From: cleong at nflc dot org
Operating system: Windows 2000
PHP version: 4.3.7
PHP Bug Type: Filesystem function related
Bug description: Thread safty issue with stream_wrapper_register?
Description:
------------
On Windows 2000, with PHP running as an Apache module,
stream_wrapper_register() would fail when there are concurent scripts
using that function. It would either fail without an error message or
causes the Apache process to crash. When there's just one script running
the function works fine.
To reproduce this bug, open a couple browser windows and go to the
reproduce code in each.
I can get around the bug by generating a random class name and protocol
name everytime (using eval for the class definition).
Reproduce code:
---------------
<?
// example class taken from manual
class VariableStream {
var $position;
var $varname;
function stream_open($path, $mode, $options, &$opened_path)
{
$url = parse_url($path);
$this->varname = $url["host"];
$this->position = 0;
return true;
}
function stream_read($count)
{
$ret = substr($GLOBALS[$this->varname], $this->position, $count);
$this->position += strlen($ret);
return $ret;
}
function stream_write($data)
{
$left = substr($GLOBALS[$this->varname], 0, $this->position);
$right = substr($GLOBALS[$this->varname], $this->position +
strlen($data));
$GLOBALS[$this->varname] = $left . $data . $right;
$this->position += strlen($data);
return strlen($data);
}
function stream_tell()
{
return $this->position;
}
function stream_eof()
{
return $this->position >= strlen($GLOBALS[$this->varname]);
}
function stream_seek($offset, $whence)
{
switch ($whence) {
case SEEK_SET:
if ($offset < strlen($GLOBALS[$this->varname]) && $offset
>= 0) {
$this->position = $offset;
return true;
} else {
return false;
}
break;
case SEEK_CUR:
if ($offset >= 0) {
$this->position += $offset;
return true;
} else {
return false;
}
break;
case SEEK_END:
if (strlen($GLOBALS[$this->varname]) + $offset >= 0) {
$this->position = strlen($GLOBALS[$this->varname]) +
$offset;
return true;
} else {
return false;
}
break;
default:
return false;
}
}
}
stream_wrapper_register("var", "VariableStream")
or die("Failed to register protocol");
$myvar = "";
$fp = fopen("var://myvar", "r+");
fwrite($fp, "line1\n");
fwrite($fp, "line2\n");
fwrite($fp, "line3\n");
rewind($fp);
while (!feof($fp)) {
echo fgets($fp);
}
session_write_close(); // in case auto-session is on
for($i = 0; $i < 30; $i++) {
// make the script run for 30 seconds
sleep(1);
}
fclose($fp);
var_dump($myvar);
?>
Expected result:
----------------
Same result in each window.
Actual result:
--------------
While the first script is still running, the second script would say
"Failed to register protocol". If you refresh the second window, sometimes
it works, sometimes it causes a general protection error.
--
Edit bug report at http://bugs.php.net/?id=28868&edit=1
--
Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=28868&r=trysnapshot4
Try a CVS snapshot (php5): http://bugs.php.net/fix.php?id=28868&r=trysnapshot5
Fixed in CVS: http://bugs.php.net/fix.php?id=28868&r=fixedcvs
Fixed in release: http://bugs.php.net/fix.php?id=28868&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=28868&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=28868&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=28868&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=28868&r=support
Expected behavior: http://bugs.php.net/fix.php?id=28868&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=28868&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=28868&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=28868&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=28868&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=28868&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=28868&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=28868&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=28868&r=float
