note 119246 added to function.pcntl-signal

A word of caution around the third parameter (restart_syscalls) in pcntl_signal(...). I kept having a repeated issue where (seemingly randomly) my script would "exit unexpectedly" (_exit_, not crash: the exit code was always 0) while tracking forked children using signal handlers. It appears that the signal handling is not at fault (indeed, PHP isn't "at fault"). Having "restart_syscalls" set to FALSE seemed to be the problem's cause. I haven't debugged the issue extensively - except to observe that the issue was highly intermittent and seemed to relate to my use of usleep() in conjunction with restart_syscalls=FALSE. My theory is the usleep() was wrongly tracking time - as described over here: http://man7.org/linux/man-pages/man2/restart_syscall.2.html Long story short, I re-enabled (which is the default value) restart_syscalls, and the issue went away. If you're curious - register_shutdown_function was still being handled correctly - so PHP definitely was _NOT_ crashing. Interestingly however, my procedural code never "resumed" after the signal was handled. I do not believe this is a bug. I believe it was ignorant user error. YMMV. ---- Server IP: 72.52.91.14 Probable Submitter: 46.227.55.4 ---- Manual Page -- http://php.net/manual/en/function.pcntl-signal.php Edit -- https://master.php.net/note/edit/119246 Del: integrated -- https://master.php.net/note/delete/119246/integrated Del: useless -- https://master.php.net/note/delete/119246/useless Del: bad code -- https://master.php.net/note/delete/119246/bad+code Del: spam -- https://master.php.net/note/delete/119246/spam Del: non-english -- https://master.php.net/note/delete/119246/non-english Del: in docs -- https://master.php.net/note/delete/119246/in+docs Del: other reasons-- https://master.php.net/note/delete/119246 Reject -- https://master.php.net/note/reject/119246 Search -- https://master.php.net/manage/user-notes.php