Originální popis anglicky:
pthread_setschedprio - dynamic thread scheduling parameters access (
REALTIME
THREADS)
Návod, kniha: POSIX Programmer's Manual
#include <pthread.h>
int pthread_setschedprio(pthread_t
thread, int
prio);
The
pthread_setschedprio() function shall set the scheduling priority for
the thread whose thread ID is given by
thread to the value given by
prio. See
Scheduling Policies for a description on how this
function call affects the ordering of the thread in the thread list for its
new priority.
If the
pthread_setschedprio() function fails, the scheduling priority of
the target thread shall not be changed.
If successful, the
pthread_setschedprio() function shall return zero;
otherwise, an error number shall be returned to indicate the error.
The
pthread_setschedprio() function may fail if:
- EINVAL
- The value of prio is invalid for the scheduling
policy of the specified thread.
- ENOTSUP
- An attempt was made to set the priority to an unsupported
value.
- EPERM
- The caller does not have the appropriate permission to set
the scheduling policy of the specified thread.
- EPERM
- The implementation does not allow the application to modify
the priority to the value specified.
- ESRCH
- The value specified by thread does not refer to an
existing thread.
The
pthread_setschedprio() function shall not return an error code of
[EINTR].
The following sections are informative.
None.
None.
The
pthread_setschedprio() function provides a way for an application to
temporarily raise its priority and then lower it again, without having the
undesired side effect of yielding to other threads of the same priority. This
is necessary if the application is to implement its own strategies for
bounding priority inversion, such as priority inheritance or priority
ceilings. This capability is especially important if the implementation does
not support the Thread Priority Protection or Thread Priority Inheritance
options, but even if those options are supported it is needed if the
application is to bound priority inheritance for other resources, such as
semaphores.
The standard developers considered that while it might be preferable
conceptually to solve this problem by modifying the specification of
pthread_setschedparam(), it was too late to make such a change, as
there may be implementations that would need to be changed. Therefore, this
new function was introduced.
None.
Scheduling Policies ,
pthread_getschedparam() , the Base
Definitions volume of IEEE Std 1003.1-2001,
<pthread.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html
.
