CocoaLumberjack GCD 使用(2)

// get current label
_queueLabel = [[NSString alloc] initWithFormat:@"%s", dispatch_queue_get_label(DISPATCH_CURRENT_QUEUE_LABEL)];


// specific check is need queue
void *key = (__bridge void *)self;
        void *nonNullValue = (__bridge void *)self;

        dispatch_queue_set_specific(_loggerQueue, key, nonNullValue, NULL);



// create group
_loggingGroup = dispatch_group_create();

// add to group
for (DDLoggerNode *loggerNode in self._loggers) {
        ...
            dispatch_group_async(_loggingGroup, loggerNode->_loggerQueue, ^{ @autoreleasepool {
                ...
            } });
        }
// wait for excutor 等待执行
        dispatch_group_wait(_loggingGroup, DISPATCH_TIME_FOREVER);


// create semaphore 1000
+ (void)initialize {
    static dispatch_once_t DDLogOnceToken;

    dispatch_once(&DDLogOnceToken, ^{
        ...
        _queueSemaphore = dispatch_semaphore_create(DDLOG_MAX_QUEUE_SIZE);
                ...
    });
}

// enqueue  -1
dispatch_block_t logBlock = ^{
        dispatch_semaphore_wait(_queueSemaphore, DISPATCH_TIME_FOREVER);
        // We're now sure we won't overflow the queue.
        // It is time to queue our log message.
        @autoreleasepool {
            [self lt_log:logMessage];
        }
    };

// dequeue +1
- (void)lt_log:(DDLogMessage *)logMessage {
    ...
        dispatch_semaphore_signal(_queueSemaphore);
    ...
}

group 保证多任务,完成通知

semaphore 保证限制处理的资源数量,进行的数量控制

Dispatch_get_queue_label 获取当前队列的名称

dispatch_queue_set_specific 设置 特定值