TaskManager.cpp revision c3c58e015fa30a0ad87d4af2b95b7071baa8ffe4 
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/sysinfo.h>
18#if defined(HAVE_PTHREADS)
19#include <sys/resource.h>
20#endif
21
22#include "TaskManager.h"
23#include "Task.h"
24#include "TaskProcessor.h"
25#include "utils/MathUtils.h"
26
27namespace android {
28namespace uirenderer {
29
30///////////////////////////////////////////////////////////////////////////////
31// Manager
32///////////////////////////////////////////////////////////////////////////////
33
34TaskManager::TaskManager() {
35    // Get the number of available CPUs. This value does not change over time.
36    int cpuCount = sysconf(_SC_NPROCESSORS_CONF);
37
38    int workerCount = MathUtils::max(1, cpuCount / 2);
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#if defined(HAVE_PTHREADS)
87    setpriority(PRIO_PROCESS, 0, PRIORITY_FOREGROUND);
88#endif
89    return NO_ERROR;
90}
91
92bool TaskManager::WorkerThread::threadLoop() {
93    mSignal.wait();
94    Vector<TaskWrapper> tasks;
95    {
96        Mutex::Autolock l(mLock);
97        tasks = mTasks;
98        mTasks.clear();
99    }
100
101    for (size_t i = 0; i < tasks.size(); i++) {
102        const TaskWrapper& task = tasks.itemAt(i);
103        task.mProcessor->process(task.mTask);
104    }
105
106    return true;
107}
108
109bool TaskManager::WorkerThread::addTask(TaskWrapper task) {
110    if (!isRunning()) {
111        run(mName.string(), PRIORITY_DEFAULT);
112    } else if (exitPending()) {
113        return false;
114    }
115
116    Mutex::Autolock l(mLock);
117    ssize_t index = mTasks.add(task);
118    mSignal.signal();
119
120    return index >= 0;
121}
122
123size_t TaskManager::WorkerThread::getTaskCount() const {
124    Mutex::Autolock l(mLock);
125    return mTasks.size();
126}
127
128void TaskManager::WorkerThread::exit() {
129    requestExit();
130    mSignal.signal();
131}
132
133}; // namespace uirenderer
134}; // namespace android
135