X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fkern%2Fpreempt.c;h=9af6c0d1b402a973cc144532c15c2f1ae5d15d2f;hb=022b3bd1d64ec490ddd0e8e3d72c0d1405504c31;hp=f068a8a82c24d314d159e84a045422de18b55475;hpb=87302355709b6d5ac0592024b84207ba86baa82e;p=bertos.git

diff --git a/bertos/kern/preempt.c b/bertos/kern/preempt.c
index f068a8a8..9af6c0d1 100644
--- 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);
+}