Update to 2018_v4 image and new build system. (#598)

* 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

hal/src/main/native/include/HAL/handles/LimitedClassedHandleResource.h

@@ -0,0 +1,115 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2016-2017. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#pragma once
+
+#include <stdint.h>
+
+#include <array>
+#include <memory>
+
+#include "HAL/Types.h"
+#include "HAL/cpp/make_unique.h"
+#include "HAL/cpp/priority_mutex.h"
+#include "HAL/handles/HandlesInternal.h"
+
+namespace hal {
+
+/**
+ * The LimitedClassedHandleResource class is a way to track handles. This
+ * version
+ * allows a limited number of handles that are allocated sequentially.
+ *
+ * @tparam THandle The Handle Type (Must be typedefed from HAL_Handle)
+ * @tparam TStruct The struct type held by this resource
+ * @tparam size The number of resources allowed to be allocated
+ * @tparam enumValue The type value stored in the handle
+ *
+ */
+template <typename THandle, typename TStruct, int16_t size,
+          HAL_HandleEnum enumValue>
+class LimitedClassedHandleResource : public HandleBase {
+  friend class LimitedClassedHandleResourceTest;
+
+ public:
+  LimitedClassedHandleResource() = default;
+  LimitedClassedHandleResource(const LimitedClassedHandleResource&) = delete;
+  LimitedClassedHandleResource& operator=(const LimitedClassedHandleResource&) =
+      delete;
+
+  THandle Allocate(std::shared_ptr<TStruct> toSet);
+  std::shared_ptr<TStruct> Get(THandle handle);
+  void Free(THandle handle);
+  void ResetHandles() override;
+
+ private:
+  std::array<std::shared_ptr<TStruct>, size> m_structures;
+  std::array<hal::priority_mutex, size> m_handleMutexes;
+  hal::priority_mutex m_allocateMutex;
+};
+
+template <typename THandle, typename TStruct, int16_t size,
+          HAL_HandleEnum enumValue>
+THandle
+LimitedClassedHandleResource<THandle, TStruct, size, enumValue>::Allocate(
+    std::shared_ptr<TStruct> toSet) {
+  // globally lock to loop through indices
+  std::lock_guard<hal::priority_mutex> sync(m_allocateMutex);
+  for (int16_t i = 0; i < size; i++) {
+    if (m_structures[i] == nullptr) {
+      // if a false index is found, grab its specific mutex
+      // and allocate it.
+      std::lock_guard<hal::priority_mutex> sync(m_handleMutexes[i]);
+      m_structures[i] = toSet;
+      return static_cast<THandle>(createHandle(i, enumValue, m_version));
+    }
+  }
+  return HAL_kInvalidHandle;
+}
+
+template <typename THandle, typename TStruct, int16_t size,
+          HAL_HandleEnum enumValue>
+std::shared_ptr<TStruct> LimitedClassedHandleResource<
+    THandle, TStruct, size, enumValue>::Get(THandle handle) {
+  // get handle index, and fail early if index out of range or wrong handle
+  int16_t index = getHandleTypedIndex(handle, enumValue, m_version);
+  if (index < 0 || index >= size) {
+    return nullptr;
+  }
+  std::lock_guard<hal::priority_mutex> sync(m_handleMutexes[index]);
+  // return structure. Null will propogate correctly, so no need to manually
+  // check.
+  return m_structures[index];
+}
+
+template <typename THandle, typename TStruct, int16_t size,
+          HAL_HandleEnum enumValue>
+void LimitedClassedHandleResource<THandle, TStruct, size, enumValue>::Free(
+    THandle handle) {
+  // get handle index, and fail early if index out of range or wrong handle
+  int16_t index = getHandleTypedIndex(handle, enumValue, m_version);
+  if (index < 0 || index >= size) return;
+  // lock and deallocated handle
+  std::lock_guard<hal::priority_mutex> sync(m_allocateMutex);
+  std::lock_guard<hal::priority_mutex> lock(m_handleMutexes[index]);
+  m_structures[index].reset();
+}
+
+template <typename THandle, typename TStruct, int16_t size,
+          HAL_HandleEnum enumValue>
+void LimitedClassedHandleResource<THandle, TStruct, size,
+                                  enumValue>::ResetHandles() {
+  {
+    std::lock_guard<hal::priority_mutex> lock(m_allocateMutex);
+    for (int i = 0; i < size; i++) {
+      std::lock_guard<hal::priority_mutex> sync(m_handleMutexes[i]);
+      m_structures[i].reset();
+    }
+  }
+  HandleBase::ResetHandles();
+}
+}  // namespace hal