gistfile1.cpp

///////
            check_al_error();
            alGetSourcei(SourceID, AL_BUFFERS_PROCESSED, &SourceBuffersProcessed);
            alGetSourcei(SourceID, AL_BUFFERS_QUEUED, &SourceBuffersQueued);
            check_al_error();
            //
            printf("\tfill_and_queue_buffers pre-q - AL_BUFFERS_QUEUED: %d\n", SourceBuffersQueued);
            printf("\tfill_and_queue_buffers pre-q - AL_BUFFERS_PROCESSED: %d\n", SourceBuffersProcessed);
            check_al_error();
            /////////
            alSourceQueueBuffers(SourceID, 1, &Buffers[i]);
            //////////
            check_al_error();
            alGetSourcei(SourceID, AL_BUFFERS_PROCESSED, &SourceBuffersProcessed);
            alGetSourcei(SourceID, AL_BUFFERS_QUEUED, &SourceBuffersQueued);
            check_al_error();
            //
            printf("\tfill_and_queue_buffers post-q - AL_BUFFERS_QUEUED: %d\n", SourceBuffersQueued);
            printf("\tfill_and_queue_buffers post-q - AL_BUFFERS_PROCESSED: %d\n", SourceBuffersProcessed);
            check_al_error();
            
Output:

fill_and_queue_buffers pre-q - AL_BUFFERS_QUEUED: 0
fill_and_queue_buffers pre-q - AL_BUFFERS_PROCESSED: 0
fill_and_queue_buffers post-q - AL_BUFFERS_QUEUED: 1
fill_and_queue_buffers post-q - AL_BUFFERS_PROCESSED: 1