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      1 /*
      2  * Copyright (C) 2019 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 #include "CommonPool.h"
     18 
     19 #include <sys/resource.h>
     20 #include <utils/Trace.h>
     21 #include "renderthread/RenderThread.h"
     22 
     23 #include <array>
     24 
     25 namespace android {
     26 namespace uirenderer {
     27 
     28 CommonPool::CommonPool() {
     29     ATRACE_CALL();
     30 
     31     CommonPool* pool = this;
     32     // Create 2 workers
     33     for (int i = 0; i < THREAD_COUNT; i++) {
     34         std::thread worker([pool, i] {
     35             {
     36                 std::array<char, 20> name{"hwuiTask"};
     37                 snprintf(name.data(), name.size(), "hwuiTask%d", i);
     38                 auto self = pthread_self();
     39                 pthread_setname_np(self, name.data());
     40                 setpriority(PRIO_PROCESS, 0, PRIORITY_FOREGROUND);
     41                 auto startHook = renderthread::RenderThread::getOnStartHook();
     42                 if (startHook) {
     43                     startHook(name.data());
     44                 }
     45             }
     46             pool->workerLoop();
     47         });
     48         worker.detach();
     49     }
     50 }
     51 
     52 CommonPool& CommonPool::instance() {
     53     static CommonPool pool;
     54     return pool;
     55 }
     56 
     57 void CommonPool::post(Task&& task) {
     58     instance().enqueue(std::move(task));
     59 }
     60 
     61 void CommonPool::enqueue(Task&& task) {
     62     std::unique_lock lock(mLock);
     63     while (!mWorkQueue.hasSpace()) {
     64         lock.unlock();
     65         usleep(100);
     66         lock.lock();
     67     }
     68     mWorkQueue.push(std::move(task));
     69     if (mWaitingThreads == THREAD_COUNT || (mWaitingThreads > 0 && mWorkQueue.size() > 1)) {
     70         mCondition.notify_one();
     71     }
     72 }
     73 
     74 void CommonPool::workerLoop() {
     75     std::unique_lock lock(mLock);
     76     while (true) {
     77         if (!mWorkQueue.hasWork()) {
     78             mWaitingThreads++;
     79             mCondition.wait(lock);
     80             mWaitingThreads--;
     81         }
     82         // Need to double-check that work is still available now that we have the lock
     83         // It may have already been grabbed by a different thread
     84         while (mWorkQueue.hasWork()) {
     85             auto work = mWorkQueue.pop();
     86             lock.unlock();
     87             work();
     88             lock.lock();
     89         }
     90     }
     91 }
     92 
     93 void CommonPool::waitForIdle() {
     94     instance().doWaitForIdle();
     95 }
     96 
     97 void CommonPool::doWaitForIdle() {
     98     std::unique_lock lock(mLock);
     99     while (mWaitingThreads != THREAD_COUNT) {
    100         lock.unlock();
    101         usleep(100);
    102         lock.lock();
    103     }
    104 }
    105 
    106 }  // namespace uirenderer
    107 }  // namespace android