sleep | 易学教程

perl background process

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问题 I am trying to run a background process in perl. I create a child process, which is used to call another perl script. I want to run few lines of code parallely with this child process. And after the child process is done.I want to print a line of code. Main script #!/usr/bin/perl $|=1; print "before the child process\n"; my $pid = fork(); if (defined $pid) { system("perl testing.pl"); } print "before wait command\n"; wait(); print "after 20 secs of waiting\n"; testing.pl #!/usr/bin/perl print

Throttle CPU usage of only one thread intentionally

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There are a couple of other similar questions on SO, but none of them have satisfactory/relevant answers. I have a single threaded C++ program which does something essentially like this: while(true) { //do things which are cpu bound } The problem is that when I run this program it is usually the only process on my whole computer that is doing active work. With nothing else to schedule, the OS naturally schedules this program heavily and my CPU usage shoots through the roof, which I do not want . Naturally, my fan starts whirring too which is especially annoying. The way I am combating this is

Linux: How to kill Sleep

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问题 More of a conceptual question. If I write a bash script that does something like control_c() { echo goodbye exit #$ } trap control_c SIGINT while true do sleep 10 #user wants to kill process here. done control+c won't exit when sleep 10 is running. Is it because linux sleep ignores SIGINT? Is there a way to circumvent this and have the user be able to cntrl+c out of a sleep? 回答1: What you are describing is consistent with the interrupt signal going to only your bash script, not the process

Why does Sleep() slow down subsequent code for 40ms?

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问题 I originally asked about this at coderanch.com, so if you've tried to assist me there, thanks, and don't feel obliged to repeat the effort. coderanch.com is mostly a Java community, though, and this appears (after some research) to really be a Windows question, so my colleagues there and I thought this might be a more appropriate place to look for help. I have written a short program that either spins on the Windows performance counter until 33ms have passed, or else calls Sleep(33). The

Why would I use Sleep() with infinite timeout?

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问题 According to MSDN, Sleep() can be provided INFINITE value and that "indicates that the suspension should not time out". Why would I want to call Sleep() with INFINITE timeout in my program? 回答1: There's no reasons one in his sane mind would ever Sleep(INFINITE). It has no practical meaning. It is for generality and symmetry to WaitForSingleObject(..., timeout) and SleepEx(timeout), where INFINITE does make sense. Reminding, that SleepEx will try to consume things out of your thread's APC

Java Memory Behavior : Different with Thread.sleep

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问题 I am trying to do some memory analysis using visualvm. I have written a basic code that runs an infinite loop to add objects to List. package home.always.learning.java; import java.util.ArrayList; import java.util.List; public class Heaper { private static List<PersonDetails> listObj = new ArrayList<PersonDetails>(); private static final String nameConst = "Tarun Trehan"; public static void main(String[] args)throws Exception{ personListCreation(); } public static void personListCreation()

Python sleep without interfering with script?

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问题 Hey I need to know how to sleep in Python without interfering with the current script. I've tried using time.sleep() but it makes the entire script sleep. Like for example import time def func1(): func2() print("Do stuff here") def func2(): time.sleep(10) print("Do more stuff here") func1() I want it to immediately print Do stuff here, then wait 10 seconds and print Do more stuff here. 回答1: Interpreting your description literally, you need to put the print statement before the call to func2()

Typing effect in Python

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问题 I want to make such program which reads characters from a string and prints each character after some delay so its look like typing effect. Now my problem is sleep function is not working properly. It print whole sentence after long delay. import sys from time import sleep words = "This is just a test :P" for char in words: sleep(0.5) sys.stdout.write(char) I use "sys.stdout.write" for removing whitespace between characters. 回答1: you should use sys.stdout.flush() after each iteration The

Python kill thread

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问题 I'm trying to kill a thread in python. An exception would be the preferred way to do it, as a graceful exit of the run method of the thread through a try:except: pair would allow to close resources. I tried : Is there any way to kill a Thread in Python? , but is specifies that is doesn't work while the code is executing a system call (like time.sleep). Is there a way to raise an exception in another thread (or process, in don't mind,) that work no mater what the thread is executing? 回答1: In

Does Thread.sleep throw if the thread was already interrupted?

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问题 Given a thread which was interrupted while it was not blocked (i.e. no InterruptedException was thrown), does that thread throw an InterruptedException when it later attempts to sleep? The documentation does not state this clearly: InterruptedException - if any thread has interrupted the current thread. The interrupted status of the current thread is cleared when this exception is thrown. 回答1: Yes, it does. The documentation perhaps isn't crystal clear on that point, but this is easy to both