pthread_attr_getschedpolicy, pthread_attr_setschedpolicy - get and set the schedpolicy attribute (REALTIME THREADS)
[THR TPS] #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 schedpolicy attribute in the attr argument.
The supported values of policy 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, [TSP] 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].
After these attributes have been set, a thread can be created with the specified attributes using pthread_create(). Using these routines does not affect the current running thread.
See Thread Scheduling for further details on thread scheduling attributes and their default settings.
pthread_attr_destroy(), pthread_attr_getscope(), pthread_attr_getinheritsched(), pthread_attr_getschedparam(), pthread_create(), the Base Definitions volume of IEEE Std 1003.1-2001, <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 restrict keyword is added to the pthread_attr_getschedpolicy() prototype for alignment with the ISO/IEC 9899:1999 standard.
IEEE Std 1003.1-2001/Cor 2-2004, item XSH/TC2/D6/79 is applied, adding a reference to Thread Scheduling in the APPLICATION USAGE section.
IEEE Std 1003.1-2001/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.