ios - NSOperationQueue 的 maxConcurrentOperationCount 的默认值

Question

如标题所示，NSOperationQueue 的 maxConcurrentOperationCount 默认值是多少？

是否设置为值1？

Answer 1

来自documentation ,

The maximum number of concurrent operations set explicitly on the receiver using the setMaxConcurrentOperationCount: method. If no value has been explicitly set, this method returns NSOperationQueueDefaultMaxConcurrentOperationCount by default.

所以它是 NSOperationQueueDefaultMaxConcurrentOperationCount。如果设置此项，它将根据可用处理器的数量和其他相关因素选择合适的值。

这就是it is defined :

enum {
  NSOperationQueueDefaultMaxConcurrentOperationCount = -1
};

NSOperationQueueDefaultMaxConcurrentOperationCount: The default maximum number of operations is determined dynamically by the NSOperationQueue object based on current system conditions.