.\" Copyright (c) 2017, Michael Kerrisk .\" .\" %%%LICENSE_START(VERBATIM) .\" Permission is granted to make and distribute verbatim copies of this .\" manual provided the copyright notice and this permission notice are .\" preserved on all copies. .\" .\" Permission is granted to copy and distribute modified versions of this .\" manual under the conditions for verbatim copying, provided that the .\" entire resulting derived work is distributed under the terms of a .\" permission notice identical to this one. .\" .\" Since the Linux kernel and libraries are constantly changing, this .\" manual page may be incorrect or out-of-date. The author(s) assume no .\" responsibility for errors or omissions, or for damages resulting from .\" the use of the information contained herein. The author(s) may not .\" have taken the same level of care in the production of this manual, .\" which is licensed free of charge, as they might when working .\" professionally. .\" .\" Formatted or processed versions of this manual, if unaccompanied by .\" the source, must acknowledge the copyright and authors of this work. .\" %%%LICENSE_END .\" .TH PTHREAD_MUTEXATTR_GETPSHARED 3 2017-09-13 "Linux" "Linux Programmer's Manual" .SH NAME pthread_mutexattr_getpshared, pthread_mutexattr_setpshared \- get/set process-shared mutex attribute .SH SYNOPSIS .nf .B #include .PP .BI "int pthread_mutexattr_getpshared(const pthread_mutexattr_t *" attr , .BI " int *" pshared ); .BI "int pthread_mutexattr_setpshared(pthread_mutexattr_t *" attr , .BI " int " pshared ); .fi .PP Compile and link with \fI\-pthread\fP. .SH DESCRIPTION These functions get and set the process-shared attribute in a mutex attributes object. This attribute must be appropriately set to ensure correct, efficient operation of a mutex created using this attributes object. .PP The process-shared attribute can have one of the following values: .TP .B PTHREAD_PROCESS_PRIVATE Mutexes created with this attributes object are to be shared only among threads in the same process that initialized the mutex. This is the default value for the process-shared mutex attribute. .TP .B PTHREAD_PROCESS_SHARED Mutexes created with this attributes object can be shared between any threads that have access to the memory containing the object, including threads in different processes. .PP .BR pthread_mutexattr_getpshared () places the value of the process-shared attribute of the mutex attributes object referred to by .IR attr in the location pointed to by .IR pshared . .PP .BR pthread_mutexattr_setpshared () sets the value of the process-shared attribute of the mutex attributes object referred to by .IR attr to the value specified in .BR pshared . .PP If .I attr does not refer to an initialized mutex attributes object, the behavior is undefined. .SH RETURN VALUE On success, these functions return 0. On error, they return a positive error number. .SH ERRORS .BR pthread_mutexattr_setpshared () can fail with the following errors: .TP .B EINVAL The value specified in .I pshared is invalid. .TP .B ENOTSUP .I pshared is .BR PTHREAD_PROCESS_SHARED but the implementation does not support process-shared mutexes. .SH CONFORMING TO POSIX.1-2001, POSIX.1-2008. .SH SEE ALSO .ad l .nh .BR pthread_mutexattr_init (3), .BR pthreads (7) .SH COLOPHON This page is part of release 5.10 of the Linux .I man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at \%https://www.kernel.org/doc/man\-pages/.