Display the scheduler name instead of the current CPU in the "task"
shell command. The current CPU could be misleading in case locking
protocols are involved. The "cpuuse" command can be used to obtain the
current CPU.
Add the special thread queue name _Thread_queue_Object_name to mark
thread queues embedded in an object with identifier. Using the special
thread state STATES_THREAD_QUEUE_WITH_IDENTIFIER is not reliable for
this purpose since the thread wait information and thread state are
protected by different SMP locks in separate critical sections. Remove
STATES_THREAD_QUEUE_WITH_IDENTIFIER.
Add and use _Thread_queue_Object_initialize().
Update #2858.
Replace STATES_DELAYING with STATES_WAITING_FOR_TIME.
There is no need for separate timeout thread states. The
Thread_Control::Timer::header and Watchdog_Control::cpu members can be
used to figure out the kind of timeout.
Initialize thread queue context early preferably outside the critical
section.
Remove implicit _Thread_queue_Context_initialize() from
_Thread_Wait_acquire().
The _Thread_Lock_acquire() function had a potentially infinite run-time
due to the lack of fairness at atomic operations level.
Update #2412.
Update #2556.
Update #2765.
Introduce map/unmap priority scheduler operations to map thread priority
values from/to the user domain to/from the scheduler domain. Use the
map priority operation to validate the thread priority. The EDF
schedulers use this new operation to distinguish between normal
priorities and priorities obtain through a job release.
Update #2173.
Update #2556.
Add CORE_recursive_mutex_Control and CORE_ceiling_mutex_Control to avoid
the run-time evaluation of attributes to figure out how a particular
mutex methods should behave. Start with the no protocol variants. This
eliminates the CORE_MUTEX_DISCIPLINES_FIFO and
CORE_MUTEX_DISCIPLINES_PRIORITY disciplines.
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.
Split _Thread_Close() into _Thread_Join() and _Thread_Cancel() to
prepare for a re-use in pthread_join() and pthread_cancel().
Update #2555.
Update #2626.
This field was only by the monitor in non-multiprocessing
configurations. Add new field Thread_Wait_information::remote_id in
multiprocessing configurations and use it for the remote procedure call
thread queue.
Add _Thread_Wait_get_id() to obtain the object identifier for debug and
system information tools. Ensure the object layout via static asserts.
Add test cases to sptests/spthreadq01.
Notepads where a feature of RTEMS' tasks that simply functioned in
the same way as POSIX keys or threaded local storage (TLS). They were
introduced well before per task variables, which are also deprecated,
and were barely used in favor of their POSIX alternatives.
In addition to their scarce usage, Notepads took up unnecessary memory.
For each task:
- 16 32-bit integers were allocated.
- A total of 64 bytes per task per thread.
This is especially critical in low memory and safety-critical applications.
They are also defined as uint32_t, and therefore are not guaranteed to
hold a pointer.
Lastly, they are not portable solutions for SMP and uniprocessor systems,
like POSIX keys and TLS.
updates #2493.
This mutex implementation uses a thread priority queue with a simple
priority inheritance mechanism (similar to the object based mutexes).
The storage space must be supplied by the user (16 bytes on 32-bit
targets).
Move the storage for the thread queue heads to the threads. Each thread
provides a set of thread queue heads allocated from a dedicated memory
pool. In case a thread blocks on a queue, then it lends its heads to
the queue. In case the thread unblocks, then it takes a free set of
threads from the queue. Since a thread can block on at most one queue
this works. This mechanism is used in FreeBSD. The motivation for this
change is to reduce the memory demands of the synchronization objects.
On a 32-bit uni-processor configuration the Thread_queue_Control size is
now 8 bytes, compared to 64 bytes in RTEMS 4.10 (other changes reduced
the size as well).
A thread join is twofold. There is one thread that exists and an
arbitrary number of threads that wait for the thread exit (one-to-many
relation). The exiting thread may want to wait for a thread that wants
to join its exit (STATES_WAITING_FOR_JOIN_AT_EXIT in
_POSIX_Thread_Exit()). On the other side we need a thread queue for all
the threads that wait for the exit of one particular thread
(STATES_WAITING_FOR_JOIN in pthread_join()).
Update #2035.
