ID: 25853
Updated by: [EMAIL PROTECTED]
Reported By: morgan at mindviz dot com
-Status: Open
+Status: Bogus
-Bug Type: Feature/Change Request
+Bug Type: *General Issues
Operating System: RedHat Linux 8.0
PHP Version: 4.3.3
New Comment:
I was a bit fast with this, thanks to Ilia who pointed out the flaws in
your example. Try the following and you'll
see that unset() does free the memory just fine:
#!/root/php-4.3.3/php -n
<?php
$my_pid = getmypid();
for($z = 0; $z < 10; $z++) {
$test_array = array();
for($i = 0; $i < 5; $i++) {
$test_array[] = str_repeat("testing", 100000);
}
echo "$z: MEMORY USAGE BEFORE UNSET ( % KB PID ) : ".`ps -eo
%mem,rss,pid | grep $my_pid`;
unset($test_array);
echo "$z: MEMORY USAGE AFTER UNSET ( % KB PID ) : ".`ps -eo
%mem,rss,pid | grep $my_pid`."\n";
}
exit;
?>
Previous Comments:
------------------------------------------------------------------------
[2003-10-13 19:45:34] morgan at mindviz dot com
As it stands right now my real php cli app that I'm
running on my server has slowly grown to 100MB in
memory so far, and is still going up because of this
problem.
I'm actually considering moving to perl or something
else because for non web-based scripts and apps that
don't terminate right away this is a horrible flaw.
------------------------------------------------------------------------
[2003-10-13 19:40:18] morgan at mindviz dot com
so then what function does free memory? Clearly if you
have a cli version of php for servers or daemon
applications there is a need to free the memory used by
variables or any server could potentially exhaust the
system's available memory.
I don't see how that is bogus in any which way.
If you are creating a never ending application that
actually does stuff, read files of varying sizes and
uses variables to temporarily store the data in memory
there is an obvious need to free up the memory used by
those variables when they are no longer needed since
the daemon application won't ever terminate.
Is there going to be a solution for this? or is there a
function that I have overlooked that will free up the
memory of a variable that I no longer need?
------------------------------------------------------------------------
[2003-10-13 18:00:51] [EMAIL PROTECTED]
unset() does not free any memory. This is by design.
------------------------------------------------------------------------
[2003-10-13 13:17:25] morgan at mindviz dot com
Description:
------------
Basically I'm writing a php-CLI server application that
will never exit unlike an apache process. I have been
attempting to find out why slowly but surely the memory
usage of my CLI app steadily goes up until it has
exhausted all my available memory.
The server app will read in large data sets at times
and then attempts to free those with the unset
function. With further inspection it seems that even
though unset is called the script still has a hold on
or uses the allocated memory and never returns it to
the system.
The code below is a small script that I put together to
show the issue I am seeing, it is quite easy to
reproduce the problem.
As with my server application if the script below was
run forever and the max value of $z in the loop was set
extremely high it would run until all the system's
memory was used up, since unset is not actually
returning any of the used memory for the test_array
back to the system.
Reproduce code:
---------------
#!/root/php-4.3.3/php -n
<?php
$my_pid = getmypid();
echo "GOT PID: ".`ps -eo %mem,rss,pid | grep $my_pid`."\n";
for($z = 0; $z < 10; $z++) {
$test_array = array();
// Build a Test 5x(1000*$z) array, will show incremental mem
usage and after unset
// line will test_array's memory will not be free'd
for($i = 0; $i < 5; $i++) {
for($j = 0; $j < 1000*$z; $j++) {
$test_array[$i][$j] = "testing $i $j\n";
}
}
echo "$z: MEMORY USAGE BEFORE UNSET ( % KB PID ) : ".`ps -eo
%mem,rss,pid | grep $my_pid`;
unset($test_var);
echo "$z: MEMORY USAGE AFTER UNSET ( % KB PID ) : ".`ps -eo
%mem,rss,pid | grep $my_pid`."\n";
}
exit;
?>
Expected result:
----------------
GOT PID: 0.1 1524 3178
0: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.1 1532
3178
0: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.1 1524
3178
1: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.2 2132
3178
1: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.1 1524
3178
2: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.3 2740
3178
2: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.1 1524
3178
3: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.3 3368
3178
3: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.1 1524
3178
4: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.4 3952
3178
4: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.1 1524
3178
5: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.5 4620
3178
5: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.1 1524
3178
6: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.5 5204
3178
6: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.1 1524
3178
7: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.6 5792
3178
7: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.1 1524
3178
8: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.7 6376
3178
8: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.1 1524
3178
9: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.7 7124
3178
9: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.1 1524
3178
Actual result:
--------------
GOT PID: 0.1 1524 3178
0: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.1 1532
3178
0: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.1 1532
3178
1: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.2 2132
3178
1: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.2 2132
3178
2: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.3 2740
3178
2: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.3 2740
3178
3: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.3 3368
3178
3: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.3 3368
3178
4: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.4 3952
3178
4: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.4 3952
3178
5: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.5 4620
3178
5: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.5 4620
3178
6: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.5 5204
3178
6: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.5 5204
3178
7: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.6 5792
3178
7: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.6 5792
3178
8: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.7 6376
3178
8: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.7 6376
3178
9: MEMORY USAGE BEFORE UNSET ( % KB PID ) : 0.7 7124
3178
9: MEMORY USAGE AFTER UNSET ( % KB PID ) : 0.7 7124
3178
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