lm3s1968: add graphic to the example.

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

diff --git a/bertos/kern/proc_p.h b/bertos/kern/proc_p.h
index f1b5aa34805503296c4954ea248cf17186fecdb1..56c810819b56964d2d16c83fe29075fbde8f3e5b 100644 (file)
--- a/bertos/kern/proc_p.h
+++ b/bertos/kern/proc_p.h
@@ -49,8 +49,46 @@
 #include <cpu/irq.h>          // IRQ_ASSERT_DISABLED()
 
 #include <kern/proc.h>   // struct Process
-#include <kern/idle.h>        // idle_proc
 
+/*
+ * Check if the process context switch can be performed directly by the
+ * architecture-dependent asm_switch_context() or if it must be delayed
+ * because we're in the middle of an ISR.
+ *
+ * Return true if asm_switch_context() can be executed, false
+ * otherwise.
+ *
+ * NOTE: if an architecture does not implement IRQ_RUNNING() this function
+ * always returns true.
+ */
+#define CONTEXT_SWITCH_FROM_ISR()      (!IRQ_RUNNING())
+
+#ifndef asm_switch_context
+/**
+ * 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);
+#endif
+
+/*
+ * 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.
@@ -71,9 +109,10 @@ extern REGISTER Process     *current_process;
 extern REGISTER List     proc_ready_list;
 
 #if CONFIG_KERN_PRI
-       #define prio_next()     (LIST_EMPTY(&proc_ready_list) ? idle_proc->link.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)
@@ -81,6 +120,7 @@ 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)
@@ -145,10 +185,21 @@ INLINE void sched_reenqueue(struct Process *proc)
 }
 #endif //CONFIG_KERN_PRI
 
-/// Schedule another process *without* adding the current one to the ready list.
-void proc_switch(void);
+/* Process trampoline */
 void proc_entry(void);
 
+/* Schedule another process *without* adding the current one to the ready list. */
+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);
+
 #if CONFIG_KERN_MONITOR
        /** Initialize the monitor */
        void monitor_init(void);