Get variable refcount

> On Tue, May 30, 2017 at 9:11 AM, Martijn van Duren <php@list.imperialat.at> > wrote: > >> Hello internals@, >> >> I'm new to this list, so let me first introduce myself. >> My name is Martijn van Duren and I work for a webhosting company in the >> Netherlands. Apart from that I'm also an OpenBSD h^Hslacker. >> >> tl;dr: >> How do I properly use Z_REFCOUNT on a zval? >> >> I'm faced with the following issue: >> I've build a framework which allows to talk to a remote interface over >> a persistent connection. This interface can return variables of >> arbitrary types. When an object is returned it is stored locally in an >> array accompanied by its id. This way I can ensure that the same object >> (and not an identical object) is returned on multiple requests. >> >> The problem I'm facing is that because this interface holds a reference >> of the object it's never truly released and thus a memory leak. For the >> application I use it for this is not an issue, but that might change in >> the future. >> >> To solve this I was thinking of creating a small extension which exports >> a function that gives me the active reference count. This way I could >> check in certain parts of the code if there's more than 1 variables >> linked to the object and if not, remove it from the internal array. >> This would not give a 100% result, but it's still better than hanging on >> to everything all the time. >> >> When playing with the extension I made the following function: >> PHP_FUNCTION(refcount) >> { >> zval var; >> zend_long refcount; >> >> if (zend_parse_parameters(ZEND_NUM_ARGS(), "z", &var) == FAILURE) { >> return; >> } >> >> refcount = (zend_long) Z_REFCOUNT(var); >> >> RETURN_LONG(refcount); >> } >> >> Which didn't returned what I expected: >> $ php -r 'dl("refcount.so"); for ($a = 0; $a < 4; $a++) >> echo refcount($a)."\n";' >> 0 >> 1 >> 2 >> 3 >> >> Could someone point me to what I'm doing wrong with Z_REFCOUNT? >> If there is a better way to solve my actual problem I would be all ears >> of course. >> >> Sincerely, >> >> Martijn van Duren >> > > Since PHP 7 not all zval types are refcounted. Before accessing Z_REFCOUNT > you should first use Z_REFCOUNTED to check if a refcount exists. You are > testing with integers, which is one of the not reference counted types. > (Objects are always reference counted.)

> > From your description, it sounds like you might be looking for the weakref > PECL extension.