The following functions are fully supported in this release:
ER sta_tsk(
ID tskid,
INT stacd )
void ext_tsk( void )
void exd_tsk( void )
ER dis_dsp( void )
ER ena_dsp( void )
ER chg_pri(
ID tskid,
PRI tskpri )
ER rot_rdq(
PRI tskpri )
ER get_tid(
ID *p_tskid )
ER ref_tsk(
T_RTSK *pk_rtsk,
ID tskid )
ER ter_tsk(
ID tskid )
ER rel_wai(
ID tskid )
The following two functions are supported in this release,
when enabled with the configuration option
CYGPKG_UITRON_TASKS_CREATE_DELETE
with some restrictions:
ER cre_tsk(
ID tskid,
T_CTSK *pk_ctsk )
ER del_tsk(
ID tskid )
These functions are restricted as follows:
Because of the static initialization facilities provided for
system objects, a task is allocated stack space statically in the
configuration. So while tasks can be created and deleted, the same
stack space is used for that task (task ID number) each time. Thus
the stack size (pk_ctsk->stksz) requested in cre_tsk() is
checked for being less than that which was statically allocated,
and otherwise ignored. This ensures that the new task will have
enough stack to run. For this reason del_tsk() does
not in any sense free the memory that was in use for the task's
stack.
The task attributes (pk_ctsk->tskatr) are
ignored; current versions of eCos do not need
to know whether a task is written in assembler or C/C++ so
long as the procedure call standard appropriate to the CPU is followed.
For all these calls, an invalid task id (tskid) (less than
1 or greater than the number of configured tasks) only returns E_ID
when bad params return errors (
CYGSEM_UITRON_BAD_PARAMS_RETURN_ERRORS
is enabled, see above).
Similarly, the following conditions are only checked for,
and only return errors if
CYGSEM_UITRON_BAD_PARAMS_RETURN_ERRORS
is enabled:
pk_crtk in
cre_tsk()
is a valid pointer, otherwise return E_PAR
ter_tsk()
or
rel_wai()
on the calling task returns E_OBJ
the CPU is not locked already in
dis_dsp()
and
ena_dsp()
; returns E_CTX
priority level in
chg_pri()
and
rot_rdq()
is checked for validity, E_PAR
return value pointer in
get_tid()
and
ref_tsk()
is a valid pointer, or E_PAR
The following conditions are checked for, and return
error codes if appropriate, regardless of the setting of
CYGSEM_UITRON_BAD_PARAMS_RETURN_ERRORS
:
When create and delete functions
cre_tsk()
and
del_tsk()
are supported, all calls which use a valid task ID number check
that the task exists; if not, E_NOEXS is returned
When supported,
cre_tsk()
: the task must not already exist; otherwise E_OBJ
When supported,
cre_tsk()
: the requested stack size must not be larger than that statically
configured for the task; see the configuration options
“Static initializers”, and “Default stack size”.
Else E_NOMEM
When supported,
del_tsk()
: the underlying
eCos
thread must not be running - this would imply either a bug or some
program bypassing the
µITRON compatibility layer and manipulating the thread directly.
E_OBJ
sta_tsk()
: the task must be dormant, else E_OBJ
ter_tsk()
: the task must not be dormant, else E_OBJ
chg_pri()
: the task must not be dormant, else E_OBJ
rel_wai()
: the task must be in
WAIT or WAIT-SUSPEND
state, else E_OBJ
