Closed
Description
Description
The following code:
<?php
ini_set('display_errors', '1');
ini_set('display_startup_errors', '1');
error_reporting(E_ALL);
// store processes in an array as [$pid => $process, ...]
$processes = [];
// catch signals from child processes and unset processes from the array
pcntl_async_signals(true);
pcntl_signal(SIGCHLD, function($sig, $info) use (&$processes) {
unset($processes[$info['pid']]);
}, false);
// open 10 processes and store them in an array
foreach (range(0, 10) as $i) {
$process = proc_open('echo $$', [], $pipes); // prints the pid to STDOUT
$pid = proc_get_status($process)['pid'];
$processes[$pid] = $process;
}
// wait for all processes to exit
while(true) {
echo ' processes remaining:' . count($processes) . PHP_EOL;
if (empty($processes)) {
break;
}
sleep(1);
}
// Check that all processes have been removed.
var_dump($processes);Resulted in this output:
921
922
processes remaining:9
925
926
924
processes remaining:8
923
processes remaining:6
931
929
927
processes remaining:5
928
930
processes remaining:2
processes remaining:2
processes remaining:2
processes remaining:2
processes remaining:2
processes remaining:2
processes remaining:2
...
But I expected this output instead:
837
838
processes remaining:10
842
840
processes remaining:8
processes remaining:7
846
841
processes remaining:6
847
processes remaining:5
processes remaining:4
839
843
processes remaining:3
844
processes remaining:1
845
processes remaining:0
array(0) {
}
There were some rare cases where the script would exit with code 255 with no errors.
root@c09c0fa26c4d:/app# php test.php
933
934
936
processes remaining:8
937
935
processes remaining:7
938
939
941
processes remaining:5
940
942
943
root@c09c0fa26c4d:/app# echo $?
255
PHP Version
PHP 8.2.7 (cli) (built: Jun 13 2023 23:05:53) (NTS)
Operating System
Debian GNU/Linux 12