteObjectInterface *)interface
	{
	if (!_remoteObjectProxies)
	_remoteObjectProxies = [NSMapTable strongToWeakObjectsMapTable];

	if (id remoteObjectProxy = [_remoteObjectProxies objectForKey:interface.identifier])
	return remoteObjectProxy;

	RetainPtr<NSString> identifier = adoptNS([interface.identifier copy]);
	auto remoteObject = adoptNS([[WKRemoteObject alloc] _initWithObjectRegistry:self interface:interface]);
	[_remoteObjectProxies setObject:remoteObject.get() forKey:identifier.get()];

	return remoteObject.autorelease();
	}

	- (id)_initWithWebPage:(WebKit::WebPage&)page
	{
	if (!(self = [super init]))
	return nil;

	_remoteObjectRegistry = std::make_unique<WebKit::RemoteObjectRegistry>(self, page);

	return self;
	}

	- (id)_initWithWebPageProxy:(WebKit::WebPageProxy&)page
	{
	if (!(self = [super init]))
	return nil;

	_remoteObjectRegistry = std::make_unique<WebKit::RemoteObjectRegistry>(self, page);

	return self;
	}

	- (void)_invalidate
	{
	_remoteObjectRegistry = nullptr;
	}

	static uint64_t generateReplyIdentifier()
	{
	static uint64_t identifier;

	return ++identifier;
	}

	- (void)_sendInvocation:(NSInvocation )invocation interface:(_WKRemoteObjectInterface )interface
	{
	std::unique_ptr<WebKit::RemoteObjectInvocation::ReplyInfo> replyInfo;

	NSMethodSignature *methodSignature = invocation.methodSignature;
	for (NSUInteger i = 0, count = methodSignature.numberOfArguments; i < count; ++i) {
	const char *type = [methodSignature getArgumentTypeAtIndex:i];

	if (strcmp(type, "@?"))
	continue;

	if (replyInfo)
	[NSException raise:NSInvalidArgumentException format:@"Only one reply block is allowed per message send. (%s)", sel_getName(invocation.selector)];

	id replyBlock = nullptr;
	[invocation getArgument:&replyBlock atIndex:i];
	if (!replyBlock)
	[NSException raise:NSInvalidArgumentException format:@"A NULL reply block was passed into a message. (%s)", sel_getName(invocation.selector)];

	const char* replyBlockSignature = _Block_signature((__bridge void*)replyBlock);

	if (strcmp([NSMethodSignature signatureWithObjCTypes:replyBlockSignature].methodReturnType, "v"))
	[NSException raise:NSInvalidArgumentException format:@"Return value of block argument must be 'void'. (%s)", sel_getName(invocation.selector)];

	replyInfo = std::make_unique<WebKit::RemoteObjectInvocation::ReplyInfo>(generateReplyIdentifier(), replyBlockSignature);

	// Replace the block object so we won't try to encode it.
	id null = nullptr;
	[invocation setArgument:&null atIndex:i];

	ASSERT(!_pendingReplies.contains(replyInfo->replyID));
	_pendingReplies.add(replyInfo->replyID, PendingReply(interface, invocation.selector, replyBlock));
	}

	RetainPtr<WKRemoteObjectEncoder> encoder = adoptNS([[WKRemoteObjectEncoder alloc] init]);

	[encoder encodeObject:invocation forKey:invocationKey];

	if (!_remoteObjectRegistry)
	return;

	_remoteObjectRegistry->sendInvocation(WebKit::RemoteObjectInvocation(interface.identifier, [encoder rootObjectDictionary], WTFMove(replyInfo)));
	}

	- (WebKit::RemoteObjectRegistry&)remoteObjectRegistry
	{
	return *_remoteObjectRegistry;
	}

	- (void)_invokeMethod:(const WebKit::RemoteObjectInvocation&)remoteObjectInvocation
	{
	auto& interfaceIdentifier = remoteObjectInvocation.interfaceIdentifier();
	auto* encodedInvocation = remoteObjectInvocation.encodedInvocation();

	auto interfaceAndObject = _exportedObjects.get(interfaceIdentifier);
	if (!interfaceAndObject.second) {
	NSLog(@"Did not find a registered object for the interface \"%@\"", (NSString *)interfaceIdentifier);
	return;
	}

	RetainPtr<_WKRemoteObjectInterface> interface = interfaceAndObject.second;

	auto decoder = adoptNS([[WKRemoteObjectDecoder alloc] initWithInterface:interface.get() rootObjectDictionary:encodedInvocation replyToSelector:nullptr]);

	NSInvocation *invocation = nil;

	@try {
	invocation = [decoder decodeObjectOfClass:[NSInvocation class] forKey:invocationKey];
	} @catch (NSException *exception) {
	NSLog(@"Exception caught during decoding of message: %@", exception);
	}

	if (auto* replyInfo = remoteObjectInvocation.replyInfo()) {
	NSMethodSignature *methodSignature = invocation.methodSignature;

	// Look for the block argument.
	for (NSUInteger i = 0, count = methodSignature.numberOfArguments; i < count; ++i) {
	const char *type = [methodSignature getArgumentTypeAtIndex:i];

	if (strcmp(type, "@?"))
	continue;

	// We found the block.
	// FIXME: Validate the signature.
	NSMethodSignature *wireBlockSignature = [NSMethodSignature signatureWithObjCTypes:replyInfo->blockSignature.utf8().data()];

	RetainPtr<_WKRemoteObjectRegistry> remoteObjectRegistry = self;
	uint64_t replyID = replyInfo->replyID;

	class ReplyBlockCallChecker : public WTF::ThreadSafeRefCounted<ReplyBlockCallChecker> {
	public:
	static Ref<ReplyBlockCallChecker> create(_WKRemoteObjectRegistry registry, uint64_t replyID) { return adoptRef(new ReplyBlockCallChecker(registry, replyID)); }

	~ReplyBlockCallChecker()
	{
	if (m_didCallReplyBlock)
	return;

	// FIXME: Instead of not sending anything when the remote object registry is null, we should
	// keep track of all reply block checkers and invalidate them (sending the unused reply message) in
	// -[_WKRemoteObjectRegistry _invalidate].
	if (!m_remoteObjectRegistry->_remoteObjectRegistry)
	return;

	m_remoteObjectRegistry->_remoteObjectRegistry->sendUnusedReply(m_replyID);
	}

	void didCallReplyBlock() { m_didCallReplyBlock = true; }

	private:
	ReplyBlockCallChecker(_WKRemoteObjectRegistry *registry, uint64_t replyID)
	: m_remoteObjectRegistry(registry)
	, m_replyID(replyID)
	{
	}

	RetainPtr<_WKRemoteObjectRegistry> m_remoteObjectRegistry;
	uint64_t m_replyID = 0;
	bool m_didCallReplyBlock = false;
	};

	RefPtr<ReplyBlockCallChecker> checker = ReplyBlockCallChecker::create(self, replyID);
	id replyBlock = __NSMakeSpecialForwardingCaptureBlock(wireBlockSignature._typeString.UTF8String, [interface, remoteObjectRegistry, replyID, checker](NSInvocation *invocation) {
	auto encoder = adoptNS([[WKRemoteObjectEncoder alloc] init]);
	[encoder encodeObject:invocation forKey:invocationKey];

	remoteObjectRegistry->_remoteObjectRegistry->sendReplyBlock(replyID, WebKit::UserData([encoder rootObjectDictionary]));
	checker->didCallReplyBlock();
	});

	[invocation setArgument:&replyBlock atIndex:i];

	// Make sure that the block won't be destroyed before the invocation.
	objc_setAssociatedObject(invocation, replyBlockKey, replyBlock, OBJC_ASSOCIATION_RETAIN);
	[replyBlock release];

	break;
	}
	}

	invocation.target = interfaceAndObject.first.get();

	@try {
	[invocation invoke];
	} @catch (NSException *exception) {
	NSLog(@"%@: Warning: Exception caught during invocation of received message, dropping incoming message .\nException: %@", self, exception);
	}
	}

	- (void)_callReplyWithID:(uint64_t)replyID blockInvocation:(const WebKit::UserData&)blockInvocation
	{
	auto encodedInvocation = blockInvocation.object();
	if (!encodedInvocation \|\| encodedInvocation->type() != API::Object::Type::Dictionary)
	return;

	auto it = _pendingReplies.find(replyID);
	if (it == _pendingReplies.end())
	return;

	auto pendingReply = it->value;
	_pendingReplies.remove(it);

	auto decoder = adoptNS([[WKRemoteObjectDecoder alloc] initWithInterface:pendingReply.interface.get() rootObjectDictionary:static_cast<API::Dictionary*>(encodedInvocation) replyToSelector:pendingReply.selector]);

	NSInvocation *replyInvocation = nil;

	@try {
	replyInvocation = [decoder decodeObjectOfClass:[NSInvocation class] forKey:invocationKey];
	} @catch (NSException *exception) {
	NSLog(@"Exception caught during decoding of reply: %@", exception);
	return;
	}

	[replyInvocation setTarget:pendingReply.block.get()];
	[replyInvocation invoke];
	}

	- (void)_releaseReplyWithID:(uint64_t)replyID
	{
	_pendingReplies.remove(replyID);
	}

	@end