<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<HTML
><HEAD
><TITLE
>atomic_sub_and_test</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
REL="HOME"
TITLE="The Linux Kernel API"
HREF="book1.html"><LINK
REL="UP"
TITLE="Atomic and pointer manipulation"
HREF="x73.html"><LINK
REL="PREVIOUS"
TITLE="atomic_sub"
HREF="r172.html"><LINK
REL="NEXT"
TITLE="atomic_inc"
HREF="r242.html"></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"
>The Linux Kernel API</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="r172.html"
ACCESSKEY="P"
><<< Previous</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="r242.html"
ACCESSKEY="N"
>Next >>></A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="AEN207"
></A
><SPAN
CLASS="phrase"
><SPAN
CLASS="PHRASE"
>atomic_sub_and_test</SPAN
></SPAN
></H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN211"
></A
><H2
>Name</H2
>atomic_sub_and_test -- subtract value from variable and test result
</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN214"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN216"
></A
><P
></P
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <TT
CLASS="FUNCTION"
>atomic_sub_and_test </TT
></CODE
>(int <TT
CLASS="PARAMETER"
><I
>i</I
></TT
>, atomic_t * <TT
CLASS="PARAMETER"
><I
>v</I
></TT
>);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN224"
></A
><H2
>Arguments</H2
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="PARAMETER"
><I
>i</I
></TT
></DT
><DD
><P
> integer value to subtract
</P
></DD
><DT
><TT
CLASS="PARAMETER"
><I
>v</I
></TT
></DT
><DD
><P
> pointer of type atomic_t
</P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN237"
></A
><H2
>Description</H2
><P
> Atomically subtracts <TT
CLASS="PARAMETER"
><I
>i</I
></TT
> from <TT
CLASS="PARAMETER"
><I
>v</I
></TT
> and returns
true if the result is zero, or false for all
other cases. Note that the guaranteed
useful range of an atomic_t is only 24 bits.
</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="r172.html"
ACCESSKEY="P"
><<< Previous</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="book1.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="r242.html"
ACCESSKEY="N"
>Next >>></A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><SPAN
CLASS="phrase"
><SPAN
CLASS="PHRASE"
>atomic_sub</SPAN
></SPAN
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="x73.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><SPAN
CLASS="phrase"
><SPAN
CLASS="PHRASE"
>atomic_inc</SPAN
></SPAN
></TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
