Initial (nonworking) draft of preemptive task switching

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

diff --git a/bertos/kern/proc_p.h b/bertos/kern/proc_p.h
index 7dad780d4fb03098ce3f388afcee3750acec50bb..a98f9428aa65f684ad414c4f2a0267c67f0547a1 100644 (file)
--- a/bertos/kern/proc_p.h
+++ b/bertos/kern/proc_p.h
@@ -34,7 +34,6 @@
  * \brief Internal scheduler structures and definitions for processes.
  *
  * \version $Id$
- *
  * \author Bernie Innocenti <bernie@codewiz.org>
  */
 
@@ -46,7 +45,11 @@
 
 #include <cpu/types.h>        /* for cpu_stack_t */
 
-#include <mware/list.h>
+#include <struct/list.h>
+
+#if CONFIG_KERN_PREEMPTIVE
+       #include <ucontext.h> // XXX
+#endif
 
 typedef struct Process
 {
@@ -61,6 +64,8 @@ typedef struct Process
 
 #if CONFIG_KERN_PREEMPTIVE
        int          forbid_cnt;  /**< Nesting count for proc_forbid()/proc_permit(). */
+       bool         leaving;     /**< XXX: maybe global? */
+       ucontext_t   context;
 #endif
 
 #if CONFIG_KERN_HEAP
@@ -94,11 +99,24 @@ typedef struct Process
 /** Track running processes. */
 extern REGISTER Process        *CurrentProcess;
 
-/** Track ready processes. */
+/**
+ * Track ready processes.
+ *
+ * Access to this list must be protected with a proc_forbid() / proc_premit()
+ * pair, or with SCHED_ATOMIC()
+ */
 extern REGISTER List     ProcReadyList;
 
 
-/** Enqueue a task in the ready list. */
+/**
+ * Enqueue a task in the ready list.
+ *
+ * Always use this macro to instert a process in the ready list, as its
+ * might vary to implement a different scheduling algorithms.
+ *
+ * \note This macro is *NOT* protected against the scheduler.  Access to
+ *       this list must be performed with interrupts disabled.
+ */
 #define SCHED_ENQUEUE(proc)  ADDTAIL(&ProcReadyList, &(proc)->link)
 
 /** Schedule to another process *without* adding the current to the ready list. */
@@ -119,4 +137,3 @@ void proc_schedule(void);
 #endif /* CONFIG_KERN_MONITOR */
 
 #endif /* KERN_PROC_P_H */
-