Differences between 1.5 and 1.5.3

[mahmoodn]

I see some differences between the code structure of nvbit_at_ctx_init and nvbit_at_ctx_term from 1.5 to 1.5.3.

1.5:

void nvbit_at_ctx_init(CUcontext ctx) {
    recv_thread_started = true;
    channel_host.init(0, CHANNEL_SIZE, &channel_dev, NULL);
    pthread_create(&recv_thread, NULL, recv_thread_fun, NULL);
}

void nvbit_at_ctx_term(CUcontext ctx) {
    if (recv_thread_started) {
        recv_thread_started = false;
        pthread_join(recv_thread, NULL);
    }
}

1.5.3:

void nvbit_at_ctx_init(CUcontext ctx) {
    pthread_mutex_lock(&mutex);
    if (verbose) {
        printf("MEMTRACE: STARTING CONTEXT %p\n", ctx);
    }
    CTXstate* ctx_state = new CTXstate;
    assert(ctx_state_map.find(ctx) == ctx_state_map.end());
    ctx_state_map[ctx] = ctx_state;
    cudaMallocManaged(&ctx_state->channel_dev, sizeof(ChannelDev));
    ctx_state->channel_host.init((int)ctx_state_map.size() - 1, CHANNEL_SIZE,
                                 ctx_state->channel_dev, recv_thread_fun, ctx);
    nvbit_set_tool_pthread(ctx_state->channel_host.get_thread());
    pthread_mutex_unlock(&mutex);
}

void nvbit_at_ctx_term(CUcontext ctx) {
    pthread_mutex_lock(&mutex);
    skip_callback_flag = true;
    if (verbose) {
        printf("MEMTRACE: TERMINATING CONTEXT %p\n", ctx);
    }
    /* get context state from map */
    assert(ctx_state_map.find(ctx) != ctx_state_map.end());
    CTXstate* ctx_state = ctx_state_map[ctx];

    /* flush channel */
    flush_channel<<<1, 1>>>(ctx_state->channel_dev);
    /* Make sure flush of channel is complete */
    cudaDeviceSynchronize();
    assert(cudaGetLastError() == cudaSuccess);

    ctx_state->channel_host.destroy(false);
    cudaFree(ctx_state->channel_dev);
    skip_callback_flag = false;
    delete ctx_state;
    pthread_mutex_unlock(&mutex);
}

May I know what is the logic of those functions in 1.5.3? For example, if mutex and sync calls are necessary, why they are missed in 1.5? I didn't find information in the change log.