Pattern for solving blocks retain cycle

+ (dispatch_block_t)performBlock:(void (^)(dispatch_block_t safeBlock))block
{
    dispatch_block_t strongBlock;
    __weak __block dispatch_block_t weakBlock = strongBlock = ^{
        block(weakBlock);
    };
    strongBlock();
    return strongBlock;
}

+ (void)test
{
    // Config
    const float actionFrequency = 1.0;
    const float checkFrequency = 5.0;
    const int iterationsNumber = 5;
    
    // Scheduler
    static int iteration = 0;
    dispatch_block_t strongBlock = [self.class performBlock:^(dispatch_block_t safeBlock) {
        NSLog(@"Action: %d/%d", ++iteration, iterationsNumber);
        if (iteration == iterationsNumber) return;
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(NSEC_PER_SEC / actionFrequency)), dispatch_get_main_queue(), safeBlock);
    }];
    
    // Watchdog
    __weak __block dispatch_block_t weakBlock = strongBlock;
    [self.class performBlock:^(dispatch_block_t safeBlock) {
        NSLog(@"Check: %@", weakBlock ? @"RETAINED" : @"RELEASED");
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(NSEC_PER_SEC / checkFrequency)), dispatch_get_main_queue(), safeBlock);
    }];
}