PHP Process Lock related content

<?php/** * Cachelock process lock, mainly used for cache invalidation of single process cache acquisition, to prevent excessive SQL requests through the database * to solve PHP lock control in the concurrency, through the file/eaccelerator inter-process lock * If you do not use Eaccelerator to do file lock processing, will do the corresponding directory to generate corresponding granularity of the lock * using eaccelerator in memory processing, performance is relatively high * different locks in parallel execution, similar to the MySQL InnoDB row-level lock * This class made a few changes on the basis of Sunli's Phplock http://code.google.com/p/phplock * @author Yangxinqi * */namespace common\business;class    phplock{//File lock store path private $path = null;    File handle private $fp = NULL;    Lock granularity, setting the larger the granularity the smaller the private $hashNum = 100;    Cache key Private $name;    Whether there is a eaccelerator flag private $eAccelerator = false; /** * constructor * The storage path of the incoming lock, and the name of the cache key, allowing concurrent * @param string $path Lock directory, ending with "/" @param string $name CAC He key */Public function __construct ($name, $path = ' lock\\ ') {$app _path = str_replace (' thinkphp/', ', TH        Ink_path);        $is _cli = Php_sapi_name ();        if ($is _cli = = ' CLI ' | | $is _cli = = ' Cli_server ') {$app _path = Trim (App_path, '. ');         } else {   $app _path = $app _path.        Trim (App_path, '. '); } $path = $app _path. '        /common/business/lockfile/';            if (!file_exists ($path)) {mkdir ($path);        chmod ($path, 777);        }//$path. = '/protected/runtime/cache/'; Determine if there is a eaccelerator, eaccelerator can be improved after enabling the memory lock $this->eaccelerator = function_exists ("Eaccelerator_lock")        ; if (! $this->eaccelerator) {//$this->path = $path. ( $this->_mycrc32 ($name)% $this->hashnum).            TXT '; $this->path = $path. SHA1 ($name).        TXT ';    } $this->name = $name; }/** * CRC32 * CRC32 package * @param int $string * @return int */Private Function _mycrc32 ($string) {$CRC =        ABS (CRC32 ($string));            if ($CRC & 0x80000000) {$CRC ^= 0xffffffff;        $CRC + = 1;    } return $CRC; }/** * Lock * Enter description here ... */Public Function Lock () {//If the EA memory lock cannot be opened, theOpen file Lock if (! $this->eaccelerator) {//config directory permission writable $this-&GT;FP = fopen ($this->path, ' W            +');            if ($this-&GT;FP = = = False) {return false;        } return Flock ($this->fp, LOCK_EX);        }else{return Eaccelerator_lock ($this->name); }}/** * unlock * Enter description here ... */public Function unlock () {if (! $this->eacce                Lerator) {if ($this-&GT;FP!== false) {flock ($this->fp, Lock_un);            Clearstatcache ();        }//To close fclose ($this-&GT;FP);        }else{return Eaccelerator_unlock ($this->name); }    }}