kernel: preemptive and cooperative scheduler refactoring.

[bertos.git] / bertos / kern / preempt.c

diff --git a/bertos/kern/preempt.c b/bertos/kern/preempt.c
index 9af6c0d1b402a973cc144532c15c2f1ae5d15d2f..078724b42a8e38095fb93e3c6e226d2e2b5e2d70 100644 (file)
--- 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 <bernie@codewiz.org>
- * -->
- *
- * \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 <bernie@codewiz.org>
- */
-
-#include "proc_p.h"
-#include "proc.h"
-
-#include <kern/irq.h>
-#include <cpu/frame.h> // CPU_IDLE
-#include <drv/timer.h>
-#include <cfg/module.h>
-
-
-/*
- * 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);
-}