X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fkern%2Fproc_p.h;h=56c810819b56964d2d16c83fe29075fbde8f3e5b;hb=d1b1e979862ca866eaee324e0363d57bf5a0e13b;hp=a5c7dbe3120ef6ff134039ecd4adca68c63e52f0;hpb=04188ad75e2fb6ec7d681649c1b4a171d7c9f5a3;p=bertos.git

diff --git a/bertos/kern/proc_p.h b/bertos/kern/proc_p.h
index a5c7dbe3..56c81081 100644
--- a/bertos/kern/proc_p.h
+++ b/bertos/kern/proc_p.h
@@ -48,12 +48,47 @@
 #include <cpu/types.h>        /* for cpu_stack_t */
 #include <cpu/irq.h>          // IRQ_ASSERT_DISABLED()
 
-#if CONFIG_KERN_PREEMPT
-	#include <ucontext.h> // XXX
-#endif
-
 #include <kern/proc.h>   // struct Process
 
+/*
+ * 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.
@@ -64,19 +99,32 @@
 
 
 /** Track running processes. */
-extern REGISTER Process	*CurrentProcess;
+extern REGISTER Process	*current_process;
 
 /**
  * Track ready processes.
  *
  * Access to this list must be performed with interrupts disabled
  */
-extern REGISTER List     ProcReadyList;
+extern REGISTER List     proc_ready_list;
 
 #if CONFIG_KERN_PRI
-	#define SCHED_ENQUEUE_INTERNAL(proc) LIST_ENQUEUE(&ProcReadyList, &(proc)->link)
+	#define prio_next()	(LIST_EMPTY(&proc_ready_list) ? INT_MIN : \
+					((PriNode *)LIST_HEAD(&proc_ready_list))->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)
+	#define SCHED_ENQUEUE_HEAD_INTERNAL(proc) \
+			LIST_ENQUEUE_HEAD(&proc_ready_list, &(proc)->link)
 #else
-	#define SCHED_ENQUEUE_INTERNAL(proc) ADDTAIL(&ProcReadyList, &(proc)->link)
+	#define prio_next()	0
+	#define prio_proc(proc)	0
+	#define prio_curr()	0
+
+	#define SCHED_ENQUEUE_INTERNAL(proc) ADDTAIL(&proc_ready_list, &(proc)->link)
+	#define SCHED_ENQUEUE_HEAD_INTERNAL(proc) ADDHEAD(&proc_ready_list, &(proc)->link)
 #endif
 
 /**
@@ -90,10 +138,17 @@ extern REGISTER List     ProcReadyList;
  */
 #define SCHED_ENQUEUE(proc)  do { \
 		IRQ_ASSERT_DISABLED(); \
-		LIST_ASSERT_VALID(&ProcReadyList); \
+		LIST_ASSERT_VALID(&proc_ready_list); \
 		SCHED_ENQUEUE_INTERNAL(proc); \
 	} while (0)
 
+#define SCHED_ENQUEUE_HEAD(proc)  do { \
+		IRQ_ASSERT_DISABLED(); \
+		LIST_ASSERT_VALID(&proc_ready_list); \
+		SCHED_ENQUEUE_HEAD_INTERNAL(proc); \
+	} while (0)
+
+
 #if CONFIG_KERN_PRI
 /**
  * Changes the priority of an already enqueued process.
@@ -108,10 +163,10 @@ extern REGISTER List     ProcReadyList;
 INLINE void sched_reenqueue(struct Process *proc)
 {
 	IRQ_ASSERT_DISABLED();
-	LIST_ASSERT_VALID(&ProcReadyList);
+	LIST_ASSERT_VALID(&proc_ready_list);
 	Node *n;
 	PriNode *pos = NULL;
-	FOREACH_NODE(n, &ProcReadyList)
+	FOREACH_NODE(n, &proc_ready_list)
 	{
 		if (n == &proc->link.link)
 		{
@@ -125,18 +180,25 @@ INLINE void sched_reenqueue(struct Process *proc)
 	if (pos)
 	{
 		REMOVE(&proc->link.link);
-		LIST_ENQUEUE(&ProcReadyList, &proc->link);
+		LIST_ENQUEUE(&proc_ready_list, &proc->link);
 	}
 }
 #endif //CONFIG_KERN_PRI
 
-/// Schedule another process *without* adding the current one to the ready list.
+/* Process trampoline */
+void proc_entry(void);
+
+/* Schedule another process *without* adding the current one to the ready list. */
 void proc_switch(void);
 
-#if CONFIG_KERN_PREEMPT
-void proc_entry(void (*user_entry)(void));
-void preempt_init(void);
-#endif
+/* 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 */