artf4156: Replaced synchronization primitives with C++11 equivalents

Change-Id: I90da739347e875efda2a29dd5484b6dda3cd4753

hal/lib/Athena/cpp/Semaphore.cpp

@@ -0,0 +1,34 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015. 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 $(WIND_BASE)/WPILib.  */
+/*----------------------------------------------------------------------------*/
+
+#include "HAL/cpp/Semaphore.hpp"
+
+Semaphore::Semaphore(uint32_t count) {
+  m_count = count;
+}
+
+void Semaphore::give() {
+  std::unique_lock<priority_mutex> lock(m_mutex);
+  ++m_count;
+  m_condition.notify_one();
+}
+
+void Semaphore::take() {
+  std::unique_lock<priority_mutex> lock(m_mutex);
+  m_condition.wait(lock, [this] { return m_count; } );
+  --m_count;
+}
+
+bool Semaphore::tryTake() {
+  std::unique_lock<priority_mutex> lock(m_mutex);
+  if (m_count) {
+    --m_count;
+    return true;
+  }
+  else {
+    return false;
+  }
+}