<?php

/*
  Linha de comando
  ipcs ->  mostra blocos de memoria alocados
  ipcrm -m "shmid" ->   remove o bloco de memória referenciado por shmid
 */

class ShareResourse {

    public $nPermissions;
    public $nKey;
    public $nBytesMemorySize;
    public $nShmId;
    public $nVarKey;
    public $mVar;
    private $file;

    public function __construct($file = '') {
        $this->file = !$file ? '/tmp/sharadememory.txt' : $file;
        $this->nKey = $this->GetKey();
        $this->nBytesMemorySize = 50000;
        $this->nPermissions = 0666;
        $this->attachToSegment();
    }

    private function GetKey() {
        if (!file_exists($this->file)) {
            touch($this->file);
        }
        return ftok($this->file, 'R');
    }

    public function attachToSegment() {
        $this->nShmId = shm_attach($this->nKey, $this->nBytesMemorySize, $this->nPermissions);
    }

    public function detachFromSegment() {
        shm_detach($this->nShmId);
    }

    public function removeSegment() {
        shm_remove($this->nShmId);
    }

    public function getVarFromSegment() {
        return shm_get_var($this->nShmId, $this->nVarKey);
    }

    /**
     * Puts a PHP variable into shared memory (or updates an existing one for the given variable key).
     *
     * @return boolean returns TRUE on success/FALSE on error
     */
    public function putVarToSegment($var) {
        /*
         * Transforma boolean em inteiro.
         */
        if (is_bool($var)) {
            if ($var)
                $var = 1;
            else
                $var = 0;
        }
        return shm_put_var($this->nShmId, $this->nVarKey, $var);
    }

    public function removeVarFromSgement() {
        shm_remove_var($this->nShmId, $this->nVarKey);
    }

}

// end class
?>