MQX Software Solutionsのトピックlwevent functionality in a task

lwevent functionality in a task

norbertoj — Fri, 09 Sep 2016 15:59:31 GMT

Hi!!!!

I have som problems with _lewent_wait. I have a task that do two things, First, configure some buttons (Enable, Disable in SW, in a uint8 variable) for request of other task (control task),; second, detect an event (pressed or released) and report it to control task. My problem is that if I use _lewent wait_ticks, the code blocks in only waiting an event, and doesn't read the messages of control task. Is there other way with the library of lwevent?

Sincerely,

Norberto Jiménez

Re: lwevent functionality in a task

danielchen — Mon, 12 Sep 2016 06:28:12 GMT

Hi Norberto:

Yes, waiting on event bit is a blocking call. Any task can set or clear bits event field, or interrupt service routine can also set or clear bits. once the condition specified to unblock is being met, the task state will change from blocked to ready, and the scheduler will be called to see whether a context switch should be done.

Please refer to the following demo for lwevent usage.

C:\Freescale\Freescale_MQX_4_2\mqx\examples\lwevent

Regards

Daniel

Re: lwevent functionality in a task

norbertoj — Mon, 12 Sep 2016 22:52:59 GMT

Hi Daniel.

I have my task waiting for an event bit(_lwevent_wait_ticks() ) from a function that check if a button is pressed. I have another task that send a message (Create from _lwmsgq_init() ) in order to configure some characteristics of the button. I don't know if there is a way to unlock the task without use _lwevent_set(), like _task_ready(). Or , Is better assigned another event bit, and get the mask event bits?

Regards,

Norberto.