[hal, wpilib] Switch PCM to be a single object that is allowed to be duplicated (#3475)

Having PCM as a singleton is a problem, as multiple things need to use it, and that gets really ugly. This changes PCM's to be a reference counted object, that can be passed around and constructed from multiple places.

In Java, this is using a map to hold a data store with a ref count, and allocating new objects any time a duplicate is requested.

In C++, this uses a trick constructor to store a PCM instance in the data store itself. This instance can then be passed to base objects using std::shared_ptr's aliasing constructor, which means constructing a solenoid from a PCM is not allocating after the 1st one.

This did require removing sendable from PCM. A compressor class was added back in to act as sendable for the PCM.

After this change is finished, the only change RobotBuilder and Team Code would require is passing a module type to solenoid constructors.

Co-authored-by: sciencewhiz <sciencewhiz@users.noreply.github.com>

wpilibc/src/main/native/cpp/Compressor.cpp

@@ -0,0 +1,72 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include "frc/Compressor.h"
+
+#include <hal/FRCUsageReporting.h>
+#include <hal/Ports.h>
+#include <wpi/sendable/SendableBuilder.h>
+#include <wpi/sendable/SendableRegistry.h>
+
+#include "frc/Errors.h"
+
+using namespace frc;
+
+Compressor::Compressor(int module, PneumaticsModuleType moduleType)
+    : m_module{PneumaticsBase::GetForType(module, moduleType)} {
+  if (!m_module->ReserveCompressor()) {
+    throw FRC_MakeError(err::ResourceAlreadyAllocated, "{}", module);
+  }
+
+  SetClosedLoopControl(true);
+
+  HAL_Report(HALUsageReporting::kResourceType_Compressor, module + 1);
+  wpi::SendableRegistry::AddLW(this, "Compressor", module);
+}
+
+Compressor::Compressor(PneumaticsModuleType moduleType)
+    : Compressor{PneumaticsBase::GetDefaultForType(moduleType), moduleType} {}
+
+Compressor::~Compressor() {
+  m_module->UnreserveCompressor();
+}
+
+void Compressor::Start() {
+  SetClosedLoopControl(true);
+}
+
+void Compressor::Stop() {
+  SetClosedLoopControl(false);
+}
+
+bool Compressor::Enabled() const {
+  return m_module->GetCompressor();
+}
+
+bool Compressor::GetPressureSwitchValue() const {
+  return m_module->GetPressureSwitch();
+}
+
+double Compressor::GetCompressorCurrent() const {
+  return m_module->GetCompressorCurrent();
+}
+
+void Compressor::SetClosedLoopControl(bool on) {
+  m_module->SetClosedLoopControl(on);
+}
+
+bool Compressor::GetClosedLoopControl() const {
+  return m_module->GetClosedLoopControl();
+}
+
+void Compressor::InitSendable(wpi::SendableBuilder& builder) {
+  builder.SetSmartDashboardType("Compressor");
+  builder.AddBooleanProperty(
+      "Closed Loop Control", [=]() { return GetClosedLoopControl(); },
+      [=](bool value) { SetClosedLoopControl(value); });
+  builder.AddBooleanProperty(
+      "Enabled", [=] { return Enabled(); }, nullptr);
+  builder.AddBooleanProperty(
+      "Pressure switch", [=]() { return GetPressureSwitchValue(); }, nullptr);
+}