From 57da5b0bdc06a8a69c740616f145cb9fe28f8c9f Mon Sep 17 00:00:00 2001
From: bernie <bernie@38d2e660-2303-0410-9eaa-f027e97ec537>
Date: Fri, 15 Aug 2008 19:34:39 +0000
Subject: [PATCH] preempt: much closer

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@1642 38d2e660-2303-0410-9eaa-f027e97ec537
---
 app/demo/demo.mk      |  1 +
 bertos/kern/preempt.c | 50 +++++++++++++++++++++++++++++++------------
 bertos/kern/proc.c    |  7 ++----
 bertos/kern/proc_p.h  |  5 +++++
 4 files changed, 44 insertions(+), 19 deletions(-)

diff --git a/app/demo/demo.mk b/app/demo/demo.mk
index 941e28a6..a66e0f89 100644
--- a/app/demo/demo.mk
+++ b/app/demo/demo.mk
@@ -19,6 +19,7 @@ TRG += demo
 
 # FIXME: we want to use g++ for C source too
 CC = g++
+CXX = g++
 
 demo_CXXSRC = \
 	bertos/emul/emul.cpp \
diff --git a/bertos/kern/preempt.c b/bertos/kern/preempt.c
index dfa343d7..ab3fc7a8 100644
--- a/bertos/kern/preempt.c
+++ b/bertos/kern/preempt.c
@@ -92,10 +92,12 @@ void proc_preempt(void)
 
 	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
@@ -109,11 +111,13 @@ void proc_preempt(void)
 		 * are reloaded.
 		 */
 		IRQ_ENABLE;
-		CPU_IDLE;
+		//FIXME: calls Qt stuff from sighandler! CPU_IDLE;
 		MEMORY_BARRIER;
 		IRQ_DISABLE;
+	TRACEMSG("hello3");
 	}
 	IRQ_ENABLE;
+	TRACEMSG("hello4");
 }
 
 void proc_preempt_timer(void)
@@ -121,12 +125,20 @@ void proc_preempt_timer(void)
 	// TODO: check Quantum
 
 	alarm(1);
-	ATOMIC(SCHED_ENQUEUE(CurrentProcess));
-	proc_schedule();
+
+	if (CurrentProcess)
+	{
+		TRACEMSG("preempting %p:%s", CurrentProcess, CurrentProcess->monitor.name);
+		ATOMIC(SCHED_ENQUEUE(CurrentProcess));
+		proc_schedule();
+	}
 }
 
 void proc_schedule(void)
 {
+	TRACE;
+
+	// Will invoke proc_preempt() in interrupt context
 	kill(0, SIGUSR1);
 }
 
@@ -137,21 +149,27 @@ void proc_yield(void)
 	proc_schedule();
 }
 
+void proc_entry(void (*user_entry)(void))
+{
+	user_entry();
+	proc_exit();
+}
+
 /* signal handler */
 void irq_entry(int signum)
 {
 	Process *old_process;
 
-	TRACEMSG("storing %p:%s", CurrentProcess, CurrentProcess->monitor.name);
-	CurrentProcess->leaving = false;
-	getcontext(&CurrentProcess->context);
+//	TRACEMSG("storing %p:%s", CurrentProcess, CurrentProcess->monitor.name);
+//	CurrentProcess->leaving = false;
+//	getcontext(&CurrentProcess->context);
 	/* We get here in two ways: directly, and after setcontext() below */
 
-	if (CurrentProcess->leaving)
-	{
-		TRACEMSG("leaving to %p:%s", CurrentProcess, CurrentProcess->monitor.name);
-		return;
-	}
+//	if (CurrentProcess->leaving)
+//	{
+//		TRACEMSG("leaving to %p:%s", CurrentProcess, CurrentProcess->monitor.name);
+//		return;
+//	}
 
 	old_process = CurrentProcess;
 
@@ -159,9 +177,13 @@ void irq_entry(int signum)
 
 	if (old_process != CurrentProcess)
 	{
-		TRACEMSG("launching %p:%s", CurrentProcess, CurrentProcess->monitor.name);
-		CurrentProcess->leaving = true;
-		setcontext(&CurrentProcess->context);
+		TRACEMSG("switching from %p:%s to %p:%s",
+			old_process, old_process->monitor.name,
+			CurrentProcess, CurrentProcess->monitor.name);
+		swapcontext(&old_process->context, &CurrentProcess->context);
+//		TRACEMSG("launching %p:%s", CurrentProcess, CurrentProcess->monitor.name);
+//		CurrentProcess->leaving = true;
+//		setcontext(&CurrentProcess->context);
 		/* not reached */
 	}
 
diff --git a/bertos/kern/proc.c b/bertos/kern/proc.c
index afe9e34a..3f254892 100644
--- a/bertos/kern/proc.c
+++ b/bertos/kern/proc.c
@@ -52,9 +52,6 @@
 
 #include <string.h>           /* memset() */
 
-#if CONFIG_KERN_PREEMPT
-#include "preempt.h"
-#endif
 
 /*
  * The scheduer tracks ready processes by enqueuing them in the
@@ -209,7 +206,7 @@ struct Process *proc_new_with_name(UNUSED(const char *, name), void (*entry)(voi
 	proc->context.uc_stack.ss_sp = stack_base;
 	proc->context.uc_stack.ss_size = stack_size;
 	proc->context.uc_link = NULL;
-	makecontext(&proc->context, entry, 0);
+	makecontext(&proc->context, (void (*)(void))proc_entry, 1, entry);
 
 #else // !CONFIG_KERN_PREEMPT
 	/* Initialize process stack frame */
@@ -248,7 +245,7 @@ void proc_rename(struct Process *proc, const char *name)
  */
 void proc_exit(void)
 {
-	TRACE;
+	TRACEMSG("%p:%s", CurrentProcess, CurrentProcess->monitor.name);
 
 #if CONFIG_KERN_MONITOR
 	monitor_remove(CurrentProcess);
diff --git a/bertos/kern/proc_p.h b/bertos/kern/proc_p.h
index a98f9428..fbac38fc 100644
--- a/bertos/kern/proc_p.h
+++ b/bertos/kern/proc_p.h
@@ -122,6 +122,11 @@ extern REGISTER List     ProcReadyList;
 /** Schedule to another process *without* adding the current to the ready list. */
 void proc_schedule(void);
 
+#if CONFIG_KERN_PREEMPT
+void proc_entry(void (*user_entry)(void));
+void preempt_init(void);
+#endif
+
 #if CONFIG_KERN_MONITOR
 	/** Initialize the monitor */
 	void monitor_init(void);
-- 
2.25.1