diff options
Diffstat (limited to 'nuttx/sched/sched_setpriority.c')
| -rw-r--r-- | nuttx/sched/sched_setpriority.c | 115 |
1 files changed, 58 insertions, 57 deletions
diff --git a/nuttx/sched/sched_setpriority.c b/nuttx/sched/sched_setpriority.c index c5b7839aa..6aa0789ea 100644 --- a/nuttx/sched/sched_setpriority.c +++ b/nuttx/sched/sched_setpriority.c @@ -2,7 +2,7 @@ * sched/sched_setpriority.c * * Copyright (C) 2009 Gregory Nutt. All rights reserved. - * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * Author: Gregory Nutt <gnutt@nuttx.org> * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -80,20 +80,20 @@ * Description: * This function sets the priority of a specified task. * - * NOTE: Setting a task's priority to the same value has a similar - * effect to sched_yield() -- The task will be moved to after all other - * tasks with the same priority. + * NOTE: Setting a task's priority to the same value has a similar effect + * to sched_yield() -- The task will be moved to after all other tasks + * with the same priority. * * Inputs: * tcb - the TCB of task to reprioritize. * sched_priority - The new task priority * * Return Value: - * On success, sched_setparam() returns 0 (OK). On error, -1 - * (ERROR) is returned, and errno is set appropriately. + * On success, sched_setparam() returns 0 (OK). On error, -1 (ERROR) is + * returned, and errno is set appropriately. * - * EINVAL The parameter 'param' is invalid or does not make - * sense for the current scheduling policy. + * EINVAL The parameter 'param' is invalid or does not make sense for the + * current scheduling policy. * EPERM The calling task does not have appropriate privileges. * ESRCH The task whose ID is pid could not be found. * @@ -127,76 +127,77 @@ int sched_setpriority(FAR _TCB *tcb, int sched_priority) task_state = tcb->task_state; switch (task_state) { - /* CASE 1. The task is running or ready-to-run and a context switch - * may be caused by the re-prioritization - */ + /* CASE 1. The task is running or ready-to-run and a context switch + * may be caused by the re-prioritization + */ - case TSTATE_TASK_RUNNING: + case TSTATE_TASK_RUNNING: - /* A context switch will occur if the new priority of the running - * task becomes less than OR EQUAL TO the next highest priority - * ready to run task. - */ + /* A context switch will occur if the new priority of the running + * task becomes less than OR EQUAL TO the next highest priority + * ready to run task. + */ - if (sched_priority <= tcb->flink->sched_priority) - { - /* A context switch will occur. */ + if (sched_priority <= tcb->flink->sched_priority) + { + /* A context switch will occur. */ - up_reprioritize_rtr(tcb, (uint8_t)sched_priority); - } + up_reprioritize_rtr(tcb, (uint8_t)sched_priority); + } - /* Otherwise, we can just change priority since it has no effect */ + /* Otherwise, we can just change priority since it has no effect */ - else - { - /* Change the task priority */ + else + { + /* Change the task priority */ - tcb->sched_priority = (uint8_t)sched_priority; - } - break; + tcb->sched_priority = (uint8_t)sched_priority; + } + break; - /* CASE 2. The task is running or ready-to-run and a context switch - * may be caused by the re-prioritization - */ + /* CASE 2. The task is running or ready-to-run and a context switch + * may be caused by the re-prioritization + */ - case TSTATE_TASK_READYTORUN: + case TSTATE_TASK_READYTORUN: - /* A context switch will occur if the new priority of the ready-to - * run task is (strictly) greater than the current running task - */ + /* A context switch will occur if the new priority of the ready-to + * run task is (strictly) greater than the current running task + */ - if (sched_priority > rtcb->sched_priority) - { - /* A context switch will occur. */ + if (sched_priority > rtcb->sched_priority) + { + /* A context switch will occur. */ - up_reprioritize_rtr(tcb, (uint8_t)sched_priority); - } + up_reprioritize_rtr(tcb, (uint8_t)sched_priority); + } + + /* Otherwise, we can just change priority and re-schedule (since it + * have no other effect). + */ - /* Otherwise, we can just change priority and re-schedule (since it - * have no other effect). - */ + else + { + /* Remove the TCB from the ready-to-run task list */ - else - { - /* Remove the TCB from the ready-to-run task list */ + ASSERT(!sched_removereadytorun(tcb)); - ASSERT(!sched_removereadytorun(tcb)); + /* Change the task priority */ - /* Change the task priority */ + tcb->sched_priority = (uint8_t)sched_priority; - tcb->sched_priority = (uint8_t)sched_priority; + /* Put it back into the ready-to-run task list */ - /* Put it back into the ready-to-run task list */ + ASSERT(!sched_addreadytorun(tcb)); + } + break; - ASSERT(!sched_addreadytorun(tcb)); - } - break; + /* CASE 3. The task is not in the ready to run list. Changing its + * Priority cannot effect the currently executing task. + */ - /* CASE 3. The task is not in the ready to run list. Changing its - * Priority cannot effect the currently executing task. - */ + default: - default: /* CASE 3a. The task resides in a prioritized list. */ if (g_tasklisttable[task_state].prioritized) |