Question

我有一个通过boost :: python：

公开的C ++类

class RunnerState {
public:
    RunnerState(std::string& input) : m_output(3, 0) {  }
    std::vector<int>& get_output() { return m_output; }
    void run() {
        std::unique_lock<std::mutex> running(m);
        t = new std::thread([this] (std::unique_lock<std::mutex> running) {
            sleep(10);
        }, std::move(running));
    }
    bool is_running() {
        if(m.try_lock()) {
            m.unlock();
            return false;
        }
        return true;
    }
private:
    std::thread *t;
    std::mutex m;
};

BOOST_PYTHON_MODULE(librunner)
{
    class_<std::vector<int>>("int_vector").def(vector_indexing_suite<std::vector<int>>());
    class_<RunnerState, boost::noncopyable>("RunnerState", init<std::string>())
        .def("get_output", &RunnerState::get_output, return_value_policy<copy_non_const_reference>())
        .def("run", &RunnerState::run)
        .def("is_running", &RunnerState::run);
}

然后由Flask webservice使用：

from flask import Flask, request
import librunner
app = Flask(__name__)
current_run = None

@app.route('/run', methods=['POST'])
def run():
    data = request.get_data()
    current_run = librunner.Run(data)
    output = current_run.get_output()
    # do something with output...
    current_run.run()
    return "Success!", 200, {'Content-Type': 'text/plain'}

@app.route('/running')
def running():
    result = False
    if current_run != None:
        result = current_run.is_running()
    return str(result), 200, {'Content-Type': 'text/plain'}

问题是POST的{{1}}请求在C ++中创建的线程退出之前不会返回。为什么呢？

我猜这与Boost :: Python返回值策略和Boost :: Python有关，使得返回值保持指定时间，但我无法明确指出问题是。

Answer 1

这里的问题是函数不能访问current_run全局，而是每个函数都获得一个名为current_run的本地。通过将python更改为：

来解决此问题

from flask import Flask, request
import librunner
app = Flask(__name__)
current_run = None

@app.route('/run', methods=['POST'])
def run():
    data = request.get_data()
    global current_run
    current_run = librunner.Run(data)
    output = current_run.get_output()
    # do something with output...
    current_run.run()
    return "Success!", 200, {'Content-Type': 'text/plain'}

@app.route('/running')
def running():
    result = False
    global current_run
    if current_run != None:
        result = current_run.is_running()
    return str(result), 200, {'Content-Type': 'text/plain'}

Flask，boost :: python和线程

1 个答案: