Programming :: Measure CPU Time Spent On A Code Block (with C Or C++)?
Jul 31, 2011
I have a C program like this:
...
CODE_BLOCK;
...
I want to know how much CPU time spent on CODE_BLOCK. Since the process executing CODE_BLOCK may be preempted during execution, this CPU time may not be equal to the (wall-clock) time elapsed from the beginning of CODE_BLOCK to the end of it.
how can I measure time of N processes and N threads and then compare this time to prove that threads are faster than processes. understanding C code, or also for some good way to measure time of N processes and N threads for C.
I'm just wondering what the limits for time are. I have a program that always takes exactly 20 ms, so I assume this is the lowest it can measure, but I want to see if there's some sort of documentation of this.
I'm doing a program and I want it to execute some code during n seconds. For example e put a command in the shell like this 'ls % 10' and the program should run the command ls for 10 seconds.I'm trying something like this:
I wanted to know how can I set a period of time to a tcp connection to wait for request or respond for tcp block read. which system call or function I can use? Does any body know a very simple quick and easy reference on web for socket programing that has lots of socket programing examples in it?
I am trying to write suitable .pro file for my application. I need real-time library. Have you some ideas how to do that? I just need the line for linking with real-time library...
I want to measure the startup time of any GUI app (e.g. firefox) using the time(1) command. However, timing is measured until the app is closed, which has to be done manually by exiting it or clicking X.
How can I get the app to load, terminate immediately and give me the startup time?
I usually develop python code with emacs, emacs being in python code. On my desktop a version is installed and/or configured that way, so I easily can choose a region in the code and simply click on a menu option to comment out this block of code (i.e. at the begin of each line in the selected code two '##' are put). That is very convenient.
However, on my Laptop, running F12 and emacs 23.1.1, this menu option is missing! I searched within google and found the hint that by pressing 'C-c #' I also can comment out a selected region. But on my emacs it says: 'C-c # is undefined'. Am I missing something? Anyone any idea how to fix/install/update/solve this problem, so I can easily choose a couple of python lines and comment them out?
can I change the ECC code for a block of a file stored on a flash drive by any means ? of a file stored on a HDD (though I don't think there would be a difference between the two)Maybe , through some hardware interrupts or anything like that?Also if possible I need the solution to be in C/C++.
Is there anyway that I can prevent access to the hosts file, or any file for that matter, for a time that I can specify, so that within that time no one will be able to open and edit the said file?
I'm trying to block a site for a certain time.How to Block(deny) perticuler website in certain times of the day , by using squid ? and it seemed promising.I added the lines to my squid.conf
acl office_time time MTWHF 3:00-21:00 acl bad url_regex "/etc/squid/block.acl http_access deny bad !office_time
created a block.acl in the same directory and restarted it.
I run a small home server (Debian 4), which acts as my gateway to the internet (ie, firewall) and runs a web server, dhcp, dns, and acts as a file server to the rest of the machines on my home network. Now I know it's never a smart idea to have all those services running on the same machine that is acting as a firewall, but I don't fancy running multiple servers just for home use, as it's mainly allowing me to learn system administration.
I noticed a few days ago that my internet had become unbearably slow, to the point where I could sometimes not load web pages. I spent a while searching through log files on my gateway, to try and find out what was eating up all of my bandwidth. When I came to apache's access.log file, I was confronted with this:
Multiple requests to my server, for totally random websites. I didn't even know it was possible to make those types of queries to a webserver. The only thing that is on the web server is a browser based torrent client. I have only shown a small snippet of the log file, but there are around 90k lines to different web addresses, from many different IPs. What I want to know, is what is happening? :S Why is someone querying MY web server, for web sites totally unrelated to it? And most of all, how can I stop it. My initial was to try and use iptables to block multiple requests from the same ip within a certain time frame, which I think would work as the server shouldn't really get many queries from external networks.
I am running ubuntu 9.10 and was wondering how to disable write access in python. I want to stop .pyc extensions from saving every time I run a .py file.
how graphs can be plotted on a web interface on real time ? I have a web interface coded in PHP mostly and for graphs I have jpgraphs. But the job needs the graphs to be real time not static. As of now there's a server side program that writes onto a csv file. I read data from the file and plot it using jpgraph when the page loads. Is there anyway I can code real-time dynamic graphs on a web interface ?
I am using Debian linux. I have 100 timers running. If a timer expired which will generate a signal and it was mapped to a same function handler. All the timers are mapped to one function handler. The problem is if the timer expires one at a time, the function handler called at a time. But if the 2 timers expires at a time, the function handler is called one time only instead 2 times. Is it possible to invoke the function handler as many times based on timer expirary happens simultaneoulsy?
So, I usually write/find a test case generator for any code that I write. This type of code generally leads to some file output. To be thorough, I try and generate many different files to test my code on.
Say the command is like this:
Is there a way to automate this for many different values of the parameters and generate many different files?
I tried:
I wasn't able to use the $i in the filename, and without it the command gave me no errors, but did nothing else either. I know the Unix command line is very powerful, and I have a feeling that this should be possible, but I just don't know how to do it.
I am trying to set time using settimeofday in linux. But it sets local time. i.e works like SetLocalTime in windows. But I want to set system time(like SetSystemTime in windows). I could'nt find no other api in linux. What should i do? I had tried with mktime/gmtime apis
I have been having a lot of trouble lately with installing from CD/DVD. The DVD reader/writer on this laptop is new. Nevertheless, trying to install Ubuntu onto an exernal HD, I get 'input output error on sr0 logical block (a large number) After a long time the booting proceeds to a point, but I never get the actual installation started, and have to shut down manually.
The CD is fine, says the Ubuntu-checker. I just installed using my sons laptop, and there was no trouble. Question: does this indicate a motherboard failure? A memory block damaged? Do you know of a diagnostic tool I can use to check the reading of a CD/DVD?
I tried to get a block of lines in awk, but unfortunately it returns output of one line only. I don't state the code here, because it's too short and too poor. What exactly I wanted to do: from file "/boot/grub/menu.lst" get blocks of lines, starting by title and ending by Now I have just
I have one password text file: username<tab>password, I want to wrote any bash script to check if certain user exist at this file, if did exist print out the password. I get stocked at password value to AWK if block:
#!/bin/bash FILE="$1" if [ ! -e "$FILE" ] then
[code]....
it not work , but if I change toassword=$(awk < $FILE -F\t '{ if (test $1=="JIMMY2") print $2;}') it works, anything wrong $1==$user_name? $FILE is the password file, -F\t is use tab as delimiter.