The compiler is not picky right now, but these are actually all syntax
errors:
- await is only valid in an async function
- async functions that use yield are actually async generators (a construct
not supported by the compiler right now)
This is useful in situations where the ThreadSafeFlag is reused and needs
to be cleared of any previous, unwanted event.
For example, clear the flag at the start of an operation, trigger the
operation (eg an I2C write), then (a)wait for an external event to set the
flag (eg a pin IRQ). Further events may trigger the flag again but these
are unwanted and should be cleared before the next cycle starts.
These are internal names and can be safely renamed without affecting user
code. push_sorted() and push_head() are merged into a single push()
method, which is already how the C version is implemented. pop_head() is
simply renamed to pop().
The changes are:
- q.push_sorted(task, t) -> q.push(task, t)
- q.push_head(task) -> q.push(task)
- q.pop_head() -> q.pop()
The shorter names and removal of push_head() leads to a code size reduction
of between 40 and 64 bytes on bare-metal targets.
Signed-off-by: Damien George <damien@micropython.org>
This is a MicroPython-extension that allows for code running in IRQ
(hard or soft) or scheduler context to sequence asyncio code.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
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.
Jim Mussared
Damien Tournoud
Damien George
Ned Konz
Damien George