access-queue

访问队列最多允许N并发访问保护类型。 它是一个异步并发原语，旨在支持某些背压模式。 // This queue limits the number of simultaneous references to `inner` to 4 let queue = AccessQueue :: new (inner, 4 ); // get an inner reference let inner1 = queue. access (). await ; // get more (from other concurrent tasks) let inner2 = queue. access (). await ; let inner3 = queue. access (). await ; let inner4 = queue. access (). await ; // this access