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.
The _Heap_Extend() has now the same signature as _Heap_Initialize().
The 4th parameter is ignored (page size in _Heap_Initialize()).
Add Heap_Area and Heap_Initialization_or_extend_handler.
Add and test _Heap_No_extend().
This helps to do a table based heap initialization and extension.
Create a table of Heap_Area elements and iterate through it. Set the
handler to _Heap_Initialize() in the first iteration and then to
_Heap_Extend().
Use _Workspace_Allocate_or_fatal_error() consistently in case auto
extend is turned off. This helps to avoid undefined behaviour in
_API_Mutex_Allocate() in case _API_Mutex_Information() fails.
Rename rtems_filesystem_location_exists_in_same_fs_instance_as() into
rtems_filesystem_location_exists_in_same_instance_as() for consistency
with other file system instance related functions.
Rename rtems_filesystem_location_is_root() into
rtems_filesystem_location_is_instance_root() to distinguish this from
the file system root directory of the current task environment.
Reject the removal of file system instance root nodes in rmdir() and
unlink() and return the EBUSY error status. File system instances can
be removed with unmount(). Remove root node special cases in IMFS,
DOSFS, and RFS.
The changes in _Thread_Dispatch() of commits
dad36c52b8 and
d4dc7c8196 introduced a severe bug which
destroys the real-time properties of RTEMS completely.
Consider the following scenario. We have three tasks L (lowest
priority), M (middle priority), and H (highest priority). Now let a
thread dispatch from M to L happen. An interrupt occurs in
_Thread_Dispatch() here:
void _Thread_Dispatch( void )
{
[...]
post_switch:
_ISR_Enable( level );
<-- INTERRUPT
<-- AFTER INTERRUPT
_Thread_Unnest_dispatch();
_API_extensions_Run_postswitch();
}
The interrupt event makes task H ready. The interrupt code will see
_Thread_Dispatch_disable_level > 0 and thus doesn't perform a
_Thread_Dispatch(). Now we return to position "AFTER INTERRUPT". This
means task L executes now although task H is ready! Task H will execute
once someone calls _Thread_Dispatch().
Formerly, mghttpd was conditional only on networking being
enabled. It uses on pthread and must also be conditional
on POSIX threads support being enabled.
