Edit report at https://bugs.php.net/bug.php?id=64644&edit=1

 ID:                 64644
 Updated by:         ras...@php.net
 Reported by:        matteosistisette at gmail dot com
 Summary:            Client-side abortion should be detected regardless
                     of sending output
 Status:             Not a bug
 Type:               Bug
 Package:            *General Issues
 Operating System:   Linux
 PHP Version:        5.3.24
 Block user comment: N
 Private report:     N

 New Comment:

They are basically saying that we could try to hack around Apache and try to 
write directly to do direct socket ops on a socket opened and managed by 
Apache. 
Very bad idea. I don't know of any environment that attempts to do this. See 
this conversation about the same issue in Django, for example:

http://stackoverflow.com/questions/6019145/how-do-i-detect-an-aborted-
connection-in-django

This isn't something we are going to address with hacks in PHP.


Previous Comments:
------------------------------------------------------------------------
[2013-04-13 23:41:08] matteosistisette at gmail dot com

Response from Apache developers: 
https://issues.apache.org/bugzilla/show_bug.cgi?id=54842#c1

I'm not sure I fully understand it but it seems they say there actually IS a 
way 
PHP can figure out if the connection is closed without attempting to write.

------------------------------------------------------------------------
[2013-04-13 22:15:41] matteosistisette at gmail dot com

Unbelievable. Then the huge design flaw is in Apache.

------------------------------------------------------------------------
[2013-04-13 21:59:18] ras...@php.net

Apache handles the communication with the client browser and provides no 
mechanism for PHP to discover a client abort except on an actual write.

------------------------------------------------------------------------
[2013-04-13 21:56:04] matteosistisette at gmail dot com

Ok, I see. The problem is that I hadn't disabled gzip in Apache, so the output 
wasn't being flushed until the end. As documented:

"""PHP will not detect that the user has aborted the connection until an 
attempt 
is made to send information to the client. Simply using an echo statement does 
not guarantee that information is sent, see flush()."""

However, this is a huge design flaw. PHP definitely should be able to detect 
the 
client's abortion when it happens and not the next time it attempts to actually 
send output. Having to change the way output is handled just in order to be 
able 
to detect client disconnection is ridiculous (and not always feasible).

I don't know if the server API currently provides a way for the server (i.e. 
Apache) to inform PHP of the client's disconnection, but if there is not it 
must 
be provided.

------------------------------------------------------------------------
[2013-04-13 21:52:32] ras...@php.net

What you are missing is that your single-character output is getting buffered. 
There is no way to detect a client abort until you actually try to send 
something 
to the client either by filling the output buffer and having it send 
automatically or by forcing it by calling flush() after your echo. So in your 
test case, add a flush() call after your echo "." and you will see it works as 
documented.

------------------------------------------------------------------------


The remainder of the comments for this report are too long. To view
the rest of the comments, please view the bug report online at

    https://bugs.php.net/bug.php?id=64644


-- 
Edit this bug report at https://bugs.php.net/bug.php?id=64644&edit=1

Reply via email to