What's the value of `ignore_user_abort` directive in phpinfo() ?

PHP Core

Directive Local     Value    Master Value 
ignore_user_abort     Off    Off

I prefer to keep with php4 for backward compatibility. I would understand if no update to this was made because this is an old version, but this appears to be a bug that should be fixed even in php4.

We just want to know if it works in 5.1 or not.

installed snapshot version as C:\php5, same results... Script continues after pushing stop on client browser.

Does your script output anything..?
See also the user notes here:
http://www.php.net/manual/en/function.connection-aborted.php

yes, my outputs data...

It pipes data through proc_open to a process in 8 or 16 kb chunks. It should stop sending data to my process and close it when the connection is aborted... I will try some tests with this function.

Your page needs to output data to _browser_.

yes, it does output data to the browser. My mistake, i forgot to mention that after the data is piped to the program, the stdout is piped into the browser.

Try with some other script which does NOT pipe anything anywhere..

I wrote a test script just for this purpose:

<?php

echo "hey";
$handler=fopen("tmp.txt","w");
while(true) {
    fwrite($handler, "Hey\n");
}
?>

The echo _should_ be enough to display data for connections aborted. In any case, i hit the "stop" button... and the script continues to run taking 100% cpu time and the tmp.txt grows indefinitely. 

In case it is of any use, I am on windows 2003 using php through ISAPI.

Does this code work for you?
<?php
$handler=fopen("tmp.txt","w");
while(true) {
    echo "hey";
    fwrite($handler, "Hey\n");
}
?>

I get a lot of "hey"'s, then click "stop" on the browser and the script is still running in the background taking up 100% cpu and making temp.txt 10 MB large.

Does it happen with Apache? (try it if you haven't done so yet)

apache on windows? I do not have apache and do not have the ability to install it on this server. I know when I run similar scripts on apache under linux, I have no problems.

Yes, Apache is also very easy to install on Windows.
You can get it from http://httpd.apache.org/
It's not only much better webserver than IIS, it actually works. :)

If this is true, PHP documentation should have a note that it does not support IIS fully.

Ok... I took Philip's advice from irc://irc.freenode.net/##php and actually ran the simple while(true) {} script in apache2 with the latest php snapshot... Same results, except apache2 seemed to respect the 30 second execution limits... This isn?t just an IIS bug if it makes anyone more inclined to fix it.

Please try using this CVS snapshot:

  http://snaps.php.net/php5.2-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php5.2-win32-latest.zip

Using latest snapshot. Same issue.

PHP detects aborted connection if the underlying "write buffer to the client" call fails. If it doesn't fail and continues to write the data to nowhere, PHP can't do anything about it.