我编写了一个非常简单的玩具程序,根据用户指定的时间要求完成线程内任务的执行。代码和示例输出如下。会发生什么情况是,每次运行代码时,任务完成时间都会在用户指定的时间的+ delta范围内。例如,如果用户想要在5秒内完成程序,则根据运行代码的CPU,它可以在5093或5012毫秒内完成。我想添加一些代码,它可以自动确定特定CPU为特定版本的JVM提供的最低延迟。根据该检测代码,可以将一个delta值添加到该行中,如:if ((taskRunTime > patience+delta) && t.isAlive())
,以便系统为任务执行时间带来更高精度。请提出一些建议。确定Java程序的确定性线程执行
代码:
public class ThreadExample
{
static void threadMessage(String message)
{
String threadName = Thread.currentThread().getName();
System.out.format("%s: %s%n", threadName, message);
}
private static class MessageLoop implements Runnable
{
public void run()
{
String importantInfo[] =
{
"A new integrated approach to programming",
"The innovative approach of the system",
"The input of a tracking system",
"A simulation system is then used for collision checking"
};
try
{
for (int i = 0; i < importantInfo.length; i++)
{
Thread.sleep(4000);
threadMessage(importantInfo[i]);
}
}
catch (InterruptedException e)
{
threadMessage("I wasn't done!");
}
}
}
public static void main(String args[]) throws InterruptedException
{
//Delay, in milliseconds before we interrupt MessageLoop
long patience = 1000 * 60 * 60;
//If command line argument present, gives patience in seconds.
if (args.length > 0)
{
try {
patience = Long.parseLong(args[0]) * 1000;
} catch (NumberFormatException e) {
System.err.println("Argument must be an integer.");
System.exit(1);
}
}
threadMessage("Starting MessageLoop thread");
long startTime = System.currentTimeMillis(),taskRunTime=0;
Thread t = new Thread(new MessageLoop());
t.start();
threadMessage("Waiting for MessageLoop thread to finish");
//loop until MessageLoop thread exits
while (t.isAlive())
{
threadMessage("Still waiting...");
//Wait maximum of 1 second for MessageLoop thread to finish.
t.join(100);
taskRunTime=System.currentTimeMillis() - startTime;
if ((taskRunTime > patience) && t.isAlive())
{
threadMessage("Tired of waiting...task is running longer than the patience you set or the default!");
t.interrupt();
t.join();
}
}
threadMessage("Finally out of thread!");
System.out.println("Time to complete task="+taskRunTime+"ms");
}
}
从英特尔迅驰1.7 Ghz的计算机输出样品(Java的热点(TM)客户端虚拟机(建设10.0 - B23,混合模式))
java -jar ThreadExample.jar 5
main: Starting MessageLoop thread
main: Waiting for MessageLoop thread to finish
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
Thread-0: A new integrated approach to programming
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Still waiting...
main: Tired of waiting...task is running longer than the patience you set or the default!
Thread-0: I wasn't done!
main: Finally out of thread!
那么你建议使用并发工具?我在哪里可以找到允许确定性执行并发任务的代码编写示例?在这个特别简单的例子中,我并没有对任务协调和并发性感到困扰,因为我正在确定决定论。当然,一旦我安排了多项任务,问题就会出现,但我想先从简单的事情开始。 – iceman 2009-08-11 22:15:32