.\"Generated by db2man.xsl. Don't modify this, modify the source.
.de Sh \" Subsection
.br
.if t .Sp
.ne 5
.PP
\fB\\$1\fR
.PP
..
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Ip \" List item
.br
.ie \\n(.$>=3 .ne \\$3
.el .ne 3
.IP "\\$1" \\$2
..
.TH "__TEST_AND_CLEAR_B" 9 "August 2005" "Kernel Hackers Manual" "LINUX"
.SH NAME
__test_and_clear_bit \- Clear a bit and return its old value
.SH "SYNOPSIS"
.ad l
.hy 0
.HP 28
int\ \fB__test_and_clear_bit\ \fR\ (int\ \fInr\fR, volatile\ unsigned\ long\ *\ \fIaddr\fR);
.ad
.hy

.SH "ARGUMENTS"

.TP
\fInr\fR
Bit to clear

.TP
\fIaddr\fR
Address to count from

.SH "DESCRIPTION"

.PP
This operation is non\-atomic and can be reordered\&. If two examples of this operation race, one can appear to succeed but actually fail\&. You must protect multiple accesses with a lock\&.