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      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 #define LOG_TAG "Camera3-Status"
     18 #define ATRACE_TAG ATRACE_TAG_CAMERA
     19 //#define LOG_NDEBUG 0
     20 
     21 #include <utils/Log.h>
     22 #include <utils/Trace.h>
     23 #include <ui/Fence.h>
     24 
     25 #include "device3/StatusTracker.h"
     26 #include "device3/Camera3Device.h"
     27 
     28 namespace android {
     29 
     30 namespace camera3 {
     31 
     32 StatusTracker::StatusTracker(wp<Camera3Device> parent) :
     33         mComponentsChanged(false),
     34         mParent(parent),
     35         mNextComponentId(0),
     36         mIdleFence(new Fence()),
     37         mDeviceState(IDLE) {
     38 }
     39 
     40 StatusTracker::~StatusTracker() {
     41 }
     42 
     43 int StatusTracker::addComponent() {
     44     int id;
     45     ssize_t err;
     46     {
     47         Mutex::Autolock l(mLock);
     48         id = mNextComponentId++;
     49         ALOGV("%s: Adding new component %d", __FUNCTION__, id);
     50 
     51         err = mStates.add(id, IDLE);
     52         ALOGE_IF(err < 0, "%s: Can't add new component %d: %s (%zd)",
     53                 __FUNCTION__, id, strerror(-err), err);
     54     }
     55 
     56     if (err >= 0) {
     57         Mutex::Autolock pl(mPendingLock);
     58         mComponentsChanged = true;
     59         mPendingChangeSignal.signal();
     60     }
     61 
     62     return err < 0 ? err : id;
     63 }
     64 
     65 void StatusTracker::removeComponent(int id) {
     66     ssize_t idx;
     67     {
     68         Mutex::Autolock l(mLock);
     69         ALOGV("%s: Removing component %d", __FUNCTION__, id);
     70         idx = mStates.removeItem(id);
     71     }
     72 
     73     if (idx >= 0) {
     74         Mutex::Autolock pl(mPendingLock);
     75         mComponentsChanged = true;
     76         mPendingChangeSignal.signal();
     77     }
     78 
     79     return;
     80 }
     81 
     82 
     83 void StatusTracker::markComponentIdle(int id, const sp<Fence>& componentFence) {
     84     markComponent(id, IDLE, componentFence);
     85 }
     86 
     87 void StatusTracker::markComponentActive(int id) {
     88     markComponent(id, ACTIVE, Fence::NO_FENCE);
     89 }
     90 
     91 void StatusTracker::markComponent(int id, ComponentState state,
     92         const sp<Fence>& componentFence) {
     93     ALOGV("%s: Component %d is now %s", __FUNCTION__, id,
     94             state == IDLE ? "idle" : "active");
     95     Mutex::Autolock l(mPendingLock);
     96 
     97     StateChange newState = {
     98         id,
     99         state,
    100         componentFence
    101     };
    102 
    103     mPendingChangeQueue.add(newState);
    104     mPendingChangeSignal.signal();
    105 }
    106 
    107 void StatusTracker::requestExit() {
    108     // First mark thread dead
    109     Thread::requestExit();
    110     // Then exit any waits
    111     mPendingChangeSignal.signal();
    112 }
    113 
    114 StatusTracker::ComponentState StatusTracker::getDeviceStateLocked() {
    115     for (size_t i = 0; i < mStates.size(); i++) {
    116         if (mStates.valueAt(i) == ACTIVE) {
    117             ALOGV("%s: Component %d not idle", __FUNCTION__,
    118                     mStates.keyAt(i));
    119             return ACTIVE;
    120         }
    121     }
    122     // - If not yet signaled, getSignalTime returns INT64_MAX
    123     // - If invalid fence or error, returns -1
    124     // - Otherwise returns time of signalling.
    125     // Treat -1 as 'signalled', since HAL may not be using fences, and want
    126     // to be able to idle in case of errors.
    127     nsecs_t signalTime = mIdleFence->getSignalTime();
    128     bool fencesDone = signalTime != INT64_MAX;
    129 
    130     ALOGV_IF(!fencesDone, "%s: Fences still to wait on", __FUNCTION__);
    131 
    132     return fencesDone ? IDLE : ACTIVE;
    133 }
    134 
    135 bool StatusTracker::threadLoop() {
    136     status_t res;
    137 
    138     // Wait for state updates
    139     {
    140         Mutex::Autolock pl(mPendingLock);
    141         while (mPendingChangeQueue.size() == 0 && !mComponentsChanged) {
    142             res = mPendingChangeSignal.waitRelative(mPendingLock,
    143                     kWaitDuration);
    144             if (exitPending()) return false;
    145             if (res != OK) {
    146                 if (res != TIMED_OUT) {
    147                     ALOGE("%s: Error waiting on state changes: %s (%d)",
    148                             __FUNCTION__, strerror(-res), res);
    149                 }
    150                 // TIMED_OUT is expected
    151                 break;
    152             }
    153         }
    154     }
    155 
    156     // After new pending states appear, or timeout, check if we're idle.  Even
    157     // with timeout, need to check to account for fences that may still be
    158     // clearing out
    159     sp<Camera3Device> parent;
    160     {
    161         Mutex::Autolock pl(mPendingLock);
    162         Mutex::Autolock l(mLock);
    163 
    164         // Collect all pending state updates and see if the device
    165         // collectively transitions between idle and active for each one
    166 
    167         // First pass for changed components or fence completions
    168         ComponentState prevState = getDeviceStateLocked();
    169         if (prevState != mDeviceState) {
    170             // Only collect changes to overall device state
    171             mStateTransitions.add(prevState);
    172         }
    173         // For each pending component state update, check if we've transitioned
    174         // to a new overall device state
    175         for (size_t i = 0; i < mPendingChangeQueue.size(); i++) {
    176             const StateChange &newState = mPendingChangeQueue[i];
    177             ssize_t idx = mStates.indexOfKey(newState.id);
    178             // Ignore notices for unknown components
    179             if (idx >= 0) {
    180                 // Update single component state
    181                 mStates.replaceValueAt(idx, newState.state);
    182                 mIdleFence = Fence::merge(String8("idleFence"),
    183                         mIdleFence, newState.fence);
    184                 // .. and see if overall device state has changed
    185                 ComponentState newState = getDeviceStateLocked();
    186                 if (newState != prevState) {
    187                     mStateTransitions.add(newState);
    188                 }
    189                 prevState = newState;
    190             }
    191         }
    192         mPendingChangeQueue.clear();
    193         mComponentsChanged = false;
    194 
    195         // Store final state after all pending state changes are done with
    196 
    197         mDeviceState = prevState;
    198         parent = mParent.promote();
    199     }
    200 
    201     // Notify parent for all intermediate transitions
    202     if (mStateTransitions.size() > 0 && parent.get()) {
    203         for (size_t i = 0; i < mStateTransitions.size(); i++) {
    204             bool idle = (mStateTransitions[i] == IDLE);
    205             ALOGV("Camera device is now %s", idle ? "idle" : "active");
    206             parent->notifyStatus(idle);
    207         }
    208     }
    209     mStateTransitions.clear();
    210 
    211     return true;
    212 }
    213 
    214 } // namespace android
    215 
    216 } // namespace camera3
    217