[Xen-devel] [PATCH] MiniOS timeouts

[Grzegorz Milos <gm281@xxxxxxxxx>]

The patch adds timeouts to MiniOS threads. The patch is based on 
original patch by Robert Kaiser.
Signed-off-by: Grzegorz Milos <gm281@xxxxxxxxx>

Keir could you apply please?

Also, Anil, do you still have problems with compiling MiniOS? It works, 
for me. I finally have time to deal with any problems you might have.
Cheers
Gregor

diff -r 3cc0b589c235 -r 1facc5f0d408 extras/mini-os/README
--- a/extras/mini-os/README     Tue Oct 17 08:59:11 2006
+++ b/extras/mini-os/README     Tue Nov 14 18:58:52 2006
@@ -26,5 +26,5 @@
 - to start it do the following in domain0 (assuming xend is running)
   # xm create domain_config
 
-this starts the kernel and prints out a bunch of stuff and then every
-1000 timer interrupts the system time.
+this starts the kernel and prints out a bunch of stuff and then once
+every second the system time.
diff -r 3cc0b589c235 -r 1facc5f0d408 extras/mini-os/include/sched.h
--- a/extras/mini-os/include/sched.h    Tue Oct 17 08:59:11 2006
+++ b/extras/mini-os/include/sched.h    Tue Nov 14 18:58:52 2006
@@ -2,6 +2,7 @@
 #define __SCHED_H__
 
 #include <list.h>
+#include <time.h>
 
 struct thread
 {
@@ -11,6 +12,7 @@
     unsigned long ip;  /* Instruction pointer */
     struct list_head thread_list;
     u32 flags;
+    s_time_t wakeup_time;
 };
 
 
@@ -36,5 +38,6 @@
 
 void wake(struct thread *thread);
 void block(struct thread *thread);
+void sleep(u32 millisecs);
 
 #endif /* __SCHED_H__ */
diff -r 3cc0b589c235 -r 1facc5f0d408 extras/mini-os/include/time.h
--- a/extras/mini-os/include/time.h     Tue Oct 17 08:59:11 2006
+++ b/extras/mini-os/include/time.h     Tue Nov 14 18:58:52 2006
@@ -7,8 +7,9 @@
  *        File: time.h
  *      Author: Rolf Neugebauer (neugebar@xxxxxxxxxxxxx)
  *     Changes: Grzegorz Milos (gm281@xxxxxxxxx)
+ *              Robert Kaiser (kaiser@xxxxxxxxxxxxxxxxxxxxxxxxxx)
  *              
- *        Date: Jul 2003, changesJun 2005
+ *        Date: Jul 2003, changes: Jun 2005, Sep 2006
  * 
  * Environment: Xen Minimal OS
  * Description: Time and timer functions
@@ -57,7 +58,8 @@
 void     init_time(void);
 s_time_t get_s_time(void);
 s_time_t get_v_time(void);
+u64      monotonic_clock(void);
 void     gettimeofday(struct timeval *tv);
-void     block_domain(u32 millisecs);
+void     block_domain(s_time_t until);
 
 #endif /* _TIME_H_ */
diff -r 3cc0b589c235 -r 1facc5f0d408 extras/mini-os/kernel.c
--- a/extras/mini-os/kernel.c   Tue Oct 17 08:59:11 2006
+++ b/extras/mini-os/kernel.c   Tue Nov 14 18:58:52 2006
@@ -6,6 +6,7 @@
  * 
  * Copyright (c) 2002-2003, K A Fraser & R Neugebauer
  * Copyright (c) 2005, Grzegorz Milos, Intel Research Cambridge
+ * Copyright (c) 2006, Robert Kaiser, FH Wiesbaden
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to
@@ -66,11 +67,24 @@
     /* test_xenbus(); */
 }
 
+void periodic_thread(void *p)
+{
+    struct timeval tv;
+    printk("Periodic thread started.\n");
+    for(;;)
+    {
+        gettimeofday(&tv);
+        printk("T(s=%ld us=%ld)\n", tv.tv_sec, tv.tv_usec);
+        sleep(1000);
+    }
+}
+
 /* This should be overridden by the application we are linked against. */
 __attribute__((weak)) int app_main(start_info_t *si)
 {
     printk("Dummy main: start_info=%p\n", si);
     create_thread("xenbus_tester", xenbus_tester, si);
+    create_thread("periodic_thread", periodic_thread, si);
     return 0;
 }
 
diff -r 3cc0b589c235 -r 1facc5f0d408 extras/mini-os/sched.c
--- a/extras/mini-os/sched.c    Tue Oct 17 08:59:11 2006
+++ b/extras/mini-os/sched.c    Tue Nov 14 18:58:52 2006
@@ -5,7 +5,7 @@
  *
  *        File: sched.c
  *      Author: Grzegorz Milos
- *     Changes: 
+ *     Changes: Robert Kaiser
  *              
  *        Date: Aug 2005
  * 
@@ -142,6 +142,54 @@
     printk("\n");
 }
 
+/* Find the time when the next timeout expires. If this is more than
+   10 seconds from now, return 10 seconds from now. */
+static s_time_t blocking_time(void)
+{
+    struct thread *thread;
+    struct list_head *iterator;
+    s_time_t min_wakeup_time;
+    unsigned long flags;
+    local_irq_save(flags);
+    /* default-block the domain for 10 seconds: */
+    min_wakeup_time = NOW() + SECONDS(10);
+
+    /* Thread list needs to be protected */
+    list_for_each(iterator, &idle_thread->thread_list)
+    {
+        thread = list_entry(iterator, struct thread, thread_list);
+        if(!is_runnable(thread) && thread->wakeup_time != 0LL)
+        {
+            if(thread->wakeup_time < min_wakeup_time)
+            {
+                min_wakeup_time = thread->wakeup_time;
+            }
+        }
+    }
+    local_irq_restore(flags);
+    return(min_wakeup_time);
+}
+
+/* Wake up all threads with expired timeouts. */
+static void wake_expired(void)
+{
+    struct thread *thread;
+    struct list_head *iterator;
+    s_time_t now = NOW();
+    unsigned long flags;
+    local_irq_save(flags);
+    /* Thread list needs to be protected */
+    list_for_each(iterator, &idle_thread->thread_list)
+    {
+        thread = list_entry(iterator, struct thread, thread_list);
+        if(!is_runnable(thread) && thread->wakeup_time != 0LL)
+        {
+            if(thread->wakeup_time <= now)
+                wake(thread);
+        }
+    }
+    local_irq_restore(flags);
+}
 
 void schedule(void)
 {
@@ -229,8 +277,9 @@
     stack_push(thread, (unsigned long) data);
     thread->ip = (unsigned long) thread_starter;
      
-    /* Not runable, not exited */ 
+    /* Not runable, not exited, not sleeping */
     thread->flags = 0;
+    thread->wakeup_time = 0LL;
     set_runnable(thread);
     local_irq_save(flags);
     if(idle_thread != NULL) {
@@ -247,20 +296,34 @@
 
 void block(struct thread *thread)
 {
+    thread->wakeup_time = 0LL;
     clear_runnable(thread);
 }
 
+void sleep(u32 millisecs)
+{
+    struct thread *thread = get_current();
+    thread->wakeup_time = NOW()  + MILLISECS(millisecs);
+    clear_runnable(thread);
+    schedule();
+}
+
 void wake(struct thread *thread)
 {
+    thread->wakeup_time = 0LL;
     set_runnable(thread);
 }
 
 void idle_thread_fn(void *unused)
 {
+    s_time_t until;
     for(;;)
     {
         schedule();
-        block_domain(10000);
+        /* block until the next timeout expires, or for 10 secs, whichever 
comes first */
+        until = blocking_time();
+        block_domain(until);
+        wake_expired();
     }
 }
 
@@ -278,7 +341,7 @@
                          "push %1\n\t" 
                          "ret"                                            
                          :"=m" (idle_thread->sp)
-                         :"m" (idle_thread->ip));                          
+                         :"m" (idle_thread->ip));                              
                      
 #endif
 }
 
diff -r 3cc0b589c235 -r 1facc5f0d408 extras/mini-os/time.c
--- a/extras/mini-os/time.c     Tue Oct 17 08:59:11 2006
+++ b/extras/mini-os/time.c     Tue Nov 14 18:58:52 2006
@@ -3,6 +3,7 @@
  * (C) 2003 - Rolf Neugebauer - Intel Research Cambridge
  * (C) 2002-2003 - Keir Fraser - University of Cambridge 
  * (C) 2005 - Grzegorz Milos - Intel Research Cambridge
+ * (C) 2006 - Robert Kaiser - FH Wiesbaden
  ****************************************************************************
  *
  *        File: time.c
@@ -194,21 +195,15 @@
 }
 
 
-static void print_current_time(void)
-{
-    struct timeval tv;    
-
-    gettimeofday(&tv);
-    printk("T(s=%ld us=%ld)\n", tv.tv_sec, tv.tv_usec);
-}
-
-
-void block_domain(u32 millisecs)
+void block_domain(s_time_t until)
 {
     struct timeval tv;
     gettimeofday(&tv);
-    HYPERVISOR_set_timer_op(monotonic_clock() + 1000000LL * (s64) millisecs);
-    HYPERVISOR_sched_op(SCHEDOP_block, 0);
+    if(monotonic_clock() < until)
+    {
+        HYPERVISOR_set_timer_op(until);
+        HYPERVISOR_sched_op(SCHEDOP_block, 0);
+    }
 }
 
 
@@ -217,15 +212,8 @@
  */
 static void timer_handler(evtchn_port_t ev, struct pt_regs *regs, void *ign)
 {
-    static int i;
-
     get_time_values_from_xen();
     update_wallclock();
-    i++;
-    if (i >= 1000) {
-        print_current_time();
-        i = 0;
-    }
 }
 
 

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