Can you give more indication of why you think this is classified as a memory leak, and not just normal memory usage for that extension?

The code below isn't calling https://www.php.net/manual/en/function.shmop-delete.php to free the memory, so it's not too surprising some is resident.

Also, 1000 * 65kb would be 65Mb if it was a memory leak. As you say it's only 4 MegaByte that sounds, like it's not leaking, just taking a bit more memory than you might expect.

4KB memory independent of the size of allocated memory in "c" or "n" open mode

1000 interations $shmophsw=shmop_open(0x4051, "c", 0777, 1);
shmop_close($shmophsw); or shmop_open(0x4051, "c", 0777, 65536); give same result:
httpd.exe increase 4MB working ram.


shmop_delete() not change behaviour
(and how use shmop if delete segment after create?)

$shmophsw=shmop_open(0x4051, "a", 0, 0); give same behaviour: each add 4KB httpd.exe

This looks like a Windows only issue, and the culprit appears to
be that we're not unmapping the shm->descriptor if it's no longer
needed[1].

[1] <https://github.com/php/php-src/blob/php-7.3.9/TSRM/tsrm_win32.c#L731>

it possible to fix in current or future version?