Edit report at https://bugs.php.net/bug.php?id=61369&edit=1
ID: 61369
Comment by: igor at scalr dot com
Reported by: llongo at sata-hts dot com
Summary: shm_put_var problem
Status: Open
Type: Bug
Package: Semaphore related
Operating System: CentOS release 6.2 (Final)
PHP Version: Irrelevant
Block user comment: N
Private report: N
New Comment:
I have the same issue on CentOS 6.X. I found that with the same version of php
and
all extensions, problem exists on CentOS 6, but everything works on CentOS 5.
The
only difference is kernel version, on CentOS 6 it's 2.6.32.
Any help on this issue would be appreciated, because shm functionality is
critical
for our application.
Previous Comments:
------------------------------------------------------------------------
[2012-03-13 09:03:08] llongo at sata-hts dot com
I've seen the bug with php version 5.3.3 that comes with Centos 6.2 (php-5.3.3-
3.el6_2.6.x86_64). With the same version of php in Centos 5.7 (php53-5.3.3-
1.el5_7.6) the test script works in the right way.
------------------------------------------------------------------------
[2012-03-13 08:56:37] llongo at sata-hts dot com
Description:
------------
There is a problem with shm_put_var: when you call shm_put_var with a "long"
string as value (100 chars at least) in a shared memory area with some
variables
already created, after updating the other variables with successive calls to
shm_put_var, this variables become non-existent and you cannot get their values
with shm_get_var.
Test script:
---------------
<?php
$key = 1000;
$test1 = "short string";
$test2 = "long string with at least 100 characters
abcdefghilmnopqrstuvzabcdefghilmnopqrstuvzabcdefghilmnopqrstuvzabcdefghilmnopqrstuvz";
$test3 = "different short string";
$res = shm_attach($key); // attach to shared memory
if (false === shm_put_var ($res,1,$test1)) { // write var 1
echo "unable to put var 1 with ".$test1."\n";
}
if (false === shm_put_var ($res,2,$test1)) { // write var 2
echo "unable to put var 2 with ".$test1."\n";
}
if (false === shm_put_var ($res,3,$test2)) { // write var 3
echo "unable to put var 3 with ".$test2."\n";
}
if (false === shm_put_var ($res,2,$test3)) { // write again var 2 =>
after this put var, var 2 and 3 disappear... bug?
echo "unable to put var 2 with ".$test1."\n";
}
if (false === ($var = shm_get_var ($res,2))) { // get var 2
echo "Error reading variable 2, bug!\n";
var_dump($var);
} else {
echo "variable 2: ".$var."\n";
}
shm_remove($res); // remove shared memory
shm_detach($res);
exit;
?>
Expected result:
----------------
variable 2: different short string
Actual result:
--------------
Error reading variable 2, bug!
bool(false)
And php warning:
PHP Warning: shm_get_var(): variable key 2 doesn't exist in
/root/test_bug_shm.php on line 19
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=61369&edit=1
