Bug #65596 [Wfx->Nab]: usleep prevents script timeout

Edit report at https://bugs.php.net/bug.php?id=65596&edit=1 ID: 65596 Updated by: johannes@php.net Reported by: ukrtelecom at gmail dot com Summary: usleep prevents script timeout -Status: Wont fix +Status: Not a bug Type: Bug Package: *General Issues Operating System: Linux PHP Version: 5.4Git-2013-08-30 (snap) Block user comment: N Private report: N New Comment: What happens depends on the operating system, in general we tr tomeasure the time spent on cpu, not the time elapsed. On systems which have setitimer (Linux and other unixes) we use setitimer with ITIMER_PROF, which, in my linux system's man page is documented as ITIMER_PROF decrements both when the process executes and when the system is executing on behalf of the process. During sleep nothing is being executed. Previous Comments: ------------------------------------------------------------------------ [2013-08-30 18:26:45] anon at anon dot anon @ab Well of course it's solvable. 1. sleepTime = min(specifiedTime, timeLimit - scriptTime) 2. Do system call. 3. scriptTime += sleepTime I don't understand why you track script time in such a bizarre fashion that it somehow doesn't contribute to the time limit anyway. ------------------------------------------------------------------------ [2013-08-30 18:00:25] ab@php.net This is unsolvable in PHP, sleep is a system call so it will suspend the execution . It can be only interrupted by a signal which can't be thrown from PHP because the execution is suspended :) ------------------------------------------------------------------------ [2013-08-30 15:47:44] ukrtelecom at gmail dot com Description: ------------ Usleeped time does not count in total timeout time. Commenting out line 11 "usleep(10)" in the test script results with expected Fatal timeout in 2 seconds. Enabling line 11 "usleep(10)" makes script exit by condition in 50 seconds. Increasing waiting time to 100 seconds in line 2 results with timeout Fatal error in 60-70 sec. PHP 5.4.20-dev (cli) (built: Aug 30 2013 14:18:16) Copyright (c) 1997-2013 The PHP Group Zend Engine v2.4.0, Copyright (c) 1998-2013 Zend Technologies ./configure --disable-libxml --disable-xml --disable-simplexml --disable- xmlreader --disable-xmlwriter --disable-dom --without-pear OS Ubuntu 12.04 LTS Linux precise64 3.2.0-23-generic #36-Ubuntu SMP Tue Apr 10 20:39:51 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux Test script: --------------- <?php $wait = 50; echo ini_get('max_execution_time'); set_time_limit(2); $ts = time(); while(true) { // usleep for 10 microseconds usleep(10); if ((time()- $ts) > $wait) { echo time() -$ts; echo "\n\nFailed! " . ini_get('max_execution_time') . "\n"; break; } } Expected result: ---------------- 0 Fatal error: Maximum execution time of 2 seconds exceeded in /home/vagrant/t.php on line 12 Actual result: -------------- #with wait time 50 sec: $ date; php t.php ; date Fri Aug 30 15:40:54 UTC 2013 0 51 Failed! 2 Fri Aug 30 15:41:45 UTC 2013 #with wait time 100 sec: $ date; php t.php ; date Fri Aug 30 15:35:45 UTC 2013 0 Fatal error: Maximum execution time of 2 seconds exceeded in /home/vagrant/t.php on line 12 Fri Aug 30 15:36:40 UTC 2013 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=65596&edit=1