A background callback must never outlive its related object. By
collecting the head of the linked list of background tasks, this will
not happen.
One hypothetical case where this could happen is if an MP3Decoder is
deleted while its callback to fill its buffer is scheduled.
In time, we should transition interrupt driven background tasks out of the
overall run_background_tasks into distinct background callbacks,
so that the number of checks that occur with each tick is reduced.
Length was stored as a 16-bit number always. Most translations have
a max length far less. For example, US English translation lengths
always fit in just 8 bits. probably all languages fit in 9 bits.
This also has the side effect of reducing the alignment of
compressed_string_t from 2 bytes to 1.
testing performed: ran in german and english on pyruler, printed messages
looked right.
Firmware size, en_US
Before: 3044 bytes free in flash
After: 3408 bytes free in flash
Firmware size, de_DE (with #2967 merged to restore translations)
Before: 1236 bytes free in flash
After: 1600 bytes free in flash
This PR refines the _bleio API. It was originally motivated by
the addition of a new CircuitPython service that enables reading
and modifying files on the device. Moving the BLE lifecycle outside
of the VM motivated a number of changes to remove heap allocations
in some APIs.
It also motivated unifying connection initiation to the Adapter class
rather than the Central and Peripheral classes which have been removed.
Adapter now handles the GAP portion of BLE including advertising, which
has moved but is largely unchanged, and scanning, which has been enhanced
to return an iterator of filtered results.
Once a connection is created (either by us (aka Central) or a remote
device (aka Peripheral)) it is represented by a new Connection class.
This class knows the current connection state and can discover and
instantiate remote Services along with their Characteristics and
Descriptors.
Relates to #586
* Fixes safe mode on the SAMD51. The "preserved" value was being
clobbered by the bootloader.
* Fixes auto-reload loop when in safe mode.
* Fixes reading Group children with [].
* Check that a TileGrid actually moves before queueing a refresh.
* Fix Hallowing.
* Fix builds without displayio.
* Fix y bounds that appears as untrollable row of pixels.
* Add scrolling to TileGrid.
* Remove Sprite to save space. TileGrid is a drop in replacement.
It wasn't being run due to a rework done only on the atmel-samd port.
The rework itself isn't needed now that the heap check triggers safe
mode instead of throwing a Python exception. So, I've removed the
rework.
This creates a common safe mode mechanic that ports can share.
As a result, the nRF52 now has safe mode support as well.
The common safe mode adds a 700ms delay at startup where a reset
during that window will cause a reset into safe mode. This window
is designated by a yellow status pixel and flashing the single led
three times.
A couple NeoPixel fixes are included for the nRF52 as well.
Fixes#1034. Fixes#990. Fixes#615.
The backtrace cannot be given because it relies on the validity
of the qstr data structures on the heap which may have been
corrupted.
In fact, it still can crash hard when the bytecode itself is
overwritten. To fix, we'd need a way to skip gathering the
backtrace completely.
This also increases the default stack size on M4s so it can
accomodate the stack needed by ASF4s nvm API.
