| /* |
| * Copyright (C) 2012 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include <errno.h> |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <string.h> |
| |
| #include <unistd.h> |
| #include <fcntl.h> |
| |
| #include <utils/Log.h> |
| |
| #include "DisplayHardware/DisplayHardwareBase.h" |
| #include "SurfaceFlinger.h" |
| |
| // ---------------------------------------------------------------------------- |
| namespace android { |
| |
| static char const * const kSleepFileName = "/sys/power/wait_for_fb_sleep"; |
| static char const * const kWakeFileName = "/sys/power/wait_for_fb_wake"; |
| |
| // ---------------------------------------------------------------------------- |
| |
| DisplayHardwareBase::DisplayEventThread::DisplayEventThread( |
| const sp<SurfaceFlinger>& flinger) |
| : Thread(false), mFlinger(flinger) { |
| } |
| |
| DisplayHardwareBase::DisplayEventThread::~DisplayEventThread() { |
| } |
| |
| void DisplayHardwareBase::DisplayEventThread::onFirstRef() { |
| if (initCheck() == NO_ERROR) { |
| run("DisplayEventThread", PRIORITY_URGENT_DISPLAY); |
| } else { |
| ALOGW("/sys/power/wait_for_fb_{wake|sleep} don't exist"); |
| } |
| } |
| |
| status_t DisplayHardwareBase::DisplayEventThread::initCheck() const { |
| return ((access(kSleepFileName, R_OK) == 0 && |
| access(kWakeFileName, R_OK) == 0)) ? NO_ERROR : NO_INIT; |
| } |
| |
| bool DisplayHardwareBase::DisplayEventThread::threadLoop() { |
| |
| if (waitForFbSleep() == NO_ERROR) { |
| sp<SurfaceFlinger> flinger = mFlinger.promote(); |
| ALOGD("About to give-up screen, flinger = %p", flinger.get()); |
| if (flinger != 0) { |
| mBarrier.close(); |
| flinger->screenReleased(0); |
| mBarrier.wait(); |
| } |
| if (waitForFbWake() == NO_ERROR) { |
| sp<SurfaceFlinger> flinger = mFlinger.promote(); |
| ALOGD("Screen about to return, flinger = %p", flinger.get()); |
| if (flinger != 0) { |
| flinger->screenAcquired(0); |
| } |
| return true; |
| } |
| } |
| |
| // error, exit the thread |
| return false; |
| } |
| |
| status_t DisplayHardwareBase::DisplayEventThread::waitForFbSleep() { |
| int err = 0; |
| char buf; |
| int fd = open(kSleepFileName, O_RDONLY, 0); |
| // if the file doesn't exist, the error will be caught in read() below |
| do { |
| err = read(fd, &buf, 1); |
| } while (err < 0 && errno == EINTR); |
| close(fd); |
| ALOGE_IF(err<0, "*** ANDROID_WAIT_FOR_FB_SLEEP failed (%s)", strerror(errno)); |
| return err < 0 ? -errno : int(NO_ERROR); |
| } |
| |
| status_t DisplayHardwareBase::DisplayEventThread::waitForFbWake() { |
| int err = 0; |
| char buf; |
| int fd = open(kWakeFileName, O_RDONLY, 0); |
| // if the file doesn't exist, the error will be caught in read() below |
| do { |
| err = read(fd, &buf, 1); |
| } while (err < 0 && errno == EINTR); |
| close(fd); |
| ALOGE_IF(err<0, "*** ANDROID_WAIT_FOR_FB_WAKE failed (%s)", strerror(errno)); |
| return err < 0 ? -errno : int(NO_ERROR); |
| } |
| |
| status_t DisplayHardwareBase::DisplayEventThread::releaseScreen() const { |
| mBarrier.open(); |
| return NO_ERROR; |
| } |
| |
| // ---------------------------------------------------------------------------- |
| |
| DisplayHardwareBase::DisplayHardwareBase(const sp<SurfaceFlinger>& flinger, |
| uint32_t displayIndex) |
| : mScreenAcquired(true) |
| { |
| mDisplayEventThread = new DisplayEventThread(flinger); |
| } |
| |
| DisplayHardwareBase::~DisplayHardwareBase() { |
| // request exit |
| mDisplayEventThread->requestExitAndWait(); |
| } |
| |
| bool DisplayHardwareBase::canDraw() const { |
| return mScreenAcquired; |
| } |
| |
| void DisplayHardwareBase::releaseScreen() const { |
| status_t err = mDisplayEventThread->releaseScreen(); |
| if (err >= 0) { |
| mScreenAcquired = false; |
| } |
| } |
| |
| void DisplayHardwareBase::acquireScreen() const { |
| mScreenAcquired = true; |
| } |
| |
| bool DisplayHardwareBase::isScreenAcquired() const { |
| return mScreenAcquired; |
| } |
| |
| }; // namespace android |