java 实时优先级高于应有的

Question

*** warning: Java real-time priorities >=11 not usable, using priority 10 (cause: Operation not permitted)

目前正在尝试出现此错误消息的项目。

在 Vmware、eclipse ide 和 jamaica vm

中使用 Xfce 环境

这到底有什么问题？系统优先级为10时出现java实时优先级大于11的错误，如何设置更高的优先级？

我的代码

package realtime;
import javax.realtime.*;


class seconds extends RealtimeThread{

    int secs = 0;
    int mins = 0;
    int hours=0;


    public seconds(SchedulingParameters sched, ReleaseParameters rel)
    {
        super(sched,rel);
    }
    public void run() {
        while(true) {
            secs++;

            System.out.println("seconds" + secs);
            if(secs>58) {
                mins ++;
                secs = 0;
            }
            boolean ok = waitForNextPeriod();
        }
    }

}

class minutes extends RealtimeThread{
    private minutes min = null;
    private seconds sec = null;
    int mins = 0;
    int hours = 0;

    public minutes(SchedulingParameters sched, ReleaseParameters rel)
    {
        super(sched,rel);
    }

    public void run() {
        while(true) {
            mins++;

            System.out.println("minutes" + mins);
            if(mins>58) {
                hours ++;
                mins = 0;
            }
            boolean ok = waitForNextPeriod();
        }
    }

}

class hours extends RealtimeThread{
    private minutes min = null;
    private seconds sec = null;
    private hours hour=null;
    int mins = 0;
    int hours = 0;
    int day =0;

    public hours(SchedulingParameters sched, ReleaseParameters rel)
    {
        super(sched,rel);
    }

    public void run() {
        while(true) {
            mins++;

            System.out.println("hours" + hours);
            if(hours>24) {
                day ++;
                hours= 0;
            }
            boolean ok = waitForNextPeriod();
        }
    }

}


public class Q1 {
    private minutes min = null;
    private seconds sec = null;
    private hours hour = null;

    Q1(){
        PriorityParameters hoursched = new PriorityParameters(PriorityScheduler.instance().getMaxPriority());
        ReleaseParameters hoursrel = new PeriodicParameters(new RelativeTime(59*59*1000,1000));
        PriorityParameters minsched = new PriorityParameters(PriorityScheduler.instance().getMinPriority());
        ReleaseParameters minrel = new PeriodicParameters(new RelativeTime(59000,1000));
        PriorityParameters secsched = new PriorityParameters(PriorityScheduler.instance().getMaxPriority());
        ReleaseParameters secrel = new PeriodicParameters(new RelativeTime(1000,0));

        hour = new hours(hoursched,hoursrel);
        min = new minutes(minsched, minrel);
        sec = new seconds(secsched, secrel);

        hour.start();
        min.start();
        sec.start();
    }   

    public static void main(String[] args) {
        Q1 t = new Q1();
    }


}

Answer 1

这是 JamaicaVM 手册中的常见问题解答：

答案是：

"The creation of a thread with real-time priority was not permitted by the operating system. Instead JamaicaVM created a thread with normal priority. This means that real-time scheduling is not available, and that the application will likely not work properly.

On off-the-shelf Linux systems, use of real-time priorities requires super-user privileges. That is, starting the application with sudo will resolve the issue. Alternatively, the priority limits for particular users or groups may be changed by editing /etc/security/limits.conf and setting rtprio to the maximum native priority used. For the default priority map used by JamaicaVM on Linux, setting the rtprio limit to 80 is sufficient."

java 实时优先级高于应有的

java real-time priorities is higher than it should be

java

real-time

jamaicavm