pthread_attr_getdetachstate - Man Page

get and set the detachstate attribute

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.

Synopsis

#include <pthread.h>

int pthread_attr_getdetachstate(const pthread_attr_t *attr,
    int *detachstate);
int pthread_attr_setdetachstate(pthread_attr_t *attr, int detachstate);

Description

The detachstate attribute controls whether the thread is created in a detached state. If the thread is created detached, then use of the ID of the newly created thread by the pthread_detach() or pthread_join() function is an error.

The pthread_attr_getdetachstate() and pthread_attr_setdetachstate() functions, respectively, shall get and set the detachstate attribute in the attr object.

For pthread_attr_getdetachstate(), detachstate shall be set to either PTHREAD_CREATE_DETACHED or PTHREAD_CREATE_JOINABLE.

For pthread_attr_setdetachstate(), the application shall set detachstate to either PTHREAD_CREATE_DETACHED or PTHREAD_CREATE_JOINABLE.

A value of PTHREAD_CREATE_DETACHED shall cause all threads created with attr to be in the detached state, whereas using a value of PTHREAD_CREATE_JOINABLE shall cause all threads created with attr to be in the joinable state. The default value of the detachstate attribute shall be PTHREAD_CREATE_JOINABLE.

The behavior is undefined if the value specified by the attr argument to pthread_attr_getdetachstate() or pthread_attr_setdetachstate() does not refer to an initialized thread attributes object.

Return Value

Upon successful completion, pthread_attr_getdetachstate() and pthread_attr_setdetachstate() shall return a value of 0; otherwise, an error number shall be returned to indicate the error.

The pthread_attr_getdetachstate() function stores the value of the detachstate attribute in detachstate if successful.

Errors

The pthread_attr_setdetachstate() function shall fail if:

EINVAL: The value of detachstate was not valid

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

The following sections are informative.

Examples

Retrieving the detachstate Attribute

This example shows how to obtain the detachstate attribute of a thread attribute object.

#include <pthread.h>

pthread_attr_t thread_attr;
int            detachstate;
int            rc;

/* code initializing thread_attr */
...

rc = pthread_attr_getdetachstate (&thread_attr, &detachstate);
if (rc!=0) {
    /* handle error */
    ...
}
else {
    /* legal values for detachstate are:
     * PTHREAD_CREATE_DETACHED or PTHREAD_CREATE_JOINABLE
     */
     ...
}

Application Usage

None.

Rationale

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

Future Directions

None.

Copyright

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. 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.opengroup.org/unix/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 .

Referenced By

pthread_attr_destroy(3p), pthread_attr_getstack(3p), pthread_attr_getstacksize(3p), pthread.h(0p).

2017 IEEE/The Open Group POSIX Programmer's Manual