Description:
------------
i run the code below in the cmd, it tooks warning Warning: shm_put_var(): not 
enough shared memory left in 
/usr/local/agent/bin/a.php on line 15
i set the shmmax > 100M
when the process > 1 ,the error shows
when the process = 1, it seems ok.

Test script:
---------------
#!/usr/local/services/php/bin/php
<?php
// Example
$key = ftok(__FILE__, 'a');
$shm = shm_attach($key);
shm_remove($shm);
$shm = shm_attach($key);
for($i = 0; $i < 3; $i++) {
    $pid = pcntl_fork();
    if ($pid) {
        
    } else {
        //child
        $pid = posix_getpid();
        for($i = 0; $i < 100000; $i++) {
            shm_put_var($shm, $pid, microtime(true));
        }
        exit;
    }
}
?> 

Actual result:
--------------
Warning: shm_put_var(): not enough shared memory left in 
/usr/local/agent/bin/a.php on line 15