TL;DR; Weird thing happens with php8+ when using Amazon Linux 2. Using docker images from php for php8+ the same test pasts. Issue appears to be related to the specific packages installed not php as a whole. BUT it does also show some odd things happening by moving code about.
I'm not sure how to debug php-meminfo itself, but I have a really odd one that I was able to replicate down to a small test. The test consists of TestClass in which I want to use the static Current() method to get a single instance of the class.
<?php
class TestClass
{
protected static $CurrentInstance;
public static function Current() : TestClass
{
// Check if there is an instance created already.
if (isset(static::$CurrentInstance))
{
return static::$CurrentInstance;
}
// If not create and return it.
static::$CurrentInstance = new TestClass();
return static::$CurrentInstance;
}
}
$some_bool = false;
if ($some_bool === true)
{
$test = TestClass::Current();
}
meminfo_dump(fopen('/tmp/my_dump_file.json', 'w'));
echo time();This will result in SIGSEGV which will result in apache giving a 503 response. But things get really odd really quick.
If you change
if ($some_bool === true)
{
$test = TestClass::Current();
}to
if ($some_bool === true)
{
TestClass::Current();
}then the code will work. Maybe something about having a reference to the variable? But it's odd because the code will never execute as $some_bool is false.
Another oddity is if you move the declaration outside of the if then it will also work as expected.
$test = TestClass::Current();
if ($some_bool === true)
{
}EDIT: I also just found it has nothing to do with the static variable. The new minimum test case is
<?php
class TestClass
{
}
$some_bool = false;
if ($some_bool === true)
{
$test = new TestClass();
}
meminfo_dump(fopen('/tmp/my_dump_file.json', 'w'));
echo time();I should have also included specs. This is running on a Amazon Linux 2 EC2 instance. php version is
# php -v
PHP 8.0.28 (cli) (built: Mar 28 2023 17:41:50) ( NTS )
Copyright (c) The PHP Group
Zend Engine v4.0.28, Copyright (c) Zend Technologies
with Zend OPcache v8.0.28, Copyright (c), by Zend Technologies
As for php-meminfo, I built it from the current master source.
EDIT 2:
This can be replicated without the TestClass
<?php
$some_bool = false;
if ($some_bool === true)
{
$test = new stdClass();
}
meminfo_dump(fopen('/tmp/my_dump_file.json', 'w'));
echo time();EDIT 3:
Looks like maybe it has something to do with code being removed when executed or something.
This works
<?php
$some_bool = false;
if ($some_bool === false)
{
$test = new stdClass();
}
meminfo_dump(fopen('/tmp/my_dump_file.json', 'w'));
echo time();This does not
<?php
$some_bool = false;
if ($some_bool === true)
{
$test = new stdClass();
}
meminfo_dump(fopen('/tmp/my_dump_file.json', 'w'));
echo time();But in saying that this works and it shouldn't according to the above example
<?php
$some_bool = true;
if (false)
{
$test = new stdClass();
}
meminfo_dump(fopen('/tmp/my_dump_file.json', 'w'));
echo time();But then this also works
<?php
$some_bool = false;
$test = null;
if ($some_bool === true)
{
$test = new stdClass();
}
meminfo_dump(fopen('/tmp/my_dump_file.json', 'w'));
echo time();You can also get this to fail with primatives.
<?php
$some_bool = false;
if ($some_bool === true)
{
$test = 1;
}
meminfo_dump(fopen('/tmp/my_dump_file.json', 'w'));
echo time();
TL;DR; Weird thing happens with php8+ when using Amazon Linux 2. Using docker images from php for php8+ the same test pasts. Issue appears to be related to the specific packages installed not php as a whole. BUT it does also show some odd things happening by moving code about.
I'm not sure how to debug php-meminfo itself, but I have a really odd one that I was able to replicate down to a small test. The test consists of
TestClassin which I want to use the staticCurrent()method to get a single instance of the class.This will result in SIGSEGV which will result in apache giving a 503 response. But things get really odd really quick.
If you change
to
then the code will work. Maybe something about having a reference to the variable? But it's odd because the code will never execute as
$some_boolis false.Another oddity is if you move the declaration outside of the if then it will also work as expected.
EDIT: I also just found it has nothing to do with the static variable. The new minimum test case is
I should have also included specs. This is running on a Amazon Linux 2 EC2 instance. php version is
As for php-meminfo, I built it from the current master source.
EDIT 2:
This can be replicated without the TestClass
EDIT 3:
Looks like maybe it has something to do with code being removed when executed or something.
This works
This does not
But in saying that this works and it shouldn't according to the above example
But then this also works
You can also get this to fail with primatives.