TaskManager.cpp revision 815f2a093a4b44863fe9ffdb1986a2d5425ffef8 
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    int workerCount = MathUtils::max(1, cpuCount / 2);
37    for (int i = 0; i < workerCount; i++) {
38        String8 name;
39        name.appendFormat("hwuiTask%d", i + 1);
40        mThreads.add(new WorkerThread(name));
41    }
42}
43
44TaskManager::~TaskManager() {
45    for (size_t i = 0; i < mThreads.size(); i++) {
46        mThreads[i]->exit();
47    }
48}
49
50bool TaskManager::canRunTasks() const {
51    return mThreads.size() > 0;
52}
53
54void TaskManager::stop() {
55    for (size_t i = 0; i < mThreads.size(); i++) {
56        mThreads[i]->exit();
57    }
58}
59
60bool TaskManager::addTaskBase(const sp<TaskBase>& task, const sp<TaskProcessorBase>& processor) {
61    if (mThreads.size() > 0) {
62        TaskWrapper wrapper(task, processor);
63
64        size_t minQueueSize = INT_MAX;
65        sp<WorkerThread> thread;
66
67        for (size_t i = 0; i < mThreads.size(); i++) {
68            if (mThreads[i]->getTaskCount() < minQueueSize) {
69                thread = mThreads[i];
70                minQueueSize = mThreads[i]->getTaskCount();
71            }
72        }
73
74        return thread->addTask(wrapper);
75    }
76    return false;
77}
78
79///////////////////////////////////////////////////////////////////////////////
80// Thread
81///////////////////////////////////////////////////////////////////////////////
82
83status_t TaskManager::WorkerThread::readyToRun() {
84    setpriority(PRIO_PROCESS, 0, PRIORITY_FOREGROUND);
85    return NO_ERROR;
86}
87
88bool TaskManager::WorkerThread::threadLoop() {
89    mSignal.wait();
90    Vector<TaskWrapper> tasks;
91    {
92        Mutex::Autolock l(mLock);
93        tasks = mTasks;
94        mTasks.clear();
95    }
96
97    for (size_t i = 0; i < tasks.size(); i++) {
98        const TaskWrapper& task = tasks.itemAt(i);
99        task.mProcessor->process(task.mTask);
100    }
101
102    return true;
103}
104
105bool TaskManager::WorkerThread::addTask(TaskWrapper task) {
106    if (!isRunning()) {
107        run(mName.string(), PRIORITY_DEFAULT);
108    } else if (exitPending()) {
109        return false;
110    }
111
112    ssize_t index;
113    {
114        Mutex::Autolock l(mLock);
115        index = mTasks.add(task);
116    }
117    mSignal.signal();
118
119    return index >= 0;
120}
121
122size_t TaskManager::WorkerThread::getTaskCount() const {
123    Mutex::Autolock l(mLock);
124    return mTasks.size();
125}
126
127void TaskManager::WorkerThread::exit() {
128    requestExit();
129    mSignal.signal();
130}
131
132}; // namespace uirenderer
133}; // namespace android
134