PHP 4.0 Bug #5122 Updated: db.c - call to flock() - lock relased too early when close() is called

ID: 5122 Updated by: sniper Reported By: wcampbell@chello.com Status: Feedback Bug Type: DBM/DBA related Assigned To: Comments: Could you provide some sample script to test this..? --Jani Previous Comments: [2000-08-20 04:02:06] sniper@php.net Does this problem still persist with more recent version of php (from CVS or http://snaps.php.net) ?? --Jani --------------------------------------------------------------------------- [2000-06-19 14:01:05] wcampbell@chello.com The function php_dbm_open() in db.c contains the following lines ... if (lockfd) { flock(lockfd,LOCK_EX); close(lockfd); } else { php_error(E_WARNING, "Unable to establish lock: %s",filename); } I don't think that this will achieve what is intended - at least not under Solaris where PHP implements flock() in terms of fnctl(). (I strongly suspect that this problem will also show itself under other versions of UNIX). The reason is that the lock will be released immediately after it is obtained by the call to close(). I noticed this problem under PHP 3.0.12 but I have looked at the source code of PHP 4.0.0 to verify that this problem hasn't been fixed there. --------------------------------------------------------------------------- Full Bug description available at: http://bugs.php.net/?id=5122