diff options
Diffstat (limited to 'nuttx/sched/sched_getparam.c')
-rw-r--r-- | nuttx/sched/sched_getparam.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/nuttx/sched/sched_getparam.c b/nuttx/sched/sched_getparam.c new file mode 100644 index 000000000..47eab4988 --- /dev/null +++ b/nuttx/sched/sched_getparam.c @@ -0,0 +1,146 @@ +/************************************************************************ + * sched/sched_getparam.c + * + * Copyright (C) 2007, 2009 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 <sys/types.h> +#include <sched.h> + +#include "os_internal.h" + +/************************************************************************ + * Definitions + ************************************************************************/ + +/************************************************************************ + * Private Type Declarations + ************************************************************************/ + +/************************************************************************ + * Global Variables + ************************************************************************/ + +/************************************************************************ + * Private Variables + ************************************************************************/ + +/************************************************************************ + * Private Function Prototypes + ************************************************************************/ + +/************************************************************************ + * Private Functions + ************************************************************************/ + +/************************************************************************ + * Public Functions + ************************************************************************/ + +/************************************************************************ + * Name: sched_getparam + * + * Description: + * This function gets the scheduling priority of the task + * specified by pid. + * + * Inputs: + * pid - the task ID of the task. If pid is zero, the priority + * of the calling task is returned. + * param - A structure whose member sched_priority is the integer + * priority. The task's priority is copied to the sched_priority + * element of this structure. + * + * Return Value: + * 0 (OK) if successful, otherwise -1 (ERROR). + * + * This function can fail if param is null or if pid does + * not correspond to any task. + * + * Assumptions: + * + ************************************************************************/ + +int sched_getparam (pid_t pid, struct sched_param * param) +{ + FAR _TCB *rtcb; + FAR _TCB *tcb; + int ret = OK; + + if (!param) + { + return ERROR; + } + + /* Check if the task to restart is the calling task */ + + rtcb = (FAR _TCB*)g_readytorun.head; + if ((pid == 0) || (pid == rtcb->pid)) + { + /* Return the priority if the calling task. */ + + param->sched_priority = (int)rtcb->sched_priority; + } + + /* Ths pid is not for the calling task, we will have to look it up */ + + else + { + /* Get the TCB associated with this pid */ + + sched_lock(); + tcb = sched_gettcb(pid); + if (!tcb) + { + /* This pid does not correspond to any known task */ + + ret = ERROR; + } + else + { + /* Return the priority of the task */ + + param->sched_priority = (int)tcb->sched_priority; + } + + sched_unlock(); + } + + return ret; +} + |