pthread_attr_init(3)pthread_attr_init(3)NAMEpthread_attr_init - Initializes a thread attributes object
pthread_attr_t *attr );
DECthreads POSIX 1003.1c Library (libpthread.so)
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
IEEE Std 1003.1c-1995, POSIX System Application Program Interface
Address of a thread attributes object to be initialized.
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_set‐
guardsize_np pthread_attr_setinheritsched pthread_attr_setschedparam
pthread_attr_setschedpolicy pthread_attr_setscope pthread_attr_set‐
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
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
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 cre‐
ation. 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.
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 not a valid thread attributes object.
Insufficient memory exists to initialize the thread attributes object.
Functions: pthread_attr_destroy(3), pthread_attr_setdetachstate(3),
Manuals: Guide to DECthreads and Programmer's Guide