rtapi_task_pause.3rtapi

CNC 的开放码,EMC2 V2.2.8版

.TH rtapi_task_pause "3rtapi" "2006-10-12" "EMC Documentation" "RTAPI"
.SH NAME

rtapi_task_pause, rtapi_task_resume \- pause and resume real-time tasks

.SH SYNTAX
.HP
void rtapi_task_pause(int \fItask_id\fR)
.HP
void rtapi_task_resume(int \fItask_id\fR)

.SH  ARGUMENTS
.IP \fItask_id\fR
An RTAPI task identifier returned by an earlier call to \fBrtapi_task_new\fR.
.SH DESCRIPTION
\fBrtapi_task_resume\fR starts a task in free-running mode. 
The task must be in the "paused" state.

A free running task runs continuously until either:
.IP 1)
It is prempted by a higher priority task.  It will resume as soon as the higher
priority task releases the CPU.
.IP 2)
It calls a blocking function, like \fBrtapi_sem_take\fR.  It will resume when
the function unblocks.
.IP 3)
It is returned to the "paused" state by \fBrtapi_task_pause\fR.  May be called
from init/cleanup code, and from within realtime tasks.



\fBrtapi_task_pause\fR causes a task to stop execution and change
to the "paused" state.  The task can be free-running or periodic.
Note that \fBrtapi_task_pause\fR may called from any task, or from init
or cleanup code, not just from the task that is to be paused.
The task will resume execution when either \fBrtapi_task_resume\fR or
\fBrtapi_task_start\fR (depending on whether this is a free-running or periodic task) is called.


.SH REALTIME CONSIDERATIONS
May be called from init/cleanup code, and from within realtime tasks.

.SH RETURN VALUE
An RTAPI status code.

.SH SEE ALSO
\fBrtapi_task_new(3rtapi)\fR, \fBrtapi_task_start(3rtapi)\fR