Changeset 408 for trunk/kernel/kern/scheduler.h

Timestamp:

Dec 5, 2017, 4:20:07 PM (6 years ago)

Author:

alain

Message:

Fix several bugs in the fork() syscall.

File:

• trunk/kernel/kern/scheduler.h (modified) (2 diffs)

trunk/kernel/kern/scheduler.h

@@ -74 +74 @@
 
 /********************************************************************************************* 
- * This function handles pending signals for all registered threads, and calls the 
- * sched_select() function to make a context switch for the core running the calling thread.
+ * This function is the only method to make a context switch. It is called in cas of TICK,
+ * or when when a thread explicitely requires a scheduling.
+ * It handles the pending signals for all threads attached to the core running the calling
+ * thread, and calls the sched_select() function to select a new thread.
+ * The cause argument is only used for debug by the sched_display() function, and 
+ * indicates the scheduling cause.
+ *********************************************************************************************
+ * @ cause    : character string defining the scheduling cause.
  ********************************************************************************************/
-void sched_yield();
+void sched_yield( char * cause );
 
 /*********************************************************************************************
@@ -101 +107 @@
 /*********************************************************************************************
  * This function does NOT modify the scheduler state.
- * It just select a thread in the list of attached threads, implementing the following policy: 
- * 1) it scan the list of kernel threads, from the next thread after the last executed one,
- *    and returns the first runnable found (can be the current thread).
- * 2) if no kernel thread found, it scan the list of user thread, from the next thread after
- *    the last executed one, and returns the first runable found (can be the current thread).
- * 3) if no runable thread found, it returns the idle thread.
+ * It just select a thread in the list of attached threads, implementing the following 
+ * three steps policy: 
+ * 1) It scan the list of kernel threads, from the next thread after the last executed one,
+ *    and returns the first runnable found : not IDLE, not blocked, client queue not empty.
+ *    It can be the current thread.
+ * 2) If no kernel thread found, it scan the list of user thread, from the next thread after
+ *    the last executed one, and returns the first runable found : not blocked.
+ *    It can be the current thread.
+ * 3) If no runable thread found, it returns the idle thread.
  *********************************************************************************************
- * @ core    : local pointer on the core descriptor.
+ * @ core    : local pointer on scheduler.
  * @ returns pointer on selected thread descriptor
  ********************************************************************************************/
-struct thread_s * sched_select( struct core_s * core );
+struct thread_s * sched_select( struct scheduler_s * sched );
 
 /*********************************************************************************************