I'm looking for some information on why fread calls max out CPU usage
on SSL connections in windows. I've tried upgrading PHP (now at 5.1.2)
and OpenSSL (now 9.8) but cannot stop fread() from slamming the
processor on long network requests.
Below is a simple way to reproduce the problem with fgets():
Create two files, one (timer.php) has to be accessable from the web
(HTTP and HTTPS) and the other can be ran from the command prompt
(pingtimer.php). When you run pingtimer.php using SSL, php.exe will
stick at 99% CPU in Task Manager. When you run it using clean sockets,
its idle while waiting for a response.
timer.php :
<?php
sleep(10);
print "<html><body>10 sec. are up!</body></html>";
?>
pingtimer.php:
<?php
//$sock = fsockopen("localhost", 80);
$sock = fsockopen("ssl://localhost", 443);
$query = "GET /timer.php HTTP/1.1\r\n";
$query .= "Host: localhost\r\n";
$query .= "Connection: Close\r\n\r\n";
fwrite($sock, $query);
while (!feof($sock)) {
echo fgets($sock, 128);
}
fclose($sock);
?>
Any info (background, workaround, etc...) would be helpful.
- Joel
2  1981  jo***********@gmail.com wrote: I'm looking for some information on why fread calls max out CPU usage
on SSL connections in windows. I've tried upgrading PHP (now at 5.1.2)
and OpenSSL (now 9.8) but cannot stop fread() from slamming the
processor on long network requests.
Below is a simple way to reproduce the problem with fgets():
Create two files, one (timer.php) has to be accessable from the web
(HTTP and HTTPS) and the other can be ran from the command prompt
(pingtimer.php). When you run pingtimer.php using SSL, php.exe will
stick at 99% CPU in Task Manager. When you run it using clean sockets,
its idle while waiting for a response.
timer.php :
<?php
sleep(10);
print "<html><body>10 sec. are up!</body></html>";
?>
pingtimer.php:
<?php
//$sock = fsockopen("localhost", 80);
$sock = fsockopen("ssl://localhost", 443);
$query = "GET /timer.php HTTP/1.1\r\n";
$query .= "Host: localhost\r\n";
$query .= "Connection: Close\r\n\r\n";
fwrite($sock, $query);
while (!feof($sock)) {
echo fgets($sock, 128);
}
fclose($sock);
?>
Any info (background, workaround, etc...) would be helpful.
- Joel
whatelse is the CPU supposed to do?
let's see:
do I/O to the network
encrypt the message
open the socket - get data from remote
decrypt the SSL data
move it somewhere (memory/disk)
more processing to display it.
If your CPU is not busy doing other things, it should take as much as it
needs to get the job done.
If you check to source posted above (timer.php), you'll notice that I'm
using a Sleep() call. There should be no data to decrypt until that
call returns. That indicates that the 99% usage is happening while the
socket is being polled for data. True, the SSL layer is more
intensive, but that should not affect the issue at hand as there is no
data being passed over the socket during the 10 sec. sleep call.
- Joel
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