usleep

usleep not working, invalid argument error

由 谁说胖子不能爱 提交于 2021-02-11 06:11:57
问题 usleep just isn't waiting any time, the errno variable accuses an invalid argument is being passed on to the function, even if i use the useconds_t type I just get the same error over and over. I have no idea what's going on here, here's the file I made for some testing. #include <stdio.h> #include <unistd.h> #include <errno.h> int main() { unsigned int delay=500000; int err=errno; printf("%d\n", err); usleep(delay); err = errno; printf("%d\n", err); return 0; } strace output: execve("./a.out

sleep and usleep start wrong

由 戏子无情 提交于 2019-12-26 09:16:37
问题 In C++ I use usleep in my "main" path and call the function out before. out(); usleep(4000000); out just prints something on the screen. Unfortunately the print appears on the screen only after 4 seconds, though the out() function call is before the usleep command. I work on a raspberry with raspbian. How can it be that not first the function out() ; is called and then usleep starts but the other way round? 回答1: In C++ in order to decrease the time of IO we have buffered output. What that

Control a loop --> stopping it for a certain interval of time

由 时光总嘲笑我的痴心妄想 提交于 2019-12-25 03:06:19
问题 guys I am trying to do something very interesting! I want to stop a loop for an interval of time, then display a message during that time and then let the loop continue. And of course in the next iteration it should stop again at the same place for some time and display the message again. Here is my code but the problem is that the elements are sorted too fast (the loop doesn't actually stop) and therefore the messages are not is dispayed as I wish. I wounder if there is something like the

Adobe Air SQLite synchronous busy timeout / SQLite concurrent access / avoid busy loop

由 為{幸葍}努か 提交于 2019-12-24 06:47:12
问题 this is my first post here. I'm asking because I ran out of clues and I was unable to find anything about this specific issue. My question is: In Adobe AIR, is there a way to do a synchronous usleep() equivalent (delay execution of 200ms), alternatively is there a way to specify the SQLite busy timeout somewhere? I have an AIR application which uses the database in synchronous mode because the code cannot cope with the need of events/callbacks in SQL queries. The database sometimes is

Delaying Code Execution on OSX 10.10

由 馋奶兔 提交于 2019-12-21 06:16:13
问题 I've encountered a very strange issue that affects my code running only on OSX 10.10 systems. I've seen this anomaly occur on over 25 OSX 10.10 systems running my code, whereas the exact same code did not exhibit this behavior before upgrading (10.7). Furthermore, this issue is not 100% reproducible in that it occurs randomly ~0-5% of the time. While testing the code, nothing else critical or CPU exhaustive is occurring on the machine. Even if something else was happening, the very fact that

Why do std::cout and printf() not print between usleep() delays?

由 非 Y 不嫁゛ 提交于 2019-12-04 06:41:56
问题 i have a program that is supposed to print "Hello, World!" in slowly scrolling text. I am using the unistd.h library for the usleep() function, and i'm using std::cout to print the characters to the standard output: #include <iostream> #include <stdio.h> #include <unistd.h> char hello[13]={'H','e','l','l','o',',',' ','W','o','r','l','d'}; int main (){ for(int i=0; i<14; i++){ std::cout<<hello[i]; //it prints the entire string after usleep(100000); //100000 ms, but it should print a char after

Delaying Code Execution on OSX 10.10

由 荒凉一梦 提交于 2019-12-03 21:58:30
I've encountered a very strange issue that affects my code running only on OSX 10.10 systems. I've seen this anomaly occur on over 25 OSX 10.10 systems running my code, whereas the exact same code did not exhibit this behavior before upgrading (10.7). Furthermore, this issue is not 100% reproducible in that it occurs randomly ~0-5% of the time. While testing the code, nothing else critical or CPU exhaustive is occurring on the machine. Even if something else was happening, the very fact that the delays I'm experiencing are soooo ridiculously long make that conclusion seem suspicious. Anyhow,

usleep() to calculate elapsed time behaves weird

由 拜拜、爱过 提交于 2019-12-02 04:20:35
问题 I am calculating time elapsed in milli seconds for each successive call to handler function using the code below. When i use usleep(1000) i.e. 1 ms time difference between each call is 10 ms and when i use usleep(1000000) i.e. 1 sec surprisingly time interval between each call falls down to less than 1 ms. Following is the code snippet : #include<stdio.h> #include<stdlib.h> #include<sys/time.h> #include<unistd.h> struct timeval start_time; void handler(int); int main() { struct timeval

Difference among sleep() and usleep() in PHP

由 与世无争的帅哥 提交于 2019-12-01 02:14:20
Can any body explain me what is the difference among sleep() and usleep() in PHP. I have directed to use following scripts to do chat application for long pulling but in this script I am getting same effect using usleep(25000); or without usleep(25000); page1.php <script src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js" type="text/javascript"></script> <script> var lpOnComplete = function(response) { console.log(response); // do more processing lpStart(); }; var lpStart = function() { $.post('page2.php', {}, lpOnComplete, 'json'); }; $(document).ready(lpStart); </script> page2

Difference among sleep() and usleep() in PHP

由 柔情痞子 提交于 2019-11-30 21:43:52
问题 Can any body explain me what is the difference among sleep() and usleep() in PHP. I have directed to use following scripts to do chat application for long pulling but in this script I am getting same effect using usleep(25000); or without usleep(25000); page1.php <script src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js" type="text/javascript"></script> <script> var lpOnComplete = function(response) { console.log(response); // do more processing lpStart(); }; var lpStart =
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