Ask the memory sharing about the problem!

Ask for memory sharing problems!!!

The code is as follows:

 
 
$sysid = $shmkey = Ftok (__file__, ' t ');
$flags = "C";
$mode = 0766;
$size = 1024;

$shmid = Shmop_open ($sysid, $flags, $mode, $size);
Shmop_write ($shmid, "Hello", 0);
$len = Shmop_size ($shmid);
$cont = Shmop_read ($sysid, 0, "Hello");
Var_dump ($cont);
Shmop_delete ($shmid);
Shmop_close ($shmid);

This piece of code error, what is the matter?

PHP Warning:  shmop_read (): No shared memory segment with an ID of [1946257823] in/home/admin/codes/php/shmop/client.p HP on line 8

Warning:shmop_read (): No shared memory segment with a ID of [1946257823] in/home/admin/codes/php/shmop/client.php on Li NE 8

------to solve the idea----------------------
$cont = Shmop_read ($shmid, 0, "Hello");

