Déclenche un événement quand mémoire > x ou mémoire < y

memory-trigger.php

#!/usr/bin/php -q
<?php
ini_set('display_errors', 1);

function get_memory() {
    foreach (file('/proc/meminfo') as $ri) {
        $m[strtok($ri, ':')] = strtok('');
    }
    return 100 - round(($m['MemFree'] + $m['Buffers'] + $m['Cached']) / $m['MemTotal'] * 100);
}

$pids = array();

//
// Options du programme
$options = getopt('', array('min:', 'max:', 'overflow:', 'low:', 'delay:'));
if (sizeof($options) != 5) {
    die('Usage :'
            . PHP_EOL . './' . basename(__FILE__)
            . PHP_EOL . "\t" . '--min=20 (percent)'
            . PHP_EOL . "\t" . '--max=80 (percent)'
            . PHP_EOL . "\t" . '--overflow=/usr/bin/whenTooMuch'
            . PHP_EOL . "\t" . '--low=/usr/bin/whenTooFew'
            . PHP_EOL . "\t" . '--delay=5 (seconds)'
            . PHP_EOL
    );
}
//
// Options
$min = $options['min'];
$max = $options['max'];
$programOverflow = $options['overflow'];
$programLow = $options['low'];
$delay = $options['delay'];
$arguments = array("");

$start = null;
$lastEvent = null;


//
// Fork
$pid = pcntl_fork();
if ($pid) {
    exit();
}
$pid = null;
$pending = false;


//
// Signals
declare(ticks = 1);
pcntl_signal(SIGTERM, "sig_handler");
pcntl_signal(SIGHUP, "sig_handler");
pcntl_signal(SIGINT, "sig_handler");
pcntl_signal(SIGUSR1, "sig_handler");

function sig_handler($signo) {
    global $pids;
    echo 'I received ' . $signo . PHP_EOL;
    if ($signo == SIGTERM || $signo == SIGHUP || $signo == SIGINT) {

        //
        // Transférer aux enfants
        foreach ($pids as $p) {
            posix_kill($p, $signo);
        }

        //
        // Tuer les enfants
        foreach ($pids as $p) {
            pcntl_waitpid($p, $status);
        }

        echo sprintf('All kids of %s are killed', getmypid()) . PHP_EOL;
        exit;
    } else if ($signo == SIGUSR1) {
        // pas encore
    }
}

while (true) {

    //
    // déclencheur
    $memory = get_memory();
    if (
            ($memory >= $max )
            || ($memory <= $min )
    ) {
        $event = ($memory >= $max ) ? 'tooMuch' : 'tooFew';

        //
        // Redémarre le délai quand la mémoire fait des bonds
        if ($event == 'tooMuch' && $lastEvent != 'tooMuch') {
            $start = null;
        } elseif ($event == 'tooFiew' && $lastEvent != 'tooFiew') {
            $start = null;
        }
        $programToLaunch = $event == 'tooMuch' ? $programOverflow : $programLow;
        $lastEvent = $event == 'tooMuch' ? 'tooMuch' : 'tooFiew';


        //
        // Processus
        if (is_null($start)) {
            $start = mktime();
        } else {
            //
            // Délai dépasse
            if (mktime() - $start > $delay) {
                //
                // On le lance qu'un seul script à la fois
                if (!$pending) {
                    $pid = pcntl_fork();
                    if ($pid === 0) {
                        // child
                        pcntl_exec($programToLaunch, $arguments);
                        exit;
                    } else {
                        //
                        // Stocker les enfants
                        $pids[] = $pid;
                        $pending = true;
                        pcntl_waitpid($pid, $status, WUNTRACED);
                        if (pcntl_wifexited($status)) {
                            $pending = false;
                        } else if (pcntl_wifstopped($status)) {
                            $pending = false;
                        } else if (pcntl_wifsignaled($status)) {
                            $pending = false;
                        }
                        $start = null;
                    }
                } else {
                    //echo 'DEJA EN COURS' . PHP_EOL;
                }
            }
        }
    } else {
        $start = null;
    }

// Sleep to avoid freezes
    sleep(1);
    gc_collect_cycles();
}