Sometimes (like in DataFlash) the size of the ring buffer will be
determined in run time and the object can have size zero until proper
initialization. When this was the case, an underflow in ::get_size would
mess with the initializing algorithm.
Another issue was that the 'new' operator could fail what was not being
handled. Now, we only set the size member after we are sure 'new'
successfully allocated memory.
Constructor allocate '_samples' but there was no destructor to
deallocate it. Also, initializes '_gain' to silence CID 9144 although
'_gain' wasn't being used uninitialized because of ::init().
CID 91424
- causes immediate timeout so all samples were dropped
- now the timeout is current and respects the time-since-last-comms/packet so we can ignore stale packets
- reorder and document members.
- remove tentative of vertical alignement
- like was done for accumulated values, move the calibration
values to a struct
This converts MS56XX to use the thread started by SPI/I2C instead of
using the timer thread. This also fixes a possible starvation of the
main thread:
1) INS driver registers itself to be sampled on timer thread
2) MS56XX registers itself to be sampled on timer thread
3) Main thread waits for a sample from INS with
ins.wait_for_sample()
4) timer thread is waiting on update from MS56XX and consequently
the main thread is waiting on an I2C/SPI transfer
Besides this starvation there's another one due to reuse of the timer
lock in order to pump values from the timer thread to the main thread. A
call to the update() method when we have a sample available would need
to wait on any other driver holding the timer lock.
Now there's a lock just to pass the new values from the bus thread to
the main thread with a very tiny critical region, not waiting on any
bus transfers and/or syscalls.
We aren't going to use all the poller infra for now and we need it's
behavior a little bit different for what we are going to use:
- Do not use any "fair" time for each ready fd since we don't want
to set a timeout
- Allow to set the fd on Pollable after constructing it since we are
likely to embed Pollable inside other structs and just later be
able to open an fd.
- Let caller use the epoll flags directly - this is not in AP_HAL,
so there's no need to abstract them
Add system's polling infrastructure to be notified whenever a
file descriptor is ready to be read from or written to.
Adds a few classes:
* Poller, as an interface to epoll()
* Pollable, as an interface to a file descriptor
Tom Pittenger
AndersonRayner
Andrew Tridgell
murata
Pavel Kirienko
Murilo Belluzzo
Lucas De Marchi
Holger Steinhaus
Peter Barker
Randy Mackay
Leandro Pereira