PTHREAD_CONDATTR_GETPSHARED(3P)

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.

NAME
pthread_condattr_getpshared, pthread_condattr_setpshared — get and set the process-shared condition variable attributes

SYNOPSIS

#include <pthread.h>

int pthread_condattr_getpshared(const pthread_condattr_t *restrict attr,
    int *restrict pshared);
int pthread_condattr_setpshared(pthread_condattr_t *attr,
    int pshared);

DESCRIPTION
The pthread_condattr_getpshared() function shall obtain the value of the process-shared attribute from the attributes object referenced by attr.

The pthread_condattr_setpshared() function shall set the process-shared attribute in an initialized attributes object referenced by attr.

The process-shared attribute is set to PTHREAD_PROCESS_SHARED to permit a condition variable to be operated upon by any thread that has access to the memory where the condition variable is allocated, even if the condition variable is allocated in memory that is shared by multiple processes. If the process-shared attribute is PTHREAD_PROCESS_PRIVATE, the condition variable shall only be operated upon by threads created within the same process as the thread that initialized the condition variable; if threads of differing processes attempt to operate on such a condition variable, the behavior is undefined. The default value of the attribute is PTHREAD_PROCESS_PRIVATE.

The behavior is undefined if the value specified by the attr argument to pthread_condattr_getpshared() or pthread_condattr_setpshared() does not refer to an initialized condition variable attributes object.

RETURN VALUE
If successful, the pthread_condattr_setpshared() function shall return zero; otherwise, an error number shall be returned to indicate the error.

If successful, the pthread_condattr_getpshared() function shall return zero and store the value of the process-shared attribute of attr into the object referenced by the pshared parameter. Otherwise, an error number shall be returned to indicate the error.

ERRORS
The pthread_condattr_setpshared() function may fail if:

EINVAL
    The new value specified for the attribute is outside the range of legal values for that attribute.

These functions shall not return an error code of [EINTR].

The following sections are informative.

EXAMPLES
None.

APPLICATION USAGE
None.

RATIONALE
If an implementation detects that the value specified by the attr argument to pthread_condattr_getpshared() or pthread_condattr_setpshared() does not refer to an initialized condition variable attributes object, it is recommended that the function should fail and report an [EINVAL] error.

FUTURE DIRECTIONS
None.

SEE ALSO
pthread_create(), pthread_cond_destroy(), pthread_condattr_destroy(), pthread_mutex_destroy()

The Base Definitions volume of POSIX.1-2008, <pthread.h>

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 .