note 62004 deleted from function.flock by danbrown
| From: | danbrown@php.net | Date: | Mon, 18 May 2009 00:39:15 +0000 |
| Subject: | note 62004 deleted from function.flock by danbrown | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-155406@lists.php.net to get a copy of this message | ||
Note Submitter: dranger AT export dash japan dot com
----
You should never have to write code like this:
<?php
while(!($canWrite=flock($f, LOCK_EX))) {
usleep(2000);
}
// go ahead and use file
fwrite(...);
fclose($f);
?>
This absolutely defeats the purpose of OS-supported locks, and what's worse is if you specify
LOCK_NB, it eats up your CPU time.
The following code will work the same way:
<?php
// this will automatically block, that is, PAUSE until the lock is released
flock($f, LOCK_EX) or die("Error getting lock!");
// go ahead and use file
fwrite(...);
fclose($f);
?>
I'm not sure what these people creating spin/sleep loops are doing.