powerstats: Introduce AoC timed data provider

Reading data from an AoC sysfs node by getline takes 1 second. In total
there are 17 AoC sysfs nodes that must be read. The worst case is taking
17 seconds long that is greater than dumpsys timeout. Therefore, we need
the timeout mechanism to ignore the AoC power stats reporting when AoC
latency exceeds the allowed time.

Bug: 219630658
Test: dumpsys android.hardware.power.stats.IPowerStats/default
Change-Id: Ic5c2a0b36728153fd2e2593599a8f2bcdb50ace4
Signed-off-by: Darren Hsu <darrenhsu@google.com>

powerstats/AocTimedStateResidencyDataProvider.cpp

@@ -0,0 +1,120 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "AocTimedStateResidencyDataProvider.h"
+
+#include <android-base/logging.h>
+#include <chrono>
+
+namespace aidl {
+namespace android {
+namespace hardware {
+namespace power {
+namespace stats {
+
+AocTimedStateResidencyDataProvider::AocTimedStateResidencyDataProvider(
+    std::vector<std::pair<std::string, std::string>> ids,
+    std::vector<std::pair<std::string, std::string>> states,
+    const uint64_t timeoutMillis)
+    : AocStateResidencyDataProvider(ids, states) {
+  static const uint64_t DEFAULT_MAX_TIME_PER_STATE_MILLIS = 120;
+
+  mTimeoutMillis =
+      timeoutMillis == 0 ? DEFAULT_MAX_TIME_PER_STATE_MILLIS * states.size() : timeoutMillis;
+
+  mAsyncThread = std::thread(&AocTimedStateResidencyDataProvider::getStateResidenciesAsync, this);
+}
+
+bool AocTimedStateResidencyDataProvider::getStateResidencies(
+    std::unordered_map<std::string, std::vector<StateResidency>> *residencies) {
+  bool ret = true;
+  std::unique_lock<std::mutex> statusLock(mStatusMutex);
+
+  if (mAsyncStatus != COMPLETED) {
+    LOG(ERROR) << "The async thread is not ready: " << mAsyncStatus;
+    return false;
+  }
+
+  mStateResidencies.clear();
+
+  mAsyncStatus = RUN;
+  mRunCond.notify_one();
+
+  auto timeout = std::chrono::steady_clock::now() + std::chrono::milliseconds(mTimeoutMillis);
+  auto isCompleted =
+      mCompletedCond.wait_until(statusLock, timeout, [this]{ return mAsyncStatus == COMPLETED; });
+
+  if (isCompleted) {
+    for (const auto &residency : mStateResidencies) {
+      residencies->emplace(residency.first, residency.second);
+    }
+  } else {
+    LOG(ERROR) << __func__ << " for AoC timed out: " << mTimeoutMillis << " ms";
+    ret = false;
+  }
+
+  return ret;
+}
+
+void AocTimedStateResidencyDataProvider::getStateResidenciesAsync() {
+  std::unique_lock<std::mutex> statusLock(mStatusMutex);
+
+  mAsyncStatus = COMPLETED;
+
+  while (1) {
+    mRunCond.wait(statusLock, [this]{ return mAsyncStatus == RUN; });
+
+    mAsyncStatus = RUNNING;
+    statusLock.unlock();
+
+    // States from the same power entity are merged.
+    for (const auto &providerList : mProviders) {
+      int32_t stateId = 0;
+      std::string curEntity = providerList.first;
+      std::vector<StateResidency> stateResidencies;
+
+      // Iterate over each provider in the providerList, appending each of the states
+      for (const auto &provider : providerList.second) {
+        std::unordered_map<std::string, std::vector<StateResidency>> residency;
+        provider->getStateResidencies(&residency);
+
+        // Each provider should only return data for curEntity but checking anyway
+        if (residency.find(curEntity) != residency.end()) {
+          for (auto &r : residency.at(curEntity)) {
+            /*
+             * Modifying stateId here because we are stitching together infos from
+             * multiple GenericStateResidencyDataProviders. stateId must be modified
+             * to maintain uniqueness for a given entity
+             */
+            r.id = stateId++;
+            stateResidencies.push_back(r);
+          }
+        }
+      }
+      mStateResidencies.emplace(curEntity, stateResidencies);
+    }
+
+    statusLock.lock();
+    mAsyncStatus = COMPLETED;
+    mCompletedCond.notify_one();
+  } // while loop
+}
+
+}  // namespace stats
+}  // namespace power
+}  // namespace hardware
+}  // namespace android
+}  // namespace aidl

powerstats/include/AocStateResidencyDataProvider.h

@@ -33,7 +33,7 @@ class AocStateResidencyDataProvider : public PowerStats::IStateResidencyDataProv
         std::unordered_map<std::string, std::vector<StateResidency>> *residencies) override;
     std::unordered_map<std::string, std::vector<State>> getInfo() override;
 
-  private:
+  protected:
     std::unordered_map<std::string /* entity name */,
         std::vector<std::unique_ptr<GenericStateResidencyDataProvider>> /* providers */> mProviders;
 };
@@ -42,4 +42,4 @@ class AocStateResidencyDataProvider : public PowerStats::IStateResidencyDataProv
 }  // namespace power
 }  // namespace hardware
 }  // namespace android
-}  // namespace aidl
+}  // namespace aidl

powerstats/include/AocTimedStateResidencyDataProvider.h

@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#pragma once
+
+#include "AocStateResidencyDataProvider.h"
+
+#include <condition_variable>
+#include <mutex>
+#include <thread>
+#include <PowerStatsAidl.h>
+
+namespace aidl {
+namespace android {
+namespace hardware {
+namespace power {
+namespace stats {
+
+enum AsyncStatus {
+  COMPLETED,
+  RUN,
+  RUNNING
+};
+
+class AocTimedStateResidencyDataProvider : public AocStateResidencyDataProvider {
+ public:
+  AocTimedStateResidencyDataProvider(
+      std::vector<std::pair<std::string, std::string>> ids,
+      std::vector<std::pair<std::string, std::string>> states,
+      const uint64_t timeoutMillis);
+  ~AocTimedStateResidencyDataProvider() = default;
+
+  bool getStateResidencies(
+      std::unordered_map<std::string, std::vector<StateResidency>> *residencies) override;
+
+ private:
+  void getStateResidenciesAsync();
+
+  uint64_t mTimeoutMillis;
+  std::thread mAsyncThread;
+  std::mutex mStatusMutex;
+  std::condition_variable mRunCond;
+  std::condition_variable mCompletedCond;
+  std::unordered_map<std::string, std::vector<StateResidency>> mStateResidencies;
+  AsyncStatus mAsyncStatus;
+};
+
+}  // namespace stats
+}  // namespace power
+}  // namespace hardware
+}  // namespace android
+}  // namespace aidl