monitor_checkStack(): fix pasto introduced in previous change. Spotted by R.Gianassi.

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

diff --git a/bertos/kern/preempt.c b/bertos/kern/preempt.c
index f068a8a82c24d314d159e84a045422de18b55475..9af6c0d1b402a973cc144532c15c2f1ae5d15d2f 100644 (file)
--- a/bertos/kern/preempt.c
+++ b/bertos/kern/preempt.c
@@ -26,8 +26,7 @@
  * invalidate any other reasons why the executable file might be covered by
  * the GNU General Public License.
  *
- * Copyright 2001, 2004 Develer S.r.l. (http://www.develer.com/)
- * Copyright 1999, 2000, 2001, 2008 Bernie Innocenti <bernie@codewiz.org>
+ * Copyright 2008 Bernie Innocenti <bernie@codewiz.org>
  * -->
  *
  * \brief Simple realtime multitasking scheduler.
@@ -35,12 +34,16 @@
  *
  * \version $Id: proc.c 1616 2008-08-10 19:41:26Z bernie $
  * \author Bernie Innocenti <bernie@codewiz.org>
- * \author Stefano Fedrigo <aleph@develer.com>
  */
 
 #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
@@ -48,6 +51,8 @@
  */
 uint16_t Quantum;
 
+Timer preempt_timer;
+
 /**
  * Disable preemptive task switching.
  *
@@ -78,3 +83,87 @@ 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);
+}