PTHREAD_ATTR_GETSCHEDPOLICY(3) Library Functions Manual PTHREAD_ATTR_GETSCHEDPOLICY(3)

pthread_attr_getschedpolicy pthread_attr_setschedpolicy — get and set the schedpolicy attribute (REALTIME THREADS)


#include <pthread.h>

int pthread_attr_getschedpolicy(const pthread_attr_t *restrict attr,
       int *restrict policy);
int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy);

The pthread_attr_getschedpolicy () and pthread_attr_setschedpolicy () functions, respectively, shall get and set the attribute in the attr argument.

The supported values of shall include SCHED_FIFO, SCHED_RR, and SCHED_OTHER, which are defined in the <sched.h> header. When threads executing with the scheduling policy SCHED_FIFO, SCHED_RR, or SCHED_SPORADIC are waiting on a mutex, they shall acquire the mutex in priority order when the mutex is unlocked.

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

The pthread_attr_getschedpolicy () function may fail if:

The value specified by attr does not refer to an initialized thread attribute object.

The pthread_attr_setschedpolicy () function may fail if:

The value of policy is not valid, or the value specified by attr does not refer to an initialized thread attribute object.
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 xsh_chap02_09(3) for further details on thread scheduling attributes and their default settings.

None.

None.

pthread_attr_destroy(3), pthread_attr_getscope(3), pthread_attr_getinheritsched(3), pthread_attr_getschedparam(3), pthread_create(3), the Base Definitions volume of IEEE Std 1003.1-2001 (“POSIX.1”), <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_getschedpolicy () and pthread_attr_setschedpolicy () 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 SCHED_SPORADIC scheduling policy is added for alignment with IEEE Std 1003.1d-1999.

The keyword is added to the pthread_attr_getschedpolicy () 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/D6/79 is applied, adding a reference to xsh_chap02_09(3) in the APPLICATION USAGE section.

IEEE Std 1003.1-2001 (“POSIX.1”)/Cor 2-2004, item XSH/TC2/D6/80 is applied, updating the ERRORS section to include optional errors for the case when attr refers to an uninitialized thread attribute object.

footer end

January 1, 2004 posix.fail