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Diffstat (limited to 'nuttx/sched/sched_removereadytorun.c')
-rw-r--r-- | nuttx/sched/sched_removereadytorun.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/nuttx/sched/sched_removereadytorun.c b/nuttx/sched/sched_removereadytorun.c new file mode 100644 index 000000000..4982808e2 --- /dev/null +++ b/nuttx/sched/sched_removereadytorun.c @@ -0,0 +1,121 @@ +/**************************************************************************** + * shced/sched_removereadytorun.c + * + * Copyright (C) 2007-2009, 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 <stdbool.h> +#include <queue.h> +#include <assert.h> + +#include "os_internal.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Type Declarations + ****************************************************************************/ + +/**************************************************************************** + * Global Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: sched_removereadytorun + * + * Description: + * This function removes a TCB from the ready to run list. + * + * Inputs: + * rtcb - Points to the TCB that is ready-to-run + * + * Return Value: + * true if the currently active task (the head of the + * g_readytorun list) has changed. + * + * Assumptions: + * - The caller has established a critical section before calling this + * function (calling sched_lock() first is NOT a good idea -- use irqsave()). + * - The caller handles the condition that occurs if the + * the head of the g_readytorun list is changed. + * + ****************************************************************************/ + +bool sched_removereadytorun(FAR _TCB *rtcb) +{ + bool ret = false; + + /* Check if the TCB to be removed is at the head of the ready to run list. + * In this case, we are removing the currently active task. + */ + + if (!rtcb->blink) + { + /* There must always be at least one task in the list (the idle task) */ + + ASSERT(rtcb->flink != NULL); + + /* Inform the instrumentation layer that we are switching tasks */ + + sched_note_switch(rtcb, rtcb->flink); + + rtcb->flink->task_state = TSTATE_TASK_RUNNING; + ret = true; + } + + /* Remove the TCB from the ready-to-run list */ + + dq_rem((FAR dq_entry_t*)rtcb, (dq_queue_t*)&g_readytorun); + + rtcb->task_state = TSTATE_TASK_INVALID; + return ret; +} |