https://www.python.org/dev/peps/pep-0475/
This implements something similar to PEP 475 on the unix port, and for the
VfsPosix class.
There are a few differences from the CPython implementation:
- Since we call mp_handle_pending() between any ENITR's, additional
functions could be called if MICROPY_ENABLE_SCHEDULER is enabled, not
just signal handlers.
- CPython only handles signal on the main thread, so other threads will
raise InterruptedError instead of retrying. On MicroPython,
mp_handle_pending() will currently raise exceptions on any thread.
A new macro MP_HAL_RETRY_SYSCALL is introduced to reduce duplicated code
and ensure that all instances behave the same. This will also allow other
ports that use POSIX-like system calls (and use, eg, VfsPosix) to provide
their own implementation if needed.
The stack size adjustment for detecting stack overflow in threads was not
taking into account that the requested stack size could be <= 8k, in which
case the subtraction would overflow. This is fixed in this commit by
ensuring that the adjustment can't be more than the available size.
This fixes the test tests/thread/thread_stacksize1.py which sometimes
crashes with a segmentation fault because of an uncaught NLR jump, which is
a "maximum recursion depth exceeded" exception.
Suggested-by: @dpgeorge
Implements Task and TaskQueue classes in C, using a pairing-heap data
structure. Using this reduces RAM use of each Task, and improves overall
performance of the uasyncio scheduler.
Includes a test where the (non uasyncio) client does a RST on the
connection, as a simple TCP server/client test where both sides are using
uasyncio, and a test for TCP stream close then write.
This commit adds a completely new implementation of the uasyncio module.
The aim of this version (compared to the original one in micropython-lib)
is to be more compatible with CPython's asyncio module, so that one can
more easily write code that runs under both MicroPython and CPython (and
reuse CPython asyncio libraries, follow CPython asyncio tutorials, etc).
Async code is not easy to write and any knowledge users already have from
CPython asyncio should transfer to uasyncio without effort, and vice versa.
The implementation here attempts to provide good compatibility with
CPython's asyncio while still being "micro" enough to run where MicroPython
runs. This follows the general philosophy of MicroPython itself, to make it
feel like Python.
The main change is to use a Task object for each coroutine. This allows
more flexibility to queue tasks in various places, eg the main run loop,
tasks waiting on events, locks or other tasks. It no longer requires
pre-allocating a fixed queue size for the main run loop.
A pairing heap is used to queue Tasks.
It's currently implemented in pure Python, separated into components with
lazy importing for optional components. In the future parts of this
implementation can be moved to C to improve speed and reduce memory usage.
But the aim is to maintain a pure-Python version as a reference version.
To enable lazy loading of submodules (among other things), which is very
useful for MicroPython libraries that want to have optional subcomponents.
Disabled explicitly on minimal ports.
David Lechner
David Lechner
Damien George