score: Fix _Thread_Delay_ended() on SMP

Suppose we have two tasks A and B and two processors.  Task A is about
to delete task B.  Now task B calls rtems_task_wake_after(1) on the
other processor.  Task B will block on the Giant lock.  Task A
progresses with the task B deletion until it has to wait for
termination.  Now task B obtains the Giant lock, sets its state to
STATES_DELAYING, initializes its watchdog timer and waits.  Eventually
_Thread_Delay_ended() is called, but now _Thread_Get() returned NULL
since the thread is already marked as deleted.  Thus task B remained
forever in the STATES_DELAYING state.

Instead of passing the thread identifier use the thread control block
directly via the watchdog user argument.  This makes
_Thread_Delay_ended() also a bit more efficient.

1 files changed, 7 insertions, 5 deletions

diff --git a/cpukit/rtems/src/taskwakewhen.c b/cpukit/rtems/src/taskwakewhen.c
index 01e855a125..a1fc15f047 100644
--- a/cpukit/rtems/src/taskwakewhen.c
+++ b/cpukit/rtems/src/taskwakewhen.c
@@ -29,6 +29,7 @@ rtems_status_code rtems_task_wake_when(
 )
 {
   Watchdog_Interval   seconds;
+  Thread_Control     *executing;
 
   if ( !_TOD_Is_set() )
     return RTEMS_NOT_DEFINED;
@@ -47,15 +48,16 @@ rtems_status_code rtems_task_wake_when(
     return RTEMS_INVALID_CLOCK;
 
   _Thread_Disable_dispatch();
-    _Thread_Set_state( _Thread_Executing, STATES_WAITING_FOR_TIME );
+    executing = _Thread_Executing;
+    _Thread_Set_state( executing, STATES_WAITING_FOR_TIME );
     _Watchdog_Initialize(
-      &_Thread_Executing->Timer,
+      &executing->Timer,
       _Thread_Delay_ended,
-      _Thread_Executing->Object.id,
-      NULL
+      0,
+      executing
     );
     _Watchdog_Insert_seconds(
-      &_Thread_Executing->Timer,
+      &executing->Timer,
       seconds - _TOD_Seconds_since_epoch()
     );
   _Thread_Enable_dispatch();