Merge from trunk.

[bertos.git] / bertos / kern / proc_p.h

diff --git a/bertos/kern/proc_p.h b/bertos/kern/proc_p.h
index 27d65fe288193a3a78aa579c370fbb43273f1586..85cb758f9ecfd7472ea540a3547bb2261fa5717b 100644 (file)
--- a/bertos/kern/proc_p.h
+++ b/bertos/kern/proc_p.h
@@ -50,6 +50,30 @@
 
 #include <kern/proc.h>   // struct Process
 
+/**
+ * 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);
+
+/*
+ * Save context of old process and switch to new process.
+  */
+INLINE void proc_switchTo(Process *next, Process *prev)
+{
+       cpu_stack_t *dummy;
+
+       if (UNLIKELY(next == prev))
+               return;
+       /*
+        * 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.
+        */
+       asm_switch_context(&next->stack, prev ? &prev->stack : &dummy);
+}
 
 /**
  * \name Flags for Process.flags.
@@ -72,7 +96,8 @@ extern REGISTER List     proc_ready_list;
 #if CONFIG_KERN_PRI
        #define prio_next()     (LIST_EMPTY(&proc_ready_list) ? INT_MIN : \
                                        ((PriNode *)LIST_HEAD(&proc_ready_list))->pri)
-       #define prio_curr()     (current_process->link.pri)
+       #define prio_proc(proc) (proc->link.pri)
+       #define prio_curr()     prio_proc(current_process)
 
        #define SCHED_ENQUEUE_INTERNAL(proc) \
                        LIST_ENQUEUE(&proc_ready_list, &(proc)->link)
@@ -80,6 +105,7 @@ extern REGISTER List     proc_ready_list;
                        LIST_ENQUEUE_HEAD(&proc_ready_list, &(proc)->link)
 #else
        #define prio_next()     0
+       #define prio_proc(proc) 0
        #define prio_curr()     0
 
        #define SCHED_ENQUEUE_INTERNAL(proc) ADDTAIL(&proc_ready_list, &(proc)->link)
@@ -153,6 +179,9 @@ void proc_switch(void);
 /* Low level scheduling routine. */
 void proc_schedule(void);
 
+/* Low level context switch routine. */
+void proc_switchTo(Process *next, Process *prev);
+
 /* Initialize a scheduler class. */
 void proc_schedInit(void);