kazura-queue (hackage): "kazura-queue" provides an implementation of FIFO queue. It is faster than Chan, TQueue or TChan by the benefit of fetch-and-add instruction.  Main motivation of this package is to solve some difficulty of "unagi-chan" package.  In "unagi-chan", the item in the queue/chan can be lost when async exception is throwed to the read thread while waiting for read. (Although it has handler to recover lost item, it is difficult to keep FIFO in such case)  In "unagi-chan", garbage items of the queue cannot be collected immediately. Since the buffer in the queue has the reference to the items until the buffer is garbage-collected.  "kazura-queue" is slightly slower than "unagi-chan" instead of solving these issues.  "kazura-queue" lost broadcast function to improve the second issue. It means that kazura-queue is not "Chan" but is just "Queue".
Keywords: bsd3|concurrency|library