Hi.
I am trying to make my first php extension :)
I am sorry, if the question would be too newbiesh, but I just couldn't
find a more correct place to ask
here is the code:
http://loccache.googlecode.com/svn/trunk/loccache.c
I am trying to do the following:
at the minit-phase I am allocating a persistent HashTable
extension has 4 funcitons:
* loc_set($namespace, $varname, $value); // stores $value
* loc_get($namespace, $varname) // returns $value from storage
* loc_isset($namespace, $varname) // returns bool
* loc_unset($namespace, $varname) // removes varname from storage
during loc_set, I chech if there is "$namespace" item in my persistent
hashtable, and if there isn't, I create it as a child hashtable
$varname is a key in that second HashTable and $value is the value
something like:
$big_persistent_hash = array(
$namespace => array(
$varname => $value
)
);
extension build and even tends to work... kinda..
unfortunately, persistent values are not too persistent in my case, and i
keep getting memory errors.
I would be grateful for any help. the source code is not too big :)
Hi,
Alexey Zakhlestin wrote:
Hi.
I am trying to make my first php extension :)
I am sorry, if the question would be too newbiesh, but I just couldn't
find a more correct place to askhere is the code:
http://loccache.googlecode.com/svn/trunk/loccache.cI am trying to do the following:
at the minit-phase I am allocating a persistent HashTable
extension has 4 funcitons:
- loc_set($namespace, $varname, $value); // stores $value
- loc_get($namespace, $varname) // returns $value from storage
- loc_isset($namespace, $varname) // returns bool
- loc_unset($namespace, $varname) // removes varname from storage
during loc_set, I chech if there is "$namespace" item in my persistent
hashtable, and if there isn't, I create it as a child hashtable
$varname is a key in that second HashTable and $value is the valuesomething like:
$big_persistent_hash = array(
$namespace => array(
$varname => $value
)
);extension build and even tends to work... kinda..
unfortunately, persistent values are not too persistent in my case, and
i keep getting memory errors.
I would be grateful for any help. the source code is not too big :)
Tried running the web server under memory checker like valgrind?
Maybe instead of peamlloc() just do malloc()
Andrey
Tried running the web server under memory checker like valgrind?
Valgrind is linux only.. But I guess I still have one linux box.. I
will give it a try.
Maybe instead of peamlloc() just do malloc()
well.. I can do that for clarity, but zend_alloc.h has this:
#define pemalloc(size, persistent) ((persistent)?malloc(size):emalloc(size))
so, it basically maps
--
Alexey Zakhlestin
http://blog.milkfarmsoft.com/
Here is valgrind output. It definitely shows that there is a problem,
but I still can't guess where it is.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
==25913== Invalid read of size 4
==25913== at 0x82AC068: zend_hash_exists (in /usr/bin/php5)
==25913== by 0x404EE42: zif_loc_isset (loccache.c:147)
==25913== by 0x82CF6CE: (within /usr/bin/php5)
==25913== by 0x82BF0C7: execute (in /usr/bin/php5)
==25913== by 0x82A029B: zend_execute_scripts (in /usr/bin/php5)
==25913== by 0x825B6E1: php_execute_script (in /usr/bin/php5)
==25913== by 0x832F43D: main (in /usr/bin/php5)
==25913== Address 0x4B00B90 is 0 bytes after a block of size 40 alloc'd
==25913== at 0x401C38B: malloc (vg_replace_malloc.c:149)
==25913== by 0x82AB82A: _zend_hash_add_or_update (in /usr/bin/php5)
==25913== by 0x404EDB0: zif_loc_set (loccache.c:86)
==25913== by 0x82CF6CE: (within /usr/bin/php5)
==25913== by 0x82BF0C7: execute (in /usr/bin/php5)
==25913== by 0x82A029B: zend_execute_scripts (in /usr/bin/php5)
==25913== by 0x825B6E1: php_execute_script (in /usr/bin/php5)
==25913== by 0x832F43D: main (in /usr/bin/php5)
==25913==
==25913== Invalid read of size 4
==25913== at 0x82AC06D: zend_hash_exists (in /usr/bin/php5)
==25913== by 0x404EE42: zif_loc_isset (loccache.c:147)
==25913== by 0x82CF6CE: (within /usr/bin/php5)
==25913== by 0x82BF0C7: execute (in /usr/bin/php5)
==25913== by 0x82A029B: zend_execute_scripts (in /usr/bin/php5)
==25913== by 0x825B6E1: php_execute_script (in /usr/bin/php5)
==25913== by 0x832F43D: main (in /usr/bin/php5)
==25913== Address 0x0 is not stack'd, malloc'd or (recently) free'd
==25913==
==25913== Process terminating with default action of signal 11 (SIGSEGV)
==25913== Access not within mapped region at address 0x0
==25913== at 0x82AC06D: zend_hash_exists (in /usr/bin/php5)
==25913== by 0x404EE42: zif_loc_isset (loccache.c:147)
==25913== by 0x82CF6CE: (within /usr/bin/php5)
==25913== by 0x82BF0C7: execute (in /usr/bin/php5)
==25913== by 0x82A029B: zend_execute_scripts (in /usr/bin/php5)
==25913== by 0x825B6E1: php_execute_script (in /usr/bin/php5)
==25913== by 0x832F43D: main (in /usr/bin/php5)
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
--
Alexey Zakhlestin
http://blog.milkfarmsoft.com/
And here is the command I used:
valgrind which php -n tests/3.php
Here is valgrind output. It definitely shows that there is a problem,
but I still can't guess where it is.=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
==25913== Invalid read of size 4
==25913== at 0x82AC068: zend_hash_exists (in /usr/bin/php5)
==25913== by 0x404EE42: zif_loc_isset (loccache.c:147)
==25913== by 0x82CF6CE: (within /usr/bin/php5)
==25913== by 0x82BF0C7: execute (in /usr/bin/php5)
==25913== by 0x82A029B: zend_execute_scripts (in /usr/bin/php5)
==25913== by 0x825B6E1: php_execute_script (in /usr/bin/php5)
==25913== by 0x832F43D: main (in /usr/bin/php5)
--enable-debug would help to get some more info.
--
Wbr,
Antony Dovgal
I know.
but it will be very problematic to build debug-version of php there.
and that is the only linux machine around. :-(
Here is valgrind output. It definitely shows that there is a problem,
but I still can't guess where it is.=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
==25913== Invalid read of size 4
==25913== at 0x82AC068: zend_hash_exists (in /usr/bin/php5)
==25913== by 0x404EE42: zif_loc_isset (loccache.c:147)
==25913== by 0x82CF6CE: (within /usr/bin/php5)
==25913== by 0x82BF0C7: execute (in /usr/bin/php5)
==25913== by 0x82A029B: zend_execute_scripts (in /usr/bin/php5)
==25913== by 0x825B6E1: php_execute_script (in /usr/bin/php5)
==25913== by 0x832F43D: main (in /usr/bin/php5)--enable-debug would help to get some more info.
--
Wbr,
Antony Dovgal
--
Alexey Zakhlestin
http://blog.milkfarmsoft.com/
I believe, I sorted out most of the issues.
Now, the last problem: what is the official way to deep-copy
non-persistent zval into persistent zval?
I expected zval_copy_ctor to have a flag. Unfortunately, it doesn't have one.
the way I see it:
void zval_copy_ctor(zval *value, zend_bool persistent)
such declaration would break compatibility, so, probably, there's a
need to introduce
zval_pcopy_ctor(zval *value, zend_bool persistent)
{
//…
}
and
#define zval_copy_ctor(v) zval_pcopy_ctor(v, 0)
similiar to how it is done with *alloc functions
--
Alexey Zakhlestin
http://blog.milkfarmsoft.com/
Hi.
I am trying to make my first php extension :)
I am sorry, if the question would be too newbiesh, but I just couldn't
find a more correct place to ask
No need to use _exists here, zend_hash_find() returns FAILURE if it's failed to find the value.
You're doing the hash lookup twice here:
if (!zend_hash_exists(ht, ns_name, ns_len + 1)) {
return NULL;
}
zend_hash_find(ht, ns_name, ns_len + 1, (void**)&res);
Just this is enough:
if (zend_hash_find() == SUCCESS) {
return res;
}
return NULL;
And Andrey is right, valgrind is priceless when it comes to debugging memory errors.
--
Wbr,
Antony Dovgal
thanks.
fixed it in subversion
No need to use _exists here, zend_hash_find() returns FAILURE if it's failed to find the value.
You're doing the hash lookup twice here:if (!zend_hash_exists(ht, ns_name, ns_len + 1)) { return NULL; } zend_hash_find(ht, ns_name, ns_len + 1, (void**)&res);Just this is enough:
if (zend_hash_find() == SUCCESS) {
return res;
}
return NULL;And Andrey is right, valgrind is priceless when it comes to debugging memory errors.
--
Wbr,
Antony Dovgal
--
Alexey Zakhlestin
http://blog.milkfarmsoft.com/