Bug #79566 [PATCH]: Private SHM is not private on Windows

Edit report at https://bugs.php.net/bug.php?id=79566&edit=1 ID: 79566 Patch added by: cmb@php.net Reported by: cmb@php.net Summary: Private SHM is not private on Windows Status: Assigned Type: Bug Package: *Extensibility Functions Operating System: Windows only PHP Version: 7.3Git-2020-05-05 (Git) Assigned To: cmb Block user comment: N Private report: N New Comment: The following pull request has been associated: Patch Name: Support shmget(IPC_PRIVATE, …) on Windows On GitHub: https://github.com/php/php-src/pull/5519 Patch: https://github.com/php/php-src/pull/5519.patch Previous Comments: ------------------------------------------------------------------------ [2020-05-05 09:31:21] cmb@php.net Description: ------------ Calling shmop_open() with a $key that matches IPC_PRIVATE (which is usually zero on POSIX, and always zero on Windows), creates private shared memory on POSIX, but not on Windows. This is actually not particularly related to ext/shmop, but rather to our Windows emulation layer for XSI shared memory (shmget() and friends), so all extensions which use that functionality to create private SHM are affected by this. For instance, APCu[1]. [1] <https://github.com/krakjoe/apcu/issues/394> Test script: --------------- <?php $write = 'test'; $shm1 = shmop_open(0, 'c', 0777, 1024); shmop_write($shm1, $write, 0); $shm2 = shmop_open(0, 'c', 0777, 1024); $read = shmop_read($shm2, 0, 4); var_dump(is_string($read) && $read !== $write); shmop_close($shm1); shmop_close($shm2); ?> Expected result: ---------------- bool(true) Actual result: -------------- bool(false) ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=79566&edit=1