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.TH PTHREAD_MUTEXATTR_GETPSHARED "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual"

.SH PROLOG

This manual page is part of the POSIX Programmer's Manual.

The Linux implementation of this interface may differ (consult

the corresponding Linux manual page for details of Linux behavior),

or the interface may not be implemented on Linux.

.SH NAME

pthread_mutexattr_getpshared,

pthread_mutexattr_setpshared

\(em get and set the process-shared attribute

.SH SYNOPSIS

.LP

.nf

#include <pthread.h>

.P

int pthread_mutexattr_getpshared(const pthread_mutexattr_t

    *restrict \fIattr\fP, int *restrict \fIpshared\fP);

int pthread_mutexattr_setpshared(pthread_mutexattr_t *\fIattr\fP,

    int \fIpshared\fP);

.fi

.SH DESCRIPTION

The

\fIpthread_mutexattr_getpshared\fR()

function shall obtain the value of the

.IR process-shared

attribute from the attributes object referenced by

.IR attr .

.P

The

\fIpthread_mutexattr_setpshared\fR()

function shall set the

.IR process-shared

attribute in an initialized attributes object referenced by

.IR attr .

.P

The

.IR process-shared

attribute is set to PTHREAD_PROCESS_SHARED to permit a mutex

to be operated upon by any thread that has access to the memory where

the mutex is allocated, even if the mutex is allocated in memory that

is shared by multiple processes. If the

.IR process-shared

attribute is PTHREAD_PROCESS_PRIVATE, the mutex shall only be operated

upon by threads created within the same process as the thread that

initialized the mutex; if threads of differing processes attempt to

operate on such a mutex, the behavior is undefined. The default value

of the attribute shall be PTHREAD_PROCESS_PRIVATE.

.P

The behavior is undefined if the value specified by the

.IR attr

argument to

\fIpthread_mutexattr_getpshared\fR()

or

\fIpthread_mutexattr_setpshared\fR()

does not refer to an initialized mutex attributes object.

.SH "RETURN VALUE"

Upon successful completion,

\fIpthread_mutexattr_setpshared\fR()

shall return zero; otherwise, an error number shall be returned to

indicate the error.

.P

Upon successful completion,

\fIpthread_mutexattr_getpshared\fR()

shall return zero and store the value of the

.IR process-shared

attribute of

.IR attr

into the object referenced by the

.IR pshared

parameter. Otherwise, an error number shall be returned to indicate

the error.

.SH ERRORS

The

\fIpthread_mutexattr_setpshared\fR()

function may fail if:

.TP

.BR EINVAL

The new value specified for the attribute is outside the range of legal

values for that attribute.

.P

These functions shall not return an error code of

.BR [EINTR] .

.LP

.IR "The following sections are informative."

.SH EXAMPLES

None.

.SH "APPLICATION USAGE"

None.

.SH RATIONALE

If an implementation detects that the value specified by the

.IR attr

argument to

\fIpthread_mutexattr_getpshared\fR()

or

\fIpthread_mutexattr_setpshared\fR()

does not refer to an initialized mutex attributes object, it is

recommended that the function should fail and report an

.BR [EINVAL] 

error.

.SH "FUTURE DIRECTIONS"

None.

.SH "SEE ALSO"

.ad l

.IR "\fIpthread_cond_destroy\fR\^(\|)",

.IR "\fIpthread_create\fR\^(\|)",

.IR "\fIpthread_mutex_destroy\fR\^(\|)",

.IR "\fIpthread_mutexattr_destroy\fR\^(\|)"

.ad b

.P

The Base Definitions volume of POSIX.1\(hy2008,

.IR "\fB<pthread.h>\fP"

.SH COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form

from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology

-- Portable Operating System Interface (POSIX), The Open Group Base

Specifications Issue 7, Copyright (C) 2013 by the Institute of

Electrical and Electronics Engineers, Inc and The Open Group.

(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the

event of any discrepancy between this version and the original IEEE and

The Open Group Standard, the original IEEE and The Open Group Standard

is the referee document. The original Standard can be obtained online at

http://www.unix.org/online.html .

Any typographical or formatting errors that appear

in this page are most likely

to have been introduced during the conversion of the source files to

man page format. To report such errors, see

https://www.kernel.org/doc/man-pages/reporting_bugs.html .