media/libmediatranscoding/TranscodingJobScheduler.cpp - android_frameworks_av - Gitiles

 /*
  * Copyright (C) 2020 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.
  */

 //#define LOG_NDEBUG 0
 #define LOG_TAG "TranscodingJobScheduler"

 #define VALIDATE_STATE 1

 #include <inttypes.h>
 #include <media/TranscodingJobScheduler.h>
 #include <utils/Log.h>

 #include <utility>

 namespace android {

 static_assert((JobIdType)-1 < 0, "JobIdType should be signed");

 constexpr static uid_t OFFLINE_UID = -1;

 //static
 String8 TranscodingJobScheduler::jobToString(const JobKeyType& jobKey) {
     return String8::format("{client:%lld, job:%d}", (long long)jobKey.first, jobKey.second);
 }

 TranscodingJobScheduler::TranscodingJobScheduler(
         const std::shared_ptr<TranscoderInterface>& transcoder,
         const std::shared_ptr<UidPolicyInterface>& uidPolicy)
       : mTranscoder(transcoder), mUidPolicy(uidPolicy), mCurrentJob(nullptr), mResourceLost(false) {
     // Only push empty offline queue initially. Realtime queues are added when requests come in.
     mUidSortedList.push_back(OFFLINE_UID);
     mOfflineUidIterator = mUidSortedList.begin();
     mJobQueues.emplace(OFFLINE_UID, JobQueueType());
 }

 TranscodingJobScheduler::~TranscodingJobScheduler() {}

 TranscodingJobScheduler::Job* TranscodingJobScheduler::getTopJob_l() {
     if (mJobMap.empty()) {
         return nullptr;
     }
     uid_t topUid = *mUidSortedList.begin();
     JobKeyType topJobKey = *mJobQueues[topUid].begin();
     return &mJobMap[topJobKey];
 }

 void TranscodingJobScheduler::updateCurrentJob_l() {
     Job* topJob = getTopJob_l();
     Job* curJob = mCurrentJob;
     ALOGV("updateCurrentJob: topJob is %s, curJob is %s",
           topJob == nullptr ? "null" : jobToString(topJob->key).c_str(),
           curJob == nullptr ? "null" : jobToString(curJob->key).c_str());

     // If we found a topJob that should be run, and it's not already running,
     // take some actions to ensure it's running.
     if (topJob != nullptr && (topJob != curJob || topJob->state != Job::RUNNING)) {
         // If another job is currently running, pause it first.
         if (curJob != nullptr && curJob->state == Job::RUNNING) {
             mTranscoder->pause(curJob->key.first, curJob->key.second);
             curJob->state = Job::PAUSED;
         }
         // If we are not experiencing resource loss, we can start or resume
         // the topJob now.
         if (!mResourceLost) {
             if (topJob->state == Job::NOT_STARTED) {
                 mTranscoder->start(topJob->key.first, topJob->key.second, topJob->request);
             } else if (topJob->state == Job::PAUSED) {
                 mTranscoder->resume(topJob->key.first, topJob->key.second);
             }
             topJob->state = Job::RUNNING;
         }
     }
     mCurrentJob = topJob;
 }

 void TranscodingJobScheduler::removeJob_l(const JobKeyType& jobKey) {
     ALOGV("%s: job %s", __FUNCTION__, jobToString(jobKey).c_str());

     if (mJobMap.count(jobKey) == 0) {
         ALOGE("job %s doesn't exist", jobToString(jobKey).c_str());
         return;
     }

     // Remove job from uid's queue.
     const uid_t uid = mJobMap[jobKey].uid;
     JobQueueType& jobQueue = mJobQueues[uid];
     auto it = std::find(jobQueue.begin(), jobQueue.end(), jobKey);
     if (it == jobQueue.end()) {
         ALOGE("couldn't find job %s in queue for uid %d", jobToString(jobKey).c_str(), uid);
         return;
     }
     jobQueue.erase(it);

     // If this is the last job in a real-time queue, remove this uid's queue.
     if (uid != OFFLINE_UID && jobQueue.empty()) {
         mUidSortedList.remove(uid);
         mJobQueues.erase(uid);
         mUidPolicy->unregisterMonitorUid(uid);

         std::unordered_set<uid_t> topUids = mUidPolicy->getTopUids();
         moveUidsToTop_l(topUids, false /*preserveTopUid*/);
     }

     // Clear current job.
     if (mCurrentJob == &mJobMap[jobKey]) {
         mCurrentJob = nullptr;
     }

     // Remove job from job map.
     mJobMap.erase(jobKey);
 }

 /**
  * Moves the set of uids to the front of mUidSortedList (which is used to pick
  * the next job to run).
  *
  * This is called when 1) we received a onTopUidsChanged() callbcak from UidPolicy,
  * or 2) we removed the job queue for a uid because it becomes empty.
  *
  * In case of 1), if there are multiple uids in the set, and the current front
  * uid in mUidSortedList is still in the set, we try to keep that uid at front
  * so that current job run is not interrupted. (This is not a concern for case 2)
  * because the queue for a uid was just removed entirely.)
  */
 void TranscodingJobScheduler::moveUidsToTop_l(const std::unordered_set<uid_t>& uids,
                                               bool preserveTopUid) {
     // If uid set is empty, nothing to do. Do not change the queue status.
     if (uids.empty()) {
         return;
     }

     // Save the current top uid.
     uid_t curTopUid = *mUidSortedList.begin();
     bool pushCurTopToFront = false;
     int32_t numUidsMoved = 0;

     // Go through the sorted uid list once, and move the ones in top set to front.
     for (auto it = mUidSortedList.begin(); it != mUidSortedList.end();) {
         uid_t uid = *it;

         if (uid != OFFLINE_UID && uids.count(uid) > 0) {
             it = mUidSortedList.erase(it);

             // If this is the top we're preserving, don't push it here, push
             // it after the for-loop.
             if (uid == curTopUid && preserveTopUid) {
                 pushCurTopToFront = true;
             } else {
                 mUidSortedList.push_front(uid);
             }

             // If we found all uids in the set, break out.
             if (++numUidsMoved == uids.size()) {
                 break;
             }
         } else {
             ++it;
         }
     }

     if (pushCurTopToFront) {
         mUidSortedList.push_front(curTopUid);
     }
 }

 bool TranscodingJobScheduler::submit(ClientIdType clientId, JobIdType jobId, uid_t uid,
                                      const TranscodingRequestParcel& request,
                                      const std::weak_ptr<ITranscodingClientCallback>& callback) {
     JobKeyType jobKey = std::make_pair(clientId, jobId);

     ALOGV("%s: job %s, uid %d, prioirty %d", __FUNCTION__, jobToString(jobKey).c_str(), uid,
           (int32_t)request.priority);

     std::scoped_lock lock{mLock};

     if (mJobMap.count(jobKey) > 0) {
         ALOGE("job %s already exists", jobToString(jobKey).c_str());
         return false;
     }

     // TODO(chz): only support offline vs real-time for now. All kUnspecified jobs
     // go to offline queue.
     if (request.priority == TranscodingJobPriority::kUnspecified) {
         uid = OFFLINE_UID;
     }

     // Add job to job map.
     mJobMap[jobKey].key = jobKey;
     mJobMap[jobKey].uid = uid;
     mJobMap[jobKey].state = Job::NOT_STARTED;
     mJobMap[jobKey].request = request;
     mJobMap[jobKey].callback = callback;

     // If it's an offline job, the queue was already added in constructor.
     // If it's a real-time jobs, check if a queue is already present for the uid,
     // and add a new queue if needed.
     if (uid != OFFLINE_UID) {
         if (mJobQueues.count(uid) == 0) {
             mUidPolicy->registerMonitorUid(uid);
             if (mUidPolicy->isUidOnTop(uid)) {
                 mUidSortedList.push_front(uid);
             } else {
                 // Shouldn't be submitting real-time requests from non-top app,
                 // put it in front of the offline queue.
                 mUidSortedList.insert(mOfflineUidIterator, uid);
             }
         } else if (uid != *mUidSortedList.begin()) {
             if (mUidPolicy->isUidOnTop(uid)) {
                 mUidSortedList.remove(uid);
                 mUidSortedList.push_front(uid);
             }
         }
     }
     // Append this job to the uid's queue.
     mJobQueues[uid].push_back(jobKey);

     updateCurrentJob_l();

     validateState_l();
     return true;
 }

 bool TranscodingJobScheduler::cancel(ClientIdType clientId, JobIdType jobId) {
     JobKeyType jobKey = std::make_pair(clientId, jobId);

     ALOGV("%s: job %s", __FUNCTION__, jobToString(jobKey).c_str());

     std::list<JobKeyType> jobsToRemove;

     std::scoped_lock lock{mLock};

     if (jobId < 0) {
         for (auto it = mJobMap.begin(); it != mJobMap.end(); ++it) {
             if (it->first.first == clientId && it->second.uid != OFFLINE_UID) {
                 jobsToRemove.push_back(it->first);
             }
         }
     } else {
         if (mJobMap.count(jobKey) == 0) {
             ALOGE("job %s doesn't exist", jobToString(jobKey).c_str());
             return false;
         }
         jobsToRemove.push_back(jobKey);
     }

     for (auto it = jobsToRemove.begin(); it != jobsToRemove.end(); ++it) {
         // If the job has ever been started, stop it now.
         // Note that stop() is needed even if the job is currently paused. This instructs
         // the transcoder to discard any states for the job, otherwise the states may
         // never be discarded.
         if (mJobMap[*it].state != Job::NOT_STARTED) {
             mTranscoder->stop(it->first, it->second);
         }

         // Remove the job.
         removeJob_l(*it);
     }

     // Start next job.
     updateCurrentJob_l();

     validateState_l();
     return true;
 }

 bool TranscodingJobScheduler::getJob(ClientIdType clientId, JobIdType jobId,
                                      TranscodingRequestParcel* request) {
     JobKeyType jobKey = std::make_pair(clientId, jobId);

     std::scoped_lock lock{mLock};

     if (mJobMap.count(jobKey) == 0) {
         ALOGE("job %s doesn't exist", jobToString(jobKey).c_str());
         return false;
     }

     *(TranscodingRequest*)request = mJobMap[jobKey].request;
     return true;
 }

 void TranscodingJobScheduler::notifyClient(ClientIdType clientId, JobIdType jobId,
                                            const char* reason,
                                            std::function<void(const JobKeyType&)> func) {
     JobKeyType jobKey = std::make_pair(clientId, jobId);

     std::scoped_lock lock{mLock};

     if (mJobMap.count(jobKey) == 0) {
         ALOGW("%s: ignoring %s for job %s that doesn't exist", __FUNCTION__, reason,
               jobToString(jobKey).c_str());
         return;
     }

     // Only ignore if job was never started. In particular, propagate the status
     // to client if the job is paused. Transcoder could have posted finish when
     // we're pausing it, and the finish arrived after we changed current job.
     if (mJobMap[jobKey].state == Job::NOT_STARTED) {
         ALOGW("%s: ignoring %s for job %s that was never started", __FUNCTION__, reason,
               jobToString(jobKey).c_str());
         return;
     }

     ALOGV("%s: job %s %s", __FUNCTION__, jobToString(jobKey).c_str(), reason);
     func(jobKey);
 }

 void TranscodingJobScheduler::onStarted(ClientIdType clientId, JobIdType jobId) {
     notifyClient(clientId, jobId, "started", [=](const JobKeyType& jobKey) {
         auto callback = mJobMap[jobKey].callback.lock();
         if (callback != nullptr) {
             callback->onTranscodingStarted(jobId);
         }
     });
 }

 void TranscodingJobScheduler::onPaused(ClientIdType clientId, JobIdType jobId) {
     notifyClient(clientId, jobId, "paused", [=](const JobKeyType& jobKey) {
         auto callback = mJobMap[jobKey].callback.lock();
         if (callback != nullptr) {
             callback->onTranscodingPaused(jobId);
         }
     });
 }

 void TranscodingJobScheduler::onResumed(ClientIdType clientId, JobIdType jobId) {
     notifyClient(clientId, jobId, "resumed", [=](const JobKeyType& jobKey) {
         auto callback = mJobMap[jobKey].callback.lock();
         if (callback != nullptr) {
             callback->onTranscodingResumed(jobId);
         }
     });
 }

 void TranscodingJobScheduler::onFinish(ClientIdType clientId, JobIdType jobId) {
     notifyClient(clientId, jobId, "finish", [=](const JobKeyType& jobKey) {
         {
             auto clientCallback = mJobMap[jobKey].callback.lock();
             if (clientCallback != nullptr) {
                 clientCallback->onTranscodingFinished(jobId, TranscodingResultParcel({jobId, -1 /*actualBitrateBps*/}));
             }
         }

         // Remove the job.
         removeJob_l(jobKey);

         // Start next job.
         updateCurrentJob_l();

         validateState_l();
     });
 }

 void TranscodingJobScheduler::onError(ClientIdType clientId, JobIdType jobId,
                                       TranscodingErrorCode err) {
     notifyClient(clientId, jobId, "error", [=](const JobKeyType& jobKey) {
         {
             auto clientCallback = mJobMap[jobKey].callback.lock();
             if (clientCallback != nullptr) {
                 clientCallback->onTranscodingFailed(jobId, err);
             }
         }

         // Remove the job.
         removeJob_l(jobKey);

         // Start next job.
         updateCurrentJob_l();

         validateState_l();
     });
 }

 void TranscodingJobScheduler::onProgressUpdate(ClientIdType clientId, JobIdType jobId,
                                                int32_t progress) {
     notifyClient(clientId, jobId, "progress", [=](const JobKeyType& jobKey) {
         auto callback = mJobMap[jobKey].callback.lock();
         if (callback != nullptr) {
             callback->onProgressUpdate(jobId, progress);
         }
     });
 }

 void TranscodingJobScheduler::onResourceLost() {
     ALOGV("%s", __FUNCTION__);

     std::scoped_lock lock{mLock};

     // If we receive a resource loss event, the TranscoderLibrary already paused
     // the transcoding, so we don't need to call onPaused to notify it to pause.
     // Only need to update the job state here.
     if (mCurrentJob != nullptr && mCurrentJob->state == Job::RUNNING) {
         mCurrentJob->state = Job::PAUSED;
     }
     mResourceLost = true;

     validateState_l();
 }

 void TranscodingJobScheduler::onTopUidsChanged(const std::unordered_set<uid_t>& uids) {
     if (uids.empty()) {
         ALOGW("%s: ignoring empty uids", __FUNCTION__);
         return;
     }

     std::string uidStr;
     for (auto it = uids.begin(); it != uids.end(); it++) {
         if (!uidStr.empty()) {
             uidStr += ", ";
         }
         uidStr += std::to_string(*it);
     }

     ALOGD("%s: topUids: size %zu, uids: %s", __FUNCTION__, uids.size(), uidStr.c_str());

     std::scoped_lock lock{mLock};

     moveUidsToTop_l(uids, true /*preserveTopUid*/);

     updateCurrentJob_l();

     validateState_l();
 }

 void TranscodingJobScheduler::onResourceAvailable() {
     ALOGV("%s", __FUNCTION__);

     std::scoped_lock lock{mLock};

     mResourceLost = false;
     updateCurrentJob_l();

     validateState_l();
 }

 void TranscodingJobScheduler::validateState_l() {
 #ifdef VALIDATE_STATE
     LOG_ALWAYS_FATAL_IF(mJobQueues.count(OFFLINE_UID) != 1,
                         "mJobQueues offline queue number is not 1");
     LOG_ALWAYS_FATAL_IF(*mOfflineUidIterator != OFFLINE_UID,
                         "mOfflineUidIterator not pointing to offline uid");
     LOG_ALWAYS_FATAL_IF(mUidSortedList.size() != mJobQueues.size(),
                         "mUidList and mJobQueues size mismatch");

     int32_t totalJobs = 0;
     for (auto uidIt = mUidSortedList.begin(); uidIt != mUidSortedList.end(); uidIt++) {
         LOG_ALWAYS_FATAL_IF(mJobQueues.count(*uidIt) != 1, "mJobQueues count for uid %d is not 1",
                             *uidIt);
         for (auto jobIt = mJobQueues[*uidIt].begin(); jobIt != mJobQueues[*uidIt].end(); jobIt++) {
             LOG_ALWAYS_FATAL_IF(mJobMap.count(*jobIt) != 1, "mJobs count for job %s is not 1",
                                 jobToString(*jobIt).c_str());
         }

         totalJobs += mJobQueues[*uidIt].size();
     }
     LOG_ALWAYS_FATAL_IF(mJobMap.size() != totalJobs,
                         "mJobs size doesn't match total jobs counted from uid queues");
 #endif  // VALIDATE_STATE
 }

 }  // namespace android
	/*
	* Copyright (C) 2020 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.
	*/

	//#define LOG_NDEBUG 0
	#define LOG_TAG "TranscodingJobScheduler"

	#define VALIDATE_STATE 1

	#include <inttypes.h>
	#include <media/TranscodingJobScheduler.h>
	#include <utils/Log.h>

	#include <utility>

	namespace android {

	static_assert((JobIdType)-1 < 0, "JobIdType should be signed");

	constexpr static uid_t OFFLINE_UID = -1;

	//static
	String8 TranscodingJobScheduler::jobToString(const JobKeyType& jobKey) {
	return String8::format("{client:%lld, job:%d}", (long long)jobKey.first, jobKey.second);
	}

	TranscodingJobScheduler::TranscodingJobScheduler(
	const std::shared_ptr<TranscoderInterface>& transcoder,
	const std::shared_ptr<UidPolicyInterface>& uidPolicy)
	: mTranscoder(transcoder), mUidPolicy(uidPolicy), mCurrentJob(nullptr), mResourceLost(false) {
	// Only push empty offline queue initially. Realtime queues are added when requests come in.
	mUidSortedList.push_back(OFFLINE_UID);
	mOfflineUidIterator = mUidSortedList.begin();
	mJobQueues.emplace(OFFLINE_UID, JobQueueType());
	}

	TranscodingJobScheduler::~TranscodingJobScheduler() {}

	TranscodingJobScheduler::Job* TranscodingJobScheduler::getTopJob_l() {
	if (mJobMap.empty()) {
	return nullptr;
	}
	uid_t topUid = *mUidSortedList.begin();
	JobKeyType topJobKey = *mJobQueues[topUid].begin();
	return &mJobMap[topJobKey];
	}

	void TranscodingJobScheduler::updateCurrentJob_l() {
	Job* topJob = getTopJob_l();
	Job* curJob = mCurrentJob;
	ALOGV("updateCurrentJob: topJob is %s, curJob is %s",
	topJob == nullptr ? "null" : jobToString(topJob->key).c_str(),
	curJob == nullptr ? "null" : jobToString(curJob->key).c_str());

	// If we found a topJob that should be run, and it's not already running,
	// take some actions to ensure it's running.
	if (topJob != nullptr && (topJob != curJob \|\| topJob->state != Job::RUNNING)) {
	// If another job is currently running, pause it first.
	if (curJob != nullptr && curJob->state == Job::RUNNING) {
	mTranscoder->pause(curJob->key.first, curJob->key.second);
	curJob->state = Job::PAUSED;
	}
	// If we are not experiencing resource loss, we can start or resume
	// the topJob now.
	if (!mResourceLost) {
	if (topJob->state == Job::NOT_STARTED) {
	mTranscoder->start(topJob->key.first, topJob->key.second, topJob->request);
	} else if (topJob->state == Job::PAUSED) {
	mTranscoder->resume(topJob->key.first, topJob->key.second);
	}
	topJob->state = Job::RUNNING;
	}
	}
	mCurrentJob = topJob;
	}

	void TranscodingJobScheduler::removeJob_l(const JobKeyType& jobKey) {
	ALOGV("%s: job %s", __FUNCTION__, jobToString(jobKey).c_str());

	if (mJobMap.count(jobKey) == 0) {
	ALOGE("job %s doesn't exist", jobToString(jobKey).c_str());
	return;
	}

	// Remove job from uid's queue.
	const uid_t uid = mJobMap[jobKey].uid;
	JobQueueType& jobQueue = mJobQueues[uid];
	auto it = std::find(jobQueue.begin(), jobQueue.end(), jobKey);
	if (it == jobQueue.end()) {
	ALOGE("couldn't find job %s in queue for uid %d", jobToString(jobKey).c_str(), uid);
	return;
	}
	jobQueue.erase(it);

	// If this is the last job in a real-time queue, remove this uid's queue.
	if (uid != OFFLINE_UID && jobQueue.empty()) {
	mUidSortedList.remove(uid);
	mJobQueues.erase(uid);
	mUidPolicy->unregisterMonitorUid(uid);

	std::unordered_set<uid_t> topUids = mUidPolicy->getTopUids();
	moveUidsToTop_l(topUids, false /preserveTopUid/);
	}

	// Clear current job.
	if (mCurrentJob == &mJobMap[jobKey]) {
	mCurrentJob = nullptr;
	}

	// Remove job from job map.
	mJobMap.erase(jobKey);
	}

	/**
	* Moves the set of uids to the front of mUidSortedList (which is used to pick
	* the next job to run).
	*
	* This is called when 1) we received a onTopUidsChanged() callbcak from UidPolicy,
	* or 2) we removed the job queue for a uid because it becomes empty.
	*
	* In case of 1), if there are multiple uids in the set, and the current front
	* uid in mUidSortedList is still in the set, we try to keep that uid at front
	* so that current job run is not interrupted. (This is not a concern for case 2)
	* because the queue for a uid was just removed entirely.)
	*/
	void TranscodingJobScheduler::moveUidsToTop_l(const std::unordered_set<uid_t>& uids,
	bool preserveTopUid) {
	// If uid set is empty, nothing to do. Do not change the queue status.
	if (uids.empty()) {
	return;
	}

	// Save the current top uid.
	uid_t curTopUid = *mUidSortedList.begin();
	bool pushCurTopToFront = false;
	int32_t numUidsMoved = 0;

	// Go through the sorted uid list once, and move the ones in top set to front.
	for (auto it = mUidSortedList.begin(); it != mUidSortedList.end();) {
	uid_t uid = *it;

	if (uid != OFFLINE_UID && uids.count(uid) > 0) {
	it = mUidSortedList.erase(it);

	// If this is the top we're preserving, don't push it here, push
	// it after the for-loop.
	if (uid == curTopUid && preserveTopUid) {
	pushCurTopToFront = true;
	} else {
	mUidSortedList.push_front(uid);
	}

	// If we found all uids in the set, break out.
	if (++numUidsMoved == uids.size()) {
	break;
	}
	} else {
	++it;
	}
	}

	if (pushCurTopToFront) {
	mUidSortedList.push_front(curTopUid);
	}
	}

	bool TranscodingJobScheduler::submit(ClientIdType clientId, JobIdType jobId, uid_t uid,
	const TranscodingRequestParcel& request,
	const std::weak_ptr<ITranscodingClientCallback>& callback) {
	JobKeyType jobKey = std::make_pair(clientId, jobId);

	ALOGV("%s: job %s, uid %d, prioirty %d", __FUNCTION__, jobToString(jobKey).c_str(), uid,
	(int32_t)request.priority);

	std::scoped_lock lock{mLock};

	if (mJobMap.count(jobKey) > 0) {
	ALOGE("job %s already exists", jobToString(jobKey).c_str());
	return false;
	}

	// TODO(chz): only support offline vs real-time for now. All kUnspecified jobs
	// go to offline queue.
	if (request.priority == TranscodingJobPriority::kUnspecified) {
	uid = OFFLINE_UID;
	}

	// Add job to job map.
	mJobMap[jobKey].key = jobKey;
	mJobMap[jobKey].uid = uid;
	mJobMap[jobKey].state = Job::NOT_STARTED;
	mJobMap[jobKey].request = request;
	mJobMap[jobKey].callback = callback;

	// If it's an offline job, the queue was already added in constructor.
	// If it's a real-time jobs, check if a queue is already present for the uid,
	// and add a new queue if needed.
	if (uid != OFFLINE_UID) {
	if (mJobQueues.count(uid) == 0) {
	mUidPolicy->registerMonitorUid(uid);
	if (mUidPolicy->isUidOnTop(uid)) {
	mUidSortedList.push_front(uid);
	} else {
	// Shouldn't be submitting real-time requests from non-top app,
	// put it in front of the offline queue.
	mUidSortedList.insert(mOfflineUidIterator, uid);
	}
	} else if (uid != *mUidSortedList.begin()) {
	if (mUidPolicy->isUidOnTop(uid)) {
	mUidSortedList.remove(uid);
	mUidSortedList.push_front(uid);
	}
	}
	}
	// Append this job to the uid's queue.
	mJobQueues[uid].push_back(jobKey);

	updateCurrentJob_l();

	validateState_l();
	return true;
	}

	bool TranscodingJobScheduler::cancel(ClientIdType clientId, JobIdType jobId) {
	JobKeyType jobKey = std::make_pair(clientId, jobId);

	ALOGV("%s: job %s", __FUNCTION__, jobToString(jobKey).c_str());

	std::list<JobKeyType> jobsToRemove;

	std::scoped_lock lock{mLock};

	if (jobId < 0) {
	for (auto it = mJobMap.begin(); it != mJobMap.end(); ++it) {
	if (it->first.first == clientId && it->second.uid != OFFLINE_UID) {
	jobsToRemove.push_back(it->first);
	}
	}
	} else {
	if (mJobMap.count(jobKey) == 0) {
	ALOGE("job %s doesn't exist", jobToString(jobKey).c_str());
	return false;
	}
	jobsToRemove.push_back(jobKey);
	}

	for (auto it = jobsToRemove.begin(); it != jobsToRemove.end(); ++it) {
	// If the job has ever been started, stop it now.
	// Note that stop() is needed even if the job is currently paused. This instructs
	// the transcoder to discard any states for the job, otherwise the states may
	// never be discarded.
	if (mJobMap[*it].state != Job::NOT_STARTED) {
	mTranscoder->stop(it->first, it->second);
	}

	// Remove the job.
	removeJob_l(*it);
	}

	// Start next job.
	updateCurrentJob_l();

	validateState_l();
	return true;
	}

	bool TranscodingJobScheduler::getJob(ClientIdType clientId, JobIdType jobId,
	TranscodingRequestParcel* request) {
	JobKeyType jobKey = std::make_pair(clientId, jobId);

	std::scoped_lock lock{mLock};

	if (mJobMap.count(jobKey) == 0) {
	ALOGE("job %s doesn't exist", jobToString(jobKey).c_str());
	return false;
	}

	(TranscodingRequest)request = mJobMap[jobKey].request;
	return true;
	}

	void TranscodingJobScheduler::notifyClient(ClientIdType clientId, JobIdType jobId,
	const char* reason,
	std::function<void(const JobKeyType&)> func) {
	JobKeyType jobKey = std::make_pair(clientId, jobId);

	std::scoped_lock lock{mLock};

	if (mJobMap.count(jobKey) == 0) {
	ALOGW("%s: ignoring %s for job %s that doesn't exist", __FUNCTION__, reason,
	jobToString(jobKey).c_str());
	return;
	}

	// Only ignore if job was never started. In particular, propagate the status
	// to client if the job is paused. Transcoder could have posted finish when
	// we're pausing it, and the finish arrived after we changed current job.
	if (mJobMap[jobKey].state == Job::NOT_STARTED) {
	ALOGW("%s: ignoring %s for job %s that was never started", __FUNCTION__, reason,
	jobToString(jobKey).c_str());
	return;
	}

	ALOGV("%s: job %s %s", __FUNCTION__, jobToString(jobKey).c_str(), reason);
	func(jobKey);
	}

	void TranscodingJobScheduler::onStarted(ClientIdType clientId, JobIdType jobId) {
	notifyClient(clientId, jobId, "started", [=](const JobKeyType& jobKey) {
	auto callback = mJobMap[jobKey].callback.lock();
	if (callback != nullptr) {
	callback->onTranscodingStarted(jobId);
	}
	});
	}

	void TranscodingJobScheduler::onPaused(ClientIdType clientId, JobIdType jobId) {
	notifyClient(clientId, jobId, "paused", [=](const JobKeyType& jobKey) {
	auto callback = mJobMap[jobKey].callback.lock();
	if (callback != nullptr) {
	callback->onTranscodingPaused(jobId);
	}
	});
	}

	void TranscodingJobScheduler::onResumed(ClientIdType clientId, JobIdType jobId) {
	notifyClient(clientId, jobId, "resumed", [=](const JobKeyType& jobKey) {
	auto callback = mJobMap[jobKey].callback.lock();
	if (callback != nullptr) {
	callback->onTranscodingResumed(jobId);
	}
	});
	}

	void TranscodingJobScheduler::onFinish(ClientIdType clientId, JobIdType jobId) {
	notifyClient(clientId, jobId, "finish", [=](const JobKeyType& jobKey) {
	{
	auto clientCallback = mJobMap[jobKey].callback.lock();
	if (clientCallback != nullptr) {
	clientCallback->onTranscodingFinished(jobId, TranscodingResultParcel({jobId, -1 /actualBitrateBps/}));
	}
	}

	// Remove the job.
	removeJob_l(jobKey);

	// Start next job.
	updateCurrentJob_l();

	validateState_l();
	});
	}

	void TranscodingJobScheduler::onError(ClientIdType clientId, JobIdType jobId,
	TranscodingErrorCode err) {
	notifyClient(clientId, jobId, "error", [=](const JobKeyType& jobKey) {
	{
	auto clientCallback = mJobMap[jobKey].callback.lock();
	if (clientCallback != nullptr) {
	clientCallback->onTranscodingFailed(jobId, err);
	}
	}

	// Remove the job.
	removeJob_l(jobKey);

	// Start next job.
	updateCurrentJob_l();

	validateState_l();
	});
	}

	void TranscodingJobScheduler::onProgressUpdate(ClientIdType clientId, JobIdType jobId,
	int32_t progress) {
	notifyClient(clientId, jobId, "progress", [=](const JobKeyType& jobKey) {
	auto callback = mJobMap[jobKey].callback.lock();
	if (callback != nullptr) {
	callback->onProgressUpdate(jobId, progress);
	}
	});
	}

	void TranscodingJobScheduler::onResourceLost() {
	ALOGV("%s", __FUNCTION__);

	std::scoped_lock lock{mLock};

	// If we receive a resource loss event, the TranscoderLibrary already paused
	// the transcoding, so we don't need to call onPaused to notify it to pause.
	// Only need to update the job state here.
	if (mCurrentJob != nullptr && mCurrentJob->state == Job::RUNNING) {
	mCurrentJob->state = Job::PAUSED;
	}
	mResourceLost = true;

	validateState_l();
	}

	void TranscodingJobScheduler::onTopUidsChanged(const std::unordered_set<uid_t>& uids) {
	if (uids.empty()) {
	ALOGW("%s: ignoring empty uids", __FUNCTION__);
	return;
	}

	std::string uidStr;
	for (auto it = uids.begin(); it != uids.end(); it++) {
	if (!uidStr.empty()) {
	uidStr += ", ";
	}
	uidStr += std::to_string(*it);
	}

	ALOGD("%s: topUids: size %zu, uids: %s", __FUNCTION__, uids.size(), uidStr.c_str());

	std::scoped_lock lock{mLock};

	moveUidsToTop_l(uids, true /preserveTopUid/);

	updateCurrentJob_l();

	validateState_l();
	}

	void TranscodingJobScheduler::onResourceAvailable() {
	ALOGV("%s", __FUNCTION__);

	std::scoped_lock lock{mLock};

	mResourceLost = false;
	updateCurrentJob_l();

	validateState_l();
	}

	void TranscodingJobScheduler::validateState_l() {
	#ifdef VALIDATE_STATE
	LOG_ALWAYS_FATAL_IF(mJobQueues.count(OFFLINE_UID) != 1,
	"mJobQueues offline queue number is not 1");
	LOG_ALWAYS_FATAL_IF(*mOfflineUidIterator != OFFLINE_UID,
	"mOfflineUidIterator not pointing to offline uid");
	LOG_ALWAYS_FATAL_IF(mUidSortedList.size() != mJobQueues.size(),
	"mUidList and mJobQueues size mismatch");

	int32_t totalJobs = 0;
	for (auto uidIt = mUidSortedList.begin(); uidIt != mUidSortedList.end(); uidIt++) {
	LOG_ALWAYS_FATAL_IF(mJobQueues.count(*uidIt) != 1, "mJobQueues count for uid %d is not 1",
	*uidIt);
	for (auto jobIt = mJobQueues[uidIt].begin(); jobIt != mJobQueues[uidIt].end(); jobIt++) {
	LOG_ALWAYS_FATAL_IF(mJobMap.count(*jobIt) != 1, "mJobs count for job %s is not 1",
	jobToString(*jobIt).c_str());
	}

	totalJobs += mJobQueues[*uidIt].size();
	}
	LOG_ALWAYS_FATAL_IF(mJobMap.size() != totalJobs,
	"mJobs size doesn't match total jobs counted from uid queues");
	#endif // VALIDATE_STATE
	}

	} // namespace android