TaskManager.cpp revision f35c939cd70f2815582d08902ade0b9abbee6bec 
1/*
2 * Copyright (C) 2013 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 <sys/resource.h>
18#include <sys/sysinfo.h>
19
20#include "TaskManager.h"
21#include "Task.h"
22#include "TaskProcessor.h"
23#include "utils/MathUtils.h"
24
25namespace android {
26namespace uirenderer {
27
28///////////////////////////////////////////////////////////////////////////////
29// Manager
30///////////////////////////////////////////////////////////////////////////////
31
32TaskManager::TaskManager() {
33    // Get the number of available CPUs. This value does not change over time.
34    int cpuCount = sysconf(_SC_NPROCESSORS_CONF);
35
36    // Really no point in making more than 2 of these worker threads, but
37    // we do want to limit ourselves to 1 worker thread on dual-core devices.
38    int workerCount = cpuCount > 2 ? 2 : 1;
39    for (int i = 0; i < workerCount; i++) {
40        String8 name;
41        name.appendFormat("hwuiTask%d", i + 1);
42        mThreads.add(new WorkerThread(name));
43    }
44}
45
46TaskManager::~TaskManager() {
47    for (size_t i = 0; i < mThreads.size(); i++) {
48        mThreads[i]->exit();
49    }
50}
51
52bool TaskManager::canRunTasks() const {
53    return mThreads.size() > 0;
54}
55
56void TaskManager::stop() {
57    for (size_t i = 0; i < mThreads.size(); i++) {
58        mThreads[i]->exit();
59    }
60}
61
62bool TaskManager::addTaskBase(const sp<TaskBase>& task, const sp<TaskProcessorBase>& processor) {
63    if (mThreads.size() > 0) {
64        TaskWrapper wrapper(task, processor);
65
66        size_t minQueueSize = INT_MAX;
67        sp<WorkerThread> thread;
68
69        for (size_t i = 0; i < mThreads.size(); i++) {
70            if (mThreads[i]->getTaskCount() < minQueueSize) {
71                thread = mThreads[i];
72                minQueueSize = mThreads[i]->getTaskCount();
73            }
74        }
75
76        return thread->addTask(wrapper);
77    }
78    return false;
79}
80
81///////////////////////////////////////////////////////////////////////////////
82// Thread
83///////////////////////////////////////////////////////////////////////////////
84
85status_t TaskManager::WorkerThread::readyToRun() {
86    setpriority(PRIO_PROCESS, 0, PRIORITY_FOREGROUND);
87    return NO_ERROR;
88}
89
90bool TaskManager::WorkerThread::threadLoop() {
91    mSignal.wait();
92    Vector<TaskWrapper> tasks;
93    {
94        Mutex::Autolock l(mLock);
95        tasks = mTasks;
96        mTasks.clear();
97    }
98
99    for (size_t i = 0; i < tasks.size(); i++) {
100        const TaskWrapper& task = tasks.itemAt(i);
101        task.mProcessor->process(task.mTask);
102    }
103
104    return true;
105}
106
107bool TaskManager::WorkerThread::addTask(const TaskWrapper& task) {
108    if (!isRunning()) {
109        run(mName.string(), PRIORITY_DEFAULT);
110    } else if (exitPending()) {
111        return false;
112    }
113
114    ssize_t index;
115    {
116        Mutex::Autolock l(mLock);
117        index = mTasks.add(task);
118    }
119    mSignal.signal();
120
121    return index >= 0;
122}
123
124size_t TaskManager::WorkerThread::getTaskCount() const {
125    Mutex::Autolock l(mLock);
126    return mTasks.size();
127}
128
129void TaskManager::WorkerThread::exit() {
130    requestExit();
131    mSignal.signal();
132}
133
134}; // namespace uirenderer
135}; // namespace android
136