RTOS/MSP430F5659: Need guide for task sync

Nitesh Padiyar77

Genius 3745 points

Part Number: MSP430F5659

Tool/software: TI-RTOS

Hello,

I have 3 task,

Comm Task(USB Rx/Tx), Data Manager Task and Handler task(UART RX/TX),

I want to sync the comm task and Handler task, such that once i receive the USB command related UART handling, i want to lock the other USB command, or just send busy response until UART command processing is done. Which locking mechanism/blocking mechanism is good for this.

See pseudo code below.

Comm Task()

{

if(wait for the process to complete)

{

send command to Handler task

}

else

{

send busy response to USER Application over USB

}

Handler Task

{

Receive the command

Lock the OS flag/ call the Sync Mechanism

do the UART communication

release once done

}

Can any one guide me ,

i tried GateMutex enter and gateMutex Leave in Handler task , and Gatemutes Query in Comm task, I could not achieve the intended results,

Please guide me how i can achieve this, with good locking mechanism, I don't want to use Global variable mechanism, i want to use OS concept here.

How to lock using Semaphore?

Thanks in advance

Nitesh

over 8 years ago

0 Caleb Overbay over 8 years ago

TI__Genius 15370 points

Hi Nitesh,

Here are a few E2E threads I think you might find helpful:
e2e.ti.com/.../148254
e2e.ti.com/.../473876
e2e.ti.com/.../442148

Best regards,
Caleb Overbay

0 Nitesh Padiyar77 over 8 years ago in reply to Caleb Overbay

Genius 3745 points

Hello,

Can any one share mutex example for locking /unlocking without disabling H/W or Task

Thanks in advance

Nitesh

0 Caleb Overbay over 8 years ago in reply to Nitesh Padiyar77

TI__Genius 15370 points

Hi Nitesh,

I would recommend using a semaphore. You can access the count of the semaphore and react based on it's value. You can find an example of this in the examples provided with TI-RTOS called "mutex.c".

Best regards,
Caleb Overbay

0 Nitesh Padiyar77 over 8 years ago in reply to Caleb Overbay

Genius 3745 points

Hi,

If i want to acquire the semaphore in 1st task and do some activity and release the semaphore, how i can achieve this repeatedly i.e. API for acquire and release?

In second task i can read the semaphore count using getSemcoount() API correct ?

Help needed, thanks in advance
Nitesh

0 Nitesh Padiyar77 over 8 years ago in reply to Caleb Overbay

Genius 3745 points

Hello,

In Task2 i have locked few lines codes, which executes repeatedly until results are achieved. (which is UART communication with other external device)
I don't want to block the Task1 which is USB communication, instead i want to send reply BUSY which UART is working.

Please guide me, Even if semaphore used it will block the TASK1 until it is released by TASK2.
Mutex still not clear,

Thanks in advance
Nitesh

0 Caleb Overbay over 8 years ago in reply to Nitesh Padiyar77

TI__Genius 15370 points

Hi Nitesh,

Nitesh Padiyar77 said:
If i want to acquire the semaphore in 1st task and do some activity and release the semaphore, how i can achieve this repeatedly i.e. API for acquire and release?

You would use the semaphore pend and post API's shown in the example.

Nitesh Padiyar77 said:
I don't want to block the Task1 which is USB communication, instead i want to send reply BUSY which UART is working.

If you're going to use a semaphore to accomplish this, I recommend pending on the semaphore in task 2 when it starts UART communication and posting the semaphore when it has completed. Then inside task 1, you could check the semaphore count like so:

        if (Semaphore_getCount(semHandle) == 0) {
            // TASK 2 is performing UART comm
            // Send USB busy signal
        }
        else
        {
            // USB free to operate
        }

Best regards,

Caleb Overbay

0 Nitesh Padiyar77 over 8 years ago in reply to Caleb Overbay

Genius 3745 points

Hi,

Thanks Caleb,

I will implement and test it. Will let you know the status.

Nitesh

0 Caleb Overbay over 8 years ago in reply to Nitesh Padiyar77

TI__Genius 15370 points

Hi Nitesh,

Do you still need help with this issue?

Best regards,
Caleb Overbay

0 Nitesh Padiyar77 over 8 years ago in reply to Caleb Overbay

Genius 3745 points

Hi Caleb,

Thanks i have implemented and its working fine.

Regards,

Nitesh

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RTOS/MSP430F5659: Need guide for task sync