GLib's GAsyncQueue vs. POSIX message_queue

Question

Does anyone have any idea of the relative performance of GLib's GAsyncQueue vs. POSIX message_queue for inter-thread communication? I will have many small messages (both one way and request-response types), to be implemented in C on top of Linux (for now; may be ported to Windows later). I am trying to decide which one to use.

What I have found out is that using GLib is better for portability purposes, but POSIX mq's have the advantage of being able to select or poll on them.

However, I have not found any information on whose performance is better.

Answer 1

Since there were no responses to my question, I decided to run some performance tests myself. The main idea was taken from http://cybertiggyr.com/throughput/throughput.html. The test idea was:

• Create two threads (pthreads / gthreads).
• One thread produced data and wrote to the IPC in chunks till 1024 MB data was sent.
• The other thread consumed data from the IPC. I tested with chunk sizes of 4, 64, 256, 512 and 1024 bytes. I tested with GAsyncQueue (with gthreads), POSIX message queue and UNIX domain sockets (with pthreads).

Here is the result obtained:

To summarize, perf(GAsyncQueue) > perf(mq) > perf(UNIX socket), though the performances of GAsyncQueue and POSIX message queue are comparable in most cases - the difference occurs only with small message sizes.

I was wondering how GAsyncQueue is implemented to give comparable of even better performance than Linux's native message queue implementation. It is a pity that it cannot be used for inter process communication, like the other two can.