The fat_file_datasync() read every cluster of the file into the cache
and then synchronized it step-by-step. For unmodified buffers this is a
non-operation. For modified buffers this will wake-up the swapout task
which performs then a single buffer write operation. This is usually
quite inefficient. Firstly we do single buffer writes, secondly we
may perform a lot of unnecessary read operations (for huge files this is
really bad), and thirdly this leads likely to cache evictions.
The synchronization procedure is replaced by a simple
rtems_bdbuf_sync_dev(). This has the side-effect that also buffers not
related to the file are synchronized, but since the modified list is
normally short this should be acceptable.
According to POSIX the lseek() function shall not, by itself, extend the
size of a file.
Remove the size field of rtems_libio_t. A file has only one size but
may have multiple open file descriptors. Thus a file size field in the
file descriptor may lead to inconsistencies.
New default handlers rtems_filesystem_default_lseek_file() and
rtems_filesystem_default_lseek_directory().
The prototype for the clock driver tick isr varies based upon
the interrupt model used by the port. This driver was checking
solely upon a flag set by the BSP.
In particular CPU_INTERRUPT_NUMBER_OF_VECTORS and
CPU_INTERRUPT_MAXIMUM_VECTOR_NUMBER are only used on
Simple Vectored Architectures, so do not depend on
them being defined. This disables as much as possible
that is specific to the Simple Vectored Model and
not expected to be used on architectures which use
the Programmable Interrupt Controller model for
interrupt handler vectoring.
Global data was declared in system.h but should have been extern
in system.h and declared in init.c. There were duplicate symbol
linking errors on at least powerpc/mpc8260ads.
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.
When inserting to a red-black tree with duplicates the min and max pointers are
not updated properly. We need to check the key of the min/max node against the
insert node since the insert point could be the child of a node with an
identical key to the min/max node.
During node extraction from a red-black tree the min and max values are updated
incorrectly. We need to use the successor/predecessor functions to find the
next/previous node when we remove the min/max from the tree.
Make default for rtems_rbtree functions be unprotected (preemption enabled)
unless an unprotected variant e.g. rtems_rbtree_xxx_unprotected is available.
Sebastian Huber
Joel Sherrill
Gedare Bloom