Implemented setTaskPriority() and getTaskPriority() in Task HAL API
Removed all other unimplemented functions in HAL and removed spawnTask()
Replaced instances of pthread_t* with TASK typedef
Removed unused HAL error constants and removed commented-out classes and functions in wpilibj's HALLibrary
Changed Task class API to match the construction semantics of a std::thread
Change-Id: I3bc951a3da90d24c5589fae4d1ca2bb60225c873
The bindings only wrap the HAL interface, rather than the entire C++ Notifier,
as I ran into issues trying to wrap the whole Notifier (all the existing
bindings only wrap HAL components, so wrapping stuff in :wpilibc is
unexplored). As such, the new edu.wpi.first.wpilibj.Notifier is just a
re-implementation of the wpilibc/.../Notifier.cpp.
The purpose of doing this bindings is to allow Java users a better option
for running tasks which require good timing (such as control loops). The
previous method used java.util.Timer to schedule a task, causing various
issues. Although this update does improve things, Java loop timing is still
substantially worse than that of C++, and, even worse, if Java decides to call
the garbage collector at the wrong time then the loop can be delayed by
multiple milliseconds and the next iteration will be shorter to account for it
(although this particular behavior could be updated).
A few notes on individual components:
-the HAL Task.hpp and Task.cpp were modified due to compilation/linkage
issues with the JNI bindings. Nothing substantive changed.
-NotifierJNI was added to the build files for gradle.
-HALUtil was modified to include a function for getting the length of a C
pointer, rather than relying on it being 32-bit.
Change-Id: I966512d8a82c2a438ed8c8bbcc6cdc6ed186d0f2
