Bug #79900 [Opn->Csd]: Memory leaks reported in zend_objects_new with zend.enable_gc=0

Edit report at https://bugs.php.net/bug.php?id=79900&edit=1 ID: 79900 Updated by: nikic@php.net Reported by: tandre@php.net Summary: Memory leaks reported in zend_objects_new with zend.enable_gc=0 -Status: Open +Status: Closed Type: Bug Package: Scripting Engine problem PHP Version: 8.0Git-2020-07-26 (Git) Block user comment: N Private report: N New Comment: Automatic comment on behalf of nikita.ppv@gmail.com Revision: http://git.php.net/?p=php-src.git;a=commit;h=c206c742d6225c7f4c7ffbf95e33034d8de59047 Log: Fix bug #79900 Previous Comments: ------------------------------------------------------------------------ [2020-07-28 14:28:23] nikic@php.net We should probably force-run GC on shutdown (in debug builds). I don't think anything about the behavior here has actually changed, those leaks were probably just suppressed by use of "exit" previously. ------------------------------------------------------------------------ [2020-07-26 22:56:25] tandre@php.net Description: ------------ When gc is disabled, PHP builds containing --enable-debug report a variety of memory leaks during PHP shutdown. I'm not sure if this is reflective of an actual memory leak or whether this is a deliberate change in php 8.0. It's distracting when trying to debug issues, though. Many large applications disable gc because it has historically been slow in older php versions, e.g. I noticed this when running composer and http://github.com/phan/phan/ (which creates objects with reference cycles, e.g. Type to UnionType to the type itself. For example, during --enable-debug, calling gc_collect_cycles() during shutdown may cut down on noise about memory leaks, but that may itself be an inconsistency ``` » php run-tests.php -d zend.enable_gc=0 Zend/tests/bug61165.phpt --show-diff ===================================================================== PHP : /path/to/php-8.0.0-debug-plain-install/bin/php PHP_SAPI : cli PHP_VERSION : 8.0.0-dev ZEND_VERSION: 4.0.0-dev PHP_OS : Linux - Linux student3 4.15.0-72-generic #81~16.04.1-Ubuntu SMP Tue Nov 26 16:34:21 UTC 2019 x86_64 INI actual : /path/to/php-src More .INIs : --------------------------------------------------------------------- PHP : /path/to/php-src/sapi/phpdbg/phpdbg PHP_SAPI : phpdbg PHP_VERSION : 8.0.0-dev ZEND_VERSION: 4.0.0-dev PHP_OS : Linux - Linux student3 4.15.0-72-generic #81~16.04.1-Ubuntu SMP Tue Nov 26 16:34:21 UTC 2019 x86_64 INI actual : /path/to/php-src More .INIs : --------------------------------------------------------------------- CWD : /path/to/php-src Extra dirs : VALGRIND : Not used ===================================================================== Running selected tests. TEST 1/1 [Zend/tests/bug61165.phpt] ========DIFF======== 005+ [Sun Jul 26 18:45:57 2020] Script: '/path/to/php-src/Zend/tests/bug61165.php' 006+ /path/to/programming/php-src/Zend/zend_objects.c(178) : Freeing 0x00007f3c2ea039c0 (56 bytes), script=/path/to/php-src/Zend/tests/bug61165.php 007+ Last leak repeated 3 times 008+ === Total 4 memory leaks detected === ========DONE======== FAIL Bug #61165 (Segfault - strip_tags()) [Zend/tests/bug61165.phpt] ===================================================================== Number of tests : 1 1 Tests skipped : 0 ( 0.0%) -------- Tests warned : 0 ( 0.0%) ( 0.0%) Tests failed : 1 (100.0%) (100.0%) Tests passed : 0 ( 0.0%) ( 0.0%) --------------------------------------------------------------------- Time taken : 0 seconds ===================================================================== ===================================================================== FAILED TEST SUMMARY --------------------------------------------------------------------- Bug #61165 (Segfault - strip_tags()) [Zend/tests/bug61165.phpt] ===================================================================== ``` Expected result: ---------------- No memory leaks are reported, or messages should get added to clarify that php deliberately will not attempt to garbage collect cyclic object cycles if gc is disabled during shutdown. I don't see any leaks reported in a debug 7.3 build Actual result: -------------- Memory leaks are reported with --enable-debug builds during shutdown ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=79900&edit=1