SPSC_Queue

A single producer single consumer lock-free queue C++ template for ultimate low latency, which can be used in multithread conmunication as well as in shared memory IPC under Linux.

The latency of communication of a 10-200B message is within 50-100 ns between two cpu cores on the same node. Sender and receiver don't need to copy a single byte of the msg, that is, a msg is allocated in the queue memory and set by sender, then read directly by the receiver in another thread/process.

This Library mainly contains 4 C++ templates, 2 for single typed queue and 2 for variant typed queue:

SPSCQueue.h

An atomic(crash safe when used in shared-memory IPC) single typed queue template.

SPSCQueueOPT.h

An optimized implementation of SPSCQueue, in which each msg has an additional bool header and write_idx and read_idx are not shared between threads. Note that Push() and Pop() operation are not atomic so it should not be used in IPC.

SPSCVarQueue.h

An atomic(crash safe when used in shared-memory IPC) general purpose variant typed queue template, with a header before each msg. This queue is used in TCPSHM: a connection-oriented persistent message queue framework based on TCP or SHM .

SPSCVarQueueOPT.h

An optimized implementation of SPSCVarQueue, in which reader doens't need to read write_idx so latency is reduced when new msg comes. Note that SPSCVarQueueOPT is not atomic.

Test

shmq_recv.cc/shmq_send.cc

A shared memory IPC example for testing SPSCQueue/SPSCQueueOPT.

multhread_q.cc

A multi-thread example for testing SPSCQueue/SPSCQueueOPT.

multhread_varq.cc

A multi-thread example for testing SPSCVarQueue/SPSCVarQueueOPT