This function actually checks if we are not in the main thread rather
than if we are in the timer thread.
Add a new function that does what it's supposed to do.
RC_Channel: To nullptr from NULL.
AC_Fence: To nullptr from NULL.
AC_Avoidance: To nullptr from NULL.
AC_PrecLand: To nullptr from NULL.
DataFlash: To nullptr from NULL.
SITL: To nullptr from NULL.
GCS_MAVLink: To nullptr from NULL.
DataFlash: To nullptr from NULL.
AP_Compass: To nullptr from NULL.
Global: To nullptr from NULL.
Global: To nullptr from NULL.
When the buffer wraps and we do it in 2 steps, we can't actually do the
second part if it fails or if we wrote less bytes than we intended,
otherwise we will corrupt the data being sent.
We can't give the TX buffer 16 bytes more since next time begin() is
called it will compare the buffer size to the value the caller is trying
to set. In this case we would free and alloc the buffer again each time
begin was called.
This patch replaces the 'old style' ringbuffer by the ByteBuffer class.
An effort was made to keep the exchange as close as possible from a
drop-in replacement to minimize the risk of introducing bugs.
Although the exchange opens opportunities for improvement and
simplification of this class.
While at it, just like in the write case, explain why we are stopping.
For certain basic functionality, there aren't much benefit to be able to
vary the implementation easily at runtime. So instead of using virtual
functions, use regular functions that are "resolved" at link time. The
implementation of such functions is provided per board/platform.
Examples of functions that fit this include: getting the current
time (since boot), panic'ing, getting system information, rebooting.
These functions are less likely to benefit from the indirection provided
by virtual interfaces. For more complex hardware access APIs the
indirection makes more sense and ease the testing (when we have it!).
The idea is that instead of calling
hal.scheduler->panic("on the streets of london");
now use
AP_HAL::panic("on the streets of london");
A less important side-effect is that call-site code gets
smaller. Currently the compiler needs to get the hal, get the scheduler
pointer, get the right function pointer in the vtable for that
scheduler. And the call must include an extra parameter ("this"). Now it
will be just a function call, with the address resolved at link time.
This patch introduces the first functions that will be in the namespace,
further patches will implementations for each board and then switch the
call-sites. The extra init() function allow any initial setup needed for
the functions to work.