1 files changed, 227 insertions, 0 deletions
diff --git a/dom/media/systemservices/LoadManager.cpp b/dom/media/systemservices/LoadManager.cpp
new file mode 100644
index 000000000..f0f4f83a7
--- /dev/null
+++ b/dom/media/systemservices/LoadManager.cpp
@@ -0,0 +1,227 @@
+/* -*- Mode: C++; tab-width: 50; indent-tabs-mode: nil; c-basic-offset: 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 "LoadManager.h"
+#include "LoadMonitor.h"
+#include "nsString.h"
+#include "mozilla/Logging.h"
+#include "prtime.h"
+#include "prinrval.h"
+#include "prsystem.h"
+
+#include "nsString.h"
+#include "nsThreadUtils.h"
+#include "nsReadableUtils.h"
+#include "nsIObserverService.h"
+#include "mozilla/Telemetry.h"
+#include "mozilla/ArrayUtils.h"
+
+// MOZ_LOG=LoadManager:5
+mozilla::LazyLogModule gLoadManagerLog("LoadManager");
+#undef LOG
+#undef LOG_ENABLED
+#define LOG(args) MOZ_LOG(gLoadManagerLog, mozilla::LogLevel::Debug, args)
+#define LOG_ENABLED() MOZ_LOG_TEST(gLoadManagerLog, mozilla::LogLevel::Verbose)
+
+namespace mozilla {
+
+/* static */ StaticRefPtr<LoadManagerSingleton> LoadManagerSingleton::sSingleton;
+
+NS_IMPL_ISUPPORTS(LoadManagerSingleton, nsIObserver)
+
+
+LoadManagerSingleton::LoadManagerSingleton(bool aEncoderOnly,
+                                           int aLoadMeasurementInterval,
+                                           int aAveragingMeasurements,
+                                           float aHighLoadThreshold,
+                                           float aLowLoadThreshold)
+  : mLock("LoadManager"),
+    mCurrentState(webrtc::kLoadNormal),
+    mOveruseActive(false),
+    mLoadSum(0.0f),
+    mLoadSumMeasurements(0),
+    mLoadMeasurementInterval(aLoadMeasurementInterval),
+    mAveragingMeasurements(aAveragingMeasurements),
+    mHighLoadThreshold(aHighLoadThreshold),
+    mLowLoadThreshold(aLowLoadThreshold)
+{
+  LOG(("LoadManager - Initializing (%dms x %d, %f, %f)",
+       mLoadMeasurementInterval, mAveragingMeasurements,
+       mHighLoadThreshold, mLowLoadThreshold));
+  MOZ_ASSERT(mHighLoadThreshold > mLowLoadThreshold);
+  if (!aEncoderOnly) {
+    mLoadMonitor = new LoadMonitor(mLoadMeasurementInterval);
+    mLoadMonitor->Init(mLoadMonitor);
+    mLoadMonitor->SetLoadChangeCallback(this);
+  }
+
+  mLastStateChange = TimeStamp::Now();
+  for (auto &in_state : mTimeInState) {
+    in_state = 0;
+  }
+}
+
+LoadManagerSingleton::~LoadManagerSingleton()
+{
+  LOG(("LoadManager: shutting down LoadMonitor"));
+  MOZ_ASSERT(!mLoadMonitor, "why wasn't the LoadMonitor shut down in xpcom-shutdown?");
+  if (mLoadMonitor) {
+    mLoadMonitor->Shutdown();
+  }
+}
+
+nsresult
+LoadManagerSingleton::Observe(nsISupports* aSubject, const char* aTopic,
+                     const char16_t* aData)
+{
+  NS_ASSERTION(NS_IsMainThread(), "Observer invoked off the main thread");
+  nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
+
+  if (!strcmp(aTopic, "xpcom-shutdown")) {
+    obs->RemoveObserver(this, "xpcom-shutdown");
+    {
+      MutexAutoLock lock(mLock);
+      mObservers.Clear();
+    }
+    if (mLoadMonitor) {
+      mLoadMonitor->Shutdown();
+      mLoadMonitor = nullptr;
+    }
+
+    LOG(("Releasing LoadManager singleton and thread"));
+    // Note: won't be released immediately as the Observer has a ref to us
+    sSingleton = nullptr;
+  }
+  return NS_OK;
+}
+
+void
+LoadManagerSingleton::LoadChanged(float aSystemLoad, float aProcesLoad)
+{
+  MutexAutoLock lock(mLock);
+  // Update total load, and total amount of measured seconds.
+  mLoadSum += aSystemLoad;
+  mLoadSumMeasurements++;
+
+  if (mLoadSumMeasurements >= mAveragingMeasurements) {
+    double averagedLoad = mLoadSum / (float)mLoadSumMeasurements;
+
+    webrtc::CPULoadState newState = mCurrentState;
+
+    if (mOveruseActive || averagedLoad > mHighLoadThreshold) {
+      LOG(("LoadManager - LoadStressed"));
+      newState = webrtc::kLoadStressed;
+    } else if (averagedLoad < mLowLoadThreshold) {
+      LOG(("LoadManager - LoadRelaxed"));
+      newState = webrtc::kLoadRelaxed;
+    } else {
+      LOG(("LoadManager - LoadNormal"));
+      newState = webrtc::kLoadNormal;
+    }
+
+    if (newState != mCurrentState) {
+      LoadHasChanged(newState);
+    }
+
+    mLoadSum = 0;
+    mLoadSumMeasurements = 0;
+  }
+}
+
+void
+LoadManagerSingleton::OveruseDetected()
+{
+  LOG(("LoadManager - Overuse Detected"));
+  MutexAutoLock lock(mLock);
+  mOveruseActive = true;
+  if (mCurrentState != webrtc::kLoadStressed) {
+    LoadHasChanged(webrtc::kLoadStressed);
+  }
+}
+
+void
+LoadManagerSingleton::NormalUsage()
+{
+  LOG(("LoadManager - Overuse finished"));
+  MutexAutoLock lock(mLock);
+  mOveruseActive = false;
+}
+
+void
+LoadManagerSingleton::LoadHasChanged(webrtc::CPULoadState aNewState)
+{
+  mLock.AssertCurrentThreadOwns();
+  LOG(("LoadManager - Signaling LoadHasChanged from %d to %d to %d listeners",
+       mCurrentState, aNewState, mObservers.Length()));
+
+  // Record how long we spent in this state for later Telemetry or display
+  TimeStamp now = TimeStamp::Now();
+  mTimeInState[mCurrentState] += (now - mLastStateChange).ToMilliseconds();
+  mLastStateChange = now;
+
+  mCurrentState = aNewState;
+  for (size_t i = 0; i < mObservers.Length(); i++) {
+    mObservers.ElementAt(i)->onLoadStateChanged(mCurrentState);
+  }
+}
+
+void
+LoadManagerSingleton::AddObserver(webrtc::CPULoadStateObserver * aObserver)
+{
+  LOG(("LoadManager - Adding Observer"));
+  MutexAutoLock lock(mLock);
+  mObservers.AppendElement(aObserver);
+}
+
+void
+LoadManagerSingleton::RemoveObserver(webrtc::CPULoadStateObserver * aObserver)
+{
+  LOG(("LoadManager - Removing Observer"));
+  MutexAutoLock lock(mLock);
+  if (!mObservers.RemoveElement(aObserver)) {
+    LOG(("LoadManager - Element to remove not found"));
+  }
+  if (mObservers.Length() == 0) {
+    // Record how long we spent in the final state for later Telemetry or display
+    TimeStamp now = TimeStamp::Now();
+    mTimeInState[mCurrentState] += (now - mLastStateChange).ToMilliseconds();
+
+    float total = 0;
+    for (size_t i = 0; i < MOZ_ARRAY_LENGTH(mTimeInState); i++) {
+      total += mTimeInState[i];
+    }
+    // Don't include short calls; we don't have reasonable load data, and
+    // such short calls rarely reach a stable state.  Keep relatively
+    // short calls separate from longer ones
+    bool log = total > 5*PR_MSEC_PER_SEC;
+    bool small = log && total < 30*PR_MSEC_PER_SEC;
+    if (log) {
+      // Note: We don't care about rounding here; thus total may be < 100
+      Telemetry::Accumulate(small ? Telemetry::WEBRTC_LOAD_STATE_RELAXED_SHORT :
+                            Telemetry::WEBRTC_LOAD_STATE_RELAXED,
+                            (uint32_t) (mTimeInState[webrtc::CPULoadState::kLoadRelaxed]/total * 100));
+      Telemetry::Accumulate(small ? Telemetry::WEBRTC_LOAD_STATE_NORMAL_SHORT :
+                            Telemetry::WEBRTC_LOAD_STATE_NORMAL,
+                            (uint32_t) (mTimeInState[webrtc::CPULoadState::kLoadNormal]/total * 100));
+      Telemetry::Accumulate(small ? Telemetry::WEBRTC_LOAD_STATE_STRESSED_SHORT :
+                            Telemetry::WEBRTC_LOAD_STATE_STRESSED,
+                            (uint32_t) (mTimeInState[webrtc::CPULoadState::kLoadStressed]/total * 100));
+    }
+    for (auto &in_state : mTimeInState) {
+      in_state = 0;
+    }
+
+    if (mLoadMonitor) {
+      // Dance to avoid deadlock on mLock!
+      RefPtr<LoadMonitor> loadMonitor = mLoadMonitor.forget();
+      MutexAutoUnlock unlock(mLock);
+
+      loadMonitor->Shutdown();
+    }
+  }
+}
+
+
+}