Semaphor for wait a action.

BETTestSemaphor.h

//
//  BETTestSemaphor.h
//  TwitterClient
//
//  Created by Rafael Aguilar Martín on 11/11/12.
//  Copyright (c) 2012 Rafael Aguilar Martín. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface BETTestSemaphor : NSObject

@property (strong, atomic) NSMutableDictionary* flags;

+ (BETTestSemaphor *)sharedInstance;

- (BOOL)isLifted:(NSString*)key;
- (void)lift:(NSString*)key;
- (void)waitForKey:(NSString*)key;

@end

BETTestSemaphor.m

//
//  BETTestSemaphor.m
//  TwitterClient
//
//  Created by Rafael Aguilar Martín on 11/11/12.
//  Copyright (c) 2012 Rafael Aguilar Martín. All rights reserved.
//

#import "BETTestSemaphor.h"

@implementation BETTestSemaphor

+ (BETTestSemaphor *)sharedInstance
{
    static BETTestSemaphor *sharedInstance = nil;
    static dispatch_once_t once;
    
    dispatch_once(&once, ^{
        sharedInstance = [BETTestSemaphor alloc];
        sharedInstance = [sharedInstance init];
    });
    
    return sharedInstance;
}

- (instancetype)init
{
    self = [super init];
    if (self != nil) {
        self.flags = [NSMutableDictionary dictionaryWithCapacity:10];
    }
    
    return self;
}

- (BOOL)isLifted:(NSString*)key
{
    return [self.flags objectForKey:key]!=nil;
}

- (void)lift:(NSString*)key
{
    [self.flags setObject:@"YES" forKey: key];
}

- (void)waitForKey:(NSString*)key
{
    BOOL keepRunning = YES;
    while (keepRunning && [[NSRunLoop currentRunLoop] runMode: NSDefaultRunLoopMode beforeDate:[NSDate dateWithTimeIntervalSinceNow:1.0]]) {
        keepRunning = ![[BETTestSemaphor sharedInstance] isLifted: key];
    }
}

@end