This commit makes the following changes: It defines the public
`otInstance` as an empty opaque structure which is used by all public
C OpenThread APIs. It defines a new class `ot::Instance` (inheriting
from `otInstance) which is then used in core source files. The
functionality related to the instance is also moved/added into the
newly added `Instance` class (as class/static or member methods).
This commit changes the `InstanceLocator` class to keep track of a
reference to `otInstance` (instead of a pointer) to make it behave
similar to other `ObjectLocator` classes. The method `GetInstance()`
in all locator objects is updated to provide a reference (instead
of a pointer) to `otInstance`.
The logging macros are updated such that a reference to `otInstance`
is passed as the first argument (with the exception of
`otLog<Level>Plat()` macros which are used by platform code in C
domain). The documentation for log macros are also updated.
* [timer] multiple microseconds timer support
* Remove TimerSchedulerLocator, Timer inherit from Ip6Locator instead to get TimerScheduler.
* Add separate UsecTimer and UsecTimerScheduler for multiple microseconds timer support.
* [timer] refine Timer names
* Rename alarm header files to alarm-milli.h and alarm-micro.h
* Rename alarm APIs to start with otPlatAlarmMilli and otPlatAlarmMicro
* Rename Timer classes to TimerMilli/TimerMilliScheduler and TimerMicro/TimerMicroScheduler
* [Timer] Refactor Timer code structure
* Create TimerBase and TimerSchedulerBase class for common functions;
* Use TimerMilli/TimerMicro and TimerMilliScheduler/TimerMicroScheduler for different functions;
* Define AlarmApi, so then TimerMilliScheduler/TimerMicroScheduler could use different AlarmApi.
This commit new configuration option `enable-multiple-instances` and
its corresponding option `OPENTHREAD_ENABLE_MULTIPLE_INSTANCES`. When
enabled OpenThread supports handling of multiple instances. By default
this is disabled.
This commit also adds two optimizations for single instance case to
simplify the code and also help reduce memory/RAM usage:
(1) OpenThread objects/classes typically keep a reference to a higher
level object (e.g., many classes keep track of owning `ThreadNetif`)
to be able to access other objects/methods within OpenThread class
hierarchy. In single instance mode, the reference member variables are
removed and instead global functions are used to access the singleton
objects from one class to the other. To implement this, a group of
`<Object>Locator` classes are defined (e.g., `ThreadNetifLocator`,
etc.) which are then used as base class of other OpenThread classes.
(2) OpenThread objects which provide a callback/handler (e.g.,
`Timer`, `Tasklet`, etc.) have `void *mContext` member variable which
is used to keep track of the owner of the object. In single instance
mode the `mConext` member variables are removed since the owner is
expected to be a singleton and can be uniquely determined from the
callback function.
To implement this, two changes are made: First the handler methods are
modified to provide a reference to the object (e.g., `Timer` handler
will provide a `Timer &aTimer` as a parameter of its handler
callback). Second, a new base class `Context` is introduced which
hides the implementation providing an arbitrary context information. A
new static method `GetOwner(aContext)` is added to classes which own a
callback providing objects. This method help convert a `Context` to
the reference of the owner class object.
This commit changes the timer code to make the implementation robust
against late firing platform alarm case. In particular, it addresses
the (rare corner-case) scenario where alarm fire is late and the head
timer in the linked-list is already expired and then a new timer is
started with maximum interval. This can possibly violate the
requirement for `TimerScheduler::IsStringlyBefore()` method that the
two times being compared should not differ more than the maximum
interval `Timer::kMaxDt`. To address this, a new method
`Timer::DoesFireBefore()` is added to compare fire time of two timers
which checks for expired timers.
This commit also updates the timer unit test to add test cases related
to the late firing alarm.
This commit changes the `Timer` class to store the fire time instead
of start time and duration. This simplifies the `Timer` implementation
and reduces the size of a `Timer` instance. The `test_timer` unit test
is also updated to add new test cases to verify correct timer behavior
during 32-bit timer wrap.
This commit also simplifies the key rotation implementation in
`KeyManager` class. Since the key rotation time and guard time are
provided in hours unit and can span multiple days, the code tracks
number of hours since last key rotation in `mHoursSinceKeyRotation`
(using a one hour interval timer). This is then used to decide when/if
to change the key sequence.
Abtin Keshavarzian