I am using Fedora 7. To begin with, glchess used to work fine for me. Then suddenly it stopped working. It was giving a strange error. After googling a bit, I realised that it stopped working because I upgraded my Python from 2.0 to 2.5. Lucky for me though, I had python2 in my /usr/bin. So, this is the fix: I opened /usr/bin/glchess, and changed the header to
! /usr/bin/python2
And voila, it started working again!
The moral of the story is, glchess does not work with Python 2.5. It needs Python 2.
The command
$ps -eF
lists all process along-with the full command which started the process. When I ran this, I could not see the entire command due the width restriction of my terminal. This is the solution to set unlimited width:
$ps -eF -w -w
Now, suppose I want to know a specific process by its name:
$ps -F -C java -w -w
The -C option accepts a list of process name like:
$ps -F -C “java xmms” -w -w
For a list of files opened by a process, use
$/usr/sbin/lsof -p 3456 | grep XXXX
[Courtesy Prakash]
I have tried to come-up with a thread safe and a non thread safe version of a typical producer/consumer scenario.
package com.swayam.exp;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
/**
*
* @author paawak
*/
public class ProducerConsumerSimulator implements Runnable {
private final int sleepInterval;
private final List<String> list;
private final boolean producer;
private final boolean threadSafe;
public ProducerConsumerSimulator(boolean producer, boolean threadSafe,
int sleepInterval, List<String> list) {
this.producer = producer;
this.sleepInterval = sleepInterval;
this.list = list;
this.threadSafe = threadSafe;
}
public void run() {
while (true) {
try {
Thread.sleep(sleepInterval);
} catch (InterruptedException e) {
e.printStackTrace();
}
if (producer) {
produce();
if (threadSafe) {
synchronized (list) {
System.out.println("Consumer, wake-up!!!");
list.notify();
}
}
} else {
if (threadSafe) {
synchronized (list) {
try {
System.out.println("Waiting for producer...");
list.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
consume();
}
}
}
private void produce() {
Calendar cal = Calendar.getInstance();
String str = "Time Now -- " + cal.get(Calendar.MINUTE) + ":"
+ cal.get(Calendar.SECOND) + ":"
+ cal.get(Calendar.MILLISECOND);
list.add(str);
System.out.println("ADDED:: " + str);
}
private void consume() {
try {
String str = list.remove(0);
System.out.println("REMOVED:: " + str);
} catch (IndexOutOfBoundsException e) {
e.printStackTrace();
}
}
/**
* For testing
*
* @param args
* @throws InterruptedException
*/
public static void main(String[] args) throws InterruptedException {
int PRODUCER_SLEEP_INTERVAL = 1000;
int CONSUMER_SLEEP_INTERVAL = 30;
boolean THREAD_SAFE_EXECUTION = true;
List<String> list = new ArrayList<String>();
Thread producer = new Thread(new ProducerConsumerSimulator(true,
THREAD_SAFE_EXECUTION, PRODUCER_SLEEP_INTERVAL, list));
producer.start();
Thread consumer = new Thread(new ProducerConsumerSimulator(false,
THREAD_SAFE_EXECUTION, CONSUMER_SLEEP_INTERVAL, list));
consumer.start();
}
}Run this with
boolean THREAD_SAFE_EXECUTION = true;
and
boolean THREAD_SAFE_EXECUTION = false;
And see the difference yourself :).