freebsd-dev/share/man/man3/pthread_rwlockattr_getpshared.3
Pedro F. Giffuni b6413b6db8 POSIX compliance improvements in the pthread(3) functions.
This basically adds makes use of the C99 restrict keyword, and also
adds some 'const's to four threading functions: pthread_mutexattr_gettype(),
pthread_mutexattr_getprioceiling(), pthread_mutexattr_getprotocol(), and
pthread_mutex_getprioceiling. The changes are in accordance to POSIX/SUSv4-2018.

Hinted by:	DragonFlyBSD

Relnotes:	yes
MFC after:	1 month
Differential Revision:	D16722
2018-08-18 01:05:38 +00:00

87 lines
2.8 KiB
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.\" Copyright (c) 1998 Alex Nash
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.Dd August 17, 2018
.Dt PTHREAD_RWLOCKATTR_GETPSHARED 3
.Os
.Sh NAME
.Nm pthread_rwlockattr_getpshared
.Nd get the process shared attribute
.Sh LIBRARY
.Lb libpthread
.Sh SYNOPSIS
.In pthread.h
.Ft int
.Fn pthread_rwlockattr_getpshared "const pthread_rwlockattr_t *restrict attr" "int *restrict pshared"
.Sh DESCRIPTION
The
.Fn pthread_rwlockattr_getpshared
function is used to get the process shared setting of a read/write
lock attribute object.
The setting is returned via
.Fa pshared ,
and may be one of two values:
.Bl -tag -width PTHREAD_PROCESS_PRIVATE
.It Dv PTHREAD_PROCESS_SHARED
Any thread of any process that has access to the memory where the
read/write lock resides can manipulate the lock.
.It Dv PTHREAD_PROCESS_PRIVATE
Only threads created within the same process as the thread that
initialized the read/write lock can manipulate the lock.
This is
the default value.
.El
.Sh RETURN VALUES
If successful, the
.Fn pthread_rwlockattr_getpshared
function will return zero.
Otherwise an error number will be returned
to indicate the error.
.Sh ERRORS
The
.Fn pthread_rwlockattr_getpshared
function may fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Fa attr
is invalid.
.El
.Sh SEE ALSO
.Xr pthread_rwlock_init 3 ,
.Xr pthread_rwlockattr_init 3 ,
.Xr pthread_rwlockattr_setpshared 3
.Sh STANDARDS
The
.Fn pthread_rwlockattr_getpshared
function is expected to conform to
.St -susv2 .
.Sh HISTORY
The
.Fn pthread_rwlockattr_getpshared
function first appeared in
.Fx 3.0 .