PHPKonf İstanbul PHP Conference 2015


(PHP 5)

pcntl_setpriorityChange la priorité d'un processus


bool pcntl_setpriority ( int $priority [, int $pid = getmypid() [, int $process_identifier = PRIO_PROCESS ]] )

pcntl_setpriority() change la priorité de pid à priority.

Liste de paramètres


priority est généralement une valeur allant de -20 à 20. La priorité par défaut est 0 tandis qu'une valeur numérique plus petite favorise une meilleure planification. Comme les niveaux de priorité changent entre les types de systèmes et les versions de kernel, lisez la page de manuel getpriority(2) de votre système pour des détails spécifiques.


Si non spécifié, le pid du processus courant est utilisé.


Une constante parmi PRIO_PGRP, PRIO_USER ou PRIO_PROCESS.

Valeurs de retour

Cette fonction retourne TRUE en cas de succès ou FALSE si une erreur survient.

Voir aussi

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User Contributed Notes 2 notes

t dot stobbe at blackdogdev dot com
8 years ago
As for the renice function by leandro dot pereira at gmail dot com, this isn't true.  pcntl_setpriority() doesn't set the nice level of a process, but instead sets the base priority of it.  At first glance this might seem like the same thing, but on a system level, they are actually quite different.

In fact, if you're looking to use pcntl_setpriority() to prioritize your process (a tool or a daemon or what-not), I wouldn't recomend using setpriority at all, but renice it instead.  Let the system manage priorities and you'll end up with the results you were looking for.

This applies only to POSIX based systems only (as does the function presented by leandro dot pereira at gmail dot com as well).
leandro dot pereira at gmail dot com
10 years ago
The following snippet may be used under older versions of PHP to provide similar functionality.  Tested only under Linux.

function _pcntl_setpriority($priority, $pid = 0)
$priority = (int)$priority;
$pid = (int)$pid;

        if (
$priority > 20 && $priority < -20) {
        if (
$pid == 0) {
$pid = getmypid();

system("renice  $priority -p $pid") != false;

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