| prashant.n | 49b3e6465 | 2016-04-19 07:04:49 | [diff] [blame^] | 1 | // Copyright 2016 The Chromium Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #ifndef CC_RASTER_TASK_H_ |
| 6 | #define CC_RASTER_TASK_H_ |
| 7 | |
| 8 | #include <stdint.h> |
| 9 | |
| 10 | #include <vector> |
| 11 | |
| 12 | #include "base/memory/ref_counted.h" |
| 13 | #include "cc/base/cc_export.h" |
| 14 | |
| 15 | namespace cc { |
| 16 | |
| 17 | // A task which can be run by a TaskGraphRunner. To run a Task, it should be |
| 18 | // inserted into a TaskGraph, which can then be scheduled on the |
| 19 | // TaskGraphRunner. |
| 20 | class CC_EXPORT Task : public base::RefCountedThreadSafe<Task> { |
| 21 | public: |
| 22 | typedef std::vector<scoped_refptr<Task>> Vector; |
| 23 | |
| 24 | // Subclasses should implement this method. RunOnWorkerThread may be called |
| 25 | // on any thread, and subclasses are responsible for locking and thread |
| 26 | // safety. |
| 27 | virtual void RunOnWorkerThread() = 0; |
| 28 | |
| 29 | void WillRun(); |
| 30 | void DidRun(); |
| 31 | bool HasFinishedRunning() const; |
| 32 | |
| 33 | protected: |
| 34 | friend class base::RefCountedThreadSafe<Task>; |
| 35 | |
| 36 | Task(); |
| 37 | virtual ~Task(); |
| 38 | |
| 39 | bool will_run_; |
| 40 | bool did_run_; |
| 41 | }; |
| 42 | |
| 43 | // A task dependency graph describes the order in which to execute a set |
| 44 | // of tasks. Dependencies are represented as edges. Each node is assigned |
| 45 | // a category, a priority and a run count that matches the number of |
| 46 | // dependencies. Priority range from 0 (most favorable scheduling) to UINT16_MAX |
| 47 | // (least favorable). Categories range from 0 to UINT16_MAX. It is up to the |
| 48 | // implementation and its consumer to determine the meaning (if any) of a |
| 49 | // category. A TaskGraphRunner implementation may chose to prioritize certain |
| 50 | // categories over others, regardless of the individual priorities of tasks. |
| 51 | struct CC_EXPORT TaskGraph { |
| 52 | struct Node { |
| 53 | typedef std::vector<Node> Vector; |
| 54 | |
| 55 | Node(Task* task, |
| 56 | uint16_t category, |
| 57 | uint16_t priority, |
| 58 | uint32_t dependencies) |
| 59 | : task(task), |
| 60 | category(category), |
| 61 | priority(priority), |
| 62 | dependencies(dependencies) {} |
| 63 | |
| 64 | Task* task; |
| 65 | uint16_t category; |
| 66 | uint16_t priority; |
| 67 | uint32_t dependencies; |
| 68 | }; |
| 69 | |
| 70 | struct Edge { |
| 71 | typedef std::vector<Edge> Vector; |
| 72 | |
| 73 | Edge(const Task* task, Task* dependent) |
| 74 | : task(task), dependent(dependent) {} |
| 75 | |
| 76 | const Task* task; |
| 77 | Task* dependent; |
| 78 | }; |
| 79 | |
| 80 | TaskGraph(); |
| 81 | TaskGraph(const TaskGraph& other); |
| 82 | ~TaskGraph(); |
| 83 | |
| 84 | void Swap(TaskGraph* other); |
| 85 | void Reset(); |
| 86 | |
| 87 | Node::Vector nodes; |
| 88 | Edge::Vector edges; |
| 89 | }; |
| 90 | |
| 91 | } // namespace cc |
| 92 | |
| 93 | #endif // CC_RASTER_TASK_H_ |