Commit graph

19 commits

Author SHA1 Message Date
Joe Finney
b2e9369771 microbit: BUGFIX DoS attacks on the MessageBus
- Enures an event listener is not deleted whilst a fiber is activiely processing a queue
 - Added support for resurrection of event listeners in cases where identical listeners are removed/added repetitively.
2015-11-01 12:59:52 +00:00
Joe Finney
84da6a4a09 microbit: Minor bug fixes and refinements
- Add maximum depth for event queues, to prevent buggy scripts causing total memory exhaustion.
  - Suppress generation of A/B click events when A+B click is generated
  - preservation of event ordering on messagebus for resursive event generation cases.
  - bugfix of message bus processing to prevent occasional dual processing of events
  - bugfix MicroBitDisplay to behave correctly when delay parameter is zero.
2015-10-31 10:27:38 +00:00
Joe Finney
0fa8296048 microbit: BUGFIX safe deletion of listeners
also correction to minor bu in MicroBitFiber that could conceivably send more
notifications that it should...
2015-10-29 00:08:33 +00:00
Joe Finney
1eeaeca2c6 microbit: BUGFIX - correct initialization of MicroBitListener
code now correctly initiailizes the evt_queue filed needed to prevent
lockup during event processing (understandably!).
2015-10-28 14:17:12 +00:00
Joe Finney
424b825185 Merge branch 'master' into simplified-eventing
Conflicts:
	inc/MicroBitMessageBus.h
2015-10-18 18:20:03 +01:00
Joe Finney
80f79f7faf Merge branch 'master' into ble-profile
Conflicts:
	source/CMakeLists.txt
	source/MicroBit.cpp
	source/MicroBitFiber.cpp
	source/MicroBitMessageBus.cpp
	source/MicroBitSuperMain.cpp
2015-10-18 17:54:37 +01:00
Joe Finney
aca544677e microbit: Updates to enable queing of display animation calls
Updates to change the behaviour of the scroll/print/animate faily of function away
from being pre-emtive and instead prroviding queing behaviour.

Minor updates to provide complete sets of async equivalent operations

Updates to the scheduler to provide wait/notify/waitone semantics.
2015-10-17 20:35:16 +01:00
Joe Finney
18236810a3 microbit: BLE Profile Beta 1
First functionally complete BLE profile, matching BLE speicfication v1.6.
More specifically, the following services are now functional:

  - AccelerometerService
  - MeganetometerService
  - EventService
  - TemperatureServide
  - IOPinService
  - DFUService
  - ButtonService
  - LEDService

Also, updates to underlying device drivers to enable greater configurability:

  - MicroBitCompass now supports variable sample rates and temperature sensing
  - MicroBitAccelerometer now supports variable sample rates and ranges
  - MicroBitThermometer introduced
  - MicroBitMessageBus adapted to permit enumeration and block removal of listeners

Finally, MicroBit DFU Service has been changed to the new UUIDs specificed in v1.6 of BLE spec.
2015-09-28 21:40:44 +01:00
Joe Finney
eb5ed28f74 microbit: First cut at MicroBitButtonService and microBitIOPinService
Strictly still development - untested code.
2015-09-22 16:13:08 +01:00
Joe Finney
3cfc7ec6e7 microbit: Ammendments to ensure fiber is never pages out due to eventing and minor cleanups
- renamed fiber flag to be more general.
- renamed idle to idleFiber to be consistent with the rest of the code.
- factored content of idle() into a funciton to avoid dupication.
- added test case to MessageBus::process() to avoid forking fibers if not requested.
- removed fiber_allow_run_idle_within mutator in favour of exposing currentFiber, as a more general solution.
2015-09-19 21:44:58 +01:00
Joe Finney
2c9f63902c microbit: Message Bus updates to support URGENT events queue optimisations
Added new URGENT listener type, that ensures immediate, non queuing delivery of events.
Introduced two-pass algorithm into message bus. Only events with an event listener are now
queued at ingress - this reduces unecessary memory usage for 'uninteresting' events.
2015-09-18 23:20:44 +01:00
Jonathan Protzenko
78ad8a1646 Small tweak for the new ignore function. 2015-09-16 12:08:09 -07:00
Joe Finney
3395f66d3d microbit: Added configurable event processing options into MicroBitEvent
Events in the micro:bit runtime are normally launched through making an instance
of the MicroBitEvent class. This update added configuration support to all the
code creating the MicroBitEvent decide if the newly created event should then be
automatically queued on the MessageBus or processed immediately by event handlers.
2015-09-12 11:34:16 +01:00
Joe Finney
a875d5fccd microbit: Added configurable concurrency modes for MicroBitMessageBus handlers.
MessageBus handlers can now have one of four concurrency modes for the eventuality
of an event being raised whilst a previous event is still being processed. An additional
(optional) parameter is provided to the listen() functions to allow this to be selected
on a per event handler basis. The permissable options are:

MESSAGE_BUS_LISTENER_REENTRANT:
The event handler is fired with the new event, regardless of whether or not
a previous event is still be processed by that handler.

MESSAGE_BUS_LISTENER_QUEUE_IF_BUSY:
The new event is queued until such a time as the previous event has completed
execution. The new event is then processed. This option does not preclude the
processing of the new event by other event handlers.

MESSAGE_BUS_LISTENER_DROP_IF_BUSY:
The new event is dropped, and will never be processed the the event handler.
This option does not preclude the processing of the new event by other event handlers.

MESSAGE_BUS_LISTENER_NONBLOCKING:
The event handler is self-declaring that it never blocks. This flag is used purely
for optimisation, as it permits direct execution of the event hadnelr without inducing
any overhead from the scheduler.

In addition, the following minor revisions were made in this release:

* Cleanup of the #include dependencies contained in the microbit-dal .h files
* Bugfix to the scheduler block on event matching code.
* Introduced a MICROBIT_ID_ALERT MessageBus channel, for general purpose eventing using nonces.
2015-09-11 16:39:38 +01:00
Joe Finney
51493092ff microbit: Added support to remove MicroBitListener event handlers. 2015-09-10 12:53:39 +01:00
Joe Finney
8ea2e953c8 microbit: Added C++ member function callback support into MicroBitMessageBus
Event callbacks can now be transparently added to any C++ member function
matching the MicroBitMessageBud signature:  void fn(MicroBitEvent e)
2015-09-10 00:04:27 +01:00
Joe Finney
857a626ed0 microbit: Memory Optimisation Mega Update
This release contains a widespread set of updates and optimisations to the micro:bit
runtime, with a view to reducing the SRAM footprint of the whole system. This is to
provide as much usable HEAP storage for application programs as possible.

Specific updates and optimisations include:

  - Additional compilation flags to allow the core micro:bit runtime to be configured.
    These are defined in MicroBitConfig.h

  - A custom heap allocator. This is now included for two reasons:

    1) To provide a simple mechanism to to utilise both the mbed heap space and other memory
       regions (such as unused memory in the SoftDevice region) as a single virtual heap.
    2) To address some issues that have been noted that are attributable to heap fragmentation.
       The micro:bit heap allocator has a simple algorithm, but one that is chosen to respond
       well to the relativelt high 'heap churn' found in the micro:bit environment.

    All micro:bit components and user programs now use this heap allocator trasparently.

  - Updates to BLE services to remove persistent references to their GATT services. This consumes
    vast amounts SRAM, rather unecessarily. Instead only handles to the relevant GATT characteristics
    are now stored. This specifically includes:
      + MicroBitDFUService
      + MicroBitEventService
      + DeviceInformationService

  - Updates to the Fiber scheduler to save SRAM. More specifically:
      + Removed the need to hold an empty processor context to intialise fibers.
      + The IDLE fiber now runs without a stack
      + fiber stacks are now only created when a fiber is descheduled for the first time, thereby reducing heap churn.
      + the 'main' fiber is now recycled into the fiber_pool if it leaves app_main()
      + fibers created through invoke() now only maintains the necessary part of teh parent stack that is needed, thereby
        reducing the stack size of spawned fibers.

  - Updates to the Message Bus to reduce the overall memory footprint of processing events. More specifically:
      + Event handlers are now always called using invoke(), such that non-blocking event handlers no longer need
        a dedicated fiber to execute - thereby saving SRAM and processor time.
      + Processing of events from the event queue is now rate paced. Events only continue to be processed as long as there
        are no fibers on the run queue. i.e. event processing is no longer greedy, thereby reducing the number of fibers
        created on the runqueue.

  - Updates to BLUEZOENE code to bring up core BLE services even if they are not enabled by default. This allows
    programs that do not require BLE to operate to benefit from the full range of SRAM, whilst still allowing the
    device to be programmed over BLE.

  - Updates to the Soft Device initialisation configuration, reducing the size of the GATT table held in the top 1.8K
    of its 8K memory region to around 800 bytes. This is sufficient to run the default set of BLE services on the micro:bit
    so the additional memory is configured as HEAP storage by MicroBitHeapAllocator.

  - Minor changes to a range of components to integrate with the above changes.
    + rename of free() to release() in DynamicPWM to avoid namespace collision with MicroBitHeap free()
    + rename of fork_on_block to invoke() to enhance readbility.

  - Many code cleanups and updates to out of date comments.
2015-08-31 23:25:10 +01:00
Joe Finney
58d24ab0a8 microbit: Updated MicroBitMessageBus to use fork_on_block functionality
Updates the MicroBitMessageBus implementation to use fork_on_block() calls rather
than create_fiber() calls when servicing events. This provides greater optimisation
for non-blocking event handlers.

More specifically, this update:

 - Replaces calls to create_fiber() ith fork_on_block during event send operations.
 - Adds a queue of events, to ensure events generated from interrupt context are not serviced in interrupt context.
 - Registers a listener with the idle process to empty the event queue.
2015-08-19 23:35:45 +01:00
James Devine
538e1c48bd microbit-dal: Initial Commit
This is the first commit of the microbit-dal on GitHub.
This repository contains the runtime, which is a light
weight operating system developed by Lancaster University.
2015-08-12 11:53:41 +01:00