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 
24 #include "Signal.h"
25 
26 #include <vector>
27 
28 namespace android {
29 namespace uirenderer {
30 
31 template <typename T>
32 class Task;
33 class TaskBase;
34 
35 template <typename T>
36 class TaskProcessor;
37 class TaskProcessorBase;
38 
39 class TaskManager {
40 public:
41     TaskManager();
42     ~TaskManager();
43 
44     /**
45      * Returns true if this task  manager can run tasks,
46      * false otherwise. This method will typically return
47      * false on a single CPU core device.
48      */
49     bool canRunTasks() const;
50 
51     /**
52      * Stops all allocated threads. Adding tasks will start
53      * the threads again as necessary.
54      */
55     void stop();
56 
57 private:
58     template <typename T>
59     friend class TaskProcessor;
60 
61     template<typename T>
addTask(const sp<Task<T>> & task,const sp<TaskProcessor<T>> & processor)62     bool addTask(const sp<Task<T> >& task, const sp<TaskProcessor<T> >& processor) {
63         return addTaskBase(sp<TaskBase>(task), sp<TaskProcessorBase>(processor));
64     }
65 
66     bool addTaskBase(const sp<TaskBase>& task, const sp<TaskProcessorBase>& processor);
67 
68     struct TaskWrapper {
TaskWrapperTaskWrapper69         TaskWrapper(): mTask(), mProcessor() { }
70 
TaskWrapperTaskWrapper71         TaskWrapper(const sp<TaskBase>& task, const sp<TaskProcessorBase>& processor):
72             mTask(task), mProcessor(processor) {
73         }
74 
75         sp<TaskBase> mTask;
76         sp<TaskProcessorBase> mProcessor;
77     };
78 
79     class WorkerThread: public Thread {
80     public:
WorkerThread(const String8 name)81         WorkerThread(const String8 name): mSignal(Condition::WAKE_UP_ONE), mName(name) { }
82 
83         bool addTask(const TaskWrapper& task);
84         size_t getTaskCount() const;
85         void exit();
86 
87     private:
88         virtual status_t readyToRun() override;
89         virtual bool threadLoop() override;
90 
91         // Lock for the list of tasks
92         mutable Mutex mLock;
93         std::vector<TaskWrapper> mTasks;
94 
95         // Signal used to wake up the thread when a new
96         // task is available in the list
97         mutable Signal mSignal;
98 
99         const String8 mName;
100     };
101 
102     std::vector<sp<WorkerThread> > mThreads;
103 };
104 
105 }; // namespace uirenderer
106 }; // namespace android
107 
108 #endif // ANDROID_HWUI_TASK_MANAGER_H
109