diff options
| -rw-r--r-- | docs/library/micropython.rst | 8 | ||||
| -rw-r--r-- | py/scheduler.c | 8 |
2 files changed, 15 insertions, 1 deletions
diff --git a/docs/library/micropython.rst b/docs/library/micropython.rst index b17dfa9a75..31b24903f1 100644 --- a/docs/library/micropython.rst +++ b/docs/library/micropython.rst @@ -136,6 +136,14 @@ Functions the heap may be locked) and scheduling a function to call later will lift those restrictions. + On multi-threaded ports, the scheduled function's behaviour depends on + whether the Global Interpreter Lock (GIL) is enabled for the specific port: + + - If GIL is enabled, the function can preempt any thread and run in its + context. + - If GIL is disabled, the function will only preempt the main thread and run + in its context. + Note: If `schedule()` is called from a preempting IRQ, when memory allocation is not allowed and the callback to be passed to `schedule()` is a bound method, passing this directly will fail. This is because creating a diff --git a/py/scheduler.c b/py/scheduler.c index 3eae8b4fa3..2170b9577e 100644 --- a/py/scheduler.c +++ b/py/scheduler.c @@ -236,7 +236,13 @@ void mp_handle_pending(bool raise_exc) { // Handle any pending callbacks. #if MICROPY_ENABLE_SCHEDULER - if (MP_STATE_VM(sched_state) == MP_SCHED_PENDING) { + bool run_scheduler = (MP_STATE_VM(sched_state) == MP_SCHED_PENDING); + #if MICROPY_PY_THREAD && !MICROPY_PY_THREAD_GIL + // Avoid races by running the scheduler on the main thread, only. + // (Not needed if GIL enabled, as GIL ensures thread safety here.) + run_scheduler = run_scheduler && mp_thread_is_main_thread(); + #endif + if (run_scheduler) { mp_sched_run_pending(); } #endif |