Home | History | Annotate | Download | only in surfaceflinger 
      1 /*
      2  * Copyright 2018 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #pragma once
     18 
     19 #include <condition_variable>
     20 #include <deque>
     21 #include <mutex>
     22 #include <thread>
     23 #include <unordered_map>
     24 
     25 #include <android-base/thread_annotations.h>
     26 
     27 #include <binder/IBinder.h>
     28 #include <gui/ITransactionCompletedListener.h>
     29 #include <ui/Fence.h>
     30 
     31 namespace android {
     32 
     33 struct CallbackIdsHash {
     34     // CallbackId vectors have several properties that let us get away with this simple hash.
     35     // 1) CallbackIds are never 0 so if something has gone wrong and our CallbackId vector is
     36     // empty we can still hash 0.
     37     // 2) CallbackId vectors for the same listener either are identical or contain none of the
     38     // same members. It is sufficient to just check the first CallbackId in the vectors. If
     39     // they match, they are the same. If they do not match, they are not the same.
     40     std::size_t operator()(const std::vector<CallbackId>& callbackIds) const {
     41         return std::hash<CallbackId>{}((callbackIds.empty()) ? 0 : callbackIds.front());
     42     }
     43 };
     44 
     45 class CallbackHandle : public RefBase {
     46 public:
     47     CallbackHandle(const sp<ITransactionCompletedListener>& transactionListener,
     48                    const std::vector<CallbackId>& ids, const sp<IBinder>& sc);
     49 
     50     sp<ITransactionCompletedListener> listener;
     51     std::vector<CallbackId> callbackIds;
     52     wp<IBinder> surfaceControl;
     53 
     54     bool releasePreviousBuffer = false;
     55     sp<Fence> previousReleaseFence;
     56     nsecs_t acquireTime = -1;
     57     nsecs_t latchTime = -1;
     58 };
     59 
     60 class TransactionCompletedThread {
     61 public:
     62     ~TransactionCompletedThread();
     63 
     64     void run();
     65 
     66     // Adds listener and callbackIds in case there are no SurfaceControls that are supposed
     67     // to be included in the callback. This functions should be call before attempting to add any
     68     // callback handles.
     69     status_t addCallback(const sp<ITransactionCompletedListener>& transactionListener,
     70                          const std::vector<CallbackId>& callbackIds);
     71 
     72     // Informs the TransactionCompletedThread that there is a Transaction with a CallbackHandle
     73     // that needs to be latched and presented this frame. This function should be called once the
     74     // layer has received the CallbackHandle so the TransactionCompletedThread knows not to send
     75     // a callback for that Listener/Transaction pair until that CallbackHandle has been latched and
     76     // presented.
     77     status_t registerPendingCallbackHandle(const sp<CallbackHandle>& handle);
     78     // Notifies the TransactionCompletedThread that a pending CallbackHandle has been presented.
     79     status_t addPresentedCallbackHandles(const std::deque<sp<CallbackHandle>>& handles);
     80 
     81     // Adds the Transaction CallbackHandle from a layer that does not need to be relatched and
     82     // presented this frame.
     83     status_t addUnpresentedCallbackHandle(const sp<CallbackHandle>& handle);
     84 
     85     void addPresentFence(const sp<Fence>& presentFence);
     86 
     87     void sendCallbacks();
     88 
     89 private:
     90     void threadMain();
     91 
     92     status_t findTransactionStats(const sp<ITransactionCompletedListener>& listener,
     93                                   const std::vector<CallbackId>& callbackIds,
     94                                   TransactionStats** outTransactionStats) REQUIRES(mMutex);
     95 
     96     status_t addCallbackHandle(const sp<CallbackHandle>& handle) REQUIRES(mMutex);
     97 
     98     class ThreadDeathRecipient : public IBinder::DeathRecipient {
     99     public:
    100         // This function is a no-op. isBinderAlive needs a linked DeathRecipient to work.
    101         // Death recipients needs a binderDied function.
    102         //
    103         // (isBinderAlive checks if BpBinder's mAlive is 0. mAlive is only set to 0 in sendObituary.
    104         // sendObituary is only called if linkToDeath was called with a DeathRecipient.)
    105         void binderDied(const wp<IBinder>& /*who*/) override {}
    106     };
    107     sp<ThreadDeathRecipient> mDeathRecipient;
    108 
    109     struct ITransactionCompletedListenerHash {
    110         std::size_t operator()(const sp<ITransactionCompletedListener>& listener) const {
    111             return std::hash<IBinder*>{}((listener) ? IInterface::asBinder(listener).get()
    112                                                     : nullptr);
    113         }
    114     };
    115 
    116     // Protects the creation and destruction of mThread
    117     std::mutex mThreadMutex;
    118 
    119     std::thread mThread GUARDED_BY(mThreadMutex);
    120 
    121     std::mutex mMutex;
    122     std::condition_variable_any mConditionVariable;
    123 
    124     std::unordered_map<
    125             sp<ITransactionCompletedListener>,
    126             std::unordered_map<std::vector<CallbackId>, uint32_t /*count*/, CallbackIdsHash>,
    127             ITransactionCompletedListenerHash>
    128             mPendingTransactions GUARDED_BY(mMutex);
    129     std::unordered_map<sp<ITransactionCompletedListener>, std::deque<TransactionStats>,
    130                        ITransactionCompletedListenerHash>
    131             mCompletedTransactions GUARDED_BY(mMutex);
    132 
    133     bool mRunning GUARDED_BY(mMutex) = false;
    134     bool mKeepRunning GUARDED_BY(mMutex) = true;
    135 
    136     sp<Fence> mPresentFence GUARDED_BY(mMutex);
    137 };
    138 
    139 } // namespace android
    140