/*
 * -----------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 42):
 * <stoklund@2pi.dk> wrote this file.  As long as you retain this notice you can
 * do whatever you want with this stuff. If we meet some day, and you think this
 * stuff is worth it, you can buy me a beer in return.     Jakob Stoklund Olesen
 * -----------------------------------------------------------------------------
 */

#import <Foundation/Foundation.h>

// A YAMessageQueue allows asynchronous communication between threads without
// the archiving done by distributed objects. Each YAMessageQueue instance
// delivers mesages on one thread, determined by the deliverInCurrentThread
// message.

@interface YAMessageQueue : NSObject {
    NSLock *lock;
    NSMutableArray *queue;
    CFRunLoopRef runLoop;
    CFRunLoopSourceRef runLoopSource;
}

// Return the default message queue for the current thread.
+ (YAMessageQueue*)defaultQueue;

// Create queue ready for receiving messages, but not delivering any yet.
- (id)init;

// Register queue with the current run loop so all messages are delivered in
// the current thread. Only call once. The queue will be set as the default
// for the thread if there is not already one.
- (void)deliverInCurrentThread;

// Create an autoreleased proxy for target that delivers messages
// asynchronously. The proxy is thread safe - it can be used from multiple
// threads.
- (id)proxyForTarget:(id)target;

@end

// These are the proxies returned by proxyForTarget:
@interface YAMessageQueueingProxy : NSProxy {
    id target;
    YAMessageQueue *queue;
    Protocol *protocol;
}

// It is OK to create proxies with this initializer, but it is easier to use
// -[YAMessageQueue proxyForTarget:]
// The target and queue are both retained by the proxy.
- (id)initWithTarget:target queue:(YAMessageQueue*)queue;

// If a protocol is set, the target will not be touched in the calling thread.
// (Except retain/release). If no protocol is set,
// -[methodSignatureForSelector:] will be sent to the target in the calling
// thread. 
// This method is not thread safe.
- (void)setProtocolForProxy:(Protocol *)aProtocol;

// Set a new target - it will be retained
// This method is not thread safe.
- (void)setTargetForProxy:(id)target;
@end