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Diffstat (limited to 'nuttx/arch/sim/src/up_reprioritizertr.c')
| -rw-r--r-- | nuttx/arch/sim/src/up_reprioritizertr.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/nuttx/arch/sim/src/up_reprioritizertr.c b/nuttx/arch/sim/src/up_reprioritizertr.c new file mode 100644 index 0000000000..d4d91a88e1 --- /dev/null +++ b/nuttx/arch/sim/src/up_reprioritizertr.c @@ -0,0 +1,169 @@ +/************************************************************ + * up_reprioritizertr.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_reprioritize_rtr + * + * Description: + * Called when the priority of a running or + * ready-to-run task changes and the reprioritization will + * cause a context switch. Two cases: + * + * 1) The priority of the currently running task drops and the next + * task in the ready to run list has priority. + * 2) An idle, ready to run task's priority has been raised above the + * the priority of the current, running task and it now has the + * priority. + * + * Inputs: + * tcb: The TCB of the task that has been reprioritized + * priority: The new task priority + * + ************************************************************/ + +void up_reprioritize_rtr(_TCB *tcb, ubyte priority) +{ + /* Verify that the caller is sane */ + + if (tcb->task_state < FIRST_READY_TO_RUN_STATE || + tcb->task_state > LAST_READY_TO_RUN_STATE || + priority < SCHED_PRIORITY_MIN || + priority > SCHED_PRIORITY_MAX) + { + PANIC(OSERR_BADREPRIORITIZESTATE); + } + else + { + _TCB *rtcb = (_TCB*)g_readytorun.head; + boolean switch_needed; + + dbg("TCB=%p PRI=%d\n", tcb, priority); + + /* Remove the tcb task from the ready-to-run list. + * sched_removereadytorun will return TRUE if we just + * remove the head of the ready to run list. + */ + + switch_needed = sched_removereadytorun(tcb); + + /* Setup up the new task priority */ + + tcb->sched_priority = (ubyte)priority; + + /* Return the task to the specified blocked task list. + * sched_addreadytorun will return TRUE if the task was + * added to the new list. We will need to perform a context + * switch only if the EXCLUSIVE or of the two calls is non-zero + * (i.e., one and only one the calls changes the head of the + * ready-to-run list). + */ + + switch_needed ^= sched_addreadytorun(tcb); + + /* Now, perform the context switch if one is needed */ + + if (switch_needed) + { + /* If we are going to do a context switch, then now is the right + * time to add any pending tasks back into the ready-to-run list. + * task list now + */ + + if (g_pendingtasks.head) + { + sched_mergepending(); + } + + /* Copy the exception context into the TCB at the (old) head of the + * g_readytorun Task list. if up_setjmp returns a non-zero + * value, then this is really the previously running task restarting! + */ + + if (!up_setjmp(rtcb->xcp.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); + + /* The way that we handle signals in the simulation is kind of + * a kludge. This would be unsafe in a truly multi-threaded, interrupt + * driven environment. + */ + + if (rtcb->xcp.sigdeliver) + { + dbg("Delivering signals TCB=%p\n", rtcb); + ((sig_deliver_t)rtcb->xcp.sigdeliver)(rtcb); + rtcb->xcp.sigdeliver = NULL; + } + + /* Then switch contexts */ + + up_longjmp(rtcb->xcp.regs, 1); + } + } + } +} |