Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 870 insertions, 0 deletions

diff --git a/widget/nsUserIdleService.cpp b/widget/nsUserIdleService.cpp
new file mode 100644
index 0000000000..7b54a4749d
--- /dev/null
+++ b/widget/nsUserIdleService.cpp
@@ -0,0 +1,870 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:expandtab:shiftwidth=2:tabstop=2:
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsUserIdleService.h"
+#include "nsString.h"
+#include "nsIObserverService.h"
+#include "nsDebug.h"
+#include "nsCOMArray.h"
+#include "nsXULAppAPI.h"
+#include "prinrval.h"
+#include "mozilla/Logging.h"
+#include "prtime.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/Services.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/Telemetry.h"
+#include <algorithm>
+
+#ifdef MOZ_WIDGET_ANDROID
+#  include <android/log.h>
+#endif
+
+using namespace mozilla;
+
+// After the twenty four hour period expires for an idle daily, this is the
+// amount of idle time we wait for before actually firing the idle-daily
+// event.
+#define DAILY_SIGNIFICANT_IDLE_SERVICE_SEC (3 * 60)
+
+// In cases where it's been longer than twenty four hours since the last
+// idle-daily, this is the shortend amount of idle time we wait for before
+// firing the idle-daily event.
+#define DAILY_SHORTENED_IDLE_SERVICE_SEC 60
+
+// Pref for last time (seconds since epoch) daily notification was sent.
+#define PREF_LAST_DAILY "idle.lastDailyNotification"
+
+// Number of seconds in a day.
+#define SECONDS_PER_DAY 86400
+
+static LazyLogModule sLog("idleService");
+
+#define LOG_TAG "GeckoIdleService"
+#define LOG_LEVEL ANDROID_LOG_DEBUG
+
+// Use this to find previously added observers in our array:
+class IdleListenerComparator {
+ public:
+  bool Equals(IdleListener a, IdleListener b) const {
+    return (a.observer == b.observer) && (a.reqIdleTime == b.reqIdleTime);
+  }
+};
+
+////////////////////////////////////////////////////////////////////////////////
+//// nsUserIdleServiceDaily
+
+NS_IMPL_ISUPPORTS(nsUserIdleServiceDaily, nsIObserver, nsISupportsWeakReference)
+
+NS_IMETHODIMP
+nsUserIdleServiceDaily::Observe(nsISupports*, const char* aTopic,
+                                const char16_t*) {
+  MOZ_LOG(sLog, LogLevel::Debug,
+          ("nsUserIdleServiceDaily: Observe '%s' (%d)", aTopic,
+           mShutdownInProgress));
+
+  if (strcmp(aTopic, "profile-after-change") == 0) {
+    // We are back. Start sending notifications again.
+    mShutdownInProgress = false;
+    return NS_OK;
+  }
+
+  if (strcmp(aTopic, "xpcom-will-shutdown") == 0 ||
+      strcmp(aTopic, "profile-change-teardown") == 0) {
+    mShutdownInProgress = true;
+  }
+
+  if (mShutdownInProgress || strcmp(aTopic, OBSERVER_TOPIC_ACTIVE) == 0) {
+    return NS_OK;
+  }
+  MOZ_ASSERT(strcmp(aTopic, OBSERVER_TOPIC_IDLE) == 0);
+
+  MOZ_LOG(sLog, LogLevel::Debug,
+          ("nsUserIdleServiceDaily: Notifying idle-daily observers"));
+#ifdef MOZ_WIDGET_ANDROID
+  __android_log_print(LOG_LEVEL, LOG_TAG, "Notifying idle-daily observers");
+#endif
+
+  // Send the idle-daily observer event
+  nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+  NS_ENSURE_STATE(observerService);
+  (void)observerService->NotifyObservers(nullptr, OBSERVER_TOPIC_IDLE_DAILY,
+                                         nullptr);
+
+  // Notify the category observers.
+  nsCOMArray<nsIObserver> entries;
+  mCategoryObservers.GetEntries(entries);
+  for (int32_t i = 0; i < entries.Count(); ++i) {
+    (void)entries[i]->Observe(nullptr, OBSERVER_TOPIC_IDLE_DAILY, nullptr);
+  }
+
+  // Stop observing idle for today.
+  (void)mIdleService->RemoveIdleObserver(this, mIdleDailyTriggerWait);
+
+  // Set the last idle-daily time pref.
+  int32_t nowSec = static_cast<int32_t>(PR_Now() / PR_USEC_PER_SEC);
+  Preferences::SetInt(PREF_LAST_DAILY, nowSec);
+
+  // Force that to be stored so we don't retrigger twice a day under
+  // any circumstances.
+  nsIPrefService* prefs = Preferences::GetService();
+  if (prefs) {
+    prefs->SavePrefFile(nullptr);
+  }
+
+  MOZ_LOG(
+      sLog, LogLevel::Debug,
+      ("nsUserIdleServiceDaily: Storing last idle time as %d sec.", nowSec));
+#ifdef MOZ_WIDGET_ANDROID
+  __android_log_print(LOG_LEVEL, LOG_TAG, "Storing last idle time as %d",
+                      nowSec);
+#endif
+
+  // Note the moment we expect to get the next timer callback
+  mExpectedTriggerTime =
+      PR_Now() + ((PRTime)SECONDS_PER_DAY * (PRTime)PR_USEC_PER_SEC);
+
+  MOZ_LOG(sLog, LogLevel::Debug,
+          ("nsUserIdleServiceDaily: Restarting daily timer"));
+
+  // Start timer for the next check in one day.
+  (void)mTimer->InitWithNamedFuncCallback(
+      DailyCallback, this, SECONDS_PER_DAY * PR_MSEC_PER_SEC,
+      nsITimer::TYPE_ONE_SHOT, "nsUserIdleServiceDaily::Observe");
+
+  return NS_OK;
+}
+
+nsUserIdleServiceDaily::nsUserIdleServiceDaily(nsIUserIdleService* aIdleService)
+    : mIdleService(aIdleService),
+      mTimer(NS_NewTimer()),
+      mCategoryObservers(OBSERVER_TOPIC_IDLE_DAILY),
+      mShutdownInProgress(false),
+      mExpectedTriggerTime(0),
+      mIdleDailyTriggerWait(DAILY_SIGNIFICANT_IDLE_SERVICE_SEC) {}
+
+void nsUserIdleServiceDaily::Init() {
+  // First check the time of the last idle-daily event notification. If it
+  // has been 24 hours or higher, or if we have never sent an idle-daily,
+  // get ready to send an idle-daily event. Otherwise set a timer targeted
+  // at 24 hours past the last idle-daily we sent.
+
+  int32_t lastDaily = Preferences::GetInt(PREF_LAST_DAILY, 0);
+  // Setting the pref to -1 allows to disable idle-daily, and it's particularly
+  // useful in tests. Normally there should be no need for the user to set
+  // this value.
+  if (lastDaily == -1) {
+    MOZ_LOG(sLog, LogLevel::Debug,
+            ("nsUserIdleServiceDaily: Init: disabled idle-daily"));
+    return;
+  }
+
+  int32_t nowSec = static_cast<int32_t>(PR_Now() / PR_USEC_PER_SEC);
+  if (lastDaily < 0 || lastDaily > nowSec) {
+    // The time is bogus, use default.
+    lastDaily = 0;
+  }
+  int32_t secondsSinceLastDaily = nowSec - lastDaily;
+
+  MOZ_LOG(sLog, LogLevel::Debug,
+          ("nsUserIdleServiceDaily: Init: seconds since last daily: %d",
+           secondsSinceLastDaily));
+
+  // If it has been twenty four hours or more or if we have never sent an
+  // idle-daily event get ready to send it during the next idle period.
+  if (secondsSinceLastDaily > SECONDS_PER_DAY) {
+    // Check for a "long wait", e.g. 48-hours or more.
+    bool hasBeenLongWait =
+        (lastDaily && (secondsSinceLastDaily > (SECONDS_PER_DAY * 2)));
+
+    MOZ_LOG(
+        sLog, LogLevel::Debug,
+        ("nsUserIdleServiceDaily: has been long wait? %d", hasBeenLongWait));
+
+    // StageIdleDaily sets up a wait for the user to become idle and then
+    // sends the idle-daily event.
+    StageIdleDaily(hasBeenLongWait);
+  } else {
+    MOZ_LOG(sLog, LogLevel::Debug,
+            ("nsUserIdleServiceDaily: Setting timer a day from now"));
+#ifdef MOZ_WIDGET_ANDROID
+    __android_log_print(LOG_LEVEL, LOG_TAG, "Setting timer a day from now");
+#endif
+
+    // According to our last idle-daily pref, the last idle-daily was fired
+    // less then 24 hours ago. Set a wait for the amount of time remaining.
+    int32_t milliSecLeftUntilDaily =
+        (SECONDS_PER_DAY - secondsSinceLastDaily) * PR_MSEC_PER_SEC;
+
+    MOZ_LOG(sLog, LogLevel::Debug,
+            ("nsUserIdleServiceDaily: Seconds till next timeout: %d",
+             (SECONDS_PER_DAY - secondsSinceLastDaily)));
+
+    // Mark the time at which we expect this to fire. On systems with faulty
+    // timers, we need to be able to cross check that the timer fired at the
+    // expected time.
+    mExpectedTriggerTime =
+        PR_Now() + (milliSecLeftUntilDaily * PR_USEC_PER_MSEC);
+
+    (void)mTimer->InitWithNamedFuncCallback(
+        DailyCallback, this, milliSecLeftUntilDaily, nsITimer::TYPE_ONE_SHOT,
+        "nsUserIdleServiceDaily::Init");
+  }
+
+  // Register for when we should terminate/pause
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+  if (obs) {
+    MOZ_LOG(
+        sLog, LogLevel::Debug,
+        ("nsUserIdleServiceDaily: Registering for system event observers."));
+    obs->AddObserver(this, "xpcom-will-shutdown", true);
+    obs->AddObserver(this, "profile-change-teardown", true);
+    obs->AddObserver(this, "profile-after-change", true);
+  }
+}
+
+nsUserIdleServiceDaily::~nsUserIdleServiceDaily() {
+  if (mTimer) {
+    mTimer->Cancel();
+    mTimer = nullptr;
+  }
+}
+
+void nsUserIdleServiceDaily::StageIdleDaily(bool aHasBeenLongWait) {
+  NS_ASSERTION(mIdleService, "No idle service available?");
+  MOZ_LOG(sLog, LogLevel::Debug,
+          ("nsUserIdleServiceDaily: Registering Idle observer callback "
+           "(short wait requested? %d)",
+           aHasBeenLongWait));
+#ifdef MOZ_WIDGET_ANDROID
+  __android_log_print(LOG_LEVEL, LOG_TAG, "Registering Idle observer callback");
+#endif
+  mIdleDailyTriggerWait =
+      (aHasBeenLongWait ? DAILY_SHORTENED_IDLE_SERVICE_SEC
+                        : DAILY_SIGNIFICANT_IDLE_SERVICE_SEC);
+  (void)mIdleService->AddIdleObserver(this, mIdleDailyTriggerWait);
+}
+
+// static
+void nsUserIdleServiceDaily::DailyCallback(nsITimer* aTimer, void* aClosure) {
+  MOZ_LOG(sLog, LogLevel::Debug,
+          ("nsUserIdleServiceDaily: DailyCallback running"));
+#ifdef MOZ_WIDGET_ANDROID
+  __android_log_print(LOG_LEVEL, LOG_TAG, "DailyCallback running");
+#endif
+
+  nsUserIdleServiceDaily* self = static_cast<nsUserIdleServiceDaily*>(aClosure);
+
+  // Check to be sure the timer didn't fire early. This currently only
+  // happens on android.
+  PRTime now = PR_Now();
+  if (self->mExpectedTriggerTime && now < self->mExpectedTriggerTime) {
+    // Timer returned early, reschedule to the appropriate time.
+    PRTime delayTime = self->mExpectedTriggerTime - now;
+
+    // Add 10 ms to ensure we don't undershoot, and never get a "0" timer.
+    delayTime += 10 * PR_USEC_PER_MSEC;
+
+    MOZ_LOG(sLog, LogLevel::Debug,
+            ("nsUserIdleServiceDaily: DailyCallback resetting timer to %" PRId64
+             " msec",
+             delayTime / PR_USEC_PER_MSEC));
+#ifdef MOZ_WIDGET_ANDROID
+    __android_log_print(LOG_LEVEL, LOG_TAG,
+                        "DailyCallback resetting timer to %" PRId64 " msec",
+                        delayTime / PR_USEC_PER_MSEC);
+#endif
+
+    (void)self->mTimer->InitWithNamedFuncCallback(
+        DailyCallback, self, delayTime / PR_USEC_PER_MSEC,
+        nsITimer::TYPE_ONE_SHOT, "nsUserIdleServiceDaily::DailyCallback");
+    return;
+  }
+
+  // Register for a short term wait for idle event. When this fires we fire
+  // our idle-daily event.
+  self->StageIdleDaily(false);
+}
+
+/**
+ * The idle services goal is to notify subscribers when a certain time has
+ * passed since the last user interaction with the system.
+ *
+ * On some platforms this is defined as the last time user events reached this
+ * application, on other platforms it is a system wide thing - the preferred
+ * implementation is to use the system idle time, rather than the application
+ * idle time, as the things depending on the idle service are likely to use
+ * significant resources (network, disk, memory, cpu, etc.).
+ *
+ * When the idle service needs to use the system wide idle timer, it typically
+ * needs to poll the idle time value by the means of a timer.  It needs to
+ * poll fast when it is in active idle mode (when it has a listener in the idle
+ * mode) as it needs to detect if the user is active in other applications.
+ *
+ * When the service is waiting for the first listener to become idle, or when
+ * it is only monitoring application idle time, it only needs to have the timer
+ * expire at the time the next listener goes idle.
+ *
+ * The core state of the service is determined by:
+ *
+ * - A list of listeners.
+ *
+ * - A boolean that tells if any listeners are in idle mode.
+ *
+ * - A delta value that indicates when, measured from the last non-idle time,
+ *   the next listener should switch to idle mode.
+ *
+ * - An absolute time of the last time idle mode was detected (this is used to
+ *   judge if we have been out of idle mode since the last invocation of the
+ *   service.
+ *
+ * There are four entry points into the system:
+ *
+ * - A new listener is registered.
+ *
+ * - An existing listener is deregistered.
+ *
+ * - User interaction is detected.
+ *
+ * - The timer expires.
+ *
+ * When a new listener is added its idle timeout, is compared with the next idle
+ * timeout, and if lower, that time is stored as the new timeout, and the timer
+ * is reconfigured to ensure a timeout around the time the new listener should
+ * timeout.
+ *
+ * If the next idle time is above the idle time requested by the new listener
+ * it won't be informed until the timer expires, this is to avoid recursive
+ * behavior and to simplify the code.  In this case the timer will be set to
+ * about 10 ms.
+ *
+ * When an existing listener is deregistered, it is just removed from the list
+ * of active listeners, we don't stop the timer, we just let it expire.
+ *
+ * When user interaction is detected, either because it was directly detected or
+ * because we polled the system timer and found it to be unexpected low, then we
+ * check the flag that tells us if any listeners are in idle mode, if there are
+ * they are removed from idle mode and told so, and we reset our state
+ * caculating the next timeout and restart the timer if needed.
+ *
+ * ---- Build in logic
+ *
+ * In order to avoid restarting the timer endlessly, the timer function has
+ * logic that will only restart the timer, if the requested timeout is before
+ * the current timeout.
+ *
+ */
+
+////////////////////////////////////////////////////////////////////////////////
+//// nsUserIdleService
+
+namespace {
+nsUserIdleService* gIdleService;
+}  // namespace
+
+already_AddRefed<nsUserIdleService> nsUserIdleService::GetInstance() {
+  RefPtr<nsUserIdleService> instance(gIdleService);
+  return instance.forget();
+}
+
+nsUserIdleService::nsUserIdleService()
+    : mCurrentlySetToTimeoutAt(TimeStamp()),
+      mIdleObserverCount(0),
+      mDeltaToNextIdleSwitchInS(UINT32_MAX),
+      mLastUserInteraction(TimeStamp::Now()) {
+  MOZ_ASSERT(!gIdleService);
+  gIdleService = this;
+  if (XRE_IsParentProcess()) {
+    mDailyIdle = new nsUserIdleServiceDaily(this);
+    mDailyIdle->Init();
+  }
+}
+
+nsUserIdleService::~nsUserIdleService() {
+  if (mTimer) {
+    mTimer->Cancel();
+  }
+
+  MOZ_ASSERT(gIdleService == this);
+  gIdleService = nullptr;
+}
+
+NS_IMPL_ISUPPORTS(nsUserIdleService, nsIUserIdleService,
+                  nsIUserIdleServiceInternal)
+
+NS_IMETHODIMP
+nsUserIdleService::AddIdleObserver(nsIObserver* aObserver,
+                                   uint32_t aIdleTimeInS) {
+  NS_ENSURE_ARG_POINTER(aObserver);
+  // We don't accept idle time at 0, and we can't handle idle time that are too
+  // high either - no more than ~136 years.
+  NS_ENSURE_ARG_RANGE(aIdleTimeInS, 1, (UINT32_MAX / 10) - 1);
+
+  if (profiler_thread_is_being_profiled_for_markers()) {
+    nsAutoCString timeCStr;
+    timeCStr.AppendInt(aIdleTimeInS);
+    PROFILER_MARKER_TEXT("UserIdle::AddObserver", OTHER, MarkerStack::Capture(),
+                         timeCStr);
+  }
+
+  if (XRE_IsContentProcess()) {
+    dom::ContentChild* cpc = dom::ContentChild::GetSingleton();
+    cpc->AddIdleObserver(aObserver, aIdleTimeInS);
+    return NS_OK;
+  }
+
+  MOZ_LOG(sLog, LogLevel::Debug,
+          ("idleService: Register idle observer %p for %d seconds", aObserver,
+           aIdleTimeInS));
+#ifdef MOZ_WIDGET_ANDROID
+  __android_log_print(LOG_LEVEL, LOG_TAG,
+                      "Register idle observer %p for %d seconds", aObserver,
+                      aIdleTimeInS);
+#endif
+
+  // Put the time + observer in a struct we can keep:
+  IdleListener listener(aObserver, aIdleTimeInS);
+
+  // XXX(Bug 1631371) Check if this should use a fallible operation as it
+  // pretended earlier.
+  mArrayListeners.AppendElement(listener);
+
+  // Create our timer callback if it's not there already.
+  if (!mTimer) {
+    mTimer = NS_NewTimer();
+    NS_ENSURE_TRUE(mTimer, NS_ERROR_OUT_OF_MEMORY);
+  }
+
+  // Check if the newly added observer has a smaller wait time than what we
+  // are waiting for now.
+  if (mDeltaToNextIdleSwitchInS > aIdleTimeInS) {
+    // If it is, then this is the next to move to idle (at this point we
+    // don't care if it should have switched already).
+    MOZ_LOG(
+        sLog, LogLevel::Debug,
+        ("idleService: Register: adjusting next switch from %d to %d seconds",
+         mDeltaToNextIdleSwitchInS, aIdleTimeInS));
+#ifdef MOZ_WIDGET_ANDROID
+    __android_log_print(LOG_LEVEL, LOG_TAG,
+                        "Register: adjusting next switch from %d to %d seconds",
+                        mDeltaToNextIdleSwitchInS, aIdleTimeInS);
+#endif
+
+    mDeltaToNextIdleSwitchInS = aIdleTimeInS;
+    ReconfigureTimer();
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsUserIdleService::RemoveIdleObserver(nsIObserver* aObserver,
+                                      uint32_t aTimeInS) {
+  NS_ENSURE_ARG_POINTER(aObserver);
+  NS_ENSURE_ARG(aTimeInS);
+
+  if (profiler_thread_is_being_profiled_for_markers()) {
+    nsAutoCString timeCStr;
+    timeCStr.AppendInt(aTimeInS);
+    PROFILER_MARKER_TEXT("UserIdle::RemoveObserver", OTHER,
+                         MarkerStack::Capture(), timeCStr);
+  }
+
+  if (XRE_IsContentProcess()) {
+    dom::ContentChild* cpc = dom::ContentChild::GetSingleton();
+    cpc->RemoveIdleObserver(aObserver, aTimeInS);
+    return NS_OK;
+  }
+
+  IdleListener listener(aObserver, aTimeInS);
+
+  // Find the entry and remove it, if it was the last entry, we just let the
+  // existing timer run to completion (there might be a new registration in a
+  // little while.
+  IdleListenerComparator c;
+  nsTArray<IdleListener>::index_type listenerIndex =
+      mArrayListeners.IndexOf(listener, 0, c);
+  if (listenerIndex != mArrayListeners.NoIndex) {
+    if (mArrayListeners.ElementAt(listenerIndex).isIdle) mIdleObserverCount--;
+    mArrayListeners.RemoveElementAt(listenerIndex);
+    MOZ_LOG(sLog, LogLevel::Debug,
+            ("idleService: Remove observer %p (%d seconds), %d remain idle",
+             aObserver, aTimeInS, mIdleObserverCount));
+#ifdef MOZ_WIDGET_ANDROID
+    __android_log_print(LOG_LEVEL, LOG_TAG,
+                        "Remove observer %p (%d seconds), %d remain idle",
+                        aObserver, aTimeInS, mIdleObserverCount);
+#endif
+    return NS_OK;
+  }
+
+  // If we get here, we haven't removed anything:
+  MOZ_LOG(sLog, LogLevel::Warning,
+          ("idleService: Failed to remove idle observer %p (%d seconds)",
+           aObserver, aTimeInS));
+#ifdef MOZ_WIDGET_ANDROID
+  __android_log_print(LOG_LEVEL, LOG_TAG,
+                      "Failed to remove idle observer %p (%d seconds)",
+                      aObserver, aTimeInS);
+#endif
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsUserIdleService::ResetIdleTimeOut(uint32_t idleDeltaInMS) {
+  MOZ_LOG(sLog, LogLevel::Debug,
+          ("idleService: Reset idle timeout (last interaction %u msec)",
+           idleDeltaInMS));
+
+  // Store the time
+  mLastUserInteraction =
+      TimeStamp::Now() - TimeDuration::FromMilliseconds(idleDeltaInMS);
+
+  // If no one is idle, then we are done, any existing timers can keep running.
+  if (mIdleObserverCount == 0) {
+    MOZ_LOG(sLog, LogLevel::Debug,
+            ("idleService: Reset idle timeout: no idle observers"));
+    return NS_OK;
+  }
+
+  // Mark all idle services as non-idle, and calculate the next idle timeout.
+  nsCOMArray<nsIObserver> notifyList;
+  mDeltaToNextIdleSwitchInS = UINT32_MAX;
+
+  // Loop through all listeners, and find any that have detected idle.
+  for (uint32_t i = 0; i < mArrayListeners.Length(); i++) {
+    IdleListener& curListener = mArrayListeners.ElementAt(i);
+
+    // If the listener was idle, then he shouldn't be any longer.
+    if (curListener.isIdle) {
+      notifyList.AppendObject(curListener.observer);
+      curListener.isIdle = false;
+    }
+
+    // Check if the listener is the next one to timeout.
+    mDeltaToNextIdleSwitchInS =
+        std::min(mDeltaToNextIdleSwitchInS, curListener.reqIdleTime);
+  }
+
+  // When we are done, then we wont have anyone idle.
+  mIdleObserverCount = 0;
+
+  // Restart the idle timer, and do so before anyone can delay us.
+  ReconfigureTimer();
+
+  int32_t numberOfPendingNotifications = notifyList.Count();
+
+  // Bail if nothing to do.
+  if (!numberOfPendingNotifications) {
+    return NS_OK;
+  }
+
+  // Now send "active" events to all, if any should have timed out already,
+  // then they will be reawaken by the timer that is already running.
+
+  // We need a text string to send with any state change events.
+  nsAutoString timeStr;
+
+  timeStr.AppendInt((int32_t)(idleDeltaInMS / PR_MSEC_PER_SEC));
+
+  // Send the "non-idle" events.
+  while (numberOfPendingNotifications--) {
+    MOZ_LOG(sLog, LogLevel::Debug,
+            ("idleService: Reset idle timeout: tell observer %p user is back",
+             notifyList[numberOfPendingNotifications]));
+#ifdef MOZ_WIDGET_ANDROID
+    __android_log_print(LOG_LEVEL, LOG_TAG,
+                        "Reset idle timeout: tell observer %p user is back",
+                        notifyList[numberOfPendingNotifications]);
+#endif
+    notifyList[numberOfPendingNotifications]->Observe(
+        this, OBSERVER_TOPIC_ACTIVE, timeStr.get());
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsUserIdleService::GetIdleTime(uint32_t* idleTime) {
+  // Check sanity of in parameter.
+  if (!idleTime) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  // Polled idle time in ms.
+  uint32_t polledIdleTimeMS;
+
+  bool polledIdleTimeIsValid = PollIdleTime(&polledIdleTimeMS);
+
+  MOZ_LOG(sLog, LogLevel::Debug,
+          ("idleService: Get idle time: polled %u msec, valid = %d",
+           polledIdleTimeMS, polledIdleTimeIsValid));
+
+  // timeSinceReset is in milliseconds.
+  TimeDuration timeSinceReset = TimeStamp::Now() - mLastUserInteraction;
+  uint32_t timeSinceResetInMS = timeSinceReset.ToMilliseconds();
+
+  MOZ_LOG(sLog, LogLevel::Debug,
+          ("idleService: Get idle time: time since reset %u msec",
+           timeSinceResetInMS));
+#ifdef MOZ_WIDGET_ANDROID
+  __android_log_print(LOG_LEVEL, LOG_TAG,
+                      "Get idle time: time since reset %u msec",
+                      timeSinceResetInMS);
+#endif
+
+  // If we did't get pulled data, return the time since last idle reset.
+  if (!polledIdleTimeIsValid) {
+    // We need to convert to ms before returning the time.
+    *idleTime = timeSinceResetInMS;
+    return NS_OK;
+  }
+
+  // Otherwise return the shortest time detected (in ms).
+  *idleTime = std::min(timeSinceResetInMS, polledIdleTimeMS);
+
+  return NS_OK;
+}
+
+bool nsUserIdleService::PollIdleTime(uint32_t* /*aIdleTime*/) {
+  // Default behavior is not to have the ability to poll an idle time.
+  return false;
+}
+
+nsresult nsUserIdleService::GetDisabled(bool* aResult) {
+  *aResult = mDisabled;
+  return NS_OK;
+}
+
+nsresult nsUserIdleService::SetDisabled(bool aDisabled) {
+  mDisabled = aDisabled;
+  return NS_OK;
+}
+
+void nsUserIdleService::StaticIdleTimerCallback(nsITimer* aTimer,
+                                                void* aClosure) {
+  static_cast<nsUserIdleService*>(aClosure)->IdleTimerCallback();
+}
+
+void nsUserIdleService::IdleTimerCallback(void) {
+  // Remember that we no longer have a timer running.
+  mCurrentlySetToTimeoutAt = TimeStamp();
+
+  // Find the last detected idle time.
+  uint32_t lastIdleTimeInMS = static_cast<uint32_t>(
+      (TimeStamp::Now() - mLastUserInteraction).ToMilliseconds());
+  // Get the current idle time.
+  uint32_t currentIdleTimeInMS;
+
+  if (NS_FAILED(GetIdleTime(&currentIdleTimeInMS))) {
+    MOZ_LOG(sLog, LogLevel::Info,
+            ("idleService: Idle timer callback: failed to get idle time"));
+#ifdef MOZ_WIDGET_ANDROID
+    __android_log_print(LOG_LEVEL, LOG_TAG,
+                        "Idle timer callback: failed to get idle time");
+#endif
+    return;
+  }
+
+  MOZ_LOG(sLog, LogLevel::Debug,
+          ("idleService: Idle timer callback: current idle time %u msec",
+           currentIdleTimeInMS));
+#ifdef MOZ_WIDGET_ANDROID
+  __android_log_print(LOG_LEVEL, LOG_TAG,
+                      "Idle timer callback: current idle time %u msec",
+                      currentIdleTimeInMS);
+#endif
+
+  // Check if we have had some user interaction we didn't handle previously
+  // we do the calculation in ms to lessen the chance for rounding errors to
+  // trigger wrong results.
+  if (lastIdleTimeInMS > currentIdleTimeInMS) {
+    // We had user activity, so handle that part first (to ensure the listeners
+    // don't risk getting an non-idle after they get a new idle indication.
+    ResetIdleTimeOut(currentIdleTimeInMS);
+
+    // NOTE: We can't bail here, as we might have something already timed out.
+  }
+
+  // Find the idle time in S.
+  uint32_t currentIdleTimeInS = currentIdleTimeInMS / PR_MSEC_PER_SEC;
+
+  // Restart timer and bail if no-one are expected to be in idle
+  if (mDeltaToNextIdleSwitchInS > currentIdleTimeInS) {
+    // If we didn't expect anyone to be idle, then just re-start the timer.
+    ReconfigureTimer();
+    return;
+  }
+
+  if (mDisabled) {
+    MOZ_LOG(sLog, LogLevel::Info,
+            ("idleService: Skipping idle callback while disabled"));
+
+    ReconfigureTimer();
+    return;
+  }
+
+  // Tell expired listeners they are expired,and find the next timeout
+  Telemetry::AutoTimer<Telemetry::IDLE_NOTIFY_IDLE_MS> timer;
+
+  // We need to initialise the time to the next idle switch.
+  mDeltaToNextIdleSwitchInS = UINT32_MAX;
+
+  // Create list of observers that should be notified.
+  nsCOMArray<nsIObserver> notifyList;
+
+  for (uint32_t i = 0; i < mArrayListeners.Length(); i++) {
+    IdleListener& curListener = mArrayListeners.ElementAt(i);
+
+    // We are only interested in items, that are not in the idle state.
+    if (!curListener.isIdle) {
+      // If they have an idle time smaller than the actual idle time.
+      if (curListener.reqIdleTime <= currentIdleTimeInS) {
+        // Then add the listener to the list of listeners that should be
+        // notified.
+        notifyList.AppendObject(curListener.observer);
+        // This listener is now idle.
+        curListener.isIdle = true;
+        // Remember we have someone idle.
+        mIdleObserverCount++;
+      } else {
+        // Listeners that are not timed out yet are candidates for timing out.
+        mDeltaToNextIdleSwitchInS =
+            std::min(mDeltaToNextIdleSwitchInS, curListener.reqIdleTime);
+      }
+    }
+  }
+
+  // Restart the timer before any notifications that could slow us down are
+  // done.
+  ReconfigureTimer();
+
+  int32_t numberOfPendingNotifications = notifyList.Count();
+
+  // Bail if nothing to do.
+  if (!numberOfPendingNotifications) {
+    MOZ_LOG(
+        sLog, LogLevel::Debug,
+        ("idleService: **** Idle timer callback: no observers to message."));
+    return;
+  }
+
+  // We need a text string to send with any state change events.
+  nsAutoString timeStr;
+  timeStr.AppendInt(currentIdleTimeInS);
+
+  // Notify all listeners that just timed out.
+  while (numberOfPendingNotifications--) {
+    MOZ_LOG(
+        sLog, LogLevel::Debug,
+        ("idleService: **** Idle timer callback: tell observer %p user is idle",
+         notifyList[numberOfPendingNotifications]));
+#ifdef MOZ_WIDGET_ANDROID
+    __android_log_print(LOG_LEVEL, LOG_TAG,
+                        "Idle timer callback: tell observer %p user is idle",
+                        notifyList[numberOfPendingNotifications]);
+#endif
+    nsAutoCString timeCStr;
+    timeCStr.AppendInt(currentIdleTimeInS);
+    AUTO_PROFILER_MARKER_TEXT("UserIdle::IdleCallback", OTHER, {}, timeCStr);
+    notifyList[numberOfPendingNotifications]->Observe(this, OBSERVER_TOPIC_IDLE,
+                                                      timeStr.get());
+  }
+}
+
+void nsUserIdleService::SetTimerExpiryIfBefore(TimeStamp aNextTimeout) {
+  TimeDuration nextTimeoutDuration = aNextTimeout - TimeStamp::Now();
+
+  MOZ_LOG(
+      sLog, LogLevel::Debug,
+      ("idleService: SetTimerExpiryIfBefore: next timeout %0.f msec from now",
+       nextTimeoutDuration.ToMilliseconds()));
+
+#ifdef MOZ_WIDGET_ANDROID
+  __android_log_print(LOG_LEVEL, LOG_TAG,
+                      "SetTimerExpiryIfBefore: next timeout %0.f msec from now",
+                      nextTimeoutDuration.ToMilliseconds());
+#endif
+
+  // Bail if we don't have a timer service.
+  if (!mTimer) {
+    return;
+  }
+
+  // If the new timeout is before the old one or we don't have a timer running,
+  // then restart the timer.
+  if (mCurrentlySetToTimeoutAt.IsNull() ||
+      mCurrentlySetToTimeoutAt > aNextTimeout) {
+    mCurrentlySetToTimeoutAt = aNextTimeout;
+
+    // Stop the current timer (it's ok to try'n stop it, even it isn't running).
+    mTimer->Cancel();
+
+    // Check that the timeout is actually in the future, otherwise make it so.
+    TimeStamp currentTime = TimeStamp::Now();
+    if (currentTime > mCurrentlySetToTimeoutAt) {
+      mCurrentlySetToTimeoutAt = currentTime;
+    }
+
+    // Add 10 ms to ensure we don't undershoot, and never get a "0" timer.
+    mCurrentlySetToTimeoutAt += TimeDuration::FromMilliseconds(10);
+
+    TimeDuration deltaTime = mCurrentlySetToTimeoutAt - currentTime;
+    MOZ_LOG(
+        sLog, LogLevel::Debug,
+        ("idleService: IdleService reset timer expiry to %0.f msec from now",
+         deltaTime.ToMilliseconds()));
+#ifdef MOZ_WIDGET_ANDROID
+    __android_log_print(LOG_LEVEL, LOG_TAG,
+                        "reset timer expiry to %0.f msec from now",
+                        deltaTime.ToMilliseconds());
+#endif
+
+    // Start the timer
+    mTimer->InitWithNamedFuncCallback(
+        StaticIdleTimerCallback, this, deltaTime.ToMilliseconds(),
+        nsITimer::TYPE_ONE_SHOT, "nsUserIdleService::SetTimerExpiryIfBefore");
+  }
+}
+
+void nsUserIdleService::ReconfigureTimer(void) {
+  // Check if either someone is idle, or someone will become idle.
+  if ((mIdleObserverCount == 0) && UINT32_MAX == mDeltaToNextIdleSwitchInS) {
+    // If not, just let any existing timers run to completion
+    // And bail out.
+    MOZ_LOG(sLog, LogLevel::Debug,
+            ("idleService: ReconfigureTimer: no idle or waiting observers"));
+#ifdef MOZ_WIDGET_ANDROID
+    __android_log_print(LOG_LEVEL, LOG_TAG,
+                        "ReconfigureTimer: no idle or waiting observers");
+#endif
+    return;
+  }
+
+  // Find the next timeout value, assuming we are not polling.
+
+  // We need to store the current time, so we don't get artifacts from the time
+  // ticking while we are processing.
+  TimeStamp curTime = TimeStamp::Now();
+
+  TimeStamp nextTimeoutAt =
+      mLastUserInteraction +
+      TimeDuration::FromSeconds(mDeltaToNextIdleSwitchInS);
+
+  TimeDuration nextTimeoutDuration = nextTimeoutAt - curTime;
+
+  MOZ_LOG(sLog, LogLevel::Debug,
+          ("idleService: next timeout %0.f msec from now",
+           nextTimeoutDuration.ToMilliseconds()));
+
+#ifdef MOZ_WIDGET_ANDROID
+  __android_log_print(LOG_LEVEL, LOG_TAG, "next timeout %0.f msec from now",
+                      nextTimeoutDuration.ToMilliseconds());
+#endif
+
+  SetTimerExpiryIfBefore(nextTimeoutAt);
+}