X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fkern%2Fpreempt.c;h=f77dd85eff1c632bbd73adf1053b350140cfc1ca;hb=938512200c9fbd8e08c88dbdddbdc1f030d3b663;hp=3037c15cc47f4258fb342e896b15c3937d054cbb;hpb=9d3c2ea8a3b385401bc272b18110620e03da8ba2;p=bertos.git

diff --git a/bertos/kern/preempt.c b/bertos/kern/preempt.c
index 3037c15c..f77dd85e 100644
--- a/bertos/kern/preempt.c
+++ b/bertos/kern/preempt.c
@@ -39,7 +39,7 @@
  * the time sharing interval.
  *
  * When the quantum expires the handler proc_needPreempt() checks if the
- * preemption is enabled and in this case proc_schedule() is called, that
+ * preemption is enabled and in this case preempt_schedule() is called, that
  * possibly replaces the current running thread with a different one.
  *
  * The preemption can be disabled or enabled via proc_forbid() and
@@ -86,14 +86,11 @@
 
 #include "cfg/cfg_proc.h"
 
-#if CONFIG_KERN_PREEMPT
-
 #include "proc_p.h"
 #include "proc.h"
 
 #include <kern/irq.h>
 #include <kern/monitor.h>
-#include <kern/idle.h> // idle_proc
 #include <cpu/frame.h> // CPU_IDLE
 #include <cpu/irq.h>   // IRQ_DISABLE()...
 #include <cfg/log.h>
@@ -105,14 +102,6 @@ CONFIG_DEPEND(CONFIG_KERN_PREEMPT, CONFIG_KERN);
 
 MOD_DEFINE(preempt)
 
-/**
- * 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(cpu_stack_t **new_sp, cpu_stack_t **save_sp);
-
 /* Global preemption nesting counter */
 cpu_atomic_t preempt_count;
 
@@ -123,50 +112,30 @@ cpu_atomic_t preempt_count;
  */
 int _proc_quantum;
 
+/**
+ * Define function prototypes exported outside.
+ *
+ * Required to silent gcc "no previous prototype" warnings.
+ */
+void preempt_yield(void);
+int preempt_needPreempt(void);
+void preempt_preempt(void);
+void preempt_switch(void);
+void preempt_init(void);
+
 /**
  * Call the scheduler and eventually replace the current running process.
  */
-static void proc_schedule(void)
+static void preempt_schedule(void)
 {
-	Process *old_process = current_process;
-
-	IRQ_ASSERT_DISABLED();
-
-	/* Poll on the ready queue for the first ready process */
-	LIST_ASSERT_VALID(&proc_ready_list);
-	current_process = (Process *)list_remHead(&proc_ready_list);
-	if (UNLIKELY(!current_process))
-		current_process = idle_proc;
 	_proc_quantum = CONFIG_KERN_QUANTUM;
-	/*
-	 * Optimization: don't switch contexts when the active process has not
-	 * changed.
-	 */
-	if (LIKELY(old_process != current_process))
-	{
-		cpu_stack_t *dummy;
-
-		/*
-		 * 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 */
-	LOG_INFO("resuming %p:%s\n", current_process, proc_currentName());
+	proc_schedule();
 }
 
 /**
  * Check if we need to schedule another task
  */
-int proc_needPreempt(void)
+int preempt_needPreempt(void)
 {
 	if (UNLIKELY(current_process == NULL))
 		return 0;
@@ -179,7 +148,7 @@ int proc_needPreempt(void)
 /**
  * Preempt the current task.
  */
-void proc_preempt(void)
+void preempt_preempt(void)
 {
 	IRQ_ASSERT_DISABLED();
 	ASSERT(current_process);
@@ -187,9 +156,8 @@ void proc_preempt(void)
 	/* Perform the kernel preemption */
 	LOG_INFO("preempting %p:%s\n", current_process, proc_currentName());
 	/* We are inside a IRQ context, so ATOMIC is not needed here */
-	if (current_process != idle_proc)
-		SCHED_ENQUEUE(current_process);
-	proc_schedule();
+	SCHED_ENQUEUE(current_process);
+	preempt_schedule();
 }
 
 /**
@@ -200,18 +168,18 @@ void proc_preempt(void)
  * \warning This should be considered an internal kernel function, even if it
  * is allowed, usage from application code is strongly discouraged.
  */
-void proc_switch(void)
+void preempt_switch(void)
 {
 	ASSERT(proc_preemptAllowed());
 	IRQ_ASSERT_ENABLED();
 
-	ATOMIC(proc_schedule());
+	ATOMIC(preempt_schedule());
 }
 
 /**
  * Voluntarily release the CPU.
  */
-void proc_yield(void)
+void preempt_yield(void)
 {
 	/*
 	 * Voluntary preemption while preemption is disabled is considered
@@ -224,14 +192,11 @@ void proc_yield(void)
 
 	ATOMIC(
 		SCHED_ENQUEUE(current_process);
-		proc_schedule();
+		preempt_schedule();
 	);
 }
 
 void preempt_init(void)
 {
-	idle_init();
 	MOD_INIT(preempt);
 }
-
-#endif // CONFIG_KERN_PREEMPT