diff options
Diffstat (limited to 'cpukit/score/include/rtems/score/priority.h')
| -rw-r--r-- | cpukit/score/include/rtems/score/priority.h | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/cpukit/score/include/rtems/score/priority.h b/cpukit/score/include/rtems/score/priority.h index 9cc6338288..7a8ddba763 100644 --- a/cpukit/score/include/rtems/score/priority.h +++ b/cpukit/score/include/rtems/score/priority.h @@ -8,7 +8,7 @@ * COPYRIGHT (c) 1989-2011. * On-Line Applications Research Corporation (OAR). * - * Copyright (c) 2016 embedded brains GmbH. + * Copyright (c) 2016, 2017 embedded brains GmbH. * * The license and distribution terms for this file may be * found in the file LICENSE in this distribution or at @@ -45,11 +45,23 @@ extern "C" { */ /** - * @brief A plain thread priority value. + * @brief The thread priority control. * * Lower values represent higher priorities. So, a priority value of zero * represents the highest priority thread. This value is reserved for internal * threads and the priority ceiling protocol. + * + * The format of the thread priority control depends on the context. A thread + * priority control may contain a user visible priority for API import/export. + * It may also contain a scheduler internal priority value. Values are + * translated via the scheduler map/unmap priority operations. The format of + * scheduler interal values depend on the particular scheduler implementation. + * It may for example encode a deadline in case of the EDF scheduler. + * + * The thread priority control value contained in the scheduler node + * (Scheduler_Node::Priority::value) uses the least-significant bit to indicate + * if the thread should be appended or prepended to its priority group, see + * SCHEDULER_PRIORITY_APPEND(). */ typedef uint64_t Priority_Control; |