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pthread_attr_init

Section: C Library Functions (3)
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NAME

pthread_attr_init - Initializes a thread attributes object.  

LIBRARY

DECthreads POSIX 1003.1c Library (libpthread.so)  

SYNOPSIS

#include <pthread.h>

int pthread_attr_init(
                 pthread_attr_t   *attr,);  

STANDARDS

Interfaces documented on this reference page conform to industry standards as follows:

IEEE Std 1003.1c-1995, POSIX System Application Program Interface  

PARAMETERS

Address of a thread attributes object to be initialized.  

DESCRIPTION

This routine initializes the thread attributes object specified by the attr argument with a set of default attribute values. A thread attributes object is used to specify the attributes of one or more threads when they are created. The attributes object created by this routine is used only in calls to the pthread_create(3) routine.

The following routines change individual attributes of an initialized thread attributes object: pthread_attr_setdetachstate pthread_attr_setguardsize_np pthread_attr_setinheritsched pthread_attr_setschedparam pthread_attr_setschedpolicy pthread_attr_setscope pthread_attr_setstackaddr pthread_attr_setstacksize

The attributes of the thread attributes object are initialized to default values. The default value of each attribute is discussed in the reference description for each routine listed above.

When a thread attributes object is used to create a thread, the object's attribute values determine the characteristics of the new thread. Thus, attributes objects act as additional arguments to thread creation. Changing the attributes of a thread attributes object does not affect any threads that were previously created using that attributes object.

You can use the same thread attributes object in successive calls to pthread_create(3), from any thread. (However, you cannot use the same value of the stack address attribute to create multiple threads that might run concurrently; threads cannot share a stack.) If more than one thread might change the attributes in a shared attributes object, your program must use a mutex to protect the integrity of the attributes object's contents.

When you set the scheduling policy or scheduling parameters, or both, in a thread attributes object, you must disable scheduling inheritance if you want the scheduling attributes you set to be used at thread creation. To disable scheduling inheritance, before creating the new thread use the pthread_attr_setinheritsched routine to specify the value PTHREAD_EXPLICIT_SCHED for the inherit argument.

 

RETURN VALUES

If an error condition occurs, the thread attributes object cannot be used, and this routine returns an integer value indicating the type of error. Possible return values are as follows: Successful completion. The value specified by attr is invalid. Insufficient memory exists to initialize the thread attributes object.  

ERRORS

None  

RELATED INFORMATION

Functions: pthread_attr_destroy(3), pthread_attr_setdetachstate(3), pthread_attr_setguardsize(3), pthread_attr_setinheritsched(3), pthread_attr_setschedparam(3), pthread_attr_setschedpolicy(3), pthread_attr_setscope(3), pthread_attr_setstackaddr(3), pthread_attr_setstacksize(3), pthread_create(3)

Manuals: Guide to DECthreads and Programmer's Guide

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Index

NAME
LIBRARY
SYNOPSIS
STANDARDS
PARAMETERS
DESCRIPTION
RETURN VALUES
ERRORS
RELATED INFORMATION

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Time: 02:41:33 GMT, October 02, 2010