This patch adds a simple but powerful hook into the import system, in a
CPython compatible way, by allowing to override builtins.__import__.
This does introduce some overhead to all imports but it's minor:
- the dict lookup of __import__ is bypassed if there are no modifications
to the builtins module (which is the case at start up);
- imports are not performance critical, usually done just at the start of a
script;
- compared to how much work is done in an import, looking up a value in a
dict is a relatively small additional piece of work.
JSON requires that keys of objects be strings. CPython will therefore
automatically quote simple types (NoneType, bool, int, float) when they are
used directly as keys in JSON output. To prevent subtle bugs and emit
compliant JSON, MicroPython should at least test for such keys so they
aren't silently let through. Then doing the actual quoting is a similar
cost to raising an exception, so that's what is implemented by this patch.
Fixes issue #4790.
The previous version did not work on MCUs that only had USB device mode
(compared to OTG) because of the handling of NAK. And this previous
handling of NAK had a race condition where a new packet could come in
before USBD_HID_SetNAK was called (since USBD_HID_ReceivePacket clears NAK
as part of its operation). Furthermore, the double buffering of incoming
reports was not working, only one buffer could be used at a time.
This commit rewrites the HID interface code to have a single incoming
buffer, and only calls USBD_HID_ReceivePacket after the user has read the
incoming report (similar to how the VCP does its flow control). As such,
USBD_HID_SetNAK and USBD_HID_ClearNAK are no longer needed.
API functionality from the user's point of view should be unchanged with
this commit.
Use "-f" to select filesystem mode, followed by the command to execute.
Optionally put ":" at the start of a filename to indicate that it's on the
remote device, if it would otherwise be ambiguous.
Examples:
$ pyboard.py -f ls
$ pyboard.py -f cat main.py
$ pyboard.py -f cp :main.py . # get from device
$ pyboard.py -f cp main.py : # put to device
$ pyboard.py -f rm main.py
On this port the GIL is enabled and everything works under the assumption
of the GIL, ie that a given task has exclusive access to the uPy state, and
any ISRs interrupt the current task and therefore the ISR inherits
exclusive access to the uPy state for the duration of its execution.
If the MicroPython tasks are not pinned to a specific core then an ISR may
be executed on a different core to the task, making it possible for the
main task and an ISR to execute in parallel, breaking the assumption of the
GIL.
The easiest and safest fix for this is to pin all MicroPython related code
to the same CPU core, as done by this patch. Then any ISR that accesses
MicroPython state must be registered from a MicroPython task, to ensure it
is invoked on the same core.
See issue #4895.
Milan Rossa
Damien George
Arsenijs
Paul m. p. P
Eric Poulsen
Yonatan Goldschmidt
badlyby
Amir Gonnen