The work areas (RTEMS work space and C program heap) will be initialized
now in a separate step and are no longer part of
rtems_initialize_data_structures(). Initialization is performed with
tables of Heap_Area entries. This allows usage of scattered memory
areas present on various small scale micro-controllers.
The sbrk() support API changes also. The bsp_sbrk_init() must now deal
with a minimum size for the first memory chunk to take the configured
work space size into account.
Add nanoseconds_per_tick to rtems_configuration_table. This value will
be derived from the microseconds_per_tick value. This avoids some
calculations at run-time.
Read-ahead requests were previously executed in the context of the
reading task. This blocks the reading task until the complete read
with read-ahead transfer is finished. A read-ahead task is introduced
to off-load the read-ahead transfer. This allows the reading task to
work with the requested block more quickly. The read-ahead is triggered
after two misses of ascending consecutive blocks or a read hit of a
block read by the most-recent read-ahead transfer. The read-ahead
feature is configurable and can be disabled.
Script does what is expected and tries to do it as
smartly as possible.
+ remove occurrences of two blank comment lines
next to each other after Id string line removed.
+ remove entire comment blocks which only exited to
contain CVS Ids
+ If the processing left a blank line at the top of
a file, it was removed.
The implementation of RBTree_Next was using an awkward construction to detect
and avoid accessing the false root of the red-black tree. To deal with the
false root, RBTree_Next was comparing node parents with the control node.
Instead the false root can be detected by checking if the grandparent of a
node exists; the grandparent of the tree's true root is NULL by definition
so the root of the tree is found while walking up the tree by checking for
the non-existence of a grandparent.
This change propagates into the predecessor/successor and iterate functions.
Make default for rtems_rbtree functions be unprotected (preemption enabled)
unless an unprotected variant e.g. rtems_rbtree_xxx_unprotected is available.
The per file descriptor semaphore (field of rtems_libio_t) is unused in
RTEMS. There is a considerable memory overhead due to that. A
semaphore needs roughly 124 bytes which is huge compared to the
approximately 72 bytes for the file descriptor structure itself. Device
drivers can create their own synchronization primitives in the open
handler on demand.
New macros
o _Objects_Maximum_per_allocation(),
o rtems_resource_is_unlimited(), and
o rtems_resource_maximum_per_allocation().
New function
o _Objects_Is_unlimited().
In the Red-Black Tree Heap the administration data structures are not
contained in the managed memory area. This can be used for example in a
task stack allocator which protects the task stacks from access by other
tasks.
New functions
o _RBTree_Next_unprotected(),
o _RBTree_Next(),
o _RBTree_Successor_unprotected(),
o _RBTree_Predecessor_unprotected(),
o rtems_rbtree_successor_unprotected(), and
o rtems_rbtree_predecessor_unprotected().
Change prototype of
o _RBTree_Successor(),
o _RBTree_Predecessor(),
o rtems_rbtree_successor(), and
o rtems_rbtree_predecessor().
Adds to confdefs a way to specify rtems_resource_unlimited for classic and
posix objects using a new macro CONFIGURE_OBJECTS_UNLIMITED.
Use CONFIGURE_OBJECTS_ALLOCATION_SIZE to declare the allocation size for
extending the set of objects at runtime. Updates the unlimited sample
to demonstrate how to use the new macros. Also adds new documentation in
the C User's Manual regarding configuring with unlimited objects.
o A new data structure rtems_filesystem_global_location_t was
introduced to be used for
o the mount point location in the mount table entry,
o the file system root location in the mount table entry,
o the root directory location in the user environment, and
o the current directory location in the user environment.
During the path evaluation global start locations are obtained to
ensure that the current file system instance will be not unmounted in
the meantime.
o The user environment uses now reference counting and is protected
from concurrent access.
o The path evaluation process was completely rewritten and simplified.
The IMFS, RFS, NFS, and DOSFS use now a generic path evaluation
method. Recursive calls in the path evaluation have been replaced
with iteration to avoid stack overflows. Only the evaluation of
symbolic links is recursive. No dynamic memory allocations and
intermediate buffers are used in the high level path evaluation. No
global locks are held during the file system instance specific path
evaluation process.
o Recursive symbolic link evaluation is now limited by
RTEMS_FILESYSTEM_SYMLOOP_MAX. Applications can retrieve this value
via sysconf().
o The device file system (devFS) uses now no global variables and
allocation from the workspace. Node names are allocated from the
heap.
o The upper layer lseek() performs now some parameter checks.
o The upper layer ftruncate() performs now some parameter checks.
o unmask() is now restricted to the RWX flags and protected from
concurrent access.
o The fchmod_h and rmnod_h file system node handlers are now a file
system operation.
o The unlink_h operation has been removed. All nodes are now destroyed
with the rmnod_h operation.
o New lock_h, unlock_h, clonenod_h, and are_nodes_equal_h file system
operations.
o The path evaluation and file system operations are now protected by
per file system instance lock and unlock operations.
o Fix and test file descriptor duplicate in fcntl().
o New test fstests/fsnofs01.
PR 1924/cpukit
* sapi/include/rtems/config.h: Added stack_allocate_init_hook to
rtems_configuration_table.
* sapi/include/confdefs.h: Added CONFIGURE_TASK_STACK_FROM_ALLOCATOR
and CONFIGURE_TASK_STACK_ALLOCATOR_INIT defines. Set default stack
allocator and free hook to _Workspace_Allocate() and _Workspace_Free()
respectively.
* score/src/thread.c, score/src/threadstackallocate.c,
score/src/threadstackfree.c: Update due to API changes.
PR 1924/cpukit
* sapi/include/rtems/config.h: New fields stack_space_size,
unified_work_area, and stack_allocator_avoids_work_space in
rtems_configuration_table.
* sapi/include/confdefs.h: Removed rtems_unified_work_area (this is
now part of the Configuration). Separate work space and stack space
estimate. Added CONFIGURE_TASK_STACK_ALLOCATOR_AVOIDS_WORK_SPACE
configuration option.
* libmisc/shell/main_wkspaceinfo.c, score/src/wkspace.c,
libcsupport/src/malloc_initialize.c: Update due to API changes.
PR 1906/cpukit
* sapi/Makefile.am, sapi/preinstall.am, sapi/include/confdefs.h,
score/Makefile.am, score/preinstall.am: Add the CBS (Constant
Bandwidth Server) scheduler. This is a complex scheduling policy
built atop of the EDF scheduler. Unlike other schedulers, this one
provides a user API and handles not only deadlines of tasks but also
claimed budget per period. The main aim of the scheduler is isolation
of tasks so that each task is guaranteed to meet all deadlines
regardless of how other tasks behave.
* sapi/include/rtems/cbs.h, sapi/inline/rtems/cbs.inl,
score/include/rtems/score/schedulercbs.h, score/src/schedulercbs.c,
score/src/schedulercbsattachthread.c,
score/src/schedulercbscleanup.c,
score/src/schedulercbscreateserver.c,
score/src/schedulercbsdestroyserver.c,
score/src/schedulercbsdetachthread.c,
score/src/schedulercbsgetapprovedbudget.c,
score/src/schedulercbsgetexecutiontime.c,
score/src/schedulercbsgetparameters.c,
score/src/schedulercbsgetremainingbudget.c,
score/src/schedulercbsgetserverid.c,
score/src/schedulercbsreleasejob.c,
score/src/schedulercbssetparameters.c,
score/src/schedulercbsunblock.c: New files.
PR 1886/cpukit
* sapi/include/rtems/rbtree.h, sapi/inline/rtems/rbtree.inl,
score/include/rtems/score/rbtree.h,
score/inline/rtems/score/rbtree.inl, score/src/rbtree.c,
score/src/rbtreeinsert.c: This patch enables inserting duplicate keys
into rbtree. It is possible to turn on this feature when initializing
the tree.
* sapi/include/confdefs.h: Include <bsp.h> for BSP_IDLE_TASK_BODY,
BSP_IDLE_TASK_STACK_SIZE, BSP_INTERRUPT_STACK_SIZE,
BSP_ZERO_WORKSPACE_AUTOMATICALLY, BSP_DEFAULT_UNIFIED_WORK_AREAS,
CONFIGURE_MALLOC_BSP_SUPPORTS_SBRK, and
CONFIGURE_BSP_PREREQUISITE_DRIVERS defines.
PR 1805/cpukit
* sapi/include/confdefs.h: Currently unified areas are defined
per-application. For some memory constrained and/or very dynamic
environments (BSPs), it may be better to have per-BSP default value.
This patch introduces such option. The default behaviour is left
unchanged.
PR 1804/cpukit
* sapi/include/confdefs.h: Replace obsolete THREAD_READY_CHAINS with
CONFIGURE_MEMORY_FOR_SCHEDULER and
CONFIGURE_MEMORY_PER_TASK_FOR_SCHEDULER in debug structure.
