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.