The mq_open() function returns a descriptor to a POSIX message queue
object identified by a name. This is similar to sem_open(). In
contrast to the POSIX semaphore the POSIX message queues use a separate
object for the descriptor. This extra object is superfluous, since the
object identifier can be used directly for this purpose, just like for
the semaphores.
Update #2702.
Update #2555.
These were in libcsupport for historical reasons and the placement
no longer made sense.
As part of this move, some of the files were placed under subdirectories
which reflect their installed location.
Thank you git for allowing us to move files. Years of CVS resulted
in files being somewhere they no longer belonged.
The CPU time used of a thread was previously maintained per-processor
mostly during _Thread_Dispatch(). However, on SMP configurations the
actual processor of a thread is difficult to figure out since thread
dispatching is a highly asynchronous process (e.g. via inter-processor
interrupts). Only the intended processor of a thread is known to the
scheduler easily. Do the CPU usage accounting during thread heir
updates in the context of the scheduler operations. Provide the
function _Thread_Get_CPU_time_used() to get the CPU usage of a thread
using proper locks to get a consistent value.
Close#2627.
Replace malloc_is_system_state_OK() with _Malloc_System_state() to allow
early allocations, e.g. in bsp_start(). Here the _Thread_Executing is
NULL, thus an _API_Mutex_Lock() would lead to a NULL pointer access.
Move malloc() support code to general case
rtems_heap_allocate_aligned_with_boundary(). Use
rtems_heap_allocate_aligned_with_boundary() to avoid duplicated code.
Add path length parameter to
rtems_filesystem_eval_path_start_with_root_and_current() so that users
may pass paths without a '\0' termination.
Update #2558.
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.
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).
This was obsolete and broken based upon recent time keeping changes.
Thie build option was previously enabled by adding
USE_TICKS_FOR_STATISTICS=1 to the configure command line.
This propagated into the code as preprocessor conditionals
using the __RTEMS_USE_TICKS_FOR_STATISTICS__ conditional.
These header files were only used by one BSP and they are
hardware dependent. The hardware dependency always made
them bad candidates for where they were in the tree. But
this fixes that.
Sebastian Huber
Joel Sherrill
Joel Sherrill
Aun-Ali Zaidi
Gedare Bloom
Nick Withers