Calling HALSIM_PauseTiming pauses the FPGA clock and notifiers.
Calling HALSIM_ResumeTiming resumes the FPGA clock and notifiers.
Calling HALSIM_StepTiming steps the FPGA clock and runs applicable notifiers.
This will effectively pause TimedRobot and any other notifier-based events,
but of course will not pause user threads that do not use the notifier (e.g.
image processing).
This allows high-level library classes to implement enhanced simulation
support even if no low-level corresponding simulation library exists, and
avoids the need for bit-banging complex interfaces like SPI or CAN.
Default behavior is still to run the robot main loop in the main thread.
The ability to run the robot main loop in a separate thread and add a hook
for running a different function in the main thread is needed for simulation
GUI support on some platforms.
A templated hal::Handle class is used to wrap handles to make them move-only.
This eliminates a lot of boilerplate move constructor/assignment code
in the main WPILib classes. HAL_SPIPort and HAL_I2CPort are also wrapped.
The wrapper class does not implement destruction. This would require the
wrapper class to be handle-specific (rather than generic) and would result
in more code added than it removed, plus would add header dependencies on
more HAL headers. In addition, some HAL handle release functions are more
complex (e.g. have return values) and can't be easily mapped to a destructor.
std::scoped_lock was introduced in C++17 and is strictly better than
std::lock_guard as it supports locking any number of mutexes safely.
It's also easier to use than std::lock for locking multiple mutexes at
once.
The 2019 FPGA image switched the output of auto SPI from plain bytes to a
sequence of 32-bit words (timestamp, then words with the byte values in the
least significant byte of each word).
In addition to changing the HAL and simulators to reflect this, add piecewise
integration support to wpilibc/wpilibj SPI to take advantage of the timestamps
and use it in the ADXRS450 gyro.
HAL_ReadInterruptRisingTimestamp and HAL_ReadInterruptFallingTimestamp
return time as a double. Instead, keep the raw integer count and move the
double conversion into the C++ and Java code. This enables comparison of the
time with other timers.
This allows HAL_CloseI2C() and HAL_CloseSPI() to be noops, which makes
enabling move semantics in the I2C and SPI wpilibc classes easier and
cleaner.
Fixes#1328.
This makes callback registration completely thread safe.
This patch also uses templates and macros to dramatically reduce the amount of
manual boilerplate.
