Move the writes to Thread_Control::current_priority and
Thread_Control::real_priority into _Thread_Change_priority() under the
protection of the thread lock. Add a filter function to
_Thread_Change_priority() to enable specialized variants.
Avoid race conditions during a thread priority restore with the new
Thread_Control::priority_restore_hint for an important average case
optimizations used by priority inheritance mutexes.
Update #2273.
Use thread wait flags for synchronization. The enqueue operation is now
part of the initial critical section. This is the key change and
enables fine grained locking on SMP for objects using a thread queue
like semaphores and message queues.
Update #2273.
Replace the Thread_Priority_control with more general
Thread_queue_Operations which will be used for generic priority change,
timeout, signal and wait queue operations in the future.
Update #2273.
Merge THREAD_WAIT_STATE_SATISFIED, THREAD_WAIT_STATE_TIMEOUT,
THREAD_WAIT_STATE_INTERRUPT_SATISFIED, and
THREAD_WAIT_STATE_INTERRUPT_TIMEOUT into one state
THREAD_WAIT_STATE_READY_AGAIN. This helps to write generic routines to
block a thread.
Update #2273.
Use mostly the standard watchdog operations. Use a system event for
synchronization. This implementation is simpler and offers better SMP
performance.
Close#2131.
Rewrite the _Watchdog_Insert(), _Watchdog_Remove() and
_Watchdog_Tickle() functions to use iterator items to synchronize
concurrent operations. This makes it possible to get rid of the global
variables _Watchdog_Sync_level and _Watchdog_Sync_count which are a
blocking point for scalable SMP solutions.
Update #2307.
Add watchdog header parameter to _Watchdog_Remove() to be in line with
the other operations. Add _Watchdog_Remove_ticks() and
_Watchdog_Remove_seconds() for convenience.
Update #2307.
Account for priority changes of threads executing in a foreign
partition. Exchange idle threads in case a victim node uses an idle
thread and the new scheduled node needs an idle thread.
There may be a way to reduce the memory requirements but it
will require time to ensure the math is right and it passes
on all targets. At the current time, it fails on 22 BSPs which
run on simulators.
Remove _Thread_Acquire() and _Thread_Acquire_for_executing(). Add
utility functions for the default thread lock. Use the default thread
lock for the RTEMS events. There is no need to disable thread
dispatching and a Giant acquire in _Event_Timeout() since this was
already done by the caller.
Update #2273.
The Allocator Mutex should not be locked outside a tested
service call. In an SMP test or heavily multithreaded test,
this is possible since another thread could have the lock
for an extended period of time but this is not the norm
for the tests.
updates 2319.
Since the thread current priority change and thread queue requeue is
performed in one critical section it is possible to simplify the thread
queue requeue procedure. Add a thread queue agnostic thread priority
change handler so that we are able to use alternative thread queue
implementations.
Update #2273.
