This commit adds a significant portion of the existing MicroPython asyncio
module to the webassembly port, using parts of the existing asyncio code
and some custom JavaScript parts.
The key difference to the standard asyncio is that this version uses the
JavaScript runtime to do the actual scheduling and waiting on events, eg
Promise fulfillment, timeouts, fetching URLs.
This implementation does not include asyncio.run(). Instead one just uses
asyncio.create_task(..) to start tasks and then returns to the JavaScript.
Then JavaScript will run the tasks.
The implementation here tries to reuse as much existing asyncio code as
possible, and gets all the semantics correct for things like cancellation
and asyncio.wait_for. An alternative approach would reimplement Task,
Event, etc using JavaScript Promise's. That approach is very difficult to
get right when trying to implement cancellation (because it's not possible
to cancel a JavaScript Promise).
Signed-off-by: Damien George <damien@micropython.org>
This commit adds a pyscript variant for use in https://pyscript.net/.
The configuration is:
- No ASYNCIFY, in order to keep the WASM size down and have good
performance.
- MICROPY_CONFIG_ROM_LEVEL_FULL_FEATURES to enable most features.
- Custom manifest that includes many of the python-stdlib libraries.
- MICROPY_GC_SPLIT_HEAP_AUTO to increase GC heap size instead of doing a
collection when memory is exhausted. This is needed because ASYNCIFY is
disabled. Instead the GC collection is run at the top-level before
executing any Python code.
- No MICROPY_VARIANT_ENABLE_JS_HOOK because there is no asynchronous
keyboard input to interrupt a running script.
Signed-off-by: Damien George <damien@micropython.org>
This commit cleans up and generalises the Makefile, adds support for
variants (following the unix port) and adds the "standard" variant as the
default variant.
Signed-off-by: Damien George <damien@micropython.org>
Damien George