lizhenghn123/zl_threadpool

Linux平台下C++(C++98、C++03、C++11)实现的线程池

zl_threadpool's Issues

signal missing question

I have read your code CPP03.
When program wants to stop, you will broadcast condition signal, but what if some thread is busy executing some job, I am afraid your condition signal will miss, and when this thread finish its job, it will still hold in blocking wait and can not exit as you wish.

C++11 version, condition_variable.

In file ThreadPoolCpp11/ThreadPool.h, line 105.
cond_.wait will release the associated unique_lock before the pop action.

98版本

` ThreadPool::ThreadPool(int threadNum)
{
threadsNum_ = threadNum;
createThreads();
isRunning_ = true; // <= 这里;是否应该写到前面去.
}

    int ThreadPool::createThreads()
    {
            pthread_mutex_init(&mutex_, NULL);
            pthread_cond_init(&condition_, NULL);
            threads_ = (pthread_t*)malloc(sizeof(pthread_t) * threadsNum_);
            for (int i = 0; i < threadsNum_; i++)
            {
                    pthread_create(&threads_[i], NULL, threadFunc, this); // <= 这里调用了threadFunc
            }
            return 0;
    }
    void* ThreadPool::threadFunc(void* arg)
    {
            pthread_t tid = pthread_self();
            ThreadPool* pool = static_cast<ThreadPool*>(arg);
            while (pool->isRunning_)   <= 这里;isRunning_没有初始化就拿来使用了.
            {
                    Task* task = pool->take();
                    if (!task)
                    {
                            printf("thread %lu will exit\n", tid);
                            break;
                    }

                    assert(task);
                    task->run();
            }
            return 0;
    }

`

C++98 的写法

在从任务队列中取出任务时，用了一个while(task)的写法，会不会过于复杂了。可以稍微简化一下。直接在回调函数里面进行。

void* ThreadPool::threadFunc(void* arg)
    {
        pthread_t tid = pthread_self();
        ThreadPool* pool = static_cast<ThreadPool*>(arg);
        while (pool->isRunning_)
        {
            pthread_mutex_lock(&pool->mutex_);
            while (pool->taskQueue_.empty() && pool->isRunning_) {
                pthread_cond_wait(&pool->condition_, &pool->mutex_);
            }

            Task* task = pool->taskQueue_.front();
            pool->taskQueue_.pop_front();

            pthread_mutex_unlock(&pool->mutex_);
            task->run();
        }
        return 0;
    }

#thread stuck (c11)

Is there a way to intervene if the thread is stuck? such as print the stack when the thread is stuck?