在Linux中使用升压设置线程优先级 [英] Setting thread priority in Linux with Boost

问题描述

Boost库似乎并不有一个装置，用于设置线程的优先级。这会是最好的code在Linux上使用或是否有更好的方法？

The Boost Libraries don't seem to have a device for setting a thread's priority. Would this be the best code to use on Linux or is there a better method?

boost::thread myThread( MyFunction() );

struct sched_param param;
param.sched_priority = 90;
pthread_attr_setschedparam( myThread.native_handle(), SCHED_RR, &param);

我没有Linux的编程经验很多。

I don't have alot of Linux programming experience.

推荐答案

这对我会怎么做，但搜索周围，我发现旁边没有code的例子，所以我想在判决出来以后是否基本模板最好是与否。

That's the basic template for how I would do it but after searching around I found next to no code examples so I guess the verdict is out on whether it is best or not.

问题是，升压::线程没有一个构造函数，允许pthead属性在创建线程来传递，所以你必须在线程启动后进行更改。我知道，要解决这个问题唯一的另一种方式是通过进程/线程调度继承。除非另有指示，新的线程将继承他们的创造者的日程安排/优先级，所以你可以创建工作线程之前改变当前线程，然后如果你想改回来。看起来笨拙，但它是一个另类。

The problem is that boost::thread does not have a constructor that allows pthead attributes to be passed in at thread creation so you have to make changes after the thread starts. The only other way I know to get around that is through the process/thread schedule inheritance. Unless directed otherwise, new threads will inherit the schedule/priority of their creator so you could change the current thread before creating worker threads and then change back if you want. Seems awkward but it is an alternative.

下面是希望既演示功能的示例的黑客。您可能需要改变策略和优先级酌情以root身份运行。

Here's a hack of an example that hopefully demostrates both. You may need to change policy and priority as appropriate and run as root.

小心你设置优先级的方式。各种限制。

Be careful with the way you set the priority. Various restrictions apply.

#include <iostream>
#include <boost/thread/thread.hpp>
#include <unistd.h>
#include <sched.h>
#include <cstdio>


void* threadfunc()
{
    sleep(5);
}

void displayAndChange(boost::thread& daThread)
{
    int retcode;
    int policy;

    pthread_t threadID = (pthread_t) daThread.native_handle();

    struct sched_param param;

    if ((retcode = pthread_getschedparam(threadID, &policy, &param)) != 0)
    {
        errno = retcode;
        perror("pthread_getschedparam");
        exit(EXIT_FAILURE);
    }

    std::cout << "INHERITED: ";
    std::cout << "policy=" << ((policy == SCHED_FIFO)  ? "SCHED_FIFO" :
                               (policy == SCHED_RR)    ? "SCHED_RR" :
                               (policy == SCHED_OTHER) ? "SCHED_OTHER" :
                                                         "???")
              << ", priority=" << param.sched_priority << std::endl;


    policy = SCHED_FIFO;
    param.sched_priority = 4;

    if ((retcode = pthread_setschedparam(threadID, policy, &param)) != 0)
    {
        errno = retcode;
        perror("pthread_setschedparam");
        exit(EXIT_FAILURE);
    }

    std::cout << "  CHANGED: ";
    std::cout << "policy=" << ((policy == SCHED_FIFO)  ? "SCHED_FIFO" :
                               (policy == SCHED_RR)    ? "SCHED_RR" :
                               (policy == SCHED_OTHER) ? "SCHED_OTHER" :
                                                          "???")
              << ", priority=" << param.sched_priority << std::endl;
}


int main(int argc, char* argv[])
{
    int policy, res;

    struct sched_param param;

    if ((policy = sched_getscheduler(getpid())) == -1)
    {
        perror("sched_getscheduler");
        exit(EXIT_FAILURE);
    }

    if ((res = sched_getparam(getpid(), &param)) == -1)
    {
        perror("sched_getparam");
        exit(EXIT_FAILURE);
    }

    std::cout << " ORIGINAL: ";
    std::cout << "policy=" << ((policy == SCHED_FIFO)  ? "SCHED_FIFO" :
                               (policy == SCHED_RR)    ? "SCHED_RR" :
                               (policy == SCHED_OTHER) ? "SCHED_OTHER" :
                                                          "???")
              << ", priority=" << param.sched_priority << std::endl;


    policy = SCHED_RR;
    param.sched_priority = 2;

    if ((res = sched_setscheduler(getpid(), policy, &param)) == -1)
    {
        perror("sched_setscheduler");
        exit(EXIT_FAILURE);
    }

    boost::thread t1(&threadfunc);

    displayAndChange(t1);

    t1.join();

    return 0;
}

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