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Diffstat (limited to 'nuttx/sched/sched_reprioritize.c')
-rw-r--r-- | nuttx/sched/sched_reprioritize.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/nuttx/sched/sched_reprioritize.c b/nuttx/sched/sched_reprioritize.c new file mode 100644 index 000000000..bd316ec75 --- /dev/null +++ b/nuttx/sched/sched_reprioritize.c @@ -0,0 +1,129 @@ +/**************************************************************************** + * sched/sched_reprioritize.c + * + * Copyright (C) 2009, 2012 Gregory Nutt. All rights reserved. + * 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 + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <stdint.h> +#include <sched.h> +#include <errno.h> + +#include "os_internal.h" + +#ifdef CONFIG_PRIORITY_INHERITANCE + +/**************************************************************************** + * Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Type Declarations + ****************************************************************************/ + +/**************************************************************************** + * Global Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: sched_reprioritize + * + * 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. + * + * 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. + * + * 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. + * + * Assumptions: + * + ****************************************************************************/ + +int sched_reprioritize(FAR _TCB *tcb, int sched_priority) +{ + /* This function is equivalent to sched_setpriority() BUT it also has the + * side effect of discarding all priority inheritance history. This is + * done only on explicit, user-initiated reprioritization. + */ + + int ret = sched_setpriority(tcb, sched_priority); + if (ret == 0) + { + /* Reset the base_priority -- the priority that the thread would return + * to once it posts the semaphore. + */ + + tcb->base_priority = (uint8_t)sched_priority; + + /* Discard any pending reprioritizations as well */ + +#if CONFIG_SEM_NNESTPRIO > 0 + tcb->npend_reprio = 0; +#endif + } + return ret; +} +#endif /* CONFIG_PRIORITY_INHERITANCE */ |