It seems that we can't execute python codes in two different freerots threads!!!

[FFtust]

The "mp_task" parses and executes the python file " main.py",it works well.
Now I want to create a new task to execute a python file "factory.py", just like "main.py". my code like this:

    void mp_main_py_task(void *pvParameter){
         mp_stack_set_top((void*)&pvParameter);
         mp_stack_set_limit(MP_TASK_STACK_SIZE - 512);
         pyexec_file("factory.py");
         vTaskDelete( NULL );  
   }

This new task works well ,but then,when I sent some python code or just some meaningless code to the cpu by UART, it reboot soon; I found that the configuration"mp_stack_set_top((void*)&pvParameter)" influenced the python code parsing;
Now my question is:
Using two thread to parse python codes is allowed?If so ,how can I do it?

[dpgeorge]

Using two thread to parse python codes is allowed?

No, it's not allowed the way you have done it because the VM has global state, and 2 (or more tasks) will clash in their use of this state.

If so ,how can I do it?

Multithreading is supported by the _thread module. If you want to use multithreading at the C level then look at mpthreadport.c and use mp_thread_create to make a new thread. You'll need to make sure you use the GIL correctly as well.

[FFtust]

I tried to use the _thread module,and I have saw that my codes have excuted,but later,it rebooted soon;
I configed the MICROPY_PY_THREAD and MICROPY_PY_THREAD_GIL to 1;What did you mean "use the GIL correctly",would I need to do some other configer?
the codes:

   import _thread
   def thread_entry():
        print("done")
  
  _thread.start_new_thread(thread_entry,(1,))

[dpgeorge]

I tried to use the _thread module,and I have saw that my codes have excuted,but later,it rebooted soon;

If you have some Python code that uses the _thread module and has a bug then please file a separate report for that with the code that doesn't work.

I configed the MICROPY_PY_THREAD and MICROPY_PY_THREAD_GIL to 1

They are already configured to those values, you shouldn't need to change them.

What did you mean "use the GIL correctly",would I need to do some other configer?

If you want to use threading in C (not in Python using the _thread module) then you will need to work a bit harder to get things working correctly. There's nothing extra to configure, but you need to make sure that if you create a new FreeRTOS task that is going to run some Python code then it has acquired the GIL correctly. The code in py/modthread.c (functions mod_thread_start_new_thread and thread_entry) will help you understand what to do.

[FFtust]

I have not updated to the newest version,I will try again with the newest files,thank you for your help! 

[nickzoic]

Hey Damien, Just out of interest, how practical do you think it'd be to run a second Python interpreter on the second CPU, with its own separate GIL and the two python interpreters communicating only via message passing of one sort or another? -----Nick

[dpgeorge]

how practical do you think it'd be to run a second Python interpreter on the second CPU

It's certainly possible, and not that difficult (the port for ESA does such a thing). You don't even need to have separate CPUs, you could make it so that each task has an independent interpreter, or certain tasks are bound to one, and other tasks bound to another interpreter. You just need to provide separate copies of the global VM/runtime state (mp_state_ctx), and a way for a given instance of execution to know which state it should refer to.

Whether or not this is a good/practical idea is another question :) If you have the resources it might be fun to do, but the esp32 is pretty tight on RAM.

[dpgeorge]

This is not really a bug report so closing.