Function init_for_pthread_stack_trace

src/bthread/bthread.cpp:128–178

BAIDU_THREAD_LOCAL TaskMeta* pthread_fake_meta = NULL;

bthread_t init_for_pthread_stack_trace() {
    if (NULL != pthread_fake_meta) {
        return pthread_fake_meta->tid;
    }

    TaskControl* c = get_task_control();
    if (NULL == c) {
        LOG(ERROR) << "TaskControl has not been created, "
                      "please use bthread_start_xxx before call this function";
        return INVALID_BTHREAD;
    }

    butil::ResourceId<TaskMeta> slot;
    pthread_fake_meta = butil::get_resource(&slot);
    if (BAIDU_UNLIKELY(NULL == pthread_fake_meta)) {
        LOG(ERROR) << "Fail to get TaskMeta";
        return INVALID_BTHREAD;
    }

    pthread_fake_meta->attr = BTHREAD_ATTR_PTHREAD;
    pthread_fake_meta->tid = make_tid(*pthread_fake_meta->version_butex, slot);
    // Make TaskTracer use signal trace mode for pthread.
    c->_task_tracer.set_running_status(syscall(SYS_gettid), pthread_fake_meta);

    // Release the TaskMeta at exit of pthread.
    butil::thread_atexit([]() {
        // Similar to TaskGroup::task_runner.
        bool tracing;
        {
            BAIDU_SCOPED_LOCK(pthread_fake_meta->version_lock);
            tracing = TaskTracer::set_end_status_unsafe(pthread_fake_meta);
            // If resulting version is 0,
            // change it to 1 to make bthread_t never be 0.
            if (0 == ++*pthread_fake_meta->version_butex) {
                ++*pthread_fake_meta->version_butex;
            }
        }

        if (tracing) {
            // Wait for tracing completion.
            get_task_control()->_task_tracer.WaitForTracing(pthread_fake_meta);
        }
        get_task_control()->_task_tracer.set_status(
            TASK_STATUS_UNKNOWN, pthread_fake_meta);

        butil::return_resource(get_slot(pthread_fake_meta->tid));
        pthread_fake_meta = NULL;
    });

    return pthread_fake_meta->tid;
}

void stack_trace(std::ostream& os, bthread_t tid) {
    TaskControl* c = get_task_control();