pthread_attr_getdetachstate man page

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pthread_attr_getdetachstate, pthread_attr_setdetachstate — get and set the detachstate attribute

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
     */
     ...
}

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.

See Also

pthread_attr_destroy(), pthread_attr_getstacksize(), pthread_create()

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

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2013 IEEE/The Open Group POSIX Programmer's Manual