camera/EmulatedCameraHotplugThread.cpp - device/generic/goldfish - Git at Google

 /*
  * Copyright (C) 2013 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.
  */
 //#define LOG_NDEBUG 0
 #define LOG_TAG "EmulatedCamera_HotplugThread"
 #include <cutils/log.h>

 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <sys/inotify.h>

 #include "EmulatedCameraHotplugThread.h"
 #include "EmulatedCameraFactory.h"

 #define FAKE_HOTPLUG_FILE "/data/misc/media/emulator.camera.hotplug"

 #define EVENT_SIZE (sizeof(struct inotify_event))
 #define EVENT_BUF_LEN (1024*(EVENT_SIZE+16))

 #define SubscriberInfo EmulatedCameraHotplugThread::SubscriberInfo

 namespace android {

 EmulatedCameraHotplugThread::EmulatedCameraHotplugThread(
     const int* cameraIdArray,
     size_t size) :
         Thread(/*canCallJava*/false) {

     mRunning = true;
     mInotifyFd = 0;

     for (size_t i = 0; i < size; ++i) {
         int id = cameraIdArray[i];

         if (createFileIfNotExists(id)) {
             mSubscribedCameraIds.push_back(id);
         }
     }
 }

 EmulatedCameraHotplugThread::~EmulatedCameraHotplugThread() {
 }

 status_t EmulatedCameraHotplugThread::requestExitAndWait() {
     ALOGE("%s: Not implemented. Use requestExit + join instead",
           __FUNCTION__);
     return INVALID_OPERATION;
 }

 void EmulatedCameraHotplugThread::requestExit() {
     Mutex::Autolock al(mMutex);

     ALOGV("%s: Requesting thread exit", __FUNCTION__);
     mRunning = false;

     bool rmWatchFailed = false;
     Vector<SubscriberInfo>::iterator it;
     for (it = mSubscribers.begin(); it != mSubscribers.end(); ++it) {

         if (inotify_rm_watch(mInotifyFd, it->WatchID) == -1) {

             ALOGE("%s: Could not remove watch for camID '%d',"
                   " error: '%s' (%d)",
                  __FUNCTION__, it->CameraID, strerror(errno),
                  errno);

             rmWatchFailed = true ;
         } else {
             ALOGV("%s: Removed watch for camID '%d'",
                 __FUNCTION__, it->CameraID);
         }
     }

     if (rmWatchFailed) { // unlikely
         // Give the thread a fighting chance to error out on the next
         // read
         if (close(mInotifyFd) == -1) {
             ALOGE("%s: close failure error: '%s' (%d)",
                  __FUNCTION__, strerror(errno), errno);
         }
     }

     ALOGV("%s: Request exit complete.", __FUNCTION__);
 }

 status_t EmulatedCameraHotplugThread::readyToRun() {
     Mutex::Autolock al(mMutex);

     mInotifyFd = -1;

     do {
         ALOGV("%s: Initializing inotify", __FUNCTION__);

         mInotifyFd = inotify_init();
         if (mInotifyFd == -1) {
             ALOGE("%s: inotify_init failure error: '%s' (%d)",
                  __FUNCTION__, strerror(errno), errno);
             mRunning = false;
             break;
         }

         /**
          * For each fake camera file, add a watch for when
          * the file is closed (if it was written to)
          */
         Vector<int>::const_iterator it, end;
         it = mSubscribedCameraIds.begin();
         end = mSubscribedCameraIds.end();
         for (; it != end; ++it) {
             int cameraId = *it;
             if (!addWatch(cameraId)) {
                 mRunning = false;
                 break;
             }
         }
     } while(false);

     if (!mRunning) {
         status_t err = -errno;

         if (mInotifyFd != -1) {
             close(mInotifyFd);
         }

         return err;
     }

     return OK;
 }

 bool EmulatedCameraHotplugThread::threadLoop() {

     // If requestExit was already called, mRunning will be false
     while (mRunning) {
         char buffer[EVENT_BUF_LEN];
         int length = TEMP_FAILURE_RETRY(
                         read(mInotifyFd, buffer, EVENT_BUF_LEN));

         if (length < 0) {
             ALOGE("%s: Error reading from inotify FD, error: '%s' (%d)",
                  __FUNCTION__, strerror(errno),
                  errno);
             mRunning = false;
             break;
         }

         ALOGV("%s: Read %d bytes from inotify FD", __FUNCTION__, length);

         int i = 0;
         while (i < length) {
             inotify_event* event = (inotify_event*) &buffer[i];

             if (event->mask & IN_IGNORED) {
                 Mutex::Autolock al(mMutex);
                 if (!mRunning) {
                     ALOGV("%s: Shutting down thread", __FUNCTION__);
                     break;
                 } else {
                     ALOGE("%s: File was deleted, aborting",
                           __FUNCTION__);
                     mRunning = false;
                     break;
                 }
             } else if (event->mask & IN_CLOSE_WRITE) {
                 int cameraId = getCameraId(event->wd);

                 if (cameraId < 0) {
                     ALOGE("%s: Got bad camera ID from WD '%d",
                           __FUNCTION__, event->wd);
                 } else {
                     // Check the file for the new hotplug event
                     String8 filePath = getFilePath(cameraId);
                     /**
                      * NOTE: we carefully avoid getting an inotify
                      * for the same exact file because it's opened for
                      * read-only, but our inotify is for write-only
                      */
                     int newStatus = readFile(filePath);

                     if (newStatus < 0) {
                         mRunning = false;
                         break;
                     }

                     int halStatus = newStatus ?
                         CAMERA_DEVICE_STATUS_PRESENT :
                         CAMERA_DEVICE_STATUS_NOT_PRESENT;
                     gEmulatedCameraFactory.onStatusChanged(cameraId,
                                                            halStatus);
                 }

             } else {
                 ALOGW("%s: Unknown mask 0x%x",
                       __FUNCTION__, event->mask);
             }

             i += EVENT_SIZE + event->len;
         }
     }

     if (!mRunning) {
         close(mInotifyFd);
         return false;
     }

     return true;
 }

 String8 EmulatedCameraHotplugThread::getFilePath(int cameraId) const {
     return String8::format(FAKE_HOTPLUG_FILE ".%d", cameraId);
 }

 bool EmulatedCameraHotplugThread::createFileIfNotExists(int cameraId) const
 {
     String8 filePath = getFilePath(cameraId);
     // make sure this file exists and we have access to it
     int fd = TEMP_FAILURE_RETRY(
                 open(filePath.string(), O_WRONLY | O_CREAT | O_TRUNC,
                      /* mode = ug+rwx */ S_IRWXU | S_IRWXG ));
     if (fd == -1) {
         ALOGE("%s: Could not create file '%s', error: '%s' (%d)",
              __FUNCTION__, filePath.string(), strerror(errno), errno);
         return false;
     }

     // File has '1' by default since we are plugged in by default
     if (TEMP_FAILURE_RETRY(write(fd, "1\n", /*count*/2)) == -1) {
         ALOGE("%s: Could not write '1' to file '%s', error: '%s' (%d)",
              __FUNCTION__, filePath.string(), strerror(errno), errno);
         return false;
     }

     close(fd);
     return true;
 }

 int EmulatedCameraHotplugThread::getCameraId(String8 filePath) const {
     Vector<int>::const_iterator it, end;
     it = mSubscribedCameraIds.begin();
     end = mSubscribedCameraIds.end();
     for (; it != end; ++it) {
         String8 camPath = getFilePath(*it);

         if (camPath == filePath) {
             return *it;
         }
     }

     return NAME_NOT_FOUND;
 }

 int EmulatedCameraHotplugThread::getCameraId(int wd) const {
     for (size_t i = 0; i < mSubscribers.size(); ++i) {
         if (mSubscribers[i].WatchID == wd) {
             return mSubscribers[i].CameraID;
         }
     }

     return NAME_NOT_FOUND;
 }

 SubscriberInfo* EmulatedCameraHotplugThread::getSubscriberInfo(int cameraId)
 {
     for (size_t i = 0; i < mSubscribers.size(); ++i) {
         if (mSubscribers[i].CameraID == cameraId) {
             return (SubscriberInfo*)&mSubscribers[i];
         }
     }

     return NULL;
 }

 bool EmulatedCameraHotplugThread::addWatch(int cameraId) {
     String8 camPath = getFilePath(cameraId);
     int wd = inotify_add_watch(mInotifyFd,
                                camPath.string(),
                                IN_CLOSE_WRITE);

     if (wd == -1) {
         ALOGE("%s: Could not add watch for '%s', error: '%s' (%d)",
              __FUNCTION__, camPath.string(), strerror(errno),
              errno);

         mRunning = false;
         return false;
     }

     ALOGV("%s: Watch added for camID='%d', wd='%d'",
           __FUNCTION__, cameraId, wd);

     SubscriberInfo si = { cameraId, wd };
     mSubscribers.push_back(si);

     return true;
 }

 bool EmulatedCameraHotplugThread::removeWatch(int cameraId) {
     SubscriberInfo* si = getSubscriberInfo(cameraId);

     if (!si) return false;

     if (inotify_rm_watch(mInotifyFd, si->WatchID) == -1) {

         ALOGE("%s: Could not remove watch for camID '%d', error: '%s' (%d)",
              __FUNCTION__, cameraId, strerror(errno),
              errno);

         return false;
     }

     Vector<SubscriberInfo>::iterator it;
     for (it = mSubscribers.begin(); it != mSubscribers.end(); ++it) {
         if (it->CameraID == cameraId) {
             break;
         }
     }

     if (it != mSubscribers.end()) {
         mSubscribers.erase(it);
     }

     return true;
 }

 int EmulatedCameraHotplugThread::readFile(String8 filePath) const {

     int fd = TEMP_FAILURE_RETRY(
                 open(filePath.string(), O_RDONLY, /*mode*/0));
     if (fd == -1) {
         ALOGE("%s: Could not open file '%s', error: '%s' (%d)",
              __FUNCTION__, filePath.string(), strerror(errno), errno);
         return -1;
     }

     char buffer[1];
     int length;

     length = TEMP_FAILURE_RETRY(
                     read(fd, buffer, sizeof(buffer)));

     int retval;

     ALOGV("%s: Read file '%s', length='%d', buffer='%c'",
          __FUNCTION__, filePath.string(), length, buffer[0]);

     if (length == 0) { // EOF
         retval = 0; // empty file is the same thing as 0
     } else if (buffer[0] == '0') {
         retval = 0;
     } else { // anything non-empty that's not beginning with '0'
         retval = 1;
     }

     close(fd);

     return retval;
 }

 } //namespace android
	/*
	* Copyright (C) 2013 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.
	*/
	//#define LOG_NDEBUG 0
	#define LOG_TAG "EmulatedCamera_HotplugThread"
	#include <cutils/log.h>

	#include <sys/types.h>
	#include <sys/stat.h>
	#include <fcntl.h>
	#include <sys/inotify.h>

	#include "EmulatedCameraHotplugThread.h"
	#include "EmulatedCameraFactory.h"

	#define FAKE_HOTPLUG_FILE "/data/misc/media/emulator.camera.hotplug"

	#define EVENT_SIZE (sizeof(struct inotify_event))
	#define EVENT_BUF_LEN (1024*(EVENT_SIZE+16))

	#define SubscriberInfo EmulatedCameraHotplugThread::SubscriberInfo

	namespace android {

	EmulatedCameraHotplugThread::EmulatedCameraHotplugThread(
	const int* cameraIdArray,
	size_t size) :
	Thread(/canCallJava/false) {

	mRunning = true;
	mInotifyFd = 0;

	for (size_t i = 0; i < size; ++i) {
	int id = cameraIdArray[i];

	if (createFileIfNotExists(id)) {
	mSubscribedCameraIds.push_back(id);
	}
	}
	}

	EmulatedCameraHotplugThread::~EmulatedCameraHotplugThread() {
	}

	status_t EmulatedCameraHotplugThread::requestExitAndWait() {
	ALOGE("%s: Not implemented. Use requestExit + join instead",
	__FUNCTION__);
	return INVALID_OPERATION;
	}

	void EmulatedCameraHotplugThread::requestExit() {
	Mutex::Autolock al(mMutex);

	ALOGV("%s: Requesting thread exit", __FUNCTION__);
	mRunning = false;

	bool rmWatchFailed = false;
	Vector<SubscriberInfo>::iterator it;
	for (it = mSubscribers.begin(); it != mSubscribers.end(); ++it) {

	if (inotify_rm_watch(mInotifyFd, it->WatchID) == -1) {

	ALOGE("%s: Could not remove watch for camID '%d',"
	" error: '%s' (%d)",
	__FUNCTION__, it->CameraID, strerror(errno),
	errno);

	rmWatchFailed = true ;
	} else {
	ALOGV("%s: Removed watch for camID '%d'",
	__FUNCTION__, it->CameraID);
	}
	}

	if (rmWatchFailed) { // unlikely
	// Give the thread a fighting chance to error out on the next
	// read
	if (close(mInotifyFd) == -1) {
	ALOGE("%s: close failure error: '%s' (%d)",
	__FUNCTION__, strerror(errno), errno);
	}
	}

	ALOGV("%s: Request exit complete.", __FUNCTION__);
	}

	status_t EmulatedCameraHotplugThread::readyToRun() {
	Mutex::Autolock al(mMutex);

	mInotifyFd = -1;

	do {
	ALOGV("%s: Initializing inotify", __FUNCTION__);

	mInotifyFd = inotify_init();
	if (mInotifyFd == -1) {
	ALOGE("%s: inotify_init failure error: '%s' (%d)",
	__FUNCTION__, strerror(errno), errno);
	mRunning = false;
	break;
	}

	/**
	* For each fake camera file, add a watch for when
	* the file is closed (if it was written to)
	*/
	Vector<int>::const_iterator it, end;
	it = mSubscribedCameraIds.begin();
	end = mSubscribedCameraIds.end();
	for (; it != end; ++it) {
	int cameraId = *it;
	if (!addWatch(cameraId)) {
	mRunning = false;
	break;
	}
	}
	} while(false);

	if (!mRunning) {
	status_t err = -errno;

	if (mInotifyFd != -1) {
	close(mInotifyFd);
	}

	return err;
	}

	return OK;
	}

	bool EmulatedCameraHotplugThread::threadLoop() {

	// If requestExit was already called, mRunning will be false
	while (mRunning) {
	char buffer[EVENT_BUF_LEN];
	int length = TEMP_FAILURE_RETRY(
	read(mInotifyFd, buffer, EVENT_BUF_LEN));

	if (length < 0) {
	ALOGE("%s: Error reading from inotify FD, error: '%s' (%d)",
	__FUNCTION__, strerror(errno),
	errno);
	mRunning = false;
	break;
	}

	ALOGV("%s: Read %d bytes from inotify FD", __FUNCTION__, length);

	int i = 0;
	while (i < length) {
	inotify_event* event = (inotify_event*) &buffer[i];

	if (event->mask & IN_IGNORED) {
	Mutex::Autolock al(mMutex);
	if (!mRunning) {
	ALOGV("%s: Shutting down thread", __FUNCTION__);
	break;
	} else {
	ALOGE("%s: File was deleted, aborting",
	__FUNCTION__);
	mRunning = false;
	break;
	}
	} else if (event->mask & IN_CLOSE_WRITE) {
	int cameraId = getCameraId(event->wd);

	if (cameraId < 0) {
	ALOGE("%s: Got bad camera ID from WD '%d",
	__FUNCTION__, event->wd);
	} else {
	// Check the file for the new hotplug event
	String8 filePath = getFilePath(cameraId);
	/**
	* NOTE: we carefully avoid getting an inotify
	* for the same exact file because it's opened for
	* read-only, but our inotify is for write-only
	*/
	int newStatus = readFile(filePath);

	if (newStatus < 0) {
	mRunning = false;
	break;
	}

	int halStatus = newStatus ?
	CAMERA_DEVICE_STATUS_PRESENT :
	CAMERA_DEVICE_STATUS_NOT_PRESENT;
	gEmulatedCameraFactory.onStatusChanged(cameraId,
	halStatus);
	}

	} else {
	ALOGW("%s: Unknown mask 0x%x",
	__FUNCTION__, event->mask);
	}

	i += EVENT_SIZE + event->len;
	}
	}

	if (!mRunning) {
	close(mInotifyFd);
	return false;
	}

	return true;
	}

	String8 EmulatedCameraHotplugThread::getFilePath(int cameraId) const {
	return String8::format(FAKE_HOTPLUG_FILE ".%d", cameraId);
	}

	bool EmulatedCameraHotplugThread::createFileIfNotExists(int cameraId) const
	{
	String8 filePath = getFilePath(cameraId);
	// make sure this file exists and we have access to it
	int fd = TEMP_FAILURE_RETRY(
	open(filePath.string(), O_WRONLY \| O_CREAT \| O_TRUNC,
	/* mode = ug+rwx */ S_IRWXU \| S_IRWXG ));
	if (fd == -1) {
	ALOGE("%s: Could not create file '%s', error: '%s' (%d)",
	__FUNCTION__, filePath.string(), strerror(errno), errno);
	return false;
	}

	// File has '1' by default since we are plugged in by default
	if (TEMP_FAILURE_RETRY(write(fd, "1\n", /count/2)) == -1) {
	ALOGE("%s: Could not write '1' to file '%s', error: '%s' (%d)",
	__FUNCTION__, filePath.string(), strerror(errno), errno);
	return false;
	}

	close(fd);
	return true;
	}

	int EmulatedCameraHotplugThread::getCameraId(String8 filePath) const {
	Vector<int>::const_iterator it, end;
	it = mSubscribedCameraIds.begin();
	end = mSubscribedCameraIds.end();
	for (; it != end; ++it) {
	String8 camPath = getFilePath(*it);

	if (camPath == filePath) {
	return *it;
	}
	}

	return NAME_NOT_FOUND;
	}

	int EmulatedCameraHotplugThread::getCameraId(int wd) const {
	for (size_t i = 0; i < mSubscribers.size(); ++i) {
	if (mSubscribers[i].WatchID == wd) {
	return mSubscribers[i].CameraID;
	}
	}

	return NAME_NOT_FOUND;
	}

	SubscriberInfo* EmulatedCameraHotplugThread::getSubscriberInfo(int cameraId)
	{
	for (size_t i = 0; i < mSubscribers.size(); ++i) {
	if (mSubscribers[i].CameraID == cameraId) {
	return (SubscriberInfo*)&mSubscribers[i];
	}
	}

	return NULL;
	}

	bool EmulatedCameraHotplugThread::addWatch(int cameraId) {
	String8 camPath = getFilePath(cameraId);
	int wd = inotify_add_watch(mInotifyFd,
	camPath.string(),
	IN_CLOSE_WRITE);

	if (wd == -1) {
	ALOGE("%s: Could not add watch for '%s', error: '%s' (%d)",
	__FUNCTION__, camPath.string(), strerror(errno),
	errno);

	mRunning = false;
	return false;
	}

	ALOGV("%s: Watch added for camID='%d', wd='%d'",
	__FUNCTION__, cameraId, wd);

	SubscriberInfo si = { cameraId, wd };
	mSubscribers.push_back(si);

	return true;
	}

	bool EmulatedCameraHotplugThread::removeWatch(int cameraId) {
	SubscriberInfo* si = getSubscriberInfo(cameraId);

	if (!si) return false;

	if (inotify_rm_watch(mInotifyFd, si->WatchID) == -1) {

	ALOGE("%s: Could not remove watch for camID '%d', error: '%s' (%d)",
	__FUNCTION__, cameraId, strerror(errno),
	errno);

	return false;
	}

	Vector<SubscriberInfo>::iterator it;
	for (it = mSubscribers.begin(); it != mSubscribers.end(); ++it) {
	if (it->CameraID == cameraId) {
	break;
	}
	}

	if (it != mSubscribers.end()) {
	mSubscribers.erase(it);
	}

	return true;
	}

	int EmulatedCameraHotplugThread::readFile(String8 filePath) const {

	int fd = TEMP_FAILURE_RETRY(
	open(filePath.string(), O_RDONLY, /mode/0));
	if (fd == -1) {
	ALOGE("%s: Could not open file '%s', error: '%s' (%d)",
	__FUNCTION__, filePath.string(), strerror(errno), errno);
	return -1;
	}

	char buffer[1];
	int length;

	length = TEMP_FAILURE_RETRY(
	read(fd, buffer, sizeof(buffer)));

	int retval;

	ALOGV("%s: Read file '%s', length='%d', buffer='%c'",
	__FUNCTION__, filePath.string(), length, buffer[0]);

	if (length == 0) { // EOF
	retval = 0; // empty file is the same thing as 0
	} else if (buffer[0] == '0') {
	retval = 0;
	} else { // anything non-empty that's not beginning with '0'
	retval = 1;
	}

	close(fd);

	return retval;
	}

	} //namespace android