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 #ifndef ANDROID_HWUI_TASK_MANAGER_H
18 #define ANDROID_HWUI_TASK_MANAGER_H
19 
20 #include <utils/Mutex.h>
21 #include <utils/String8.h>
22 #include <utils/Thread.h>
23 #include <utils/Vector.h>
24 
25 #include "Signal.h"
26 
27 namespace android {
28 namespace uirenderer {
29 
30 template <typename T>
31 class Task;
32 class TaskBase;
33 
34 template <typename T>
35 class TaskProcessor;
36 class TaskProcessorBase;
37 
38 class TaskManager {
39 public:
40     TaskManager();
41     ~TaskManager();
42 
43     /**
44      * Returns true if this task  manager can run tasks,
45      * false otherwise. This method will typically return
46      * false on a single CPU core device.
47      */
48     bool canRunTasks() const;
49 
50     /**
51      * Stops all allocated threads. Adding tasks will start
52      * the threads again as necessary.
53      */
54     void stop();
55 
56 private:
57     template <typename T>
58     friend class TaskProcessor;
59 
60     template<typename T>
addTask(const sp<Task<T>> & task,const sp<TaskProcessor<T>> & processor)61     bool addTask(const sp<Task<T> >& task, const sp<TaskProcessor<T> >& processor) {
62         return addTaskBase(sp<TaskBase>(task), sp<TaskProcessorBase>(processor));
63     }
64 
65     bool addTaskBase(const sp<TaskBase>& task, const sp<TaskProcessorBase>& processor);
66 
67     struct TaskWrapper {
TaskWrapperTaskWrapper68         TaskWrapper(): mTask(), mProcessor() { }
69 
TaskWrapperTaskWrapper70         TaskWrapper(const sp<TaskBase>& task, const sp<TaskProcessorBase>& processor):
71             mTask(task), mProcessor(processor) {
72         }
73 
74         sp<TaskBase> mTask;
75         sp<TaskProcessorBase> mProcessor;
76     };
77 
78     class WorkerThread: public Thread {
79     public:
WorkerThread(const String8 name)80         WorkerThread(const String8 name): mSignal(Condition::WAKE_UP_ONE), mName(name) { }
81 
82         bool addTask(TaskWrapper task);
83         size_t getTaskCount() const;
84         void exit();
85 
86     private:
87         virtual status_t readyToRun() override;
88         virtual bool threadLoop() override;
89 
90         // Lock for the list of tasks
91         mutable Mutex mLock;
92         Vector<TaskWrapper> mTasks;
93 
94         // Signal used to wake up the thread when a new
95         // task is available in the list
96         mutable Signal mSignal;
97 
98         const String8 mName;
99     };
100 
101     Vector<sp<WorkerThread> > mThreads;
102 };
103 
104 }; // namespace uirenderer
105 }; // namespace android
106 
107 #endif // ANDROID_HWUI_TASK_MANAGER_H
108