Counter LOCK~~~

[jimmyyami]

 

 

Application.lock in ASP used widely in website's visitor Counter to prevent two people enter the site at the same time. 

 

MY question is ...  how to prevent two person operate the MYSQL database exactly at the same time when the counter is based on PHP????~~

[fenway]

Don't use php based counters.

[jimmyyami]

i don't think so.  there must be some other method to solve this in PHP

[fenway]

i don't think so.  there must be some other method to solve this in PHP

 

Why do you think you can solve a database issue with php?

[jimmyyami]

If i can't control how many people has already get entrance into the apartment. Maybe i can just guard the gate not to allow two buddy go through it at the same time???

[fenway]

You can... but not with a counter... what are you actually trying to do

[jimmyyami]

flock()  might is what i need.    I hope...

 

first create a lock file as the guard dog for MySQL database.  use flock() made it able to open once simultaneously. and use it as the switch of this lock file.  the code is something like that listed as below...   

 

// ----------------------------------------------------------------------------

$lockfile  = "vclock.lock";

 

.....

 

$vclock = fopen($lockfile, "w");

if (!$vclock) {

echo " lockfile $lockfile not able to open";

exit;

}

if (!flock($vclock, LOCK_EX)) {

echo "lock $lockfile has fail";

exit;

}

// ----------------------------------------------------------------------------

if (!($fp=fopen($logfile,"r"))) {

echo "file $logfile not able to open";

exit;

}

 

flock($fp, LOCK_SH);

flock($fp, LOCK_UN);

fclose($fp);

 

.......

 

if (!($vcct=fopen($logfile,"w"))) {

echo " lockfile $lockfile not able to open";

exit;

}

if (!flock($vcct, LOCK_EX)) {

echo "lock file $logfile failure";

exit;

}

 

.........

 

}

// ----------------------------------------------------------------------------

 

[fenway]

Sure, go nuts... if you want isolation, there are database engines that support it. 

[jimmyyami]

you Chinese~~

[fenway]

you Chinese~~

Who, me? Nope.