#23331 [Opn]: Memory leak in ISAPI

ID: 23331 User updated by: jakub at icewarp dot com Reported By: jakub at icewarp dot com Status: Open Bug Type: IIS related Operating System: W2K PHP Version: 4.3.2RC1 New Comment: I was wrong about the _DllMain@12 it is called by Windows automatically. However I have found for instance this. If you load the ISAPI module and free it in a cycle again it does not free the memory. for ($i=0;$i<1000;$i++) { lh = loadlibrary("...isapi.dll"); freelibrary(lh); } After 200 cycles the process consumes 50MB. I don't think that should happen. What is wrong? Previous Comments: ------------------------------------------------------------------------ [2003-05-03 04:02:26] jakub at icewarp dot com Some more info I have found. The DllMain function from the ISAPI dll is incorrectly exported and has the name _DllMain@12 so it cannot be called by the web server. When you call the PROCESS_ATTACH and DETACH DllMain calls it raises and exception. THREAD_ATTACH and DETACH work fine but still the memory leak is there. Each call to the HttpExtensionProc leaks about 1kB of memory. Please try to have a look at it J ------------------------------------------------------------------------ [2003-05-02 08:44:36] jakub at icewarp dot com I have found out there is a worse problem. When calling the ISAPI DLL function HttpExtensionProc(Extension) to process the PHP session it leaks some memory. If you remove the call it does not leak any memory. I also made sure the WriteClientProc and such procedures in the Extension struct are empty so there could not be any leak from within the web server engine. I also tried to unload the ISAPI dll and this did not free the memory either. When run the 1000x HttpExtensionProc(Extension) to a very easy script like the following: <? echo "Hello"; ?> It leaks about 500kB. I'm not a Linux guy but I suppose if there would be a leak on Linux everybody would already know so I think it might be the ISAPI module problem only. Hopefully. Thanks Jakub ------------------------------------------------------------------------ [2003-04-29 10:21:22] sniper@php.net No feedback was provided. The bug is being suspended because we assume that you are no longer experiencing the problem. If this is not the case and you are able to provide the information that was requested earlier, please do so and change the status of the bug back to "Open". Thank you. ------------------------------------------------------------------------ [2003-04-24 12:38:03] sniper@php.net Please try using this CVS snapshot: http://snaps.php.net/php4-STABLE-latest.tar.gz For Windows: http://snaps.php.net/win32/php4-win32-STABLE-latest.zip ------------------------------------------------------------------------ [2003-04-24 09:29:46] jakub at icewarp dot com I have seen a few threads about Memory leaks in the COM object implementation here but from what I see this has never been solved. For instance this little piece of code proves it: $excel=new COM("Excel.Application"); for ($i=0;$i<50000;$i++) $excel->sheetsinnewworkbook= "1"; die(); It's not always a property that causes the memory leak. It's also the method you call when you pass strings to it. Also when you try to reference a property that does not exist. I'm using my own COM object to test it with and 5000 cycles o calling a simple 3 string parameter function uses up to 30MB of RAM. Please try to fix it. We have to use a CGI mode where every instance of PHP is freed completely. But we want to use the ISAPI it is not possible to do that now. Thank you Jakub ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=23331&edit=1