README

This package is wrapper for php sysv sem_xxx. And with string $name

Installing

from Packagist

composer require takuya/php-sysv-ipc-semaphore

from GitHub

name='php-sysv-ipc-semaphore'
composer config repositories.$name \
vcs https://github.com/takuya/$name  
composer require takuya/$name:master
composer install

Examples

<?php
$uniq_name = 'semphore_name';
$semaphore = new IPCSemaphore($uniq_name);
$semaphore->acquire();// first acquire must be success.
$semaphore->acquire(true);// multiple acquired result true
$semaphore->release();
//
// remove from IPC
//
$semaphore->destroy();

More easy way to use semaphore

Using semaphore with callback

<?php
$semaphore = new IPCSemaphore('semphore_name');
$ret = $semaphore->withLock(function(){
   // do something in lock
   echo "run in lock";
   return 1234;
});
$ret === 1234; //=> true

Using easy locking ( release() by destructor ).

<?php
function RunWithLock(){
  $semaphore = new IPCSemaphore('sem_name');
  // $lock is local scope.
  // auto released by destructor on garbage collection.
  $lock = $semaphore->lock();
  return 1234;
}
/// 
RunWithLock();

Using semaphore with try-finally

<?php
function sample($msg){
  try {
    $sem = new IPCSemaphore(str_rand(10));
    $sem->acquire(); 
    return $msg; // finally called before return.
  } finally {
    $sem->release();
  }
}

semaphore and thread-mutex

Compare to Thread and SyncMutex , SysV semaphore has one big advantage in PHP.

SysV function (ex sem_get) is bundled with PHP, no required PECL.

But, sem_get() does not accept string named. This package utilize pseudo string $name.

remove ipc by manually

If unused ipc remains. use SHELL command to remove.

ipcs -s | grep $USER | grep -oE '0x[a-f0-9]+' | xargs -I@ ipcrm --semaphore-key @