Unified time for whole BIRD

In previous versions, every thread used its own time structures,
effectively leading to different time in every thread and strange
logging messages.

The time processing code now uses global atomic variables to keep
current time available for fast concurrent reading and safe updates.

2 files changed, 15 insertions, 28 deletions

diff --git a/lib/timer.c b/lib/timer.c
index 6efcadb4..ff1fb5ef 100644
--- a/lib/timer.c
+++ b/lib/timer.c
@@ -32,6 +32,7 @@
 
 #include "nest/bird.h"
 
+#include "lib/coro.h"
 #include "lib/heap.h"
 #include "lib/resource.h"
 #include "lib/timer.h"
@@ -45,22 +46,10 @@ struct timeloop main_timeloop;
 /* Data accessed and modified from proto/bfd/io.c */
 _Thread_local struct timeloop *local_timeloop;
 
-void wakeup_kick_current(void);
-
-btime
-current_time(void)
-{
-  return local_timeloop->last_time;
-}
+_Atomic btime last_time;
+_Atomic btime real_time;
 
-btime
-current_real_time(void)
-{
-  if (!local_timeloop->real_time)
-    times_update_real_time(local_timeloop);
-
-  return local_timeloop->real_time;
-}
+void wakeup_kick_current(void);
 
 
 #define TIMER_LESS(a,b)		((a)->expires < (b)->expires)
@@ -164,8 +153,6 @@ tm_stop(timer *t)
 void
 timers_init(struct timeloop *loop, pool *p)
 {
-  times_init(loop);
-
   BUFFER_INIT(loop->timers, p, 4);
   BUFFER_PUSH(loop->timers) = NULL;
 }
@@ -178,8 +165,8 @@ timers_fire(struct timeloop *loop)
   btime base_time;
   timer *t;
 
-  times_update(loop);
-  base_time = loop->last_time;
+  times_update();
+  base_time = current_time();
 
   while (t = timers_first(loop))
   {
@@ -190,8 +177,8 @@ timers_fire(struct timeloop *loop)
     {
       btime when = t->expires + t->recurrent;
 
-      if (when <= loop->last_time)
-	when = loop->last_time + t->recurrent;
+      if (when <= base_time)
+	when = base_time + t->recurrent;
 
       if (t->randomize)
 	when += random() % (t->randomize + 1);
diff --git a/lib/timer.h b/lib/timer.h
index bc568ee6..b201b8c8 100644
--- a/lib/timer.h
+++ b/lib/timer.h
@@ -14,6 +14,10 @@
 #include "lib/buffer.h"
 #include "lib/resource.h"
 
+#include <stdatomic.h>
+
+extern _Atomic btime last_time;
+extern _Atomic btime real_time;
 
 typedef struct timer
 {
@@ -31,8 +35,6 @@ typedef struct timer
 struct timeloop
 {
   BUFFER_(timer *) timers;
-  btime last_time;
-  btime real_time;
 };
 
 static inline uint timers_count(struct timeloop *loop)
@@ -44,8 +46,8 @@ static inline timer *timers_first(struct timeloop *loop)
 extern struct timeloop main_timeloop;
 extern _Thread_local struct timeloop *local_timeloop;
 
-btime current_time(void);
-btime current_real_time(void);
+#define current_time()		atomic_load_explicit(&last_time, memory_order_acquire)
+#define current_real_time()	atomic_load_explicit(&real_time, memory_order_acquire)
 
 //#define now (current_time() TO_S)
 //#define now_real (current_real_time() TO_S)
@@ -95,9 +97,7 @@ tm_start_max(timer *t, btime after)
 }
 
 /* In sysdep code */
-void times_init(struct timeloop *loop);
-void times_update(struct timeloop *loop);
-void times_update_real_time(struct timeloop *loop);
+void times_update(void);
 
 /* For I/O loop */
 void timers_init(struct timeloop *loop, pool *p);