X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fkern%2Fpreempt.c;h=078724b42a8e38095fb93e3c6e226d2e2b5e2d70;hb=121f4d98bd4d74629809697ab66001ebcbac76ce;hp=7ecd481d0cdf57c6d4c3679fc4ccfa43f5cc794e;hpb=cfa8814ca45e8bae9b36713bc534ecb581834016;p=bertos.git diff --git a/bertos/kern/preempt.c b/bertos/kern/preempt.c index 7ecd481d..078724b4 100644 --- a/bertos/kern/preempt.c +++ b/bertos/kern/preempt.c @@ -26,152 +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 preemptive multitasking scheduler. - * - * \version $Id: proc.c 1616 2008-08-10 19:41:26Z bernie $ - * \author Bernie Innocenti - */ - -#include "proc_p.h" -#include "proc.h" - -#include -#include -#include // CPU_IDLE -#include -#include - - - -Timer preempt_timer; - -/** - * Disable preemptive task switching. - * - * 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. + * \note This file is deprecated and kept only for backward compatibility. * - * \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) -{ - IRQ_DISABLE; - - LIST_ASSERT_VALID(&ProcReadyList); - CurrentProcess = (struct Process *)list_remHead(&ProcReadyList); - LIST_ASSERT_VALID(&ProcReadyList); - ASSERT2(CurrentProcess, "no idle proc?"); - - IRQ_ENABLE; - - TRACEMSG("new proc: %p:%s", CurrentProcess, CurrentProcess ? CurrentProcess->monitor.name : "---"); - monitor_report(); -} - -void proc_preempt_timer(UNUSED_ARG(void *, param)) -{ - IRQ_DISABLE; -/* - if (!CurrentProcess->forbid_cnt) - { - TRACEMSG("preempting %p:%s", CurrentProcess, CurrentProcess->monitor.name); - LIST_ASSERT_VALID(&ProcReadyList); - SCHED_ENQUEUE(CurrentProcess); - 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) -{ - TRACE; - - ASSERT_IRQ_ENABLED(); - IRQ_DISABLE; - SCHED_ENQUEUE(CurrentProcess); - LIST_ASSERT_VALID(&ProcReadyList); - proc_schedule(); - IRQ_ENABLE; -} - -void proc_entry(void (*user_entry)(void)) -{ - user_entry(); - proc_exit(); -} - - -static cpustack_t idle_stack[CONFIG_PROC_DEFSTACKSIZE / sizeof(cpustack_t)]; - -/* - * The idle process - * - * This process never dies and never sleeps. It's also quite apathic - * and a bit antisocial. - * - * Having an idle process costs some stack space, but simplifies the - * interrupt-driven preemption logic because there is always a user - * context to which we can return. + * --> */ -static NORETURN void idle(void) -{ - for (;;) - { - TRACE; - monitor_report(); - proc_yield(); // FIXME: CPU_IDLE - } -} - -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); - - proc_new(idle, NULL, sizeof(idle_stack), idle_stack); -}