Bug #69428 [Com]: fgets blocks and consumes CPU on a non-blocking TLS stream without data

From: Date: Sat, 11 Apr 2015 23:32:51 +0000
Subject: Bug #69428 [Com]: fgets blocks and consumes CPU on a non-blocking TLS stream without data
References: 1  Groups: php.bugs 
Request: Send a blank email to php-bugs+get-191985@lists.php.net to get a copy of this message 
Edit report at https://bugs.php.net/bug.php?id=69428&edit=1

 ID:                 69428
 Comment by:         nathan dot renniewaldock at gmail dot com
 Reported by:        nathan dot renniewaldock at gmail dot com
 Summary:            fgets blocks and consumes CPU on a non-blocking TLS
                     stream without data
 Status:             Duplicate
 Type:               Bug
 Package:            OpenSSL related
 Operating System:   Ubuntu 12.04
 PHP Version:        5.6.7
 Block user comment: N
 Private report:     N

 New Comment:

Must've missed that one when searching. But that one is correct, my blank lines are from it
returning after timeout is exceeded.


Previous Comments:
------------------------------------------------------------------------
[2015-04-11 23:03:36] requinix@php.net

Related To: Bug #69402

------------------------------------------------------------------------
[2015-04-11 23:02:25] requinix@php.net

Duplicate of bug #69402

------------------------------------------------------------------------
[2015-04-11 22:56:27] nathan dot renniewaldock at gmail dot com

Description:
------------
TLS streams are blocking and consuming 100% CPU when there's no data when set to non-blocking.
Test script is using a local IRC server so I didn't have to write a server. Removing tls:// and
changing the port to 6667 works as expected.

Test script:
---------------
<?php
$context = stream_context_create();
stream_context_set_option($context, "ssl", "verify_peer", false);

$fp = stream_socket_client("tls://localhost:6697", $errno, $errstr, 10,
STREAM_CLIENT_CONNECT, $context) or die();
stream_set_blocking($fp, 0);

while (!feof($fp)) {
        echo microtime(true)." Reading...\n";
        $line = fgets($fp);
        echo microtime(true)." $line\n";

        if (!$fp) {
                usleep(10000);
        }
}
@fclose($fp);
?>

Expected result:
----------------
"Reading..." should repeat every ~10ms and CPU usage should be low


Actual result:
--------------
$ php test.php
1428791498.132599 Reading...
1428791498.171197 :localhost NOTICE AUTH :*** Looking up your hostname...

1428791498.171224 Reading...
1428791498.171237 :localhost NOTICE AUTH :*** Found your hostname (cached)

1428791498.171251 Reading...
# At this point htop shows it using 100% CPU until the server send a blank line to check the
connection hasn't broken
1428791508.17128



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