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      1 /*
      2  * Copyright (C) 2007 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 #include <assert.h>
     18 #include <errno.h>
     19 #include <stdlib.h>
     20 #include <stdio.h>
     21 #include <string.h>
     22 
     23 #include <unistd.h>
     24 #include <fcntl.h>
     25 #include <signal.h>
     26 #include <termios.h>
     27 #include <sys/ioctl.h>
     28 #include <sys/mman.h>
     29 #include <sys/time.h>
     30 #include <sys/types.h>
     31 #include <sys/resource.h>
     32 
     33 #include <linux/unistd.h>
     34 
     35 #include <utils/Log.h>
     36 
     37 #include "DisplayHardware/DisplayHardwareBase.h"
     38 #include "SurfaceFlinger.h"
     39 
     40 // ----------------------------------------------------------------------------
     41 namespace android {
     42 
     43 static char const * const kSleepFileName = "/sys/power/wait_for_fb_sleep";
     44 static char const * const kWakeFileName  = "/sys/power/wait_for_fb_wake";
     45 
     46 // ----------------------------------------------------------------------------
     47 
     48 DisplayHardwareBase::DisplayEventThreadBase::DisplayEventThreadBase(
     49         const sp<SurfaceFlinger>& flinger)
     50     : Thread(false), mFlinger(flinger) {
     51 }
     52 
     53 DisplayHardwareBase::DisplayEventThreadBase::~DisplayEventThreadBase() {
     54 }
     55 
     56 // ----------------------------------------------------------------------------
     57 
     58 DisplayHardwareBase::DisplayEventThread::DisplayEventThread(
     59         const sp<SurfaceFlinger>& flinger)
     60     : DisplayEventThreadBase(flinger)
     61 {
     62 }
     63 
     64 DisplayHardwareBase::DisplayEventThread::~DisplayEventThread()
     65 {
     66 }
     67 
     68 bool DisplayHardwareBase::DisplayEventThread::threadLoop()
     69 {
     70     int err = 0;
     71     char buf;
     72     int fd;
     73 
     74     fd = open(kSleepFileName, O_RDONLY, 0);
     75     do {
     76       err = read(fd, &buf, 1);
     77     } while (err < 0 && errno == EINTR);
     78     close(fd);
     79     LOGW_IF(err<0, "ANDROID_WAIT_FOR_FB_SLEEP failed (%s)", strerror(errno));
     80     if (err >= 0) {
     81         sp<SurfaceFlinger> flinger = mFlinger.promote();
     82         LOGD("About to give-up screen, flinger = %p", flinger.get());
     83         if (flinger != 0) {
     84             mBarrier.close();
     85             flinger->screenReleased(0);
     86             mBarrier.wait();
     87         }
     88     }
     89     fd = open(kWakeFileName, O_RDONLY, 0);
     90     do {
     91       err = read(fd, &buf, 1);
     92     } while (err < 0 && errno == EINTR);
     93     close(fd);
     94     LOGW_IF(err<0, "ANDROID_WAIT_FOR_FB_WAKE failed (%s)", strerror(errno));
     95     if (err >= 0) {
     96         sp<SurfaceFlinger> flinger = mFlinger.promote();
     97         LOGD("Screen about to return, flinger = %p", flinger.get());
     98         if (flinger != 0)
     99             flinger->screenAcquired(0);
    100     }
    101     return true;
    102 }
    103 
    104 status_t DisplayHardwareBase::DisplayEventThread::releaseScreen() const
    105 {
    106     mBarrier.open();
    107     return NO_ERROR;
    108 }
    109 
    110 status_t DisplayHardwareBase::DisplayEventThread::readyToRun()
    111 {
    112     return NO_ERROR;
    113 }
    114 
    115 status_t DisplayHardwareBase::DisplayEventThread::initCheck() const
    116 {
    117     return ((access(kSleepFileName, R_OK) == 0 &&
    118             access(kWakeFileName, R_OK) == 0)) ? NO_ERROR : NO_INIT;
    119 }
    120 
    121 // ----------------------------------------------------------------------------
    122 
    123 DisplayHardwareBase::DisplayHardwareBase(const sp<SurfaceFlinger>& flinger,
    124         uint32_t displayIndex)
    125     : mScreenAcquired(true)
    126 {
    127     mDisplayEventThread = new DisplayEventThread(flinger);
    128 }
    129 
    130 DisplayHardwareBase::~DisplayHardwareBase()
    131 {
    132     // request exit
    133     mDisplayEventThread->requestExitAndWait();
    134 }
    135 
    136 bool DisplayHardwareBase::canDraw() const
    137 {
    138     return mScreenAcquired;
    139 }
    140 
    141 void DisplayHardwareBase::releaseScreen() const
    142 {
    143     status_t err = mDisplayEventThread->releaseScreen();
    144     if (err >= 0) {
    145         mScreenAcquired = false;
    146     }
    147 }
    148 
    149 void DisplayHardwareBase::acquireScreen() const
    150 {
    151     status_t err = mDisplayEventThread->acquireScreen();
    152     if (err >= 0) {
    153         mScreenAcquired = true;
    154     }
    155 }
    156 
    157 bool DisplayHardwareBase::isScreenAcquired() const
    158 {
    159     return mScreenAcquired;
    160 }
    161 
    162 }; // namespace android
    163