<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>sem_get</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REL="HOME"
TITLE="PHP 手册"
HREF="index.html"><LINK
REL="UP"
TITLE="Semaphore, Shared Memory and IPC Functions"
HREF="ref.sem.html"><LINK
REL="PREVIOUS"
TITLE="sem_acquire"
HREF="function.sem-acquire.html"><LINK
REL="NEXT"
TITLE="sem_release"
HREF="function.sem-release.html"><META
HTTP-EQUIV="Content-type"
CONTENT="text/html; charset=UTF-8"></HEAD
><BODY
CLASS="refentry"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>PHP 手册</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="function.sem-acquire.html"
ACCESSKEY="P"
>上一页</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="function.sem-release.html"
ACCESSKEY="N"
>下一页</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="function.sem-get"
></A
>sem_get</H1
><DIV
CLASS="refnamediv"
><A
NAME="AEN205800"
></A
><P
> (PHP 3 >= 3.0.6, PHP 4, PHP 5)</P
>sem_get -- Get a semaphore id</DIV
><DIV
CLASS="refsect1"
><A
NAME="AEN205803"
></A
><H2
>Description</H2
>resource <B
CLASS="methodname"
>sem_get</B
> ( int key [, int max_acquire [, int perm [, int auto_release]]] )<BR
></BR
><P
> <B
CLASS="function"
>sem_get()</B
> returns an id that can be used to
access the System V semaphore with the given <CODE
CLASS="parameter"
>key</CODE
>.
The semaphore is created if necessary using the permission bits specified in
<CODE
CLASS="parameter"
>perm</CODE
> (defaults to 0666). The number of processes that can
acquire the semaphore simultaneously is set to <CODE
CLASS="parameter"
>max_acquire</CODE
>
(defaults to 1). Actually this value is set only if the process
finds it is the only process currently attached to the semaphore.
</P
><P
> Optional parameter <CODE
CLASS="parameter"
>auto_release</CODE
> specifies if the
semaphore should be automatically released on request shutdown.
It is available since PHP 4.3.0.
</P
><P
> Returns a positive semaphore identifier on success, or <TT
CLASS="constant"
><B
>FALSE</B
></TT
> on
error.
</P
><P
> A second call to <B
CLASS="function"
>sem_get()</B
> for the same key
will return a different semaphore identifier, but both
identifiers access the same underlying semaphore.
</P
><P
>
See also <A
HREF="function.sem-acquire.html"
><B
CLASS="function"
>sem_acquire()</B
></A
>,
<A
HREF="function.sem-release.html"
><B
CLASS="function"
>sem_release()</B
></A
>, and <A
HREF="function.ftok.html"
><B
CLASS="function"
>ftok()</B
></A
>.
</P
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="function.sem-acquire.html"
ACCESSKEY="P"
>上一页</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>起始页</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="function.sem-release.html"
ACCESSKEY="N"
>下一页</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>sem_acquire</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="ref.sem.html"
ACCESSKEY="U"
>上一级</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>sem_release</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
