kernel: preemptive and cooperative scheduler refactoring.

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

diff --git a/bertos/kern/coop.c b/bertos/kern/coop.c
index 2173126017acf0ffb2187ae5b0a3fb6f085c1ef2..078724b42a8e38095fb93e3c6e226d2e2b5e2d70 100644 (file)
--- a/bertos/kern/coop.c
+++ b/bertos/kern/coop.c
@@ -26,117 +26,7 @@
  * invalidate any other reasons why the executable file might be covered by
  * the GNU General Public License.
  *
- * Copyright 2001, 2004, 2008 Develer S.r.l. (http://www.develer.com/)
- * Copyright 1999, 2000, 2001, 2008 Bernie Innocenti <bernie@codewiz.org>
- * -->
- *
- * \brief Simple cooperative multitasking scheduler.
- *
- * \version $Id$
- * \author Bernie Innocenti <bernie@codewiz.org>
- * \author Stefano Fedrigo <aleph@develer.com>
- */
-
-#include "proc_p.h"
-#include "proc.h"
-
-// Log settings for cfg/log.h.
-#define LOG_LEVEL   KERN_LOG_LEVEL
-#define LOG_FORMAT  KERN_LOG_FORMAT
-#include <cfg/log.h>
-
-#include <cpu/irq.h>
-#include <cpu/types.h>
-#include <cpu/attr.h>
-#include <cpu/frame.h>
-
-/**
- * CPU dependent context switching routines.
+ * \note This file is deprecated and kept only for backward compatibility.
  *
- * Saving and restoring the context on the stack is done by a CPU-dependent
- * support routine which usually needs to be written in assembly.
- */
-EXTERN_C void asm_switch_context(cpu_stack_t **new_sp, cpu_stack_t **save_sp);
-
-
-/**
- * System scheduler: pass CPU control to the next process in
- * the ready queue.
- */
-static void coop_schedule(void)
-{
-       cpu_flags_t flags;
-
-       ATOMIC(LIST_ASSERT_VALID(&proc_ready_list));
-       ASSERT_USER_CONTEXT();
-       IRQ_ASSERT_ENABLED();
-
-       /* Poll on the ready queue for the first ready process */
-       IRQ_SAVE_DISABLE(flags);
-       while (!(current_process = (struct Process *)list_remHead(&proc_ready_list)))
-       {
-               /*
-                * 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 proc_ready_list. 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.
-                * \todo If there was a way to write sig_wait() so that it does not
-                * disable interrupts while waiting, there would not be any
-                * reason to do this.
-                */
-               IRQ_ENABLE;
-               CPU_IDLE;
-               MEMORY_BARRIER;
-               IRQ_DISABLE;
-       }
-       IRQ_RESTORE(flags);
-}
-
-void coop_switch(void)
-{
-       /* Remember old process to save its context later */
-       Process * const old_process = current_process;
-
-       coop_schedule();
-
-       /*
-        * Optimization: don't switch contexts when the active
-        * process has not changed.
-        */
-       if (current_process != old_process)
-       {
-               cpu_stack_t *dummy;
-
-               #if CONFIG_KERN_MONITOR
-                       LOG_INFO("Switch from %p(%s) to %p(%s)\n",
-                               old_process,    proc_name(old_process),
-                               current_process, proc_currentName());
-               #endif
-
-               /* Save context of old process and switch to new process. If there is no
-                * old process, we save the old stack pointer into a dummy variable that
-                * we ignore. In fact, this happens only when the old process has just
-                * exited.
-                * TODO: Instead of physically clearing the process at exit time, a zombie
-                * list should be created.
-                */
-               asm_switch_context(&current_process->stack, old_process ? &old_process->stack : &dummy);
-       }
-
-       /* This RET resumes the execution on the new process */
-}
-
-/**
- * Co-operative context switch
+ * -->
  */
-void coop_yield(void)
-{
-       ATOMIC(SCHED_ENQUEUE(current_process));
-       proc_switch();
-}