proc: Split cooperative scheduler in coop.c

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

diff --git a/bertos/kern/proc.c b/bertos/kern/proc.c
index 51cf0c14b3f91c8043322ff9e292155a28d8b3fd..9aa04546c35eb02e5ee425f02914a5c7839a68cb 100644 (file)
--- a/bertos/kern/proc.c
+++ b/bertos/kern/proc.c
@@ -43,31 +43,15 @@
 #include "proc.h"
 
 #include "cfg/cfg_arch.h"  /* ARCH_EMUL */
-#include <cfg/debug.h>
 #include <cfg/module.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>
 
-#include <mware/event.h>
-
 #include <string.h>           /* memset() */
 
-/**
- * CPU dependent context switching routines.
- *
- * 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(cpustack_t **new_sp, cpustack_t **save_sp);
-
 /*
  * The scheduer tracks ready processes by enqueuing them in the
  * ready list.
@@ -83,15 +67,6 @@ REGISTER List ProcReadyList;
  */
 REGISTER Process *CurrentProcess;
 
-#if CONFIG_KERN_PREEMPTIVE
-/*
- * The time sharing scheduler forces a task switch when the current
- * process has exhausted its quantum.
- */
-uint16_t Quantum;
-#endif
-
-
 #if (ARCH & ARCH_EMUL)
 /*
  * In hosted environments, we must emulate the stack on the real process stack.
@@ -251,81 +226,6 @@ void proc_rename(struct Process *proc, const char *name)
 }
 
 
-/**
- * System scheduler: pass CPU control to the next process in
- * the ready queue.
- */
-void proc_schedule(void)
-{
-       struct Process *old_process;
-       cpuflags_t flags;
-
-       ATOMIC(LIST_ASSERT_VALID(&ProcReadyList));
-       ASSERT_USER_CONTEXT();
-       ASSERT_IRQ_ENABLED();
-
-       /* Remember old process to save its context later */
-       old_process = CurrentProcess;
-
-       /* Poll on the ready queue for the first ready process */
-       IRQ_SAVE_DISABLE(flags);
-       while (!(CurrentProcess = (struct Process *)list_remHead(&ProcReadyList)))
-       {
-               /*
-                * 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.
-                * \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);
-
-       /*
-        * Optimization: don't switch contexts when the active
-        * process has not changed.
-        */
-       if (CurrentProcess != old_process)
-       {
-               cpustack_t *dummy;
-
-               #if CONFIG_KERN_MONITOR
-                       LOG_INFO("Switch from %p(%s) to %p(%s)\n",
-                               old_process,    old_process ? old_process->monitor.name : "NONE",
-                               CurrentProcess, CurrentProcess->monitor.name);
-               #endif
-
-               #if CONFIG_KERN_PREEMPTIVE
-                       /* Reset quantum for this process */
-                       Quantum = CONFIG_KERN_QUANTUM;
-               #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(&CurrentProcess->stack, old_process ? &old_process->stack : &dummy);
-       }
-
-       /* This RET resumes the execution on the new process */
-}
-
-
 /**
  * Terminate the current process
  */
@@ -369,17 +269,6 @@ void proc_exit(void)
 }
 
 
-/**
- * Co-operative context switch
- */
-void proc_switch(void)
-{
-       ATOMIC(SCHED_ENQUEUE(CurrentProcess));
-
-       proc_schedule();
-}
-
-
 /**
  * Get the pointer to the current process
  */
@@ -395,39 +284,3 @@ iptr_t proc_current_user_data(void)
 {
        return CurrentProcess->user_data;
 }
-
-
-#if CONFIG_KERN_PREEMPTIVE
-
-/**
- * Disable preemptive task switching.
- *
- * 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;
-}
-
-#endif /* CONFIG_KERN_PREEMPTIVE */