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_SERVERS_CAMERA3_STATUSTRACKER_H 18 #define ANDROID_SERVERS_CAMERA3_STATUSTRACKER_H 19 20 #include <utils/Condition.h> 21 #include <utils/Errors.h> 22 #include <utils/List.h> 23 #include <utils/Mutex.h> 24 #include <utils/Thread.h> 25 #include <utils/KeyedVector.h> 26 #include <hardware/camera3.h> 27 28 #include "common/CameraDeviceBase.h" 29 30 namespace android { 31 32 class Camera3Device; 33 class Fence; 34 35 namespace camera3 { 36 37 /** 38 * State tracking for idle and other collective state transitions. 39 * Collects idle notifications from different sources and calls the 40 * parent when all of them become idle. 41 * 42 * The parent is responsible for synchronizing the status updates with its 43 * internal state correctly, which means the notifyStatus call to the parent may 44 * block for a while. 45 */ 46 class StatusTracker: public Thread { 47 public: 48 StatusTracker(wp<Camera3Device> parent); 49 ~StatusTracker(); 50 51 // An always-invalid component ID 52 static const int NO_STATUS_ID = -1; 53 54 // Add a component to track; returns non-negative unique ID for the new 55 // component on success, negative error code on failure. 56 // New components start in the idle state. 57 int addComponent(); 58 59 // Remove existing component from idle tracking. Ignores unknown IDs 60 void removeComponent(int id); 61 62 // Set the state of a tracked component to be idle. Ignores unknown IDs; can 63 // accept a fence to wait on to complete idle. The fence is merged with any 64 // previous fences given, which means they all must signal before the 65 // component is considered idle. 66 void markComponentIdle(int id, const sp<Fence>& componentFence); 67 68 // Set the state of a tracked component to be active. Ignores unknown IDs. 69 void markComponentActive(int id); 70 71 virtual void requestExit(); 72 protected: 73 74 virtual bool threadLoop(); 75 76 private: 77 enum ComponentState { 78 IDLE, 79 ACTIVE 80 }; 81 82 void markComponent(int id, ComponentState state, 83 const sp<Fence>& componentFence); 84 85 // Guards mPendingChange, mPendingStates, mComponentsChanged 86 Mutex mPendingLock; 87 88 Condition mPendingChangeSignal; 89 90 struct StateChange { 91 int id; 92 ComponentState state; 93 sp<Fence> fence; 94 }; 95 // A queue of yet-to-be-processed state changes to components 96 Vector<StateChange> mPendingChangeQueue; 97 bool mComponentsChanged; 98 99 wp<Camera3Device> mParent; 100 101 // Guards rest of internals. Must be locked after mPendingLock if both used. 102 Mutex mLock; 103 104 int mNextComponentId; 105 106 // Current component states 107 KeyedVector<int, ComponentState> mStates; 108 // Merged fence for all processed state changes 109 sp<Fence> mIdleFence; 110 // Current overall device state 111 ComponentState mDeviceState; 112 113 // Private to threadLoop 114 115 // Determine current overall device state 116 // We're IDLE iff 117 // - All components are currently IDLE 118 // - The merged fence for all component updates has signalled 119 ComponentState getDeviceStateLocked(); 120 121 Vector<ComponentState> mStateTransitions; 122 123 static const nsecs_t kWaitDuration = 250000000LL; // 250 ms 124 }; 125 126 } // namespace camera3 127 128 } // namespace android 129 130 #endif 131