During HAL_Initialize, wait up to 100ms for a DS packet to be received. Then in RobotBase, right after calling HAL_Initialize, call each language's RefreshData function to force a high level DS update. If the DS is connected, will get joystick data. If there is no data, nothing different will happen, but in that case there's no joysticks anyway.
Using an atomic here means we are never going against a lock that is touchable from user code. That should make reading the DS data from the DS callback even safer.
The current DS thread model has some pretty major issues. It makes it difficult to know if all data is from the same remote packet, and if the data changes while the robot loop is running. Additionally, the DS thread is used for a few other things (MotorSafety and State Tracking for EducationalRobot). This also makes sim difficult, as user code has to wait for the thread to know it has new data.
This change completely rethinks how threading works in the driver station model.
First, the DS HAL system receives a new data callback, either from Netcomm or DriverStationSim. Inside the context of this callback, all the low latency data is read and put into a cache. Doing some investigation on the robot side, this is perfectly safe to do, and also ensures a ds packet will not be parsed before we finish reading the current packet data.
After all data is read, the cache is swapped with a 2nd buffer. This buffer just stores the data, none of the HAL DS calls read from this buffer. An event is then fired, stating there is new data ready to go.
Robot code calls HAL_UpdateDSData(). This swaps the 2nd buffer with a 3rd buffer, which always contains the current data. This data will not be updated until HAL_UpdateDSData is called again. Which solves the state problem.
The high level driver station classes have. an updateData() call, which calls HAL_UpdateDSData, and then update button state variables, then data log and update the NT FMS data table (Java also caches across the JNI boundary here, but that could trivially be removed). An extra event provider is provided, allowing other threads to know when this call has been completed.
IterativeRobotBase calls DS.updateData() at the beginning of each loop, and only once per loop. This means all commands will always have the same state.
All of this means there is no longer a DS thread. Everything happens synchronously. This means Sim and testing is easier, as you can just call DriverStationSim.NotifyNewData(), and then DriverStation.UpdateData(), and you can guarantee that all the DriverStation.*** data is up to date.
As for Motor Safety and Educational Robot State Handling, those can all be handled by their own threads. The Educational Thread only needs to run under EducationalRobot, and MotorSafety will only be started if there is a motor safety object enabled.
- Twine, StringRef, Format, and NativeFormatting have been removed
- Logging now uses fmtlib style formatting
- Nearly all uses of wpi::outs/errs have been replaced with fmt::print() or
std::puts()/std::fputs() (for unformatted strings).
- A wpi/fmt/raw_ostream.h header has been added to enable
fmt::print() with wpi::raw_ostream
This makes code easier to read and more consistent between C++ and Java.
Also update clang-format settings to always add a line break (even if no braces are used).
Remove WaitForCachedData as it's no longer required.
Also properly handle caching / transition detection logic that occurs at the
WPILib level.
This also changes DriverStation::IsNewControlData() to check for WPILib-level
caching instead of wrapping the HAL function.
Also move some things in HAL for consistency.
WAS:
C++:
- C APIs: #include "mockdata/AccelerometerData.h"
- User side class: #include "simulation/AccelerometerSim.h"
Java:
- JNI APIs: hal.sim.mockdata.AccelerometerData (and a few classes in hal.sim)
- User side classes: hal.sim.AccelerometerSim
IS:
C++:
- C APIs: #include "hal/simulation/AccelerometerData.h"
- C++ class: #include "frc/simulation/AccelerometerSim.h"
Java:
- JNI APIs: hal.simulation.AccelerometerData
- User side class: wpilibj.simulation.AccelerometerSim
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 next line adds a null terminator, but it's cleaner to just do a
std::memcpy() since the code already assumes a null terminator exists in
the source string.
This makes callback registration completely thread safe.
This patch also uses templates and macros to dramatically reduce the amount of
manual boilerplate.
The old headers were moved into folders because doing so avoids polluting
the system include directories.
Folder names were also normalized to lowercase.
Also switch eventName and gameSpecificData to fixed 64-byte arrays to avoid mallocs and
extra NetComm calls. This behavior matches 2018 LabView.
The DS caching is kept in Java to avoid JNI and/or massive amounts of allocations.
This does not increase latency because Java still only hits NetComm once.
Moving the DS caching benefits all languages other than Java, because it avoids the need
for individual implementations. If caching is ever added to NetComm, it will then only be
necessary to remove it from the HAL and Java rather than all languages.
Also fix the return type of HAL_IsNewControlData() and HAL_MatchType's type.
Since UsageReporting is intended to be namespaced, it is hidden when this is being used in C.
Fixes: #476Closes: #535
Ref: #1122
During shared library loading, a different libLLVM can be pulled in, causing
llvm symbols from dependent libraries to resolve to that library instead of
this one. This has been seen in the wild with the Mesa OpenGL implementation
in JavaFX applications (see wpilibsuite/shuffleboard#361).
This is clearly a very breaking change. For some level of backwards
compatibility, a namespace alias from llvm to wpi is performed in the "llvm"
headers. Unfortunately, forward declarations of llvm classes will still break,
but compilers seem to generate clear error messages in those cases
("namespace alias 'llvm' not allowed here, assuming 'wpi'").
This change also moves all the wpiutil headers to a single "wpi" subdirectory
from the previously split "llvm", "support", "tcpsockets", and "udpsockets".
Shim headers will be added for backwards compatibility in a later commit.
* Removed hal::priority_condition_variable
* Replaced uses of priority mutexes with std::mutex and std::recursive_mutex
This allowed replacing a use of std::condition_variable_any with
std::condition_variable.
* Replaced all uses of std::recursive_mutex with std::mutex equivalents
* Revert "Force OpenCV to 3.1.0 (#602)"
This reverts commit 50ed55e8e2.
* Removes Simulation
* Removes old build system
* Removes old gtest
* Adds new gmock and gtest
* Updates to new ni-libraries
* removes MyRobot (to be replaced)
* moves files to new location
* Adds new sim backend and new test executables
* updates .styleguide and .gitignore
* Changes cpp WPILibVersion to a function
MSVC throws an AV with the old version.
* Disables USBCamera on all systems except for linux
* 2018 NI Libraries
* New build system
