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/timerserverfireafter.c | 26 +++++++++++++++++++++++--- 1 file changed, 23 insertions(+), 3 deletions(-) (limited to 'cpukit/rtems/src/timerserverfireafter.c') diff --git a/cpukit/rtems/src/timerserverfireafter.c b/cpukit/rtems/src/timerserverfireafter.c index 9174459346..849de800a2 100644 --- a/cpukit/rtems/src/timerserverfireafter.c +++ b/cpukit/rtems/src/timerserverfireafter.c @@ -52,6 +52,7 @@ rtems_status_code rtems_timer_server_fire_after( { Timer_Control *the_timer; Objects_Locations location; + ISR_Level level; extern Chain_Control _Timer_Ticks_chain; if ( !_Timer_Server ) @@ -73,9 +74,28 @@ rtems_status_code rtems_timer_server_fire_after( case OBJECTS_LOCAL: (void) _Watchdog_Remove( &the_timer->Ticker ); - the_timer->the_class = TIMER_INTERVAL_ON_TASK; - _Watchdog_Initialize( &the_timer->Ticker, routine, id, user_data ); - the_timer->Ticker.initial = ticks; + + _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_ON_TASK; + _Watchdog_Initialize( &the_timer->Ticker, routine, id, user_data ); + the_timer->Ticker.initial = ticks; + _ISR_Enable( level ); _Timer_Server_stop_ticks_timer(); _Timer_Server_process_ticks_chain(); -- cgit v1.2.3