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Diffstat (limited to 'nuttx/arch/c5471/src/up_unblocktask.c')
| -rw-r--r-- | nuttx/arch/c5471/src/up_unblocktask.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/nuttx/arch/c5471/src/up_unblocktask.c b/nuttx/arch/c5471/src/up_unblocktask.c new file mode 100644 index 0000000000..98cc042baa --- /dev/null +++ b/nuttx/arch/c5471/src/up_unblocktask.c @@ -0,0 +1,160 @@ +/************************************************************ + * up_unblocktask.c + * + * Copyright (C) 2007 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * 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 Gregory Nutt 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 <debug.h> +#include <nuttx/arch.h> +#include "os_internal.h" +#include "up_internal.h" + +/************************************************************ + * Private Definitions + ************************************************************/ + +/************************************************************ + * Private Data + ************************************************************/ + +/************************************************************ + * Private Funtions + ************************************************************/ + +/************************************************************ + * Public Funtions + ************************************************************/ + +/************************************************************ + * Name: up_unblock_task + * + * Description: + * A task is currently in an inactive task list + * but has been prepped to execute. Move the TCB to the + * ready-to-run list, restore its context, and start execution. + * + * Inputs: + * tcb: Refers to the tcb to be unblocked. This tcb is + * in one of the waiting tasks lists. It must be moved to + * the ready-to-run list and, if it is the highest priority + * ready to run taks, executed. + * + ************************************************************/ + +void up_unblock_task(_TCB *tcb) +{ + /* Verify that the context switch can be performed */ + if ((tcb->task_state < FIRST_BLOCKED_STATE) || + (tcb->task_state > LAST_BLOCKED_STATE)) + { + PANIC(OSERR_BADUNBLOCKSTATE); + } + else + { + _TCB *rtcb = (_TCB*)g_readytorun.head; + + dbg("Unblocking TCB=%p\n", tcb); + + /* Remove the task from the blocked task list */ + + sched_removeblocked(tcb); + + /* Reset its timeslice. This is only meaningful for round + * robin tasks but it doesn't here to do it for everything + */ + +#if CONFIG_RR_INTERVAL > 0 + tcb->timeslice = CONFIG_RR_INTERVAL; +#endif + + /* Add the task in the correct location in the prioritized + * g_readytorun task list + */ + + if (sched_addreadytorun(tcb)) + { + /* The currently active task has changed! We need to do + * a context switch to the new task. + * + * Are we in an interrupt handler? + */ + + if (current_regs) + { + /* Yes, then we have to do things differently. + * Just copy the current_regs into the OLD rtcb. + */ + + up_copystate(rtcb->xcp.regs, current_regs); + + /* Restore the exception context of the rtcb at the (new) head + * of the g_readytorun task list. + */ + + rtcb = (_TCB*)g_readytorun.head; + dbg("New Active Task TCB=%p\n", rtcb); + + /* Then switch contexts */ + + up_copystate(current_regs, rtcb->xcp.regs); + } + + /* We are not in an interrupt andler. Copy the user C context + * into the TCB of the task that was previously active. if + * up_saveusercontext returns a non-zero value, then this is really the + * previously running task restarting! + */ + + else if (!up_saveusercontext(rtcb->xcp.regs)) + { + /* Restore the exception context of the new task that is ready to + * run (probably tcb). This is the new rtcb at the head of the + * g_readytorun task list. + */ + + rtcb = (_TCB*)g_readytorun.head; + dbg("New Active Task TCB=%p\n", rtcb); + + /* Then switch contexts */ + + up_fullcontextrestore(rtcb->xcp.regs); + } + } + } +} |