PHP Chilkat imap 组件内存泄漏

Question

Given:

1. ubuntu 18.04
2. PHP 7.2.2 (cli) (built: May 12 2019 14:29:04) ( ZTS )
3. Chilkat component 9.5.0.78

Session log is disabled.

Script running permanently, connection is via ssh and keep opened.

The following function called periodically:

protected function fetchSingle(int $uid)
{
    $e = $this->imap->fetchSingleAsMime($uid, true);
}

It is just to demonstrate, that RES and %MEM on linux top keep increasing:

And very important moment:

after fetching several big emails if there is executed then next code:

$this->imap = null;
unset($this->imap);
sleep(324);

Then RES and %MEM go down to initial values!

But without

$this->imap = null;
unset($this->imap);

RES and %MEM stay on high values!

Logically I may predict that problem inside imap CkImap object...

What can I do ? Unset periodically CkImap object and reconnect is not good solution...

Why is it so ? Maybe chilkat is storing data somewhere in itself ? And I should call some method to clear it ?

Reproducible code:

<?php

require "core/Chilkat.php";

$ckGlobal = new CkGlobal();

$ckGlobal->UnlockBundle('XXXX');

$imap = new CkImap();
$imap->put_Utf8(true);
$imap->put_Ssl(true);
$imap->put_Port(993);
$imap->put_PeekMode(true);

$imap->Connect('imap');

$imap->Login('login', 'password');

$imap->SelectMailbox('Inbox');

// UID of last message
preg_match('/UID (\d+)/', $imap->sendRawCommand("FETCH * (UID)"), $result);


$i = 0;
while(true){
    var_dump('FETCHING');
    $mime = $imap->fetchSingleAsMime($result[1], true);
    var_dump('SLEEP');
    sleep(5);
    if(++$i >= 5) {
        var_dump('UNSET');
        $imap = null;
        unset($imap);
        sleep(666);
    }
}

With the above code we fetch email each 5 seconds and RAM consumption is increasing unstoppable. But it must not, because we overwrite the $mime variable. And once imap is unset - RAM goes down to first value.

get_VerboseLogging - this is false by default. And Peek mode I also tried to set to false. Nothing helped to solve or figure out the problem.

Even after $imap->Disconnect(); RAM will not be decreased..

Answer 1

When it stays at about the same utilization level, just ignore it and add more RAM ...but when it keeps growing, then you'll have to periodically purge the leakage. With closed source you can only complain at the vendor, who might also have established best practices for using their library.

According to Chilkat_9_5_0.Imap , there is a property VerboseLogging

... and also property PeekMode might affect the memory utilization.

Answer 2

I apologize! I have checked this code more carefully and seems RAM increased until specific limit! But still interesting why it is increasing..