- PHP 手册
- 函数参考
- 进程控制扩展
- Semaphore
- Semaphore 函数
shm_remove
(PHP 4, PHP 5, PHP 7, PHP 8)
shm_remove — Removes shared memory from Unix systems
说明
shm_remove(SysvSharedMemory$shm): bool
shm_remove() removes the shared memory
shm. All data will be destroyed.
参数
-
shm -
A shared memory segment obtained from shm_attach().
返回值
成功时返回 true， 或者在失败时返回 false。
更新日志
| 版本 | 说明 |
|---|---|
| 8.0.0 |
shm expects a SysvSharedMemory
instance now; previously, a resource was expected.
|
参见
- shm_remove_var() - Removes a variable from shared memory
User Contributed Notes 3 notes
up down 1 aaron DURP segura DURP gmail DURP com ¶15 years ago
It appears that you must be connected to the shm segment in order to remove it.
<?php
shm_remove($shm);
shm_detach($shm);
?>
works, while
<?php
shm_detach($shm);
shm_remove($shm);
?>
produces "Warning: shm_remove(): The parameter is not a valid shm_identifier ..."
up
down
0
HansRich ¶8 years ago
WARNING: this function WILL NOT destroy the memory segment if there are other processes attached to it, but it will return TRUE anyways!
You will have to try to access the segment again after destroying it to make sure it was relly destroyed.
up
down
-1
cu at ulakbim dot gov dot tr ¶22 years ago
Though it says **shm_identifier** in
int shm_remove(int shm_identifier);
and
shm_attach() returns an **id** that that can be used to access the System V...
a snippet like this:
<?php
$key = 1234;
$shm=shm_attach($key);
// do whatever...
shm_remove($shm);
?>
produces an error like
Warning: 2(which is the value of $shm) is not a existing SysV shared memory key in /usr/cu/web/sema.php on line 44...
The documentation confused me a bit. I thought shm_remove would get the shm handle/id that returns from shm_attach, not the key given to shm_attach. So, use instead:
shm_remove($key);
which is what is intended indeed.
add a note
官方地址：https://www.php.net/manual/en/function.shm-remove.php