clean_ipc.php

#!/usr/bin/php
<?php
/**
 * PHP Simple Daemon IPC Cleaner
 * @author Shane Harter
 * Date: 4/15/12
 * Time: 6:06 PM
 *
 * When developing a daemon that uses Workers, it's common that crashes and kill -9's leave certain
 * kernel-level interprocess communication (IPC) resources unreleased. This script will release all allocated shared
 * memory segments, message queues, and semaphores.
 *
 * You should not run this on a production server unless you know what you're doing. Doing so could interfere with other
 * applications, servers and daemons that may be running on the system.
 *
 * If you do need to clean up IPC resources in a more selective way, on linux you can use the ipcs and ipcrm commands.
 * Running `ipcs` will show you information about each memory segment, queue and semaphore. You can then pass the ID
 * displayed there in column 2 to ipcrm, which is what we're doing in this script.
 *
 * You have to pass iprcm a flag indicating the type of resources (-m, -q, and -s for Shared Memory, Queues and Semaphores, respectively), and then the ID.
 *
 * Note:
 * If your system does not have `ipcs` or `ipcrm` binaries, install the linux-util-ng package
 */

$warning = PHP_EOL . "WARNING: This script releases all SystemV IPC resources: Shared Memory, Message Queues and Semaphores. Only run this if you want ALL resources released.
If this is a production server, you should probably not do this. See the comment block in this file for further guidance.

To FILTER a type of resource, pass in its designator. Otherwise that resource will be cleaned
-m Do Not Clean Shared Memory
-q Do Not Clean Message Queues
-s Do Not Clean Semaphores

PASS --confirm TO RUN THE CLEANER" . PHP_EOL . PHP_EOL;

$opt = getopt('mqs', array('confirm'));
if (!$opt)
    die($warning);

$ipcs = array();
exec('ipcs', $ipcs);
foreach($ipcs as $row) {

    if (!isset($opt['m'])) {
        if (strpos($row, 'Shared Memory') !== FALSE) {
            echo PHP_EOL, "Cleaning Shared Memory Segments...";
            $flag = '-m';
            continue;
        }
    }

    if (!isset($opt['q'])) {
        if (strpos($row, 'Message Queues') !== FALSE) {
            echo PHP_EOL, "Cleaning Message Queues...";
            $flag = '-q';
            continue;
        }
    }

    if (!isset($opt['s'])) {
        if (strpos($row, 'Semaphore') !== FALSE) {
            echo PHP_EOL, "Cleaning Semaphore Arrays...";
            $flag = '-s';
            continue;
        }
    }

    $row = explode(' ', $row);

    if (!isset($row[1]))
        continue;

    $id  = trim($row[1]);
    if (!is_numeric($id))
        continue;

    // Note: Consider adding filters here if you want to selectively remove resources

    echo PHP_EOL, "Removing Address {$id}";
    @exec("ipcrm {$flag} {$id}");
}

echo PHP_EOL, "** DONE **", PHP_EOL, PHP_EOL;