Bug #75945 [Opn]: php leak memory when calling database function with 'RAISE NOTICE'

Edit report at https://bugs.php.net/bug.php?id=75945&edit=1 ID: 75945 Updated by: yohgaki@php.net Reported by: hnguyen at wyebot dot com Summary: php leak memory when calling database function with 'RAISE NOTICE' Status: Open Type: Bug Package: PostgreSQL related Operating System: Ubuntu PHP Version: 7.2.2 Block user comment: N Private report: N New Comment: I haven't look into the details, but notice has it's own data structure hidden from users. These memory is cleaned up at request shutdown. Therefore, you cannot test leak by user space script. If you have excessive memory usage, e.g. hit memory_limits by raising thousands of notices, then it may be called a bug. I don't remember it stores all notices until shutdown or it has limit. Previous Comments: ------------------------------------------------------------------------ [2018-02-09 20:30:46] hnguyen at wyebot dot com Description: ------------ Whenever php make a call to a postgresql database function with the 'RAISE NOTICE' statement in it then it leaks memory. With the provided memTest.php script, if one run it on php 7.1 or 7.2, there is a memory leak reported. Testing on php 7.0 leak memory but by comparison it is much less. Please see below result. Here is a test result with php 7.2: # php -v PHP 7.2.2-1+ubuntu16.04.1+deb.sury.org+1 (cli) (built: Feb 1 2018 16:01:26) ( NTS ) Copyright (c) 1997-2018 The PHP Group Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies with Zend OPcache v7.2.2-1+ubuntu16.04.1+deb.sury.org+1, Copyright (c) 1999-2018, by Zend Technologies # ./memTest.php php-psql memory leak test for function with 'RAISE NOTICE' After 1000 runs memory lost = 84920 bytes Here is a test result with php 7.1: # php -v PHP 7.1.13-1+ubuntu16.04.1+deb.sury.org+1 (cli) (built: Jan 5 2018 13:26:45) ( NTS ) Copyright (c) 1997-2017 The PHP Group Zend Engine v3.1.0, Copyright (c) 1998-2017 Zend Technologies with Zend OPcache v7.1.13-1+ubuntu16.04.1+deb.sury.org+1, Copyright (c) 1999-2017, by Zend Technologies # ./memTest.php php-psql memory leak test for function with 'RAISE NOTICE' After 1000 runs memory lost = 84920 bytes Here is a test result with php 7.0: # php -v PHP 7.0.22-0ubuntu0.16.04.1 (cli) ( NTS ) Copyright (c) 1997-2017 The PHP Group Zend Engine v3.0.0, Copyright (c) 1998-2017 Zend Technologies with Zend OPcache v7.0.22-0ubuntu0.16.04.1, Copyright (c) 1999-2017, by Zend Technologies # ./memTest.php php-psql memory leak test for function with 'RAISE NOTICE' After 1000 runs memory lost = 112 bytes Test script: --------------- # memTest.php script # usage: ./memTest.php #!/usr/bin/env php <?php const NUM_RUNS = 1000; function addNoticeFunction($con) { $query = "CREATE OR REPLACE FUNCTION test_function () RETURNS void AS $$ BEGIN RAISE NOTICE 'Hellow World!'; END; $$ LANGUAGE plpgsql;"; // this function will cause memory leak //$query = "CREATE OR REPLACE FUNCTION test_function () RETURNS void AS $$ BEGIN END; $$ LANGUAGE plpgsql;"; // this function will not cause memory leak $rs_client = pg_query($con, $query) or die("Cannot execute query: $query\n"); if ($rs_client) pg_free_result($rs_client); } function makeAQuery($con) { $query = "SELECT test_function()"; // lose 424 byte each run $rs_client = pg_query($con, $query) or die("Cannot execute query: $query\n"); if ($rs_client) pg_free_result($rs_client); } function runQueryTests ($con) { $before = memory_get_usage(); for ($i = 0; $i < NUM_RUNS; ++$i) { makeAQuery($con); } $after = memory_get_usage(); printf("After %d runs memory lost = %4d bytes\n", NUM_RUNS, $after - $before); } print("php-psql memory leak test for function with 'RAISE NOTICE'\n"); $con = pg_pconnect("host=172.17.0.1 user=postgres") or go_die("Could not connect to server\n"); addNoticeFunction($con); runQueryTests($con); pg_close($con); ?> Expected result: ---------------- There should be 0 memory leak Actual result: -------------- There was 84920 bytes of memory leak after running the script ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=75945&edit=1