Bug #74575 [NEW]: Memory leaks with gc_collect_cycles()
From: roocster at gmail dot com
Operating system: Windows 10 x64
PHP version: 7.1.5RC1
Package: *General Issues
Bug Type: Bug
Bug description:Memory leaks with gc_collect_cycles()
Description:
------------
If make the situation described in the docs of "Collecting Cycles"
(http://php.net/manual/en/features.gc.collecting-cycles.php) the
gc_collect_cycles() doesn't collect garbage cycle reference.
After we made an array which is referenced only by itself element (cycle
reference) the gc_collect_cycles() call returns 0. That means there are
not collected cycles and we have a memory leak.
If we replace "$a = $a[0]" on "unset($a)" the garbage collector works
correctly and the gc_collect_cycles() call returns 1.
Test script:
---------------
<?php
echo "Memory usage before memory leak:\t",
memory_get_usage()," bytes",PHP_EOL;
$a = ['one'];
$a[] = &$a;
$a = $a[0];
echo "Memory usage after memory leak:\t\t",
memory_get_usage()," bytes",PHP_EOL;
echo "Number of collected cycles: ",
gc_collect_cycles(),PHP_EOL;
echo "Memory usage after gc_collect_cycles():\t",
memory_get_usage()," bytes",PHP_EOL;
Actual result:
--------------
Memory usage before memory leak: 353368 bytes
Memory usage after memory leak: 353392 bytes
Number of collected cycles: 0
Memory usage after gc_collect_cycles(): 353392 bytes
--
Edit bug report at https://bugs.php.net/bug.php?id=74575&edit=1
--
Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=74575&r=trysnapshot54
Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=74575&r=trysnapshot55
Try a snapshot (trunk): https://bugs.php.net/fix.php?id=74575&r=trysnapshottrunk
Fixed in SVN: https://bugs.php.net/fix.php?id=74575&r=fixed
Fixed in release: https://bugs.php.net/fix.php?id=74575&r=alreadyfixed
Need backtrace: https://bugs.php.net/fix.php?id=74575&r=needtrace
Need Reproduce Script: https://bugs.php.net/fix.php?id=74575&r=needscript
Try newer version: https://bugs.php.net/fix.php?id=74575&r=oldversion
Not developer issue: https://bugs.php.net/fix.php?id=74575&r=support
Expected behavior: https://bugs.php.net/fix.php?id=74575&r=notwrong
Not enough info: https://bugs.php.net/fix.php?id=74575&r=notenoughinfo
Submitted twice: https://bugs.php.net/fix.php?id=74575&r=submittedtwice
register_globals: https://bugs.php.net/fix.php?id=74575&r=globals
PHP 4 support discontinued: https://bugs.php.net/fix.php?id=74575&r=php4
Daylight Savings: https://bugs.php.net/fix.php?id=74575&r=dst
IIS Stability: https://bugs.php.net/fix.php?id=74575&r=isapi
Install GNU Sed: https://bugs.php.net/fix.php?id=74575&r=gnused
Floating point limitations: https://bugs.php.net/fix.php?id=74575&r=float
No Zend Extensions: https://bugs.php.net/fix.php?id=74575&r=nozend
MySQL Configuration Error: https://bugs.php.net/fix.php?id=74575&r=mysqlcfg
Thread (3 messages)
- roocster at gmail dot com