Squashed 'third_party/allwpilib_2017/' content from commit 35ac87d

Change-Id: I7bb6f5556c30d3f5a092e68de0be9c710c60c9f4
git-subtree-dir: third_party/allwpilib_2017
git-subtree-split: 35ac87d6ff8b7f061c4f18c9ea316e5dccd4888a
diff --git a/hal/include/HAL/cpp/Semaphore.h b/hal/include/HAL/cpp/Semaphore.h
new file mode 100644
index 0000000..53e17d7
--- /dev/null
+++ b/hal/include/HAL/cpp/Semaphore.h
@@ -0,0 +1,41 @@
+/*----------------------------------------------------------------------------*/
+/* 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 <condition_variable>
+
+#include "HAL/cpp/priority_mutex.h"
+#include "support/deprecated.h"
+
+class WPI_DEPRECATED(
+    "Semaphore scheduled for removal in 2018. Recommended to replace with a "
+    "std::mutex and std::condition_variable") Semaphore {
+ public:
+  explicit Semaphore(int32_t count = 0);
+  Semaphore(Semaphore&&);
+  Semaphore& operator=(Semaphore&&);
+
+  void give();
+  void take();
+
+  // @return true if semaphore was locked successfully. false if not.
+  bool tryTake();
+
+  static const int32_t kNoWait = 0;
+  static const int32_t kWaitForever = -1;
+
+  static const int32_t kEmpty = 0;
+  static const int32_t kFull = 1;
+
+ private:
+  priority_mutex m_mutex;
+  std::condition_variable_any m_condition;
+  int32_t m_count = 0;
+};