X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fkern%2Fpreempt.c;h=078724b42a8e38095fb93e3c6e226d2e2b5e2d70;hb=e8b0472be10fba4ca6baa62d8d483db90e28c06e;hp=9af6c0d1b402a973cc144532c15c2f1ae5d15d2f;hpb=3b33eb4b36445ee045f4cbac27f9331988205467;p=bertos.git diff --git a/bertos/kern/preempt.c b/bertos/kern/preempt.c index 9af6c0d1..078724b4 100644 --- a/bertos/kern/preempt.c +++ b/bertos/kern/preempt.c @@ -26,144 +26,7 @@ * invalidate any other reasons why the executable file might be covered by * the GNU General Public License. * - * Copyright 2008 Bernie Innocenti - * --> - * - * \brief Simple realtime multitasking scheduler. - * Context switching is only done cooperatively. - * - * \version $Id: proc.c 1616 2008-08-10 19:41:26Z bernie $ - * \author Bernie Innocenti - */ - -#include "proc_p.h" -#include "proc.h" - -#include -#include // CPU_IDLE -#include -#include - - -/* - * The time sharing scheduler forces a task switch when the current - * process has exhausted its quantum. - */ -uint16_t Quantum; - -Timer preempt_timer; - -/** - * Disable preemptive task switching. + * \note This file is deprecated and kept only for backward compatibility. * - * The scheduler maintains a per-process nesting counter. Task switching is - * effectively re-enabled only when the number of calls to proc_permit() - * matches the number of calls to proc_forbid(). - * - * Calling functions that could sleep while task switching is disabled - * is dangerous, although supported. Preemptive task switching is - * resumed while the process is sleeping and disabled again as soon as - * it wakes up again. - * - * \sa proc_permit() - */ -void proc_forbid(void) -{ - /* No need to protect against interrupts here. */ - ++CurrentProcess->forbid_cnt; -} - -/** - * Re-enable preemptive task switching. - * - * \sa proc_forbid() + * --> */ -void proc_permit(void) -{ - /* No need to protect against interrupts here. */ - --CurrentProcess->forbid_cnt; -} - - -void proc_preempt(void) -{ - TRACE; - - ATOMIC(LIST_ASSERT_VALID(&ProcReadyList)); - - TRACEMSG("hello1"); - IRQ_DISABLE; - /* Poll on the ready queue for the first ready process */ - while (!(CurrentProcess = (struct Process *)list_remHead(&ProcReadyList))) - { - //TRACEMSG("hello2"); - /* - * Make sure we physically reenable interrupts here, no matter what - * the current task status is. This is important because if we - * are idle-spinning, we must allow interrupts, otherwise no - * process will ever wake up. - * - * During idle-spinning, an interrupt can occur and it may - * modify \p ProcReadyList. To ensure that compiler reload this - * variable every while cycle we call CPU_MEMORY_BARRIER. - * The memory barrier ensure that all variables used in this context - * are reloaded. - */ - IRQ_ENABLE; - //FIXME: calls Qt stuff from sighandler! CPU_IDLE; - MEMORY_BARRIER; - IRQ_DISABLE; - //TRACEMSG("hello3"); - } - IRQ_ENABLE; - TRACEMSG("hello4"); -} - -void proc_preempt_timer(UNUSED_ARG(void *, param)) -{ - IRQ_DISABLE; - if (CurrentProcess) - { - TRACEMSG("preempting %p:%s", CurrentProcess, CurrentProcess->monitor.name); - SCHED_ENQUEUE(CurrentProcess); - IRQ_ENABLE; - proc_preempt(); - } - IRQ_ENABLE; - - timer_setDelay(&preempt_timer, CONFIG_KERN_QUANTUM); - timer_add(&preempt_timer); -} - -void proc_schedule(void) -{ - TRACE; - - // Will invoke proc_preempt() in interrupt context - kill(0, SIGUSR1); -} - -void proc_yield(void) -{ - ATOMIC(SCHED_ENQUEUE(CurrentProcess)); - - proc_schedule(); -} - -void proc_entry(void (*user_entry)(void)) -{ - user_entry(); - proc_exit(); -} - -void preempt_init(void) -{ - MOD_CHECK(irq); - MOD_CHECK(timer); - - irq_register(SIGUSR1, proc_preempt); - - timer_setSoftint(&preempt_timer, proc_preempt_timer, NULL); - timer_setDelay(&preempt_timer, CONFIG_KERN_QUANTUM); - timer_add(&preempt_timer); -}