PTHREAD_ATTR_GETSCOPE(3) Library Functions Manual PTHREAD_ATTR_GETSCOPE(3)

pthread_attr_getscope pthread_attr_setscope — get and set the contentionscope attribute (REALTIME THREADS)


#include <pthread.h>

int pthread_attr_getscope(const pthread_attr_t *restrict attr,
       int *restrict contentionscope);
int pthread_attr_setscope(pthread_attr_t *attr, int contentionscope);

The pthread_attr_getscope () and pthread_attr_setscope () functions, respectively, shall get and set the contentionscope attribute in the attr object.

The contentionscope attribute may have the values PTHREAD_SCOPE_SYSTEM, signifying system scheduling contention scope, or PTHREAD_SCOPE_PROCESS, signifying process scheduling contention scope. The symbols PTHREAD_SCOPE_SYSTEM and PTHREAD_SCOPE_PROCESS are defined in the <pthread.h> header.

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

If successful, the pthread_attr_getscope () and pthread_attr_setscope () functions shall return zero; otherwise, an error number shall be returned to indicate the error.

The pthread_attr_setscope () function may fail if:

The value of contentionscope is not valid.
An attempt was made to set the attribute to an unsupported value.

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

None.

After these attributes have been set, a thread can be created with the specified attributes using pthread_create(3). Using these routines does not affect the current running thread.

See V2_chap02(3) for further details on thread scheduling attributes and their default settings.

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

None.

pthread_attr_destroy(3) , pthread_attr_getinheritsched(3) , pthread_attr_getschedpolicy(3) , pthread_attr_getschedparam(3) , pthread_create(3)

XBD <pthread.h> , <sched.h>

First released in Issue 5. Included for alignment with the POSIX Threads Extension.

Marked as part of the Realtime Threads Feature Group.

The pthread_attr_getscope () and pthread_attr_setscope () functions are marked as part of the Threads and Thread Execution Scheduling options.

The [ENOSYS] error condition has been removed as stubs need not be provided if an implementation does not support the Thread Execution Scheduling option.

The keyword is added to the pthread_attr_getscope () prototype for alignment with the ISO/IEC 9899:1999 (“ISO C99”) standard.

IEEE Std 1003.1-2001 (“POSIX.1”)/Cor 2-2004, item XSH/TC2/D6/81 is applied, adding a reference to V2_chap02(3) in the APPLICATION USAGE section.

IEEE Std 1003.1-2001 (“POSIX.1”)/Cor 2-2004, item XSH/TC2/D6/82 is applied, updating the ERRORS section to include optional errors for the case when attr refers to an uninitialized thread attribute object.

The pthread_attr_getscope () and pthread_attr_setscope () functions are moved from the Threads option.

The [EINVAL] error for an uninitialized thread attributes object is removed; this condition results in undefined behavior.

January 1, 2008 posix.fail