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author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2016-05-13 11:22:39 +0200 |
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committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2016-05-20 07:49:38 +0200 |
commit | 862a0eeb1197539c0e69381cb5aaccb9e1c64c0f (patch) | |
tree | 05a2d2116e3a521ddf3843aba5382354507e856b /cpukit/score/src/threadrestart.c | |
parent | score: Split _Thread_Restart() (diff) | |
download | rtems-862a0eeb1197539c0e69381cb5aaccb9e1c64c0f.tar.bz2 |
score: Rework _Thread_Restart_other()
Rework _Thread_Restart_other() to use _Thread_Change_life_locked().
Cope with concurrent change requests by means of a pending request
counter.
Update #2555.
Update #2626.
Diffstat (limited to '')
-rw-r--r-- | cpukit/score/src/threadrestart.c | 88 |
1 files changed, 79 insertions, 9 deletions
diff --git a/cpukit/score/src/threadrestart.c b/cpukit/score/src/threadrestart.c index 8adbfa212a..4abfd55203 100644 --- a/cpukit/score/src/threadrestart.c +++ b/cpukit/score/src/threadrestart.c @@ -368,7 +368,7 @@ static void _Thread_Start_life_change( the_thread->budget_algorithm = the_thread->Start.budget_algorithm; the_thread->budget_callout = the_thread->Start.budget_callout; - _Thread_Set_state( the_thread, STATES_RESTARTING ); + _Thread_Set_state( the_thread, STATES_LIFE_IS_CHANGING ); _Thread_queue_Extract_with_proxy( the_thread ); _Thread_Timer_remove( the_thread ); _Thread_Raise_real_priority( the_thread, priority ); @@ -407,6 +407,64 @@ static void _Thread_Request_life_change( } } +static void _Thread_Add_life_change_request( Thread_Control *the_thread ) +{ + uint32_t pending_requests; + + _Assert( _Thread_State_is_owner( the_thread ) ); + + pending_requests = the_thread->Life.pending_life_change_requests; + the_thread->Life.pending_life_change_requests = pending_requests + 1; + + if ( pending_requests == 0 ) { + _Thread_Set_state_locked( the_thread, STATES_LIFE_IS_CHANGING ); + } +} + +static void _Thread_Remove_life_change_request( Thread_Control *the_thread ) +{ + ISR_lock_Context lock_context; + uint32_t pending_requests; + + _Thread_State_acquire( the_thread, &lock_context ); + + pending_requests = the_thread->Life.pending_life_change_requests; + the_thread->Life.pending_life_change_requests = pending_requests - 1; + + if ( pending_requests == 1 ) { + /* + * Do not remove states used for thread queues to avoid race conditions on + * SMP configurations. We could interrupt an extract operation on another + * processor disregarding the thread wait flags. Rely on + * _Thread_queue_Extract_with_proxy() for removal of these states. + */ + _Thread_Clear_state_locked( + the_thread, + STATES_LIFE_IS_CHANGING | STATES_SUSPENDED + | ( STATES_BLOCKED & ~STATES_LOCALLY_BLOCKED ) + ); + } + + _Thread_State_release( the_thread, &lock_context ); +} + +static void _Thread_Finalize_life_change( + Thread_Control *the_thread, + Priority_Control priority +) +{ + _Thread_queue_Extract_with_proxy( the_thread ); + _Thread_Timer_remove( the_thread ); + _Thread_Change_priority( + the_thread, + priority, + NULL, + _Thread_Raise_real_priority_filter, + false + ); + _Thread_Remove_life_change_request( the_thread ); +} + void _Thread_Join( Thread_Control *the_thread, States_Control waiting_for_join, @@ -486,7 +544,8 @@ bool _Thread_Restart_other( ISR_lock_Context *lock_context ) { - Per_CPU_Control *cpu_self; + Thread_Life_state previous; + Per_CPU_Control *cpu_self; _Thread_State_acquire_critical( the_thread, lock_context ); @@ -496,16 +555,27 @@ bool _Thread_Restart_other( } the_thread->Start.Entry = *entry; + previous = _Thread_Change_life_locked( + the_thread, + 0, + THREAD_LIFE_RESTARTING, + 0 + ); cpu_self = _Thread_Dispatch_disable_critical( lock_context ); - _Thread_State_release( the_thread, lock_context ); - _Thread_Request_life_change( - the_thread, - NULL, - the_thread->Start.initial_priority, - THREAD_LIFE_RESTARTING - ); + if ( _Thread_Is_life_change_allowed( previous ) ) { + _Thread_Add_life_change_request( the_thread ); + _Thread_State_release( the_thread, lock_context ); + + _Thread_Finalize_life_change( + the_thread, + the_thread->Start.initial_priority + ); + } else { + _Thread_Clear_state_locked( the_thread, STATES_SUSPENDED ); + _Thread_State_release( the_thread, lock_context ); + } _Thread_Dispatch_enable( cpu_self ); return true; |