This change adds rtems_printf and related functions and wraps the
RTEMS print plugin support into a user API. All references to the
plugin are removed and replaced with the rtems_printer interface.
Printk and related functions are made to return a valid number of
characters formatted and output.
The function attribute to check printf functions has been added
to rtems_printf and printk. No changes to remove warrnings are part
of this patch set.
The testsuite has been moved over to the rtems_printer. The testsuite
has a mix of rtems_printer access and direct print control via the
tmacros.h header file. The support for begink/endk has been removed
as it served no purpose and only confused the code base. The testsuite
has not been refactored to use rtems_printf. This is future work.
Drop superfluous <stdlib.h> include from <rtems/diskdevs.h> since this
leads to conflicts with the latest Newlib in case this header file is
used in the FreeBSD kernel space, e.g. for USB mass storage support.
Bug report by Oleg Kravtsov:
In rtems_bdbuf_swapout_processing() function there is the following
lines:
if (bdbuf_cache.sync_active && !transfered_buffers)
{
rtems_id sync_requester;
rtems_bdbuf_lock_cache ();
...
}
Here access to bdbuf_cache.sync_active is not protected with anything.
Imagine the following test case:
1. Task1 releases buffer(s) with bdbuf_release_modified() calls;
2. After a while swapout task starts and flushes all buffers;
3. In the end of that swapout flush we are before that part of code, and
assume there is task switching (just before "if (bdbuf_cache.sync_active
&& !transfered_buffers)");
4. Some other task (with higher priority) does bdbuf_release_modified
and rtems_bdbuf_syncdev().
This task successfully gets both locks sync and pool (in
rtems_bdbuf_syncdev() function), sets sync_active to true and starts
waiting for RTEMS_BDBUF_TRANSFER_SYNC event with only sync lock got.
5. Task switching happens again and we are again before "if
(bdbuf_cache.sync_active && !transfered_buffers)".
As the result we check sync_active and we come inside that "if"
statement.
6. The result is that we send RTEMS_BDBUF_TRANSFER_SYNC event! Though
ALL modified messages of that task are not flushed yet!
close#1485
Use the PTHREAD mutexes and condition variables if available. This
helps on SMP configurations to avoid the home grown condition variables
via disabled preemption.
Enabling and disabling preemption as done for single core will not work
for SMP. In the bdbuf initialization preemption handling can be avoided
in general by using pthread_once().
Add a local context structure to the SMP lock API for acquire and
release pairs. This context can be used to store the ISR level and
profiling information. It may be later used to enable more
sophisticated lock algorithms, e.g. MCS locks.
There is only one lock that cannot be used with a local context. This
is the per-CPU lock since here we would have to transfer the local
context through a context switch which is very complicated.
The readv() and writev() support was implemented in terms of multiple
calls to the read and write handlers. This imposes a problem on device
files which use an IO vector as single request entity. For example a
low-level network device (e.g. BPF(4)) may use an IO vector to create
one frame from multiple protocol layers each with its own IO vector
entry.
Show the correct index of partition's last block (partition end).
The documentation of struct rtems_bdpart_partition (P) says that the member
'end' is the "Block index for partition end (this block is not a part of the
partition)". Then, the fdisk's partition table dump should print ((P)->end -
1).
Currently, one can think that the last block of a partition P is superposing
the beginning of the partition (P + 1). Example:
----------------------------------------
PARTITION TABLE
------------+------------+--------------
BEGIN | END | TYPE
------------+------------+--------------
2048 | 133120 | FAT 32
133120 | 15628032 | FAT 32
------------+------------+--------------
With be proposed patch, it would be:
----------------------------------------
PARTITION TABLE
------------+------------+--------------
BEGIN | END | TYPE
------------+------------+--------------
2048 | 133119 | FAT 32
133120 | 15628031 | FAT 32
------------+------------+--------------
All resource allocations take place in rtems_bdbuf_init() now. After
rtems_bdbuf_init() no fatal errors can happen due to configuration
errors or resource limits. This makes it easier to detect
configuration errors for users.
