ID: 23838
Updated by: [EMAIL PROTECTED]
Reported By: dietrich dot ayala at foundstone dot com
-Status: Assigned
+Status: Feedback
Bug Type: Sockets related
Operating System: windows 2000
PHP Version: 4.3.2RC4
Assigned To: wez
New Comment:
Try using a non-zero timeout value in the stream_select() call. Zero
means return immediately if there is no data, so it will definitely eat
CPU that way.
Previous Comments:
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[2003-05-27 17:35:22] dietrich dot ayala at foundstone dot com
"cannot reproduce" is different from "didn't attempt to reproduce" ;)
Also, this is very critical! PHP doesn't look so good when even the
smallest network activity could bring the box to a crawl if anything
besides PHP is active. This is especially frustrating when the server
is localhost, so you have all your progs having to battle PHP for CPU,
and PHP doesn't even need it, except to busy-wait!
Here's the repro script. This brings CPU to 100% every time on my win2k
box. I set up a server that sleeps for a few seconds before responding,
and that showed it even more clearly than this example.
<?php
$host = 'd-w2kserv';
$port = 80;
// open connection
if(!$fp = pfsockopen($host, $port, $errno, $error_str)){
die('error: '.$error_str.$phperrormsg);
} else {
// write data
$requestMsg = "GET / HTTP/1.1\r\nHost: $host\r\n\r\n";
if([EMAIL PROTECTED]($fp, $requestMsg)) {
die('error: '.$phperrormsg);
}
// read data
do {
// array of connections
$read = array($fp);
// use stream_select() for non-busy wait
if (false === ($num_changed_streams = stream_select($read, $write =
NULL, $except = NULL, 0))) {
die('Stream_select returned error: '.$phperrormsg);
// At least on one of the streams something interesting happened
} elseif ($num_changed_streams > 0) {
if( !$data = @fgets($fp, 8192) ){
die('couldnt get data from socket, or socket returned
no data');
}
print $data;
// no more data
if (feof($fp) || $data === false || strlen($data) == 0) {
break;
}
}
} while(true);
}
?>
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[2003-05-27 17:15:21] [EMAIL PROTECTED]
Can not reproduce on Linux. (no script to test with)
Not really critical, it's just some streams thingie. :)
------------------------------------------------------------------------
[2003-05-27 14:48:53] [EMAIL PROTECTED]
Assigning to myself; it would be good if some other people could verify
if this problem exists on other platforms, and if this is a critical
issue.
------------------------------------------------------------------------
[2003-05-27 12:57:20] dietrich dot ayala at foundstone dot com
1. it doesn't seem to be doing non-busy waits. If the remote host takes
a long time to respond, the CPU is still maxed until a response is
received.
2. I've had repeatable situations where the server returned a response
right away, but stream_select() didn't return for (in our repeatable
case) 10 mins. What's it's criteria for responding? What will it do if
I pass a stream to it, which has already had everything read from it,
but is persistent, so there's no EOF/line-break/anything? It seems that
whatever its return criteria is, it isn't met sometimes.
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Edit this bug report at http://bugs.php.net/?id=23838&edit=1
