From 55e012993ca8e7ee9bf38d53158db7bc56b815b4 Mon Sep 17 00:00:00 2001 From: Joel Sherrill Date: Wed, 17 Aug 2005 22:49:56 +0000 Subject: 2005-08-17 Andrew Sinclair PR 807/rtems * rtems/src/timerfireafter.c, rtems/src/timerserverfireafter.c, score/src/watchdoginsert.c: Tighten critical section checks on an ISR using the same timer being inserted by a lower priority ISR or interupt task. --- cpukit/rtems/src/timerfireafter.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) (limited to 'cpukit/rtems/src/timerfireafter.c') diff --git a/cpukit/rtems/src/timerfireafter.c b/cpukit/rtems/src/timerfireafter.c index cead1426a4..98b5d36e91 100644 --- a/cpukit/rtems/src/timerfireafter.c +++ b/cpukit/rtems/src/timerfireafter.c @@ -51,6 +51,7 @@ rtems_status_code rtems_timer_fire_after( { Timer_Control *the_timer; Objects_Locations location; + ISR_Level level; if ( ticks == 0 ) return RTEMS_INVALID_NUMBER; @@ -68,8 +69,29 @@ rtems_status_code rtems_timer_fire_after( case OBJECTS_LOCAL: (void) _Watchdog_Remove( &the_timer->Ticker ); - the_timer->the_class = TIMER_INTERVAL; - _Watchdog_Initialize( &the_timer->Ticker, routine, id, user_data ); + + _ISR_Disable( level ); + + /* + * Check to see if the watchdog has just been inserted by a + * higher priority interrupt. If so, abandon this insert. + */ + + if ( the_timer->Ticker.state != WATCHDOG_INACTIVE ) { + _ISR_Enable( level ); + return RTEMS_SUCCESSFUL; + } + + /* + * OK. Now we now the timer was not rescheduled by an interrupt + * so we can atomically initialize it as in use. + */ + + the_timer->the_class = TIMER_INTERVAL; + _Watchdog_Initialize( &the_timer->Ticker, routine, id, user_data ); + _ISR_Enable( level ); + + _Watchdog_Insert_ticks( &the_timer->Ticker, ticks ); _Thread_Enable_dispatch(); return RTEMS_SUCCESSFUL; -- cgit v1.2.3