Squashed 'third_party/allwpilib_2019/' content from commit bd05dfa1c

Change-Id: I2b1c2250cdb9b055133780c33593292098c375b7
git-subtree-dir: third_party/allwpilib_2019
git-subtree-split: bd05dfa1c7cca74c4fac451e7b9d6a37e7b53447
diff --git a/wpilibc/src/main/native/cpp/Notifier.cpp b/wpilibc/src/main/native/cpp/Notifier.cpp
new file mode 100644
index 0000000..69a9f4e
--- /dev/null
+++ b/wpilibc/src/main/native/cpp/Notifier.cpp
@@ -0,0 +1,131 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2008-2018 FIRST. 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "frc/Notifier.h"
+
+#include <utility>
+
+#include <hal/HAL.h>
+
+#include "frc/Timer.h"
+#include "frc/Utility.h"
+#include "frc/WPIErrors.h"
+
+using namespace frc;
+
+Notifier::Notifier(TimerEventHandler handler) {
+  if (handler == nullptr)
+    wpi_setWPIErrorWithContext(NullParameter, "handler must not be nullptr");
+  m_handler = handler;
+  int32_t status = 0;
+  m_notifier = HAL_InitializeNotifier(&status);
+  wpi_setErrorWithContext(status, HAL_GetErrorMessage(status));
+
+  m_thread = std::thread([=] {
+    for (;;) {
+      int32_t status = 0;
+      HAL_NotifierHandle notifier = m_notifier.load();
+      if (notifier == 0) break;
+      uint64_t curTime = HAL_WaitForNotifierAlarm(notifier, &status);
+      if (curTime == 0 || status != 0) break;
+
+      TimerEventHandler handler;
+      {
+        std::lock_guard<wpi::mutex> lock(m_processMutex);
+        handler = m_handler;
+        if (m_periodic) {
+          m_expirationTime += m_period;
+          UpdateAlarm();
+        } else {
+          // need to update the alarm to cause it to wait again
+          UpdateAlarm(UINT64_MAX);
+        }
+      }
+
+      // call callback
+      if (handler) handler();
+    }
+  });
+}
+
+Notifier::~Notifier() {
+  int32_t status = 0;
+  // atomically set handle to 0, then clean
+  HAL_NotifierHandle handle = m_notifier.exchange(0);
+  HAL_StopNotifier(handle, &status);
+  wpi_setErrorWithContext(status, HAL_GetErrorMessage(status));
+
+  // Join the thread to ensure the handler has exited.
+  if (m_thread.joinable()) m_thread.join();
+
+  HAL_CleanNotifier(handle, &status);
+}
+
+Notifier::Notifier(Notifier&& rhs)
+    : ErrorBase(std::move(rhs)),
+      m_thread(std::move(rhs.m_thread)),
+      m_notifier(rhs.m_notifier.load()),
+      m_handler(std::move(rhs.m_handler)),
+      m_expirationTime(std::move(rhs.m_expirationTime)),
+      m_period(std::move(rhs.m_period)),
+      m_periodic(std::move(rhs.m_periodic)) {
+  rhs.m_notifier = HAL_kInvalidHandle;
+}
+
+Notifier& Notifier::operator=(Notifier&& rhs) {
+  ErrorBase::operator=(std::move(rhs));
+
+  m_thread = std::move(rhs.m_thread);
+  m_notifier = rhs.m_notifier.load();
+  rhs.m_notifier = HAL_kInvalidHandle;
+  m_handler = std::move(rhs.m_handler);
+  m_expirationTime = std::move(rhs.m_expirationTime);
+  m_period = std::move(rhs.m_period);
+  m_periodic = std::move(rhs.m_periodic);
+
+  return *this;
+}
+
+void Notifier::SetHandler(TimerEventHandler handler) {
+  std::lock_guard<wpi::mutex> lock(m_processMutex);
+  m_handler = handler;
+}
+
+void Notifier::StartSingle(double delay) {
+  std::lock_guard<wpi::mutex> lock(m_processMutex);
+  m_periodic = false;
+  m_period = delay;
+  m_expirationTime = Timer::GetFPGATimestamp() + m_period;
+  UpdateAlarm();
+}
+
+void Notifier::StartPeriodic(double period) {
+  std::lock_guard<wpi::mutex> lock(m_processMutex);
+  m_periodic = true;
+  m_period = period;
+  m_expirationTime = Timer::GetFPGATimestamp() + m_period;
+  UpdateAlarm();
+}
+
+void Notifier::Stop() {
+  int32_t status = 0;
+  HAL_CancelNotifierAlarm(m_notifier, &status);
+  wpi_setErrorWithContext(status, HAL_GetErrorMessage(status));
+}
+
+void Notifier::UpdateAlarm(uint64_t triggerTime) {
+  int32_t status = 0;
+  // Return if we are being destructed, or were not created successfully
+  auto notifier = m_notifier.load();
+  if (notifier == 0) return;
+  HAL_UpdateNotifierAlarm(notifier, triggerTime, &status);
+  wpi_setErrorWithContext(status, HAL_GetErrorMessage(status));
+}
+
+void Notifier::UpdateAlarm() {
+  UpdateAlarm(static_cast<uint64_t>(m_expirationTime * 1e6));
+}