Androidの応用から駆動へ—camera(2)---cameraHALの実現
初心者にとって、最大の疑問はシステムがhardwareをどのように呼び出すかである.ここではcameraを例に挙げて説明する.hardwareを呼び出すプログラムはcameraserviceです.hardwareを見つける方法を見てみましょう.
まずソースを貼り付けます.
void CameraServices::onFirstRef()この関数を見てください:
長い間探していたが、この関数にはhwが入っていた.get_module()という関数は、名前を見るとhardwareを取得していることがわかりますが、誰を探しているのでしょうか.ではonFirstRef()関数はいつ呼び出されますか?
onFirstRef()は、spを強く参照して新しい参照カウントを追加するときに呼び出される親RefBaseに属します.どういう意味ですか.spパッケージのクラスが初期化されたときに呼び出されます.ここではframeworks/base/services/camera/libcameraservice/CameraServices.h中class CameraService:に定義あり
明らかにここで初期化したのですが、もちろんここはポイントではありません.全部書けば、ほとんど書けません.
hw_が見つかりましたget_module()という関数は、その具体的な実装を見てみましょう.
hardware/libhardware/hardware.c
コードは次のとおりです.
その流れを見てみましょう.
実際にhardwareを探しに来た橋はこのIDでif(strcmp(id,hmi->id)!=0)ではidはframeworks/base/services/camera/libcameraservice/CameraServicesである.cppに直接付与された
次のようになります.
hmi->idのこのidはhardwareで定義すべきであることは明らかだ.
hmiがどうやって来たか見てみましょう.
この関数を追跡する必要はありません.hmiはsymから取得したに違いない.hardwareには必ずこの構造体があることを知っていますこれもhardwareを実現するためにしなければならないことです.ここでhardware.hにも説明があります.
hardwareには必ずHALという名前がありますMODULE_INFO_SYMの構造体これもhardwareを実現したものです
ステップ1:Step-1:HALという名前の実装MODULE_INFO_SYMの構造体、この構造体はhw_でなければなりませんmodule_tの冒頭で、cameraのhardwareでどのように定義されているかを見てみましょう.
commonが構造体かどうか見てみましょうhw_module_t hardware/libhardware/include/hardware/camera.h
hardwareに構造体がある以上、初期化しなければなりません.カスタム関数も実現しなければなりません.前の注釈はもう書いた.ここでは関数の実装を貼り付けるだけである.
だから自然にhardwareを実現するために呼び出されたのです
ステップ2,Step-2:open関数の実現と役割.やはりcameraHALの中のそれに対する実現を見ます.
段々包装して、HALを見てみましょう.camera_device_open:
ここで私たちは知っています.Openの役割は、指定ID番号のカメラを開くことと、デバイス構造体を充填することであり、takePicture()やstartPreview()などのHALの具体的な関数を上層部に直接呼び出すことである.
しかし、この構造体をどのように充填すればいいのでしょうか.
hardware/libhardware/include/hardware/hardware.hどう言いますか.
各デバイスはhw_device_tが開始し、methodsとattributesに続く.
では、HALでstaticの構造体を定義し、上の値を押してこのポインタに戻るといいです.HALを見る
どのように充填されているかを見てみましょう.
ここでまずcameraを見てみましょうdevice_opsの具体的な実現はHALの実現にもつながっている.
ステップ3,Step-3:具体的なデバイスの関数実装.
HALで呼び出す関数の具体的な実現はさておき、サービスがどのように呼び出すかを見てみましょう.
start_でpreviewを例に挙げる.
OK,関数呼び出しはここまででhardware内の具体的なデバイス関数を呼び出すアプリケーションの流れが完了する.HALの実現とは、上記の各関数を実現することである.協力させるだけです
作者:joseph_lee
出典:joseh_lee 2633のブログ--http://www.cnblogs.com/joseph-linux
初心者にとって、最大の疑問はシステムがhardwareをどのように呼び出すかである.ここではcameraを例に挙げて説明する.hardwareを呼び出すプログラムはcameraserviceです.hardwareを見つける方法を見てみましょう.
まずソースを貼り付けます.
void CameraServices::onFirstRef()この関数を見てください:
長い間探していたが、この関数にはhwが入っていた.get_module()という関数は、名前を見るとhardwareを取得していることがわかりますが、誰を探しているのでしょうか.ではonFirstRef()関数はいつ呼び出されますか?
onFirstRef()は、spを強く参照して新しい参照カウントを追加するときに呼び出される親RefBaseに属します.どういう意味ですか.spパッケージのクラスが初期化されたときに呼び出されます.ここではframeworks/base/services/camera/libcameraservice/CameraServices.h中class CameraService:に定義あり
明らかにここで初期化したのですが、もちろんここはポイントではありません.全部書けば、ほとんど書けません.
hw_が見つかりましたget_module()という関数は、その具体的な実装を見てみましょう.
hardware/libhardware/hardware.c
コードは次のとおりです.
その流れを見てみましょう.
実際にhardwareを探しに来た橋はこのIDでif(strcmp(id,hmi->id)!=0)ではidはframeworks/base/services/camera/libcameraservice/CameraServicesである.cppに直接付与された
次のようになります.
hmi->idのこのidはhardwareで定義すべきであることは明らかだ.
hmiがどうやって来たか見てみましょう.
この関数を追跡する必要はありません.hmiはsymから取得したに違いない.hardwareには必ずこの構造体があることを知っていますこれもhardwareを実現するためにしなければならないことです.ここでhardware.hにも説明があります.
hardwareには必ずHALという名前がありますMODULE_INFO_SYMの構造体これもhardwareを実現したものです
ステップ1:Step-1:HALという名前の実装MODULE_INFO_SYMの構造体、この構造体はhw_でなければなりませんmodule_tの冒頭で、cameraのhardwareでどのように定義されているかを見てみましょう.
commonが構造体かどうか見てみましょうhw_module_t hardware/libhardware/include/hardware/camera.h
hardwareに構造体がある以上、初期化しなければなりません.カスタム関数も実現しなければなりません.前の注釈はもう書いた.ここでは関数の実装を貼り付けるだけである.
だから自然にhardwareを実現するために呼び出されたのです
ステップ2,Step-2:open関数の実現と役割.やはりcameraHALの中のそれに対する実現を見ます.
段々包装して、HALを見てみましょう.camera_device_open:
ここで私たちは知っています.Openの役割は、指定ID番号のカメラを開くことと、デバイス構造体を充填することであり、takePicture()やstartPreview()などのHALの具体的な関数を上層部に直接呼び出すことである.
しかし、この構造体をどのように充填すればいいのでしょうか.
hardware/libhardware/include/hardware/hardware.hどう言いますか.
各デバイスはhw_device_tが開始し、methodsとattributesに続く.
では、HALでstaticの構造体を定義し、上の値を押してこのポインタに戻るといいです.HALを見る
どのように充填されているかを見てみましょう.
ここでまずcameraを見てみましょうdevice_opsの具体的な実現はHALの実現にもつながっている.
ステップ3,Step-3:具体的なデバイスの関数実装.
HALで呼び出す関数の具体的な実現はさておき、サービスがどのように呼び出すかを見てみましょう.
start_でpreviewを例に挙げる.
OK,関数呼び出しはここまででhardware内の具体的なデバイス関数を呼び出すアプリケーションの流れが完了する.HALの実現とは、上記の各関数を実現することである.協力させるだけです
作者:joseph_lee
出典:joseh_lee 2633のブログ--http://www.cnblogs.com/joseph-linux
まずソースを貼り付けます.
/*
**
** Copyright (C) 2008, 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_TAG "CameraService"
//#define LOG_NDEBUG 0
#include <stdio.h>
#include <sys/types.h>
#include <pthread.h>
#include <binder/IPCThreadState.h>
#include <binder/IServiceManager.h>
#include <binder/MemoryBase.h>
#include <binder/MemoryHeapBase.h>
#include <cutils/atomic.h>
#include <cutils/properties.h>
#include <gui/SurfaceTextureClient.h>
#include <hardware/hardware.h>
#include <media/AudioSystem.h>
#include <media/mediaplayer.h>
#include <surfaceflinger/ISurface.h>
#include <utils/Errors.h>
#include <utils/Log.h>
#include <utils/String16.h>
#include "CameraService.h"
#include "CameraHardwareInterface.h"
namespace android {
// ----------------------------------------------------------------------------
// Logging support -- this is for debugging only
// Use "adb shell dumpsys media.camera -v 1" to change it.
static volatile int32_t gLogLevel = 0;
#define LOG1(...) LOGD_IF(gLogLevel >= 1, __VA_ARGS__);
#define LOG2(...) LOGD_IF(gLogLevel >= 2, __VA_ARGS__);
static void setLogLevel(int level) {
android_atomic_write(level, &gLogLevel);
}
// ----------------------------------------------------------------------------
static int getCallingPid() {
return IPCThreadState::self()->getCallingPid();
}
static int getCallingUid() {
return IPCThreadState::self()->getCallingUid();
}
// ----------------------------------------------------------------------------
// This is ugly and only safe if we never re-create the CameraService, but
// should be ok for now.
static CameraService *gCameraService;
CameraService::CameraService()
:mSoundRef(0), mModule(0)
{
LOGI("CameraService started (pid=%d)", getpid());
gCameraService = this;
}
void CameraService::onFirstRef()
{
BnCameraService::onFirstRef();
if (hw_get_module(CAMERA_HARDWARE_MODULE_ID,
(const hw_module_t **)&mModule) < 0) {
LOGE("Could not load camera HAL module");
mNumberOfCameras = 0;
}
else {
mNumberOfCameras = mModule->get_number_of_cameras();
if (mNumberOfCameras > MAX_CAMERAS) {
LOGE("Number of cameras(%d) > MAX_CAMERAS(%d).",
mNumberOfCameras, MAX_CAMERAS);
mNumberOfCameras = MAX_CAMERAS;
}
for (int i = 0; i < mNumberOfCameras; i++) {
setCameraFree(i);
}
}
// Read the system property to determine if we have to use the
// AUDIO_STREAM_ENFORCED_AUDIBLE type.
char value[PROPERTY_VALUE_MAX];
property_get("ro.camera.sound.forced", value, "0");
if (strcmp(value, "0") != 0) {
mAudioStreamType = AUDIO_STREAM_ENFORCED_AUDIBLE;
} else {
mAudioStreamType = AUDIO_STREAM_MUSIC;
}
}
CameraService::~CameraService() {
for (int i = 0; i < mNumberOfCameras; i++) {
if (mBusy[i]) {
LOGE("camera %d is still in use in destructor!", i);
}
}
gCameraService = NULL;
}
int32_t CameraService::getNumberOfCameras() {
return mNumberOfCameras;
}
status_t CameraService::getCameraInfo(int cameraId,
struct CameraInfo* cameraInfo) {
if (!mModule) {
return NO_INIT;
}
if (cameraId < 0 || cameraId >= mNumberOfCameras) {
return BAD_VALUE;
}
struct camera_info info;
status_t rc = mModule->get_camera_info(cameraId, &info);
cameraInfo->facing = info.facing;
cameraInfo->orientation = info.orientation;
return rc;
}
sp<ICamera> CameraService::connect(
const sp<ICameraClient>& cameraClient, int cameraId) {
int callingPid = getCallingPid();
sp<CameraHardwareInterface> hardware = NULL;
LOG1("CameraService::connect E (pid %d, id %d)", callingPid, cameraId);
if (!mModule) {
LOGE("Camera HAL module not loaded");
return NULL;
}
sp<Client> client;
if (cameraId < 0 || cameraId >= mNumberOfCameras) {
LOGE("CameraService::connect X (pid %d) rejected (invalid cameraId %d).",
callingPid, cameraId);
return NULL;
}
char value[PROPERTY_VALUE_MAX];
property_get("sys.secpolicy.camera.disabled", value, "0");
if (strcmp(value, "1") == 0) {
// Camera is disabled by DevicePolicyManager.
LOGI("Camera is disabled. connect X (pid %d) rejected", callingPid);
return NULL;
}
Mutex::Autolock lock(mServiceLock);
if (mClient[cameraId] != 0) {
client = mClient[cameraId].promote();
if (client != 0) {
if (cameraClient->asBinder() == client->getCameraClient()->asBinder()) {
LOG1("CameraService::connect X (pid %d) (the same client)",
callingPid);
return client;
} else {
LOGW("CameraService::connect X (pid %d) rejected (existing client).",
callingPid);
return NULL;
}
}
mClient[cameraId].clear();
}
if (mBusy[cameraId]) {
LOGW("CameraService::connect X (pid %d) rejected"
" (camera %d is still busy).", callingPid, cameraId);
return NULL;
}
struct camera_info info;
if (mModule->get_camera_info(cameraId, &info) != OK) {
LOGE("Invalid camera id %d", cameraId);
return NULL;
}
char camera_device_name[10];
snprintf(camera_device_name, sizeof(camera_device_name), "%d", cameraId);
hardware = new CameraHardwareInterface(camera_device_name);
if (hardware->initialize(&mModule->common) != OK) {
hardware.clear();
return NULL;
}
client = new Client(this, cameraClient, hardware, cameraId, info.facing, callingPid);
mClient[cameraId] = client;
LOG1("CameraService::connect X");
return client;
}
void CameraService::removeClient(const sp<ICameraClient>& cameraClient) {
int callingPid = getCallingPid();
LOG1("CameraService::removeClient E (pid %d)", callingPid);
for (int i = 0; i < mNumberOfCameras; i++) {
// Declare this before the lock to make absolutely sure the
// destructor won't be called with the lock held.
sp<Client> client;
Mutex::Autolock lock(mServiceLock);
// This happens when we have already disconnected (or this is
// just another unused camera).
if (mClient[i] == 0) continue;
// Promote mClient. It can fail if we are called from this path:
// Client::~Client() -> disconnect() -> removeClient().
client = mClient[i].promote();
if (client == 0) {
mClient[i].clear();
continue;
}
if (cameraClient->asBinder() == client->getCameraClient()->asBinder()) {
// Found our camera, clear and leave.
LOG1("removeClient: clear camera %d", i);
mClient[i].clear();
break;
}
}
LOG1("CameraService::removeClient X (pid %d)", callingPid);
}
sp<CameraService::Client> CameraService::getClientById(int cameraId) {
if (cameraId < 0 || cameraId >= mNumberOfCameras) return NULL;
return mClient[cameraId].promote();
}
status_t CameraService::onTransact(
uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags) {
// Permission checks
switch (code) {
case BnCameraService::CONNECT:
const int pid = getCallingPid();
const int self_pid = getpid();
if (pid != self_pid) {
// we're called from a different process, do the real check
if (!checkCallingPermission(
String16("android.permission.CAMERA"))) {
const int uid = getCallingUid();
LOGE("Permission Denial: "
"can't use the camera pid=%d, uid=%d", pid, uid);
return PERMISSION_DENIED;
}
}
break;
}
return BnCameraService::onTransact(code, data, reply, flags);
}
// The reason we need this busy bit is a new CameraService::connect() request
// may come in while the previous Client's destructor has not been run or is
// still running. If the last strong reference of the previous Client is gone
// but the destructor has not been finished, we should not allow the new Client
// to be created because we need to wait for the previous Client to tear down
// the hardware first.
void CameraService::setCameraBusy(int cameraId) {
android_atomic_write(1, &mBusy[cameraId]);
}
void CameraService::setCameraFree(int cameraId) {
android_atomic_write(0, &mBusy[cameraId]);
}
// We share the media players for shutter and recording sound for all clients.
// A reference count is kept to determine when we will actually release the
// media players.
MediaPlayer* CameraService::newMediaPlayer(const char *file) {
MediaPlayer* mp = new MediaPlayer();
if (mp->setDataSource(file, NULL) == NO_ERROR) {
mp->setAudioStreamType(mAudioStreamType);
mp->prepare();
} else {
LOGE("Failed to load CameraService sounds: %s", file);
return NULL;
}
return mp;
}
void CameraService::loadSound() {
Mutex::Autolock lock(mSoundLock);
LOG1("CameraService::loadSound ref=%d", mSoundRef);
if (mSoundRef++) return;
mSoundPlayer[SOUND_SHUTTER] = newMediaPlayer("/system/media/audio/ui/camera_click.ogg");
mSoundPlayer[SOUND_RECORDING] = newMediaPlayer("/system/media/audio/ui/VideoRecord.ogg");
}
void CameraService::releaseSound() {
Mutex::Autolock lock(mSoundLock);
LOG1("CameraService::releaseSound ref=%d", mSoundRef);
if (--mSoundRef) return;
for (int i = 0; i < NUM_SOUNDS; i++) {
if (mSoundPlayer[i] != 0) {
mSoundPlayer[i]->disconnect();
mSoundPlayer[i].clear();
}
}
}
void CameraService::playSound(sound_kind kind) {
LOG1("playSound(%d)", kind);
Mutex::Autolock lock(mSoundLock);
sp<MediaPlayer> player = mSoundPlayer[kind];
if (player != 0) {
player->seekTo(0);
player->start();
}
}
// ----------------------------------------------------------------------------
CameraService::Client::Client(const sp<CameraService>& cameraService,
const sp<ICameraClient>& cameraClient,
const sp<CameraHardwareInterface>& hardware,
int cameraId, int cameraFacing, int clientPid) {
int callingPid = getCallingPid();
LOG1("Client::Client E (pid %d)", callingPid);
mCameraService = cameraService;
mCameraClient = cameraClient;
mHardware = hardware;
mCameraId = cameraId;
mCameraFacing = cameraFacing;
mClientPid = clientPid;
mMsgEnabled = 0;
mSurface = 0;
mPreviewWindow = 0;
mHardware->setCallbacks(notifyCallback,
dataCallback,
dataCallbackTimestamp,
(void *)cameraId);
// Enable zoom, error, focus, and metadata messages by default
enableMsgType(CAMERA_MSG_ERROR | CAMERA_MSG_ZOOM | CAMERA_MSG_FOCUS |
CAMERA_MSG_PREVIEW_METADATA);
// Callback is disabled by default
mPreviewCallbackFlag = CAMERA_FRAME_CALLBACK_FLAG_NOOP;
mOrientation = getOrientation(0, mCameraFacing == CAMERA_FACING_FRONT);
mPlayShutterSound = true;
cameraService->setCameraBusy(cameraId);
cameraService->loadSound();
LOG1("Client::Client X (pid %d)", callingPid);
}
// tear down the client
CameraService::Client::~Client() {
int callingPid = getCallingPid();
LOG1("Client::~Client E (pid %d, this %p)", callingPid, this);
// set mClientPid to let disconnet() tear down the hardware
mClientPid = callingPid;
disconnect();
mCameraService->releaseSound();
LOG1("Client::~Client X (pid %d, this %p)", callingPid, this);
}
// ----------------------------------------------------------------------------
status_t CameraService::Client::checkPid() const {
int callingPid = getCallingPid();
if (callingPid == mClientPid) return NO_ERROR;
LOGW("attempt to use a locked camera from a different process"
" (old pid %d, new pid %d)", mClientPid, callingPid);
return EBUSY;
}
status_t CameraService::Client::checkPidAndHardware() const {
status_t result = checkPid();
if (result != NO_ERROR) return result;
if (mHardware == 0) {
LOGE("attempt to use a camera after disconnect() (pid %d)", getCallingPid());
return INVALID_OPERATION;
}
return NO_ERROR;
}
status_t CameraService::Client::lock() {
int callingPid = getCallingPid();
LOG1("lock (pid %d)", callingPid);
Mutex::Autolock lock(mLock);
// lock camera to this client if the the camera is unlocked
if (mClientPid == 0) {
mClientPid = callingPid;
return NO_ERROR;
}
// returns NO_ERROR if the client already owns the camera, EBUSY otherwise
return checkPid();
}
status_t CameraService::Client::unlock() {
int callingPid = getCallingPid();
LOG1("unlock (pid %d)", callingPid);
Mutex::Autolock lock(mLock);
// allow anyone to use camera (after they lock the camera)
status_t result = checkPid();
if (result == NO_ERROR) {
if (mHardware->recordingEnabled()) {
LOGE("Not allowed to unlock camera during recording.");
return INVALID_OPERATION;
}
mClientPid = 0;
LOG1("clear mCameraClient (pid %d)", callingPid);
// we need to remove the reference to ICameraClient so that when the app
// goes away, the reference count goes to 0.
mCameraClient.clear();
}
return result;
}
// connect a new client to the camera
status_t CameraService::Client::connect(const sp<ICameraClient>& client) {
int callingPid = getCallingPid();
LOG1("connect E (pid %d)", callingPid);
Mutex::Autolock lock(mLock);
if (mClientPid != 0 && checkPid() != NO_ERROR) {
LOGW("Tried to connect to a locked camera (old pid %d, new pid %d)",
mClientPid, callingPid);
return EBUSY;
}
if (mCameraClient != 0 && (client->asBinder() == mCameraClient->asBinder())) {
LOG1("Connect to the same client");
return NO_ERROR;
}
mPreviewCallbackFlag = CAMERA_FRAME_CALLBACK_FLAG_NOOP;
mClientPid = callingPid;
mCameraClient = client;
LOG1("connect X (pid %d)", callingPid);
return NO_ERROR;
}
static void disconnectWindow(const sp<ANativeWindow>& window) {
if (window != 0) {
status_t result = native_window_api_disconnect(window.get(),
NATIVE_WINDOW_API_CAMERA);
if (result != NO_ERROR) {
LOGW("native_window_api_disconnect failed: %s (%d)", strerror(-result),
result);
}
}
}
void CameraService::Client::disconnect() {
int callingPid = getCallingPid();
LOG1("disconnect E (pid %d)", callingPid);
Mutex::Autolock lock(mLock);
if (checkPid() != NO_ERROR) {
LOGW("different client - don't disconnect");
return;
}
if (mClientPid <= 0) {
LOG1("camera is unlocked (mClientPid = %d), don't tear down hardware", mClientPid);
return;
}
// Make sure disconnect() is done once and once only, whether it is called
// from the user directly, or called by the destructor.
if (mHardware == 0) return;
LOG1("hardware teardown");
// Before destroying mHardware, we must make sure it's in the
// idle state.
// Turn off all messages.
disableMsgType(CAMERA_MSG_ALL_MSGS);
mHardware->stopPreview();
mHardware->cancelPicture();
// Release the hardware resources.
mHardware->release();
// Release the held ANativeWindow resources.
if (mPreviewWindow != 0) {
disconnectWindow(mPreviewWindow);
mPreviewWindow = 0;
mHardware->setPreviewWindow(mPreviewWindow);
}
mHardware.clear();
mCameraService->removeClient(mCameraClient);
mCameraService->setCameraFree(mCameraId);
LOG1("disconnect X (pid %d)", callingPid);
}
// ----------------------------------------------------------------------------
status_t CameraService::Client::setPreviewWindow(const sp<IBinder>& binder,
const sp<ANativeWindow>& window) {
Mutex::Autolock lock(mLock);
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
// return if no change in surface.
if (binder == mSurface) {
return NO_ERROR;
}
if (window != 0) {
result = native_window_api_connect(window.get(), NATIVE_WINDOW_API_CAMERA);
if (result != NO_ERROR) {
LOGE("native_window_api_connect failed: %s (%d)", strerror(-result),
result);
return result;
}
}
// If preview has been already started, register preview buffers now.
if (mHardware->previewEnabled()) {
if (window != 0) {
native_window_set_scaling_mode(window.get(),
NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW);
native_window_set_buffers_transform(window.get(), mOrientation);
result = mHardware->setPreviewWindow(window);
}
}
if (result == NO_ERROR) {
// Everything has succeeded. Disconnect the old window and remember the
// new window.
disconnectWindow(mPreviewWindow);
mSurface = binder;
mPreviewWindow = window;
} else {
// Something went wrong after we connected to the new window, so
// disconnect here.
disconnectWindow(window);
}
return result;
}
// set the Surface that the preview will use
status_t CameraService::Client::setPreviewDisplay(const sp<Surface>& surface) {
LOG1("setPreviewDisplay(%p) (pid %d)", surface.get(), getCallingPid());
sp<IBinder> binder(surface != 0 ? surface->asBinder() : 0);
sp<ANativeWindow> window(surface);
return setPreviewWindow(binder, window);
}
// set the SurfaceTexture that the preview will use
status_t CameraService::Client::setPreviewTexture(
const sp<ISurfaceTexture>& surfaceTexture) {
LOG1("setPreviewTexture(%p) (pid %d)", surfaceTexture.get(),
getCallingPid());
sp<IBinder> binder;
sp<ANativeWindow> window;
if (surfaceTexture != 0) {
binder = surfaceTexture->asBinder();
window = new SurfaceTextureClient(surfaceTexture);
}
return setPreviewWindow(binder, window);
}
// set the preview callback flag to affect how the received frames from
// preview are handled.
void CameraService::Client::setPreviewCallbackFlag(int callback_flag) {
LOG1("setPreviewCallbackFlag(%d) (pid %d)", callback_flag, getCallingPid());
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) return;
mPreviewCallbackFlag = callback_flag;
if (mPreviewCallbackFlag & CAMERA_FRAME_CALLBACK_FLAG_ENABLE_MASK) {
enableMsgType(CAMERA_MSG_PREVIEW_FRAME);
} else {
disableMsgType(CAMERA_MSG_PREVIEW_FRAME);
}
}
// start preview mode
status_t CameraService::Client::startPreview() {
LOG1("startPreview (pid %d)", getCallingPid());
return startCameraMode(CAMERA_PREVIEW_MODE);
}
// start recording mode
status_t CameraService::Client::startRecording() {
LOG1("startRecording (pid %d)", getCallingPid());
return startCameraMode(CAMERA_RECORDING_MODE);
}
// start preview or recording
status_t CameraService::Client::startCameraMode(camera_mode mode) {
LOG1("startCameraMode(%d)", mode);
Mutex::Autolock lock(mLock);
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
switch(mode) {
case CAMERA_PREVIEW_MODE:
if (mSurface == 0 && mPreviewWindow == 0) {
LOG1("mSurface is not set yet.");
// still able to start preview in this case.
}
return startPreviewMode();
case CAMERA_RECORDING_MODE:
if (mSurface == 0 && mPreviewWindow == 0) {
LOGE("mSurface or mPreviewWindow must be set before startRecordingMode.");
return INVALID_OPERATION;
}
return startRecordingMode();
default:
return UNKNOWN_ERROR;
}
}
status_t CameraService::Client::startPreviewMode() {
LOG1("startPreviewMode");
status_t result = NO_ERROR;
// if preview has been enabled, nothing needs to be done
if (mHardware->previewEnabled()) {
return NO_ERROR;
}
if (mPreviewWindow != 0) {
native_window_set_scaling_mode(mPreviewWindow.get(),
NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW);
native_window_set_buffers_transform(mPreviewWindow.get(),
mOrientation);
}
mHardware->setPreviewWindow(mPreviewWindow);
result = mHardware->startPreview();
return result;
}
status_t CameraService::Client::startRecordingMode() {
LOG1("startRecordingMode");
status_t result = NO_ERROR;
// if recording has been enabled, nothing needs to be done
if (mHardware->recordingEnabled()) {
return NO_ERROR;
}
// if preview has not been started, start preview first
if (!mHardware->previewEnabled()) {
result = startPreviewMode();
if (result != NO_ERROR) {
return result;
}
}
// start recording mode
enableMsgType(CAMERA_MSG_VIDEO_FRAME);
mCameraService->playSound(SOUND_RECORDING);
result = mHardware->startRecording();
if (result != NO_ERROR) {
LOGE("mHardware->startRecording() failed with status %d", result);
}
return result;
}
// stop preview mode
void CameraService::Client::stopPreview() {
LOG1("stopPreview (pid %d)", getCallingPid());
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) return;
disableMsgType(CAMERA_MSG_PREVIEW_FRAME);
mHardware->stopPreview();
mPreviewBuffer.clear();
}
// stop recording mode
void CameraService::Client::stopRecording() {
LOG1("stopRecording (pid %d)", getCallingPid());
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) return;
mCameraService->playSound(SOUND_RECORDING);
disableMsgType(CAMERA_MSG_VIDEO_FRAME);
mHardware->stopRecording();
mPreviewBuffer.clear();
}
// release a recording frame
void CameraService::Client::releaseRecordingFrame(const sp<IMemory>& mem) {
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) return;
mHardware->releaseRecordingFrame(mem);
}
status_t CameraService::Client::storeMetaDataInBuffers(bool enabled)
{
LOG1("storeMetaDataInBuffers: %s", enabled? "true": "false");
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) {
return UNKNOWN_ERROR;
}
return mHardware->storeMetaDataInBuffers(enabled);
}
bool CameraService::Client::previewEnabled() {
LOG1("previewEnabled (pid %d)", getCallingPid());
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) return false;
return mHardware->previewEnabled();
}
bool CameraService::Client::recordingEnabled() {
LOG1("recordingEnabled (pid %d)", getCallingPid());
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) return false;
return mHardware->recordingEnabled();
}
status_t CameraService::Client::autoFocus() {
LOG1("autoFocus (pid %d)", getCallingPid());
Mutex::Autolock lock(mLock);
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
return mHardware->autoFocus();
}
status_t CameraService::Client::cancelAutoFocus() {
LOG1("cancelAutoFocus (pid %d)", getCallingPid());
Mutex::Autolock lock(mLock);
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
return mHardware->cancelAutoFocus();
}
// take a picture - image is returned in callback
status_t CameraService::Client::takePicture(int msgType) {
LOG1("takePicture (pid %d): 0x%x", getCallingPid(), msgType);
Mutex::Autolock lock(mLock);
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
if ((msgType & CAMERA_MSG_RAW_IMAGE) &&
(msgType & CAMERA_MSG_RAW_IMAGE_NOTIFY)) {
LOGE("CAMERA_MSG_RAW_IMAGE and CAMERA_MSG_RAW_IMAGE_NOTIFY"
" cannot be both enabled");
return BAD_VALUE;
}
// We only accept picture related message types
// and ignore other types of messages for takePicture().
int picMsgType = msgType
& (CAMERA_MSG_SHUTTER |
CAMERA_MSG_POSTVIEW_FRAME |
CAMERA_MSG_RAW_IMAGE |
CAMERA_MSG_RAW_IMAGE_NOTIFY |
CAMERA_MSG_COMPRESSED_IMAGE);
enableMsgType(picMsgType);
return mHardware->takePicture();
}
// set preview/capture parameters - key/value pairs
status_t CameraService::Client::setParameters(const String8& params) {
LOG1("setParameters (pid %d) (%s)", getCallingPid(), params.string());
Mutex::Autolock lock(mLock);
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
CameraParameters p(params);
return mHardware->setParameters(p);
}
// get preview/capture parameters - key/value pairs
String8 CameraService::Client::getParameters() const {
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) return String8();
String8 params(mHardware->getParameters().flatten());
LOG1("getParameters (pid %d) (%s)", getCallingPid(), params.string());
return params;
}
// enable shutter sound
status_t CameraService::Client::enableShutterSound(bool enable) {
LOG1("enableShutterSound (pid %d)", getCallingPid());
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
if (enable) {
mPlayShutterSound = true;
return OK;
}
// Disabling shutter sound may not be allowed. In that case only
// allow the mediaserver process to disable the sound.
char value[PROPERTY_VALUE_MAX];
property_get("ro.camera.sound.forced", value, "0");
if (strcmp(value, "0") != 0) {
// Disabling shutter sound is not allowed. Deny if the current
// process is not mediaserver.
if (getCallingPid() != getpid()) {
LOGE("Failed to disable shutter sound. Permission denied (pid %d)", getCallingPid());
return PERMISSION_DENIED;
}
}
mPlayShutterSound = false;
return OK;
}
status_t CameraService::Client::sendCommand(int32_t cmd, int32_t arg1, int32_t arg2) {
LOG1("sendCommand (pid %d)", getCallingPid());
int orientation;
Mutex::Autolock lock(mLock);
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
if (cmd == CAMERA_CMD_SET_DISPLAY_ORIENTATION) {
// Mirror the preview if the camera is front-facing.
orientation = getOrientation(arg1, mCameraFacing == CAMERA_FACING_FRONT);
if (orientation == -1) return BAD_VALUE;
if (mOrientation != orientation) {
mOrientation = orientation;
if (mPreviewWindow != 0) {
native_window_set_buffers_transform(mPreviewWindow.get(),
mOrientation);
}
}
return OK;
} else if (cmd == CAMERA_CMD_ENABLE_SHUTTER_SOUND) {
switch (arg1) {
case 0:
enableShutterSound(false);
break;
case 1:
enableShutterSound(true);
break;
default:
return BAD_VALUE;
}
return OK;
} else if (cmd == CAMERA_CMD_PLAY_RECORDING_SOUND) {
mCameraService->playSound(SOUND_RECORDING);
}
return mHardware->sendCommand(cmd, arg1, arg2);
}
// ----------------------------------------------------------------------------
void CameraService::Client::enableMsgType(int32_t msgType) {
android_atomic_or(msgType, &mMsgEnabled);
mHardware->enableMsgType(msgType);
}
void CameraService::Client::disableMsgType(int32_t msgType) {
android_atomic_and(~msgType, &mMsgEnabled);
mHardware->disableMsgType(msgType);
}
#define CHECK_MESSAGE_INTERVAL 10 // 10ms
bool CameraService::Client::lockIfMessageWanted(int32_t msgType) {
int sleepCount = 0;
while (mMsgEnabled & msgType) {
if (mLock.tryLock() == NO_ERROR) {
if (sleepCount > 0) {
LOG1("lockIfMessageWanted(%d): waited for %d ms",
msgType, sleepCount * CHECK_MESSAGE_INTERVAL);
}
return true;
}
if (sleepCount++ == 0) {
LOG1("lockIfMessageWanted(%d): enter sleep", msgType);
}
usleep(CHECK_MESSAGE_INTERVAL * 1000);
}
LOGW("lockIfMessageWanted(%d): dropped unwanted message", msgType);
return false;
}
// ----------------------------------------------------------------------------
// Converts from a raw pointer to the client to a strong pointer during a
// hardware callback. This requires the callbacks only happen when the client
// is still alive.
sp<CameraService::Client> CameraService::Client::getClientFromCookie(void* user) {
sp<Client> client = gCameraService->getClientById((int) user);
// This could happen if the Client is in the process of shutting down (the
// last strong reference is gone, but the destructor hasn't finished
// stopping the hardware).
if (client == 0) return NULL;
// The checks below are not necessary and are for debugging only.
if (client->mCameraService.get() != gCameraService) {
LOGE("mismatch service!");
return NULL;
}
if (client->mHardware == 0) {
LOGE("mHardware == 0: callback after disconnect()?");
return NULL;
}
return client;
}
// Callback messages can be dispatched to internal handlers or pass to our
// client's callback functions, depending on the message type.
//
// notifyCallback:
// CAMERA_MSG_SHUTTER handleShutter
// (others) c->notifyCallback
// dataCallback:
// CAMERA_MSG_PREVIEW_FRAME handlePreviewData
// CAMERA_MSG_POSTVIEW_FRAME handlePostview
// CAMERA_MSG_RAW_IMAGE handleRawPicture
// CAMERA_MSG_COMPRESSED_IMAGE handleCompressedPicture
// (others) c->dataCallback
// dataCallbackTimestamp
// (others) c->dataCallbackTimestamp
//
// NOTE: the *Callback functions grab mLock of the client before passing
// control to handle* functions. So the handle* functions must release the
// lock before calling the ICameraClient's callbacks, so those callbacks can
// invoke methods in the Client class again (For example, the preview frame
// callback may want to releaseRecordingFrame). The handle* functions must
// release the lock after all accesses to member variables, so it must be
// handled very carefully.
void CameraService::Client::notifyCallback(int32_t msgType, int32_t ext1,
int32_t ext2, void* user) {
LOG2("notifyCallback(%d)", msgType);
sp<Client> client = getClientFromCookie(user);
if (client == 0) return;
if (!client->lockIfMessageWanted(msgType)) return;
switch (msgType) {
case CAMERA_MSG_SHUTTER:
// ext1 is the dimension of the yuv picture.
client->handleShutter();
break;
default:
client->handleGenericNotify(msgType, ext1, ext2);
break;
}
}
void CameraService::Client::dataCallback(int32_t msgType,
const sp<IMemory>& dataPtr, camera_frame_metadata_t *metadata, void* user) {
LOG2("dataCallback(%d)", msgType);
sp<Client> client = getClientFromCookie(user);
if (client == 0) return;
if (!client->lockIfMessageWanted(msgType)) return;
if (dataPtr == 0 && metadata == NULL) {
LOGE("Null data returned in data callback");
client->handleGenericNotify(CAMERA_MSG_ERROR, UNKNOWN_ERROR, 0);
return;
}
switch (msgType & ~CAMERA_MSG_PREVIEW_METADATA) {
case CAMERA_MSG_PREVIEW_FRAME:
client->handlePreviewData(msgType, dataPtr, metadata);
break;
case CAMERA_MSG_POSTVIEW_FRAME:
client->handlePostview(dataPtr);
break;
case CAMERA_MSG_RAW_IMAGE:
client->handleRawPicture(dataPtr);
break;
case CAMERA_MSG_COMPRESSED_IMAGE:
client->handleCompressedPicture(dataPtr);
break;
default:
client->handleGenericData(msgType, dataPtr, metadata);
break;
}
}
void CameraService::Client::dataCallbackTimestamp(nsecs_t timestamp,
int32_t msgType, const sp<IMemory>& dataPtr, void* user) {
LOG2("dataCallbackTimestamp(%d)", msgType);
sp<Client> client = getClientFromCookie(user);
if (client == 0) return;
if (!client->lockIfMessageWanted(msgType)) return;
if (dataPtr == 0) {
LOGE("Null data returned in data with timestamp callback");
client->handleGenericNotify(CAMERA_MSG_ERROR, UNKNOWN_ERROR, 0);
return;
}
client->handleGenericDataTimestamp(timestamp, msgType, dataPtr);
}
// snapshot taken callback
void CameraService::Client::handleShutter(void) {
if (mPlayShutterSound) {
mCameraService->playSound(SOUND_SHUTTER);
}
sp<ICameraClient> c = mCameraClient;
if (c != 0) {
mLock.unlock();
c->notifyCallback(CAMERA_MSG_SHUTTER, 0, 0);
if (!lockIfMessageWanted(CAMERA_MSG_SHUTTER)) return;
}
disableMsgType(CAMERA_MSG_SHUTTER);
mLock.unlock();
}
// preview callback - frame buffer update
void CameraService::Client::handlePreviewData(int32_t msgType,
const sp<IMemory>& mem,
camera_frame_metadata_t *metadata) {
ssize_t offset;
size_t size;
sp<IMemoryHeap> heap = mem->getMemory(&offset, &size);
// local copy of the callback flags
int flags = mPreviewCallbackFlag;
// is callback enabled?
if (!(flags & CAMERA_FRAME_CALLBACK_FLAG_ENABLE_MASK)) {
// If the enable bit is off, the copy-out and one-shot bits are ignored
LOG2("frame callback is disabled");
mLock.unlock();
return;
}
// hold a strong pointer to the client
sp<ICameraClient> c = mCameraClient;
// clear callback flags if no client or one-shot mode
if (c == 0 || (mPreviewCallbackFlag & CAMERA_FRAME_CALLBACK_FLAG_ONE_SHOT_MASK)) {
LOG2("Disable preview callback");
mPreviewCallbackFlag &= ~(CAMERA_FRAME_CALLBACK_FLAG_ONE_SHOT_MASK |
CAMERA_FRAME_CALLBACK_FLAG_COPY_OUT_MASK |
CAMERA_FRAME_CALLBACK_FLAG_ENABLE_MASK);
disableMsgType(CAMERA_MSG_PREVIEW_FRAME);
}
if (c != 0) {
// Is the received frame copied out or not?
if (flags & CAMERA_FRAME_CALLBACK_FLAG_COPY_OUT_MASK) {
LOG2("frame is copied");
copyFrameAndPostCopiedFrame(msgType, c, heap, offset, size, metadata);
} else {
LOG2("frame is forwarded");
mLock.unlock();
c->dataCallback(msgType, mem, metadata);
}
} else {
mLock.unlock();
}
}
// picture callback - postview image ready
void CameraService::Client::handlePostview(const sp<IMemory>& mem) {
disableMsgType(CAMERA_MSG_POSTVIEW_FRAME);
sp<ICameraClient> c = mCameraClient;
mLock.unlock();
if (c != 0) {
c->dataCallback(CAMERA_MSG_POSTVIEW_FRAME, mem, NULL);
}
}
// picture callback - raw image ready
void CameraService::Client::handleRawPicture(const sp<IMemory>& mem) {
disableMsgType(CAMERA_MSG_RAW_IMAGE);
ssize_t offset;
size_t size;
sp<IMemoryHeap> heap = mem->getMemory(&offset, &size);
sp<ICameraClient> c = mCameraClient;
mLock.unlock();
if (c != 0) {
c->dataCallback(CAMERA_MSG_RAW_IMAGE, mem, NULL);
}
}
// picture callback - compressed picture ready
void CameraService::Client::handleCompressedPicture(const sp<IMemory>& mem) {
disableMsgType(CAMERA_MSG_COMPRESSED_IMAGE);
sp<ICameraClient> c = mCameraClient;
mLock.unlock();
if (c != 0) {
c->dataCallback(CAMERA_MSG_COMPRESSED_IMAGE, mem, NULL);
}
}
void CameraService::Client::handleGenericNotify(int32_t msgType,
int32_t ext1, int32_t ext2) {
sp<ICameraClient> c = mCameraClient;
mLock.unlock();
if (c != 0) {
c->notifyCallback(msgType, ext1, ext2);
}
}
void CameraService::Client::handleGenericData(int32_t msgType,
const sp<IMemory>& dataPtr, camera_frame_metadata_t *metadata) {
sp<ICameraClient> c = mCameraClient;
mLock.unlock();
if (c != 0) {
c->dataCallback(msgType, dataPtr, metadata);
}
}
void CameraService::Client::handleGenericDataTimestamp(nsecs_t timestamp,
int32_t msgType, const sp<IMemory>& dataPtr) {
sp<ICameraClient> c = mCameraClient;
mLock.unlock();
if (c != 0) {
c->dataCallbackTimestamp(timestamp, msgType, dataPtr);
}
}
void CameraService::Client::copyFrameAndPostCopiedFrame(
int32_t msgType, const sp<ICameraClient>& client,
const sp<IMemoryHeap>& heap, size_t offset, size_t size,
camera_frame_metadata_t *metadata) {
LOG2("copyFrameAndPostCopiedFrame");
// It is necessary to copy out of pmem before sending this to
// the callback. For efficiency, reuse the same MemoryHeapBase
// provided it's big enough. Don't allocate the memory or
// perform the copy if there's no callback.
// hold the preview lock while we grab a reference to the preview buffer
sp<MemoryHeapBase> previewBuffer;
if (mPreviewBuffer == 0) {
mPreviewBuffer = new MemoryHeapBase(size, 0, NULL);
} else if (size > mPreviewBuffer->virtualSize()) {
mPreviewBuffer.clear();
mPreviewBuffer = new MemoryHeapBase(size, 0, NULL);
}
if (mPreviewBuffer == 0) {
LOGE("failed to allocate space for preview buffer");
mLock.unlock();
return;
}
previewBuffer = mPreviewBuffer;
memcpy(previewBuffer->base(), (uint8_t *)heap->base() + offset, size);
sp<MemoryBase> frame = new MemoryBase(previewBuffer, 0, size);
if (frame == 0) {
LOGE("failed to allocate space for frame callback");
mLock.unlock();
return;
}
mLock.unlock();
client->dataCallback(msgType, frame, metadata);
}
int CameraService::Client::getOrientation(int degrees, bool mirror) {
if (!mirror) {
if (degrees == 0) return 0;
else if (degrees == 90) return HAL_TRANSFORM_ROT_90;
else if (degrees == 180) return HAL_TRANSFORM_ROT_180;
else if (degrees == 270) return HAL_TRANSFORM_ROT_270;
} else { // Do mirror (horizontal flip)
if (degrees == 0) { // FLIP_H and ROT_0
return HAL_TRANSFORM_FLIP_H;
} else if (degrees == 90) { // FLIP_H and ROT_90
return HAL_TRANSFORM_FLIP_H | HAL_TRANSFORM_ROT_90;
} else if (degrees == 180) { // FLIP_H and ROT_180
return HAL_TRANSFORM_FLIP_V;
} else if (degrees == 270) { // FLIP_H and ROT_270
return HAL_TRANSFORM_FLIP_V | HAL_TRANSFORM_ROT_90;
}
}
LOGE("Invalid setDisplayOrientation degrees=%d", degrees);
return -1;
}
// ----------------------------------------------------------------------------
static const int kDumpLockRetries = 50;
static const int kDumpLockSleep = 60000;
static bool tryLock(Mutex& mutex)
{
bool locked = false;
for (int i = 0; i < kDumpLockRetries; ++i) {
if (mutex.tryLock() == NO_ERROR) {
locked = true;
break;
}
usleep(kDumpLockSleep);
}
return locked;
}
status_t CameraService::dump(int fd, const Vector<String16>& args) {
static const char* kDeadlockedString = "CameraService may be deadlocked
";
const size_t SIZE = 256;
char buffer[SIZE];
String8 result;
if (checkCallingPermission(String16("android.permission.DUMP")) == false) {
snprintf(buffer, SIZE, "Permission Denial: "
"can't dump CameraService from pid=%d, uid=%d
",
getCallingPid(),
getCallingUid());
result.append(buffer);
write(fd, result.string(), result.size());
} else {
bool locked = tryLock(mServiceLock);
// failed to lock - CameraService is probably deadlocked
if (!locked) {
String8 result(kDeadlockedString);
write(fd, result.string(), result.size());
}
bool hasClient = false;
for (int i = 0; i < mNumberOfCameras; i++) {
sp<Client> client = mClient[i].promote();
if (client == 0) continue;
hasClient = true;
sprintf(buffer, "Client[%d] (%p) PID: %d
",
i,
client->getCameraClient()->asBinder().get(),
client->mClientPid);
result.append(buffer);
write(fd, result.string(), result.size());
client->mHardware->dump(fd, args);
}
if (!hasClient) {
result.append("No camera client yet.
");
write(fd, result.string(), result.size());
}
if (locked) mServiceLock.unlock();
// change logging level
int n = args.size();
for (int i = 0; i + 1 < n; i++) {
if (args[i] == String16("-v")) {
String8 levelStr(args[i+1]);
int level = atoi(levelStr.string());
sprintf(buffer, "Set Log Level to %d", level);
result.append(buffer);
setLogLevel(level);
}
}
}
return NO_ERROR;
}
}; // namespace androidvoid CameraServices::onFirstRef()この関数を見てください:
void CameraService::onFirstRef()
{
BnCameraService::onFirstRef();
if (hw_get_module(CAMERA_HARDWARE_MODULE_ID,
(const hw_module_t **)&mModule) < 0) {
LOGE("Could not load camera HAL module");
mNumberOfCameras = 0;
}
else {
mNumberOfCameras = mModule->get_number_of_cameras(); // camera . camera .
if (mNumberOfCameras > MAX_CAMERAS) {
LOGE("Number of cameras(%d) > MAX_CAMERAS(%d).",
mNumberOfCameras, MAX_CAMERAS);
mNumberOfCameras = MAX_CAMERAS;
}
for (int i = 0; i < mNumberOfCameras; i++) {
setCameraFree(i);
}
}
// Read the system property to determine if we have to use the
// AUDIO_STREAM_ENFORCED_AUDIBLE type.
char value[PROPERTY_VALUE_MAX];
property_get("ro.camera.sound.forced", value, "0");
if (strcmp(value, "0") != 0) {
mAudioStreamType = AUDIO_STREAM_ENFORCED_AUDIBLE;
} else {
mAudioStreamType = AUDIO_STREAM_MUSIC;
}
}長い間探していたが、この関数にはhwが入っていた.get_module()という関数は、名前を見るとhardwareを取得していることがわかりますが、誰を探しているのでしょうか.ではonFirstRef()関数はいつ呼び出されますか?
onFirstRef()は、spを強く参照して新しい参照カウントを追加するときに呼び出される親RefBaseに属します.どういう意味ですか.spパッケージのクラスが初期化されたときに呼び出されます.ここではframeworks/base/services/camera/libcameraservice/CameraServices.h中class CameraService:に定義あり
// these are initialized in the constructor.
sp<CameraService> mCameraService; // immutable after constructor
sp<ICameraClient> mCameraClient;
int mCameraId; // immutable after constructor
int mCameraFacing; // immutable after constructor
pid_t mClientPid;
sp<CameraHardwareInterface> mHardware; // cleared after disconnect()
int mPreviewCallbackFlag;
int mOrientation; // Current display orientation
bool mPlayShutterSound;明らかにここで初期化したのですが、もちろんここはポイントではありません.全部書けば、ほとんど書けません.
hw_が見つかりましたget_module()という関数は、その具体的な実装を見てみましょう.
hardware/libhardware/hardware.c
コードは次のとおりです.
/*
* Copyright (C) 2008 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 <hardware/hardware.h>
#include <cutils/properties.h>
#include <dlfcn.h>
#include <string.h>
#include <pthread.h>
#include <errno.h>
#include <limits.h>
#define LOG_TAG "HAL"
#include <utils/Log.h>
/** Base path of the hal modules */
#define HAL_LIBRARY_PATH1 "/system/lib/hw"
#define HAL_LIBRARY_PATH2 "/vendor/lib/hw"
/**
* There are a set of variant filename for modules. The form of the filename
* is "<MODULE_ID>.variant.so" so for the led module the Dream variants
* of base "ro.product.board", "ro.board.platform" and "ro.arch" would be:
*
* led.trout.so
* led.msm7k.so
* led.ARMV6.so
* led.default.so
*/
static const char *variant_keys[] = {
"ro.hardware", /* This goes first so that it can pick up a different
file on the emulator. */
"ro.product.board",
"ro.board.platform",
"ro.arch"
};
static const int HAL_VARIANT_KEYS_COUNT =
(sizeof(variant_keys)/sizeof(variant_keys[0]));
/**
* Load the file defined by the variant and if successful
* return the dlopen handle and the hmi.
* @return 0 = success, !0 = failure.
*/
static int load(const char *id,
const char *path,
const struct hw_module_t **pHmi)
{
int status;
void *handle;
struct hw_module_t *hmi;
/*
* load the symbols resolving undefined symbols before
* dlopen returns. Since RTLD_GLOBAL is not or'd in with
* RTLD_NOW the external symbols will not be global
*/
handle = dlopen(path, RTLD_NOW);
if (handle == NULL) {
char const *err_str = dlerror();
LOGE("load: module=%s
%s", path, err_str?err_str:"unknown");
status = -EINVAL;
goto done;
}
/* Get the address of the struct hal_module_info. */
const char *sym = HAL_MODULE_INFO_SYM_AS_STR;
hmi = (struct hw_module_t *)dlsym(handle, sym);
if (hmi == NULL) {
LOGE("load: couldn't find symbol %s", sym);
status = -EINVAL;
goto done;
}
/* Check that the id matches */
if (strcmp(id, hmi->id) != 0) {
LOGE("load: id=%s != hmi->id=%s", id, hmi->id);
status = -EINVAL;
goto done;
}
hmi->dso = handle;
/* success */
status = 0;
done:
if (status != 0) {
hmi = NULL;
if (handle != NULL) {
dlclose(handle);
handle = NULL;
}
} else {
LOGV("loaded HAL id=%s path=%s hmi=%p handle=%p",
id, path, *pHmi, handle);
}
*pHmi = hmi;
return status;
}
int hw_get_module_by_class(const char *class_id, const char *inst,
const struct hw_module_t **module)
{
int status;
int i;
const struct hw_module_t *hmi = NULL;
char prop[PATH_MAX];
char path[PATH_MAX];
char name[PATH_MAX];
if (inst)
snprintf(name, PATH_MAX, "%s.%s", class_id, inst);
else
strlcpy(name, class_id, PATH_MAX);
/*
* Here we rely on the fact that calling dlopen multiple times on
* the same .so will simply increment a refcount (and not load
* a new copy of the library).
* We also assume that dlopen() is thread-safe.
*/
/* Loop through the configuration variants looking for a module */
for (i=0 ; i<HAL_VARIANT_KEYS_COUNT+1 ; i++) {
if (i < HAL_VARIANT_KEYS_COUNT) {
if (property_get(variant_keys[i], prop, NULL) == 0) {
continue;
}
snprintf(path, sizeof(path), "%s/%s.%s.so",
HAL_LIBRARY_PATH2, name, prop);
if (access(path, R_OK) == 0) break;
snprintf(path, sizeof(path), "%s/%s.%s.so",
HAL_LIBRARY_PATH1, name, prop);
if (access(path, R_OK) == 0) break;
} else {
snprintf(path, sizeof(path), "%s/%s.default.so",
HAL_LIBRARY_PATH1, name);
if (access(path, R_OK) == 0) break;
}
}
status = -ENOENT;
if (i < HAL_VARIANT_KEYS_COUNT+1) {
/* load the module, if this fails, we're doomed, and we should not try
* to load a different variant. */
status = load(class_id, path, module);
}
return status;
}
int hw_get_module(const char *id, const struct hw_module_t **module)
{
return hw_get_module_by_class(id, NULL, module);
}その流れを見てみましょう.
int hw_get_module(const char *id, const struct hw_module_t **module)
int hw_get_module_by_class(const char *class_id, const char *inst,const struct hw_module_t **module)
static int load(const char *id,const char *path,const struct hw_module_t **pHmi)
/* Check that the id matches */
if (strcmp(id, hmi->id) != 0) {
LOGE("load: id=%s != hmi->id=%s", id, hmi->id);
status = -EINVAL;
goto done;
}
...実際にhardwareを探しに来た橋はこのIDでif(strcmp(id,hmi->id)!=0)ではidはframeworks/base/services/camera/libcameraservice/CameraServicesである.cppに直接付与された
次のようになります.
if (hw_get_module(CAMERA_HARDWARE_MODULE_ID,
(const hw_module_t **)&mModule) < 0) {
LOGE("Could not load camera HAL module");
mNumberOfCameras = 0;
}hmi->idのこのidはhardwareで定義すべきであることは明らかだ.
hmiがどうやって来たか見てみましょう.
/* Get the address of the struct hal_module_info. */
const char *sym = HAL_MODULE_INFO_SYM_AS_STR;
hmi = (struct hw_module_t *)dlsym(handle, sym);この関数を追跡する必要はありません.hmiはsymから取得したに違いない.hardwareには必ずこの構造体があることを知っていますこれもhardwareを実現するためにしなければならないことです.ここでhardware.hにも説明があります.
/**
* Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
* and the fields of this data structure must begin with hw_module_t
* followed by module specific information.
*/hardwareには必ずHALという名前がありますMODULE_INFO_SYMの構造体これもhardwareを実現したものです
ステップ1:Step-1:HALという名前の実装MODULE_INFO_SYMの構造体、この構造体はhw_でなければなりませんmodule_tの冒頭で、cameraのhardwareでどのように定義されているかを見てみましょう.
commonが構造体かどうか見てみましょうhw_module_t hardware/libhardware/include/hardware/camera.h
hardwareに構造体がある以上、初期化しなければなりません.カスタム関数も実現しなければなりません.前の注釈はもう書いた.ここでは関数の実装を貼り付けるだけである.
だから自然にhardwareを実現するために呼び出されたのです
ステップ2,Step-2:open関数の実現と役割.やはりcameraHALの中のそれに対する実現を見ます.
段々包装して、HALを見てみましょう.camera_device_open:
static int HAL_camera_device_open(const struct hw_module_t* module,
const char *id,
struct hw_device_t** device)
{
int cameraId = atoi(id);
if (cameraId < 0 || cameraId >= HAL_getNumberOfCameras()) {
return -EINVAL;
}
if (g_cam_device) { // , g_cam_device , .
if (obj(g_cam_device)->getCameraId() == cameraId) {
goto done;
} else {
LOGE("Cannot open camera %d. camera %d is already running!",
cameraId, obj(g_cam_device)->getCameraId());
return -ENOSYS;
}
}
g_cam_device = (camera_device_t *)malloc(sizeof(camera_device_t));
if (!g_cam_device)
return -ENOMEM;
g_cam_device->common.tag = HARDWARE_DEVICE_TAG;
g_cam_device->common.version = 1;
g_cam_device->common.module = const_cast<hw_module_t *>(module);
g_cam_device->common.close = HAL_camera_device_close;
g_cam_device->ops = &camera_device_ops;
LOGI("%s: open camera %s", __func__, id);
g_cam_device->priv = new CameraHardwareSec(cameraId, g_cam_device);
done:
*device = (hw_device_t *)g_cam_device;
LOGI("%s: opened camera %s (%p)", __func__, id, *device);
return 0;
}ここで私たちは知っています.Openの役割は、指定ID番号のカメラを開くことと、デバイス構造体を充填することであり、takePicture()やstartPreview()などのHALの具体的な関数を上層部に直接呼び出すことである.
しかし、この構造体をどのように充填すればいいのでしょうか.
hardware/libhardware/include/hardware/hardware.hどう言いますか.
/**
* Every device data structure must begin with hw_device_t
* followed by module specific public methods and attributes.
*/各デバイスはhw_device_tが開始し、methodsとattributesに続く.
では、HALでstaticの構造体を定義し、上の値を押してこのポインタに戻るといいです.HALを見る
static camera_device_t *g_cam_device; // .
typedef struct camera_device {
hw_device_t common; // hw_device_t
camera_device_ops_t *ops; // methods
void *priv; // .
} camera_device_t;どのように充填されているかを見てみましょう.
g_cam_device->common.tag = HARDWARE_DEVICE_TAG; //hardware.h . tag .
g_cam_device->common.module = const_cast<hw_module_t *>(module); // module
g_cam_device->common.close = HAL_camera_device_close; //
g_cam_device->ops = &camera_device_ops; // . HAL .
g_cam_device->priv = new CameraHardwareSec(cameraId, g_cam_device); // hardware , HAL .ここでまずcameraを見てみましょうdevice_opsの具体的な実現はHALの実現にもつながっている.
ステップ3,Step-3:具体的なデバイスの関数実装.
#define SET_METHOD(m) m : HAL_camera_device_##m // m : HAL_camera_device_m
static camera_device_ops_t camera_device_ops = {
SET_METHOD(set_preview_window), // set_preview_window : HAL_camera_device_set_preview_window, HAL_camera_device_set_preview_window set_preview_window
SET_METHOD(set_callbacks), // set_callbacks : HAL_camera_device_set_callbacks
SET_METHOD(enable_msg_type), //
SET_METHOD(disable_msg_type),
SET_METHOD(msg_type_enabled),
SET_METHOD(start_preview),
SET_METHOD(stop_preview),
SET_METHOD(preview_enabled),
SET_METHOD(store_meta_data_in_buffers),
SET_METHOD(start_recording),
SET_METHOD(stop_recording),
SET_METHOD(recording_enabled),
SET_METHOD(release_recording_frame),
SET_METHOD(auto_focus),
SET_METHOD(cancel_auto_focus),
SET_METHOD(take_picture),
SET_METHOD(cancel_picture),
SET_METHOD(set_parameters),
SET_METHOD(get_parameters),
SET_METHOD(put_parameters),
SET_METHOD(send_command),
SET_METHOD(release),
SET_METHOD(dump),
};HALで呼び出す関数の具体的な実現はさておき、サービスがどのように呼び出すかを見てみましょう.
start_でpreviewを例に挙げる.
camera.start_preview() //
public native final void startPreview(); // JNI frameworks/base/core/java/android/hardware/Camera.java
static void android_hardware_Camera_startPreview(JNIEnv *env, jobject thiz) //JNI frameworks/base/core/jni/android_hardware_Camera.cpp
sp<Camera> camera = get_native_camera(env, thiz, NULL); // cameraClient frameworks/base/core/jni/android_hardware_Camera.cpp
camera->startPreview(); // cameraClient frameworks/base/libs/camera/Camera.cpp.
status_t CameraService::Client::startPreview(); //service frameworks/base/services/camera/libcameraservice/CameraService.cpp
status_t CameraService::Client::startCameraMode(camera_mode mode) //service frameworks/base/services/camera/libcameraservice/CameraService.cpp
status_t CameraService::Client::startPreviewMode() //service frameworks/base/services/camera/libcameraservice/CameraService.cpp
status_t startPreview() // hardware frameworks/base/services/camera/libcameraservice/CameraHardwareInterface.h
mDevice->ops->start_preview(mDevice); // HAL start_preview HAL_camera_device_start_preview. device/magiclab/common/libcamera/SecCameraHWInterface_zoom.cppOK,関数呼び出しはここまででhardware内の具体的なデバイス関数を呼び出すアプリケーションの流れが完了する.HALの実現とは、上記の各関数を実現することである.協力させるだけです
作者:joseph_lee
出典:joseh_lee 2633のブログ--http://www.cnblogs.com/joseph-linux
初心者にとって、最大の疑問はシステムがhardwareをどのように呼び出すかである.ここではcameraを例に挙げて説明する.hardwareを呼び出すプログラムはcameraserviceです.hardwareを見つける方法を見てみましょう.
まずソースを貼り付けます.
/*
**
** Copyright (C) 2008, 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_TAG "CameraService"
//#define LOG_NDEBUG 0
#include <stdio.h>
#include <sys/types.h>
#include <pthread.h>
#include <binder/IPCThreadState.h>
#include <binder/IServiceManager.h>
#include <binder/MemoryBase.h>
#include <binder/MemoryHeapBase.h>
#include <cutils/atomic.h>
#include <cutils/properties.h>
#include <gui/SurfaceTextureClient.h>
#include <hardware/hardware.h>
#include <media/AudioSystem.h>
#include <media/mediaplayer.h>
#include <surfaceflinger/ISurface.h>
#include <utils/Errors.h>
#include <utils/Log.h>
#include <utils/String16.h>
#include "CameraService.h"
#include "CameraHardwareInterface.h"
namespace android {
// ----------------------------------------------------------------------------
// Logging support -- this is for debugging only
// Use "adb shell dumpsys media.camera -v 1" to change it.
static volatile int32_t gLogLevel = 0;
#define LOG1(...) LOGD_IF(gLogLevel >= 1, __VA_ARGS__);
#define LOG2(...) LOGD_IF(gLogLevel >= 2, __VA_ARGS__);
static void setLogLevel(int level) {
android_atomic_write(level, &gLogLevel);
}
// ----------------------------------------------------------------------------
static int getCallingPid() {
return IPCThreadState::self()->getCallingPid();
}
static int getCallingUid() {
return IPCThreadState::self()->getCallingUid();
}
// ----------------------------------------------------------------------------
// This is ugly and only safe if we never re-create the CameraService, but
// should be ok for now.
static CameraService *gCameraService;
CameraService::CameraService()
:mSoundRef(0), mModule(0)
{
LOGI("CameraService started (pid=%d)", getpid());
gCameraService = this;
}
void CameraService::onFirstRef()
{
BnCameraService::onFirstRef();
if (hw_get_module(CAMERA_HARDWARE_MODULE_ID,
(const hw_module_t **)&mModule) < 0) {
LOGE("Could not load camera HAL module");
mNumberOfCameras = 0;
}
else {
mNumberOfCameras = mModule->get_number_of_cameras();
if (mNumberOfCameras > MAX_CAMERAS) {
LOGE("Number of cameras(%d) > MAX_CAMERAS(%d).",
mNumberOfCameras, MAX_CAMERAS);
mNumberOfCameras = MAX_CAMERAS;
}
for (int i = 0; i < mNumberOfCameras; i++) {
setCameraFree(i);
}
}
// Read the system property to determine if we have to use the
// AUDIO_STREAM_ENFORCED_AUDIBLE type.
char value[PROPERTY_VALUE_MAX];
property_get("ro.camera.sound.forced", value, "0");
if (strcmp(value, "0") != 0) {
mAudioStreamType = AUDIO_STREAM_ENFORCED_AUDIBLE;
} else {
mAudioStreamType = AUDIO_STREAM_MUSIC;
}
}
CameraService::~CameraService() {
for (int i = 0; i < mNumberOfCameras; i++) {
if (mBusy[i]) {
LOGE("camera %d is still in use in destructor!", i);
}
}
gCameraService = NULL;
}
int32_t CameraService::getNumberOfCameras() {
return mNumberOfCameras;
}
status_t CameraService::getCameraInfo(int cameraId,
struct CameraInfo* cameraInfo) {
if (!mModule) {
return NO_INIT;
}
if (cameraId < 0 || cameraId >= mNumberOfCameras) {
return BAD_VALUE;
}
struct camera_info info;
status_t rc = mModule->get_camera_info(cameraId, &info);
cameraInfo->facing = info.facing;
cameraInfo->orientation = info.orientation;
return rc;
}
sp<ICamera> CameraService::connect(
const sp<ICameraClient>& cameraClient, int cameraId) {
int callingPid = getCallingPid();
sp<CameraHardwareInterface> hardware = NULL;
LOG1("CameraService::connect E (pid %d, id %d)", callingPid, cameraId);
if (!mModule) {
LOGE("Camera HAL module not loaded");
return NULL;
}
sp<Client> client;
if (cameraId < 0 || cameraId >= mNumberOfCameras) {
LOGE("CameraService::connect X (pid %d) rejected (invalid cameraId %d).",
callingPid, cameraId);
return NULL;
}
char value[PROPERTY_VALUE_MAX];
property_get("sys.secpolicy.camera.disabled", value, "0");
if (strcmp(value, "1") == 0) {
// Camera is disabled by DevicePolicyManager.
LOGI("Camera is disabled. connect X (pid %d) rejected", callingPid);
return NULL;
}
Mutex::Autolock lock(mServiceLock);
if (mClient[cameraId] != 0) {
client = mClient[cameraId].promote();
if (client != 0) {
if (cameraClient->asBinder() == client->getCameraClient()->asBinder()) {
LOG1("CameraService::connect X (pid %d) (the same client)",
callingPid);
return client;
} else {
LOGW("CameraService::connect X (pid %d) rejected (existing client).",
callingPid);
return NULL;
}
}
mClient[cameraId].clear();
}
if (mBusy[cameraId]) {
LOGW("CameraService::connect X (pid %d) rejected"
" (camera %d is still busy).", callingPid, cameraId);
return NULL;
}
struct camera_info info;
if (mModule->get_camera_info(cameraId, &info) != OK) {
LOGE("Invalid camera id %d", cameraId);
return NULL;
}
char camera_device_name[10];
snprintf(camera_device_name, sizeof(camera_device_name), "%d", cameraId);
hardware = new CameraHardwareInterface(camera_device_name);
if (hardware->initialize(&mModule->common) != OK) {
hardware.clear();
return NULL;
}
client = new Client(this, cameraClient, hardware, cameraId, info.facing, callingPid);
mClient[cameraId] = client;
LOG1("CameraService::connect X");
return client;
}
void CameraService::removeClient(const sp<ICameraClient>& cameraClient) {
int callingPid = getCallingPid();
LOG1("CameraService::removeClient E (pid %d)", callingPid);
for (int i = 0; i < mNumberOfCameras; i++) {
// Declare this before the lock to make absolutely sure the
// destructor won't be called with the lock held.
sp<Client> client;
Mutex::Autolock lock(mServiceLock);
// This happens when we have already disconnected (or this is
// just another unused camera).
if (mClient[i] == 0) continue;
// Promote mClient. It can fail if we are called from this path:
// Client::~Client() -> disconnect() -> removeClient().
client = mClient[i].promote();
if (client == 0) {
mClient[i].clear();
continue;
}
if (cameraClient->asBinder() == client->getCameraClient()->asBinder()) {
// Found our camera, clear and leave.
LOG1("removeClient: clear camera %d", i);
mClient[i].clear();
break;
}
}
LOG1("CameraService::removeClient X (pid %d)", callingPid);
}
sp<CameraService::Client> CameraService::getClientById(int cameraId) {
if (cameraId < 0 || cameraId >= mNumberOfCameras) return NULL;
return mClient[cameraId].promote();
}
status_t CameraService::onTransact(
uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags) {
// Permission checks
switch (code) {
case BnCameraService::CONNECT:
const int pid = getCallingPid();
const int self_pid = getpid();
if (pid != self_pid) {
// we're called from a different process, do the real check
if (!checkCallingPermission(
String16("android.permission.CAMERA"))) {
const int uid = getCallingUid();
LOGE("Permission Denial: "
"can't use the camera pid=%d, uid=%d", pid, uid);
return PERMISSION_DENIED;
}
}
break;
}
return BnCameraService::onTransact(code, data, reply, flags);
}
// The reason we need this busy bit is a new CameraService::connect() request
// may come in while the previous Client's destructor has not been run or is
// still running. If the last strong reference of the previous Client is gone
// but the destructor has not been finished, we should not allow the new Client
// to be created because we need to wait for the previous Client to tear down
// the hardware first.
void CameraService::setCameraBusy(int cameraId) {
android_atomic_write(1, &mBusy[cameraId]);
}
void CameraService::setCameraFree(int cameraId) {
android_atomic_write(0, &mBusy[cameraId]);
}
// We share the media players for shutter and recording sound for all clients.
// A reference count is kept to determine when we will actually release the
// media players.
MediaPlayer* CameraService::newMediaPlayer(const char *file) {
MediaPlayer* mp = new MediaPlayer();
if (mp->setDataSource(file, NULL) == NO_ERROR) {
mp->setAudioStreamType(mAudioStreamType);
mp->prepare();
} else {
LOGE("Failed to load CameraService sounds: %s", file);
return NULL;
}
return mp;
}
void CameraService::loadSound() {
Mutex::Autolock lock(mSoundLock);
LOG1("CameraService::loadSound ref=%d", mSoundRef);
if (mSoundRef++) return;
mSoundPlayer[SOUND_SHUTTER] = newMediaPlayer("/system/media/audio/ui/camera_click.ogg");
mSoundPlayer[SOUND_RECORDING] = newMediaPlayer("/system/media/audio/ui/VideoRecord.ogg");
}
void CameraService::releaseSound() {
Mutex::Autolock lock(mSoundLock);
LOG1("CameraService::releaseSound ref=%d", mSoundRef);
if (--mSoundRef) return;
for (int i = 0; i < NUM_SOUNDS; i++) {
if (mSoundPlayer[i] != 0) {
mSoundPlayer[i]->disconnect();
mSoundPlayer[i].clear();
}
}
}
void CameraService::playSound(sound_kind kind) {
LOG1("playSound(%d)", kind);
Mutex::Autolock lock(mSoundLock);
sp<MediaPlayer> player = mSoundPlayer[kind];
if (player != 0) {
player->seekTo(0);
player->start();
}
}
// ----------------------------------------------------------------------------
CameraService::Client::Client(const sp<CameraService>& cameraService,
const sp<ICameraClient>& cameraClient,
const sp<CameraHardwareInterface>& hardware,
int cameraId, int cameraFacing, int clientPid) {
int callingPid = getCallingPid();
LOG1("Client::Client E (pid %d)", callingPid);
mCameraService = cameraService;
mCameraClient = cameraClient;
mHardware = hardware;
mCameraId = cameraId;
mCameraFacing = cameraFacing;
mClientPid = clientPid;
mMsgEnabled = 0;
mSurface = 0;
mPreviewWindow = 0;
mHardware->setCallbacks(notifyCallback,
dataCallback,
dataCallbackTimestamp,
(void *)cameraId);
// Enable zoom, error, focus, and metadata messages by default
enableMsgType(CAMERA_MSG_ERROR | CAMERA_MSG_ZOOM | CAMERA_MSG_FOCUS |
CAMERA_MSG_PREVIEW_METADATA);
// Callback is disabled by default
mPreviewCallbackFlag = CAMERA_FRAME_CALLBACK_FLAG_NOOP;
mOrientation = getOrientation(0, mCameraFacing == CAMERA_FACING_FRONT);
mPlayShutterSound = true;
cameraService->setCameraBusy(cameraId);
cameraService->loadSound();
LOG1("Client::Client X (pid %d)", callingPid);
}
// tear down the client
CameraService::Client::~Client() {
int callingPid = getCallingPid();
LOG1("Client::~Client E (pid %d, this %p)", callingPid, this);
// set mClientPid to let disconnet() tear down the hardware
mClientPid = callingPid;
disconnect();
mCameraService->releaseSound();
LOG1("Client::~Client X (pid %d, this %p)", callingPid, this);
}
// ----------------------------------------------------------------------------
status_t CameraService::Client::checkPid() const {
int callingPid = getCallingPid();
if (callingPid == mClientPid) return NO_ERROR;
LOGW("attempt to use a locked camera from a different process"
" (old pid %d, new pid %d)", mClientPid, callingPid);
return EBUSY;
}
status_t CameraService::Client::checkPidAndHardware() const {
status_t result = checkPid();
if (result != NO_ERROR) return result;
if (mHardware == 0) {
LOGE("attempt to use a camera after disconnect() (pid %d)", getCallingPid());
return INVALID_OPERATION;
}
return NO_ERROR;
}
status_t CameraService::Client::lock() {
int callingPid = getCallingPid();
LOG1("lock (pid %d)", callingPid);
Mutex::Autolock lock(mLock);
// lock camera to this client if the the camera is unlocked
if (mClientPid == 0) {
mClientPid = callingPid;
return NO_ERROR;
}
// returns NO_ERROR if the client already owns the camera, EBUSY otherwise
return checkPid();
}
status_t CameraService::Client::unlock() {
int callingPid = getCallingPid();
LOG1("unlock (pid %d)", callingPid);
Mutex::Autolock lock(mLock);
// allow anyone to use camera (after they lock the camera)
status_t result = checkPid();
if (result == NO_ERROR) {
if (mHardware->recordingEnabled()) {
LOGE("Not allowed to unlock camera during recording.");
return INVALID_OPERATION;
}
mClientPid = 0;
LOG1("clear mCameraClient (pid %d)", callingPid);
// we need to remove the reference to ICameraClient so that when the app
// goes away, the reference count goes to 0.
mCameraClient.clear();
}
return result;
}
// connect a new client to the camera
status_t CameraService::Client::connect(const sp<ICameraClient>& client) {
int callingPid = getCallingPid();
LOG1("connect E (pid %d)", callingPid);
Mutex::Autolock lock(mLock);
if (mClientPid != 0 && checkPid() != NO_ERROR) {
LOGW("Tried to connect to a locked camera (old pid %d, new pid %d)",
mClientPid, callingPid);
return EBUSY;
}
if (mCameraClient != 0 && (client->asBinder() == mCameraClient->asBinder())) {
LOG1("Connect to the same client");
return NO_ERROR;
}
mPreviewCallbackFlag = CAMERA_FRAME_CALLBACK_FLAG_NOOP;
mClientPid = callingPid;
mCameraClient = client;
LOG1("connect X (pid %d)", callingPid);
return NO_ERROR;
}
static void disconnectWindow(const sp<ANativeWindow>& window) {
if (window != 0) {
status_t result = native_window_api_disconnect(window.get(),
NATIVE_WINDOW_API_CAMERA);
if (result != NO_ERROR) {
LOGW("native_window_api_disconnect failed: %s (%d)", strerror(-result),
result);
}
}
}
void CameraService::Client::disconnect() {
int callingPid = getCallingPid();
LOG1("disconnect E (pid %d)", callingPid);
Mutex::Autolock lock(mLock);
if (checkPid() != NO_ERROR) {
LOGW("different client - don't disconnect");
return;
}
if (mClientPid <= 0) {
LOG1("camera is unlocked (mClientPid = %d), don't tear down hardware", mClientPid);
return;
}
// Make sure disconnect() is done once and once only, whether it is called
// from the user directly, or called by the destructor.
if (mHardware == 0) return;
LOG1("hardware teardown");
// Before destroying mHardware, we must make sure it's in the
// idle state.
// Turn off all messages.
disableMsgType(CAMERA_MSG_ALL_MSGS);
mHardware->stopPreview();
mHardware->cancelPicture();
// Release the hardware resources.
mHardware->release();
// Release the held ANativeWindow resources.
if (mPreviewWindow != 0) {
disconnectWindow(mPreviewWindow);
mPreviewWindow = 0;
mHardware->setPreviewWindow(mPreviewWindow);
}
mHardware.clear();
mCameraService->removeClient(mCameraClient);
mCameraService->setCameraFree(mCameraId);
LOG1("disconnect X (pid %d)", callingPid);
}
// ----------------------------------------------------------------------------
status_t CameraService::Client::setPreviewWindow(const sp<IBinder>& binder,
const sp<ANativeWindow>& window) {
Mutex::Autolock lock(mLock);
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
// return if no change in surface.
if (binder == mSurface) {
return NO_ERROR;
}
if (window != 0) {
result = native_window_api_connect(window.get(), NATIVE_WINDOW_API_CAMERA);
if (result != NO_ERROR) {
LOGE("native_window_api_connect failed: %s (%d)", strerror(-result),
result);
return result;
}
}
// If preview has been already started, register preview buffers now.
if (mHardware->previewEnabled()) {
if (window != 0) {
native_window_set_scaling_mode(window.get(),
NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW);
native_window_set_buffers_transform(window.get(), mOrientation);
result = mHardware->setPreviewWindow(window);
}
}
if (result == NO_ERROR) {
// Everything has succeeded. Disconnect the old window and remember the
// new window.
disconnectWindow(mPreviewWindow);
mSurface = binder;
mPreviewWindow = window;
} else {
// Something went wrong after we connected to the new window, so
// disconnect here.
disconnectWindow(window);
}
return result;
}
// set the Surface that the preview will use
status_t CameraService::Client::setPreviewDisplay(const sp<Surface>& surface) {
LOG1("setPreviewDisplay(%p) (pid %d)", surface.get(), getCallingPid());
sp<IBinder> binder(surface != 0 ? surface->asBinder() : 0);
sp<ANativeWindow> window(surface);
return setPreviewWindow(binder, window);
}
// set the SurfaceTexture that the preview will use
status_t CameraService::Client::setPreviewTexture(
const sp<ISurfaceTexture>& surfaceTexture) {
LOG1("setPreviewTexture(%p) (pid %d)", surfaceTexture.get(),
getCallingPid());
sp<IBinder> binder;
sp<ANativeWindow> window;
if (surfaceTexture != 0) {
binder = surfaceTexture->asBinder();
window = new SurfaceTextureClient(surfaceTexture);
}
return setPreviewWindow(binder, window);
}
// set the preview callback flag to affect how the received frames from
// preview are handled.
void CameraService::Client::setPreviewCallbackFlag(int callback_flag) {
LOG1("setPreviewCallbackFlag(%d) (pid %d)", callback_flag, getCallingPid());
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) return;
mPreviewCallbackFlag = callback_flag;
if (mPreviewCallbackFlag & CAMERA_FRAME_CALLBACK_FLAG_ENABLE_MASK) {
enableMsgType(CAMERA_MSG_PREVIEW_FRAME);
} else {
disableMsgType(CAMERA_MSG_PREVIEW_FRAME);
}
}
// start preview mode
status_t CameraService::Client::startPreview() {
LOG1("startPreview (pid %d)", getCallingPid());
return startCameraMode(CAMERA_PREVIEW_MODE);
}
// start recording mode
status_t CameraService::Client::startRecording() {
LOG1("startRecording (pid %d)", getCallingPid());
return startCameraMode(CAMERA_RECORDING_MODE);
}
// start preview or recording
status_t CameraService::Client::startCameraMode(camera_mode mode) {
LOG1("startCameraMode(%d)", mode);
Mutex::Autolock lock(mLock);
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
switch(mode) {
case CAMERA_PREVIEW_MODE:
if (mSurface == 0 && mPreviewWindow == 0) {
LOG1("mSurface is not set yet.");
// still able to start preview in this case.
}
return startPreviewMode();
case CAMERA_RECORDING_MODE:
if (mSurface == 0 && mPreviewWindow == 0) {
LOGE("mSurface or mPreviewWindow must be set before startRecordingMode.");
return INVALID_OPERATION;
}
return startRecordingMode();
default:
return UNKNOWN_ERROR;
}
}
status_t CameraService::Client::startPreviewMode() {
LOG1("startPreviewMode");
status_t result = NO_ERROR;
// if preview has been enabled, nothing needs to be done
if (mHardware->previewEnabled()) {
return NO_ERROR;
}
if (mPreviewWindow != 0) {
native_window_set_scaling_mode(mPreviewWindow.get(),
NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW);
native_window_set_buffers_transform(mPreviewWindow.get(),
mOrientation);
}
mHardware->setPreviewWindow(mPreviewWindow);
result = mHardware->startPreview();
return result;
}
status_t CameraService::Client::startRecordingMode() {
LOG1("startRecordingMode");
status_t result = NO_ERROR;
// if recording has been enabled, nothing needs to be done
if (mHardware->recordingEnabled()) {
return NO_ERROR;
}
// if preview has not been started, start preview first
if (!mHardware->previewEnabled()) {
result = startPreviewMode();
if (result != NO_ERROR) {
return result;
}
}
// start recording mode
enableMsgType(CAMERA_MSG_VIDEO_FRAME);
mCameraService->playSound(SOUND_RECORDING);
result = mHardware->startRecording();
if (result != NO_ERROR) {
LOGE("mHardware->startRecording() failed with status %d", result);
}
return result;
}
// stop preview mode
void CameraService::Client::stopPreview() {
LOG1("stopPreview (pid %d)", getCallingPid());
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) return;
disableMsgType(CAMERA_MSG_PREVIEW_FRAME);
mHardware->stopPreview();
mPreviewBuffer.clear();
}
// stop recording mode
void CameraService::Client::stopRecording() {
LOG1("stopRecording (pid %d)", getCallingPid());
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) return;
mCameraService->playSound(SOUND_RECORDING);
disableMsgType(CAMERA_MSG_VIDEO_FRAME);
mHardware->stopRecording();
mPreviewBuffer.clear();
}
// release a recording frame
void CameraService::Client::releaseRecordingFrame(const sp<IMemory>& mem) {
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) return;
mHardware->releaseRecordingFrame(mem);
}
status_t CameraService::Client::storeMetaDataInBuffers(bool enabled)
{
LOG1("storeMetaDataInBuffers: %s", enabled? "true": "false");
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) {
return UNKNOWN_ERROR;
}
return mHardware->storeMetaDataInBuffers(enabled);
}
bool CameraService::Client::previewEnabled() {
LOG1("previewEnabled (pid %d)", getCallingPid());
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) return false;
return mHardware->previewEnabled();
}
bool CameraService::Client::recordingEnabled() {
LOG1("recordingEnabled (pid %d)", getCallingPid());
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) return false;
return mHardware->recordingEnabled();
}
status_t CameraService::Client::autoFocus() {
LOG1("autoFocus (pid %d)", getCallingPid());
Mutex::Autolock lock(mLock);
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
return mHardware->autoFocus();
}
status_t CameraService::Client::cancelAutoFocus() {
LOG1("cancelAutoFocus (pid %d)", getCallingPid());
Mutex::Autolock lock(mLock);
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
return mHardware->cancelAutoFocus();
}
// take a picture - image is returned in callback
status_t CameraService::Client::takePicture(int msgType) {
LOG1("takePicture (pid %d): 0x%x", getCallingPid(), msgType);
Mutex::Autolock lock(mLock);
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
if ((msgType & CAMERA_MSG_RAW_IMAGE) &&
(msgType & CAMERA_MSG_RAW_IMAGE_NOTIFY)) {
LOGE("CAMERA_MSG_RAW_IMAGE and CAMERA_MSG_RAW_IMAGE_NOTIFY"
" cannot be both enabled");
return BAD_VALUE;
}
// We only accept picture related message types
// and ignore other types of messages for takePicture().
int picMsgType = msgType
& (CAMERA_MSG_SHUTTER |
CAMERA_MSG_POSTVIEW_FRAME |
CAMERA_MSG_RAW_IMAGE |
CAMERA_MSG_RAW_IMAGE_NOTIFY |
CAMERA_MSG_COMPRESSED_IMAGE);
enableMsgType(picMsgType);
return mHardware->takePicture();
}
// set preview/capture parameters - key/value pairs
status_t CameraService::Client::setParameters(const String8& params) {
LOG1("setParameters (pid %d) (%s)", getCallingPid(), params.string());
Mutex::Autolock lock(mLock);
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
CameraParameters p(params);
return mHardware->setParameters(p);
}
// get preview/capture parameters - key/value pairs
String8 CameraService::Client::getParameters() const {
Mutex::Autolock lock(mLock);
if (checkPidAndHardware() != NO_ERROR) return String8();
String8 params(mHardware->getParameters().flatten());
LOG1("getParameters (pid %d) (%s)", getCallingPid(), params.string());
return params;
}
// enable shutter sound
status_t CameraService::Client::enableShutterSound(bool enable) {
LOG1("enableShutterSound (pid %d)", getCallingPid());
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
if (enable) {
mPlayShutterSound = true;
return OK;
}
// Disabling shutter sound may not be allowed. In that case only
// allow the mediaserver process to disable the sound.
char value[PROPERTY_VALUE_MAX];
property_get("ro.camera.sound.forced", value, "0");
if (strcmp(value, "0") != 0) {
// Disabling shutter sound is not allowed. Deny if the current
// process is not mediaserver.
if (getCallingPid() != getpid()) {
LOGE("Failed to disable shutter sound. Permission denied (pid %d)", getCallingPid());
return PERMISSION_DENIED;
}
}
mPlayShutterSound = false;
return OK;
}
status_t CameraService::Client::sendCommand(int32_t cmd, int32_t arg1, int32_t arg2) {
LOG1("sendCommand (pid %d)", getCallingPid());
int orientation;
Mutex::Autolock lock(mLock);
status_t result = checkPidAndHardware();
if (result != NO_ERROR) return result;
if (cmd == CAMERA_CMD_SET_DISPLAY_ORIENTATION) {
// Mirror the preview if the camera is front-facing.
orientation = getOrientation(arg1, mCameraFacing == CAMERA_FACING_FRONT);
if (orientation == -1) return BAD_VALUE;
if (mOrientation != orientation) {
mOrientation = orientation;
if (mPreviewWindow != 0) {
native_window_set_buffers_transform(mPreviewWindow.get(),
mOrientation);
}
}
return OK;
} else if (cmd == CAMERA_CMD_ENABLE_SHUTTER_SOUND) {
switch (arg1) {
case 0:
enableShutterSound(false);
break;
case 1:
enableShutterSound(true);
break;
default:
return BAD_VALUE;
}
return OK;
} else if (cmd == CAMERA_CMD_PLAY_RECORDING_SOUND) {
mCameraService->playSound(SOUND_RECORDING);
}
return mHardware->sendCommand(cmd, arg1, arg2);
}
// ----------------------------------------------------------------------------
void CameraService::Client::enableMsgType(int32_t msgType) {
android_atomic_or(msgType, &mMsgEnabled);
mHardware->enableMsgType(msgType);
}
void CameraService::Client::disableMsgType(int32_t msgType) {
android_atomic_and(~msgType, &mMsgEnabled);
mHardware->disableMsgType(msgType);
}
#define CHECK_MESSAGE_INTERVAL 10 // 10ms
bool CameraService::Client::lockIfMessageWanted(int32_t msgType) {
int sleepCount = 0;
while (mMsgEnabled & msgType) {
if (mLock.tryLock() == NO_ERROR) {
if (sleepCount > 0) {
LOG1("lockIfMessageWanted(%d): waited for %d ms",
msgType, sleepCount * CHECK_MESSAGE_INTERVAL);
}
return true;
}
if (sleepCount++ == 0) {
LOG1("lockIfMessageWanted(%d): enter sleep", msgType);
}
usleep(CHECK_MESSAGE_INTERVAL * 1000);
}
LOGW("lockIfMessageWanted(%d): dropped unwanted message", msgType);
return false;
}
// ----------------------------------------------------------------------------
// Converts from a raw pointer to the client to a strong pointer during a
// hardware callback. This requires the callbacks only happen when the client
// is still alive.
sp<CameraService::Client> CameraService::Client::getClientFromCookie(void* user) {
sp<Client> client = gCameraService->getClientById((int) user);
// This could happen if the Client is in the process of shutting down (the
// last strong reference is gone, but the destructor hasn't finished
// stopping the hardware).
if (client == 0) return NULL;
// The checks below are not necessary and are for debugging only.
if (client->mCameraService.get() != gCameraService) {
LOGE("mismatch service!");
return NULL;
}
if (client->mHardware == 0) {
LOGE("mHardware == 0: callback after disconnect()?");
return NULL;
}
return client;
}
// Callback messages can be dispatched to internal handlers or pass to our
// client's callback functions, depending on the message type.
//
// notifyCallback:
// CAMERA_MSG_SHUTTER handleShutter
// (others) c->notifyCallback
// dataCallback:
// CAMERA_MSG_PREVIEW_FRAME handlePreviewData
// CAMERA_MSG_POSTVIEW_FRAME handlePostview
// CAMERA_MSG_RAW_IMAGE handleRawPicture
// CAMERA_MSG_COMPRESSED_IMAGE handleCompressedPicture
// (others) c->dataCallback
// dataCallbackTimestamp
// (others) c->dataCallbackTimestamp
//
// NOTE: the *Callback functions grab mLock of the client before passing
// control to handle* functions. So the handle* functions must release the
// lock before calling the ICameraClient's callbacks, so those callbacks can
// invoke methods in the Client class again (For example, the preview frame
// callback may want to releaseRecordingFrame). The handle* functions must
// release the lock after all accesses to member variables, so it must be
// handled very carefully.
void CameraService::Client::notifyCallback(int32_t msgType, int32_t ext1,
int32_t ext2, void* user) {
LOG2("notifyCallback(%d)", msgType);
sp<Client> client = getClientFromCookie(user);
if (client == 0) return;
if (!client->lockIfMessageWanted(msgType)) return;
switch (msgType) {
case CAMERA_MSG_SHUTTER:
// ext1 is the dimension of the yuv picture.
client->handleShutter();
break;
default:
client->handleGenericNotify(msgType, ext1, ext2);
break;
}
}
void CameraService::Client::dataCallback(int32_t msgType,
const sp<IMemory>& dataPtr, camera_frame_metadata_t *metadata, void* user) {
LOG2("dataCallback(%d)", msgType);
sp<Client> client = getClientFromCookie(user);
if (client == 0) return;
if (!client->lockIfMessageWanted(msgType)) return;
if (dataPtr == 0 && metadata == NULL) {
LOGE("Null data returned in data callback");
client->handleGenericNotify(CAMERA_MSG_ERROR, UNKNOWN_ERROR, 0);
return;
}
switch (msgType & ~CAMERA_MSG_PREVIEW_METADATA) {
case CAMERA_MSG_PREVIEW_FRAME:
client->handlePreviewData(msgType, dataPtr, metadata);
break;
case CAMERA_MSG_POSTVIEW_FRAME:
client->handlePostview(dataPtr);
break;
case CAMERA_MSG_RAW_IMAGE:
client->handleRawPicture(dataPtr);
break;
case CAMERA_MSG_COMPRESSED_IMAGE:
client->handleCompressedPicture(dataPtr);
break;
default:
client->handleGenericData(msgType, dataPtr, metadata);
break;
}
}
void CameraService::Client::dataCallbackTimestamp(nsecs_t timestamp,
int32_t msgType, const sp<IMemory>& dataPtr, void* user) {
LOG2("dataCallbackTimestamp(%d)", msgType);
sp<Client> client = getClientFromCookie(user);
if (client == 0) return;
if (!client->lockIfMessageWanted(msgType)) return;
if (dataPtr == 0) {
LOGE("Null data returned in data with timestamp callback");
client->handleGenericNotify(CAMERA_MSG_ERROR, UNKNOWN_ERROR, 0);
return;
}
client->handleGenericDataTimestamp(timestamp, msgType, dataPtr);
}
// snapshot taken callback
void CameraService::Client::handleShutter(void) {
if (mPlayShutterSound) {
mCameraService->playSound(SOUND_SHUTTER);
}
sp<ICameraClient> c = mCameraClient;
if (c != 0) {
mLock.unlock();
c->notifyCallback(CAMERA_MSG_SHUTTER, 0, 0);
if (!lockIfMessageWanted(CAMERA_MSG_SHUTTER)) return;
}
disableMsgType(CAMERA_MSG_SHUTTER);
mLock.unlock();
}
// preview callback - frame buffer update
void CameraService::Client::handlePreviewData(int32_t msgType,
const sp<IMemory>& mem,
camera_frame_metadata_t *metadata) {
ssize_t offset;
size_t size;
sp<IMemoryHeap> heap = mem->getMemory(&offset, &size);
// local copy of the callback flags
int flags = mPreviewCallbackFlag;
// is callback enabled?
if (!(flags & CAMERA_FRAME_CALLBACK_FLAG_ENABLE_MASK)) {
// If the enable bit is off, the copy-out and one-shot bits are ignored
LOG2("frame callback is disabled");
mLock.unlock();
return;
}
// hold a strong pointer to the client
sp<ICameraClient> c = mCameraClient;
// clear callback flags if no client or one-shot mode
if (c == 0 || (mPreviewCallbackFlag & CAMERA_FRAME_CALLBACK_FLAG_ONE_SHOT_MASK)) {
LOG2("Disable preview callback");
mPreviewCallbackFlag &= ~(CAMERA_FRAME_CALLBACK_FLAG_ONE_SHOT_MASK |
CAMERA_FRAME_CALLBACK_FLAG_COPY_OUT_MASK |
CAMERA_FRAME_CALLBACK_FLAG_ENABLE_MASK);
disableMsgType(CAMERA_MSG_PREVIEW_FRAME);
}
if (c != 0) {
// Is the received frame copied out or not?
if (flags & CAMERA_FRAME_CALLBACK_FLAG_COPY_OUT_MASK) {
LOG2("frame is copied");
copyFrameAndPostCopiedFrame(msgType, c, heap, offset, size, metadata);
} else {
LOG2("frame is forwarded");
mLock.unlock();
c->dataCallback(msgType, mem, metadata);
}
} else {
mLock.unlock();
}
}
// picture callback - postview image ready
void CameraService::Client::handlePostview(const sp<IMemory>& mem) {
disableMsgType(CAMERA_MSG_POSTVIEW_FRAME);
sp<ICameraClient> c = mCameraClient;
mLock.unlock();
if (c != 0) {
c->dataCallback(CAMERA_MSG_POSTVIEW_FRAME, mem, NULL);
}
}
// picture callback - raw image ready
void CameraService::Client::handleRawPicture(const sp<IMemory>& mem) {
disableMsgType(CAMERA_MSG_RAW_IMAGE);
ssize_t offset;
size_t size;
sp<IMemoryHeap> heap = mem->getMemory(&offset, &size);
sp<ICameraClient> c = mCameraClient;
mLock.unlock();
if (c != 0) {
c->dataCallback(CAMERA_MSG_RAW_IMAGE, mem, NULL);
}
}
// picture callback - compressed picture ready
void CameraService::Client::handleCompressedPicture(const sp<IMemory>& mem) {
disableMsgType(CAMERA_MSG_COMPRESSED_IMAGE);
sp<ICameraClient> c = mCameraClient;
mLock.unlock();
if (c != 0) {
c->dataCallback(CAMERA_MSG_COMPRESSED_IMAGE, mem, NULL);
}
}
void CameraService::Client::handleGenericNotify(int32_t msgType,
int32_t ext1, int32_t ext2) {
sp<ICameraClient> c = mCameraClient;
mLock.unlock();
if (c != 0) {
c->notifyCallback(msgType, ext1, ext2);
}
}
void CameraService::Client::handleGenericData(int32_t msgType,
const sp<IMemory>& dataPtr, camera_frame_metadata_t *metadata) {
sp<ICameraClient> c = mCameraClient;
mLock.unlock();
if (c != 0) {
c->dataCallback(msgType, dataPtr, metadata);
}
}
void CameraService::Client::handleGenericDataTimestamp(nsecs_t timestamp,
int32_t msgType, const sp<IMemory>& dataPtr) {
sp<ICameraClient> c = mCameraClient;
mLock.unlock();
if (c != 0) {
c->dataCallbackTimestamp(timestamp, msgType, dataPtr);
}
}
void CameraService::Client::copyFrameAndPostCopiedFrame(
int32_t msgType, const sp<ICameraClient>& client,
const sp<IMemoryHeap>& heap, size_t offset, size_t size,
camera_frame_metadata_t *metadata) {
LOG2("copyFrameAndPostCopiedFrame");
// It is necessary to copy out of pmem before sending this to
// the callback. For efficiency, reuse the same MemoryHeapBase
// provided it's big enough. Don't allocate the memory or
// perform the copy if there's no callback.
// hold the preview lock while we grab a reference to the preview buffer
sp<MemoryHeapBase> previewBuffer;
if (mPreviewBuffer == 0) {
mPreviewBuffer = new MemoryHeapBase(size, 0, NULL);
} else if (size > mPreviewBuffer->virtualSize()) {
mPreviewBuffer.clear();
mPreviewBuffer = new MemoryHeapBase(size, 0, NULL);
}
if (mPreviewBuffer == 0) {
LOGE("failed to allocate space for preview buffer");
mLock.unlock();
return;
}
previewBuffer = mPreviewBuffer;
memcpy(previewBuffer->base(), (uint8_t *)heap->base() + offset, size);
sp<MemoryBase> frame = new MemoryBase(previewBuffer, 0, size);
if (frame == 0) {
LOGE("failed to allocate space for frame callback");
mLock.unlock();
return;
}
mLock.unlock();
client->dataCallback(msgType, frame, metadata);
}
int CameraService::Client::getOrientation(int degrees, bool mirror) {
if (!mirror) {
if (degrees == 0) return 0;
else if (degrees == 90) return HAL_TRANSFORM_ROT_90;
else if (degrees == 180) return HAL_TRANSFORM_ROT_180;
else if (degrees == 270) return HAL_TRANSFORM_ROT_270;
} else { // Do mirror (horizontal flip)
if (degrees == 0) { // FLIP_H and ROT_0
return HAL_TRANSFORM_FLIP_H;
} else if (degrees == 90) { // FLIP_H and ROT_90
return HAL_TRANSFORM_FLIP_H | HAL_TRANSFORM_ROT_90;
} else if (degrees == 180) { // FLIP_H and ROT_180
return HAL_TRANSFORM_FLIP_V;
} else if (degrees == 270) { // FLIP_H and ROT_270
return HAL_TRANSFORM_FLIP_V | HAL_TRANSFORM_ROT_90;
}
}
LOGE("Invalid setDisplayOrientation degrees=%d", degrees);
return -1;
}
// ----------------------------------------------------------------------------
static const int kDumpLockRetries = 50;
static const int kDumpLockSleep = 60000;
static bool tryLock(Mutex& mutex)
{
bool locked = false;
for (int i = 0; i < kDumpLockRetries; ++i) {
if (mutex.tryLock() == NO_ERROR) {
locked = true;
break;
}
usleep(kDumpLockSleep);
}
return locked;
}
status_t CameraService::dump(int fd, const Vector<String16>& args) {
static const char* kDeadlockedString = "CameraService may be deadlocked
";
const size_t SIZE = 256;
char buffer[SIZE];
String8 result;
if (checkCallingPermission(String16("android.permission.DUMP")) == false) {
snprintf(buffer, SIZE, "Permission Denial: "
"can't dump CameraService from pid=%d, uid=%d
",
getCallingPid(),
getCallingUid());
result.append(buffer);
write(fd, result.string(), result.size());
} else {
bool locked = tryLock(mServiceLock);
// failed to lock - CameraService is probably deadlocked
if (!locked) {
String8 result(kDeadlockedString);
write(fd, result.string(), result.size());
}
bool hasClient = false;
for (int i = 0; i < mNumberOfCameras; i++) {
sp<Client> client = mClient[i].promote();
if (client == 0) continue;
hasClient = true;
sprintf(buffer, "Client[%d] (%p) PID: %d
",
i,
client->getCameraClient()->asBinder().get(),
client->mClientPid);
result.append(buffer);
write(fd, result.string(), result.size());
client->mHardware->dump(fd, args);
}
if (!hasClient) {
result.append("No camera client yet.
");
write(fd, result.string(), result.size());
}
if (locked) mServiceLock.unlock();
// change logging level
int n = args.size();
for (int i = 0; i + 1 < n; i++) {
if (args[i] == String16("-v")) {
String8 levelStr(args[i+1]);
int level = atoi(levelStr.string());
sprintf(buffer, "Set Log Level to %d", level);
result.append(buffer);
setLogLevel(level);
}
}
}
return NO_ERROR;
}
}; // namespace androidvoid CameraServices::onFirstRef()この関数を見てください:
void CameraService::onFirstRef()
{
BnCameraService::onFirstRef();
if (hw_get_module(CAMERA_HARDWARE_MODULE_ID,
(const hw_module_t **)&mModule) < 0) {
LOGE("Could not load camera HAL module");
mNumberOfCameras = 0;
}
else {
mNumberOfCameras = mModule->get_number_of_cameras(); // camera . camera .
if (mNumberOfCameras > MAX_CAMERAS) {
LOGE("Number of cameras(%d) > MAX_CAMERAS(%d).",
mNumberOfCameras, MAX_CAMERAS);
mNumberOfCameras = MAX_CAMERAS;
}
for (int i = 0; i < mNumberOfCameras; i++) {
setCameraFree(i);
}
}
// Read the system property to determine if we have to use the
// AUDIO_STREAM_ENFORCED_AUDIBLE type.
char value[PROPERTY_VALUE_MAX];
property_get("ro.camera.sound.forced", value, "0");
if (strcmp(value, "0") != 0) {
mAudioStreamType = AUDIO_STREAM_ENFORCED_AUDIBLE;
} else {
mAudioStreamType = AUDIO_STREAM_MUSIC;
}
}長い間探していたが、この関数にはhwが入っていた.get_module()という関数は、名前を見るとhardwareを取得していることがわかりますが、誰を探しているのでしょうか.ではonFirstRef()関数はいつ呼び出されますか?
onFirstRef()は、spを強く参照して新しい参照カウントを追加するときに呼び出される親RefBaseに属します.どういう意味ですか.spパッケージのクラスが初期化されたときに呼び出されます.ここではframeworks/base/services/camera/libcameraservice/CameraServices.h中class CameraService:に定義あり
// these are initialized in the constructor.
sp<CameraService> mCameraService; // immutable after constructor
sp<ICameraClient> mCameraClient;
int mCameraId; // immutable after constructor
int mCameraFacing; // immutable after constructor
pid_t mClientPid;
sp<CameraHardwareInterface> mHardware; // cleared after disconnect()
int mPreviewCallbackFlag;
int mOrientation; // Current display orientation
bool mPlayShutterSound;明らかにここで初期化したのですが、もちろんここはポイントではありません.全部書けば、ほとんど書けません.
hw_が見つかりましたget_module()という関数は、その具体的な実装を見てみましょう.
hardware/libhardware/hardware.c
コードは次のとおりです.
/*
* Copyright (C) 2008 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 <hardware/hardware.h>
#include <cutils/properties.h>
#include <dlfcn.h>
#include <string.h>
#include <pthread.h>
#include <errno.h>
#include <limits.h>
#define LOG_TAG "HAL"
#include <utils/Log.h>
/** Base path of the hal modules */
#define HAL_LIBRARY_PATH1 "/system/lib/hw"
#define HAL_LIBRARY_PATH2 "/vendor/lib/hw"
/**
* There are a set of variant filename for modules. The form of the filename
* is "<MODULE_ID>.variant.so" so for the led module the Dream variants
* of base "ro.product.board", "ro.board.platform" and "ro.arch" would be:
*
* led.trout.so
* led.msm7k.so
* led.ARMV6.so
* led.default.so
*/
static const char *variant_keys[] = {
"ro.hardware", /* This goes first so that it can pick up a different
file on the emulator. */
"ro.product.board",
"ro.board.platform",
"ro.arch"
};
static const int HAL_VARIANT_KEYS_COUNT =
(sizeof(variant_keys)/sizeof(variant_keys[0]));
/**
* Load the file defined by the variant and if successful
* return the dlopen handle and the hmi.
* @return 0 = success, !0 = failure.
*/
static int load(const char *id,
const char *path,
const struct hw_module_t **pHmi)
{
int status;
void *handle;
struct hw_module_t *hmi;
/*
* load the symbols resolving undefined symbols before
* dlopen returns. Since RTLD_GLOBAL is not or'd in with
* RTLD_NOW the external symbols will not be global
*/
handle = dlopen(path, RTLD_NOW);
if (handle == NULL) {
char const *err_str = dlerror();
LOGE("load: module=%s
%s", path, err_str?err_str:"unknown");
status = -EINVAL;
goto done;
}
/* Get the address of the struct hal_module_info. */
const char *sym = HAL_MODULE_INFO_SYM_AS_STR;
hmi = (struct hw_module_t *)dlsym(handle, sym);
if (hmi == NULL) {
LOGE("load: couldn't find symbol %s", sym);
status = -EINVAL;
goto done;
}
/* Check that the id matches */
if (strcmp(id, hmi->id) != 0) {
LOGE("load: id=%s != hmi->id=%s", id, hmi->id);
status = -EINVAL;
goto done;
}
hmi->dso = handle;
/* success */
status = 0;
done:
if (status != 0) {
hmi = NULL;
if (handle != NULL) {
dlclose(handle);
handle = NULL;
}
} else {
LOGV("loaded HAL id=%s path=%s hmi=%p handle=%p",
id, path, *pHmi, handle);
}
*pHmi = hmi;
return status;
}
int hw_get_module_by_class(const char *class_id, const char *inst,
const struct hw_module_t **module)
{
int status;
int i;
const struct hw_module_t *hmi = NULL;
char prop[PATH_MAX];
char path[PATH_MAX];
char name[PATH_MAX];
if (inst)
snprintf(name, PATH_MAX, "%s.%s", class_id, inst);
else
strlcpy(name, class_id, PATH_MAX);
/*
* Here we rely on the fact that calling dlopen multiple times on
* the same .so will simply increment a refcount (and not load
* a new copy of the library).
* We also assume that dlopen() is thread-safe.
*/
/* Loop through the configuration variants looking for a module */
for (i=0 ; i<HAL_VARIANT_KEYS_COUNT+1 ; i++) {
if (i < HAL_VARIANT_KEYS_COUNT) {
if (property_get(variant_keys[i], prop, NULL) == 0) {
continue;
}
snprintf(path, sizeof(path), "%s/%s.%s.so",
HAL_LIBRARY_PATH2, name, prop);
if (access(path, R_OK) == 0) break;
snprintf(path, sizeof(path), "%s/%s.%s.so",
HAL_LIBRARY_PATH1, name, prop);
if (access(path, R_OK) == 0) break;
} else {
snprintf(path, sizeof(path), "%s/%s.default.so",
HAL_LIBRARY_PATH1, name);
if (access(path, R_OK) == 0) break;
}
}
status = -ENOENT;
if (i < HAL_VARIANT_KEYS_COUNT+1) {
/* load the module, if this fails, we're doomed, and we should not try
* to load a different variant. */
status = load(class_id, path, module);
}
return status;
}
int hw_get_module(const char *id, const struct hw_module_t **module)
{
return hw_get_module_by_class(id, NULL, module);
}その流れを見てみましょう.
int hw_get_module(const char *id, const struct hw_module_t **module)
int hw_get_module_by_class(const char *class_id, const char *inst,const struct hw_module_t **module)
static int load(const char *id,const char *path,const struct hw_module_t **pHmi)
/* Check that the id matches */
if (strcmp(id, hmi->id) != 0) {
LOGE("load: id=%s != hmi->id=%s", id, hmi->id);
status = -EINVAL;
goto done;
}
...実際にhardwareを探しに来た橋はこのIDでif(strcmp(id,hmi->id)!=0)ではidはframeworks/base/services/camera/libcameraservice/CameraServicesである.cppに直接付与された
次のようになります.
if (hw_get_module(CAMERA_HARDWARE_MODULE_ID,
(const hw_module_t **)&mModule) < 0) {
LOGE("Could not load camera HAL module");
mNumberOfCameras = 0;
}hmi->idのこのidはhardwareで定義すべきであることは明らかだ.
hmiがどうやって来たか見てみましょう.
/* Get the address of the struct hal_module_info. */
const char *sym = HAL_MODULE_INFO_SYM_AS_STR;
hmi = (struct hw_module_t *)dlsym(handle, sym);この関数を追跡する必要はありません.hmiはsymから取得したに違いない.hardwareには必ずこの構造体があることを知っていますこれもhardwareを実現するためにしなければならないことです.ここでhardware.hにも説明があります.
/**
* Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
* and the fields of this data structure must begin with hw_module_t
* followed by module specific information.
*/hardwareには必ずHALという名前がありますMODULE_INFO_SYMの構造体これもhardwareを実現したものです
ステップ1:Step-1:HALという名前の実装MODULE_INFO_SYMの構造体、この構造体はhw_でなければなりませんmodule_tの冒頭で、cameraのhardwareでどのように定義されているかを見てみましょう.
commonが構造体かどうか見てみましょうhw_module_t hardware/libhardware/include/hardware/camera.h
hardwareに構造体がある以上、初期化しなければなりません.カスタム関数も実現しなければなりません.前の注釈はもう書いた.ここでは関数の実装を貼り付けるだけである.
だから自然にhardwareを実現するために呼び出されたのです
ステップ2,Step-2:open関数の実現と役割.やはりcameraHALの中のそれに対する実現を見ます.
段々包装して、HALを見てみましょう.camera_device_open:
static int HAL_camera_device_open(const struct hw_module_t* module,
const char *id,
struct hw_device_t** device)
{
int cameraId = atoi(id);
if (cameraId < 0 || cameraId >= HAL_getNumberOfCameras()) {
return -EINVAL;
}
if (g_cam_device) { // , g_cam_device , .
if (obj(g_cam_device)->getCameraId() == cameraId) {
goto done;
} else {
LOGE("Cannot open camera %d. camera %d is already running!",
cameraId, obj(g_cam_device)->getCameraId());
return -ENOSYS;
}
}
g_cam_device = (camera_device_t *)malloc(sizeof(camera_device_t));
if (!g_cam_device)
return -ENOMEM;
g_cam_device->common.tag = HARDWARE_DEVICE_TAG;
g_cam_device->common.version = 1;
g_cam_device->common.module = const_cast<hw_module_t *>(module);
g_cam_device->common.close = HAL_camera_device_close;
g_cam_device->ops = &camera_device_ops;
LOGI("%s: open camera %s", __func__, id);
g_cam_device->priv = new CameraHardwareSec(cameraId, g_cam_device);
done:
*device = (hw_device_t *)g_cam_device;
LOGI("%s: opened camera %s (%p)", __func__, id, *device);
return 0;
}ここで私たちは知っています.Openの役割は、指定ID番号のカメラを開くことと、デバイス構造体を充填することであり、takePicture()やstartPreview()などのHALの具体的な関数を上層部に直接呼び出すことである.
しかし、この構造体をどのように充填すればいいのでしょうか.
hardware/libhardware/include/hardware/hardware.hどう言いますか.
/**
* Every device data structure must begin with hw_device_t
* followed by module specific public methods and attributes.
*/各デバイスはhw_device_tが開始し、methodsとattributesに続く.
では、HALでstaticの構造体を定義し、上の値を押してこのポインタに戻るといいです.HALを見る
static camera_device_t *g_cam_device; // .
typedef struct camera_device {
hw_device_t common; // hw_device_t
camera_device_ops_t *ops; // methods
void *priv; // .
} camera_device_t;どのように充填されているかを見てみましょう.
g_cam_device->common.tag = HARDWARE_DEVICE_TAG; //hardware.h . tag .
g_cam_device->common.module = const_cast<hw_module_t *>(module); // module
g_cam_device->common.close = HAL_camera_device_close; //
g_cam_device->ops = &camera_device_ops; // . HAL .
g_cam_device->priv = new CameraHardwareSec(cameraId, g_cam_device); // hardware , HAL .ここでまずcameraを見てみましょうdevice_opsの具体的な実現はHALの実現にもつながっている.
ステップ3,Step-3:具体的なデバイスの関数実装.
#define SET_METHOD(m) m : HAL_camera_device_##m // m : HAL_camera_device_m
static camera_device_ops_t camera_device_ops = {
SET_METHOD(set_preview_window), // set_preview_window : HAL_camera_device_set_preview_window, HAL_camera_device_set_preview_window set_preview_window
SET_METHOD(set_callbacks), // set_callbacks : HAL_camera_device_set_callbacks
SET_METHOD(enable_msg_type), //
SET_METHOD(disable_msg_type),
SET_METHOD(msg_type_enabled),
SET_METHOD(start_preview),
SET_METHOD(stop_preview),
SET_METHOD(preview_enabled),
SET_METHOD(store_meta_data_in_buffers),
SET_METHOD(start_recording),
SET_METHOD(stop_recording),
SET_METHOD(recording_enabled),
SET_METHOD(release_recording_frame),
SET_METHOD(auto_focus),
SET_METHOD(cancel_auto_focus),
SET_METHOD(take_picture),
SET_METHOD(cancel_picture),
SET_METHOD(set_parameters),
SET_METHOD(get_parameters),
SET_METHOD(put_parameters),
SET_METHOD(send_command),
SET_METHOD(release),
SET_METHOD(dump),
};HALで呼び出す関数の具体的な実現はさておき、サービスがどのように呼び出すかを見てみましょう.
start_でpreviewを例に挙げる.
camera.start_preview() //
public native final void startPreview(); // JNI frameworks/base/core/java/android/hardware/Camera.java
static void android_hardware_Camera_startPreview(JNIEnv *env, jobject thiz) //JNI frameworks/base/core/jni/android_hardware_Camera.cpp
sp<Camera> camera = get_native_camera(env, thiz, NULL); // cameraClient frameworks/base/core/jni/android_hardware_Camera.cpp
camera->startPreview(); // cameraClient frameworks/base/libs/camera/Camera.cpp.
status_t CameraService::Client::startPreview(); //service frameworks/base/services/camera/libcameraservice/CameraService.cpp
status_t CameraService::Client::startCameraMode(camera_mode mode) //service frameworks/base/services/camera/libcameraservice/CameraService.cpp
status_t CameraService::Client::startPreviewMode() //service frameworks/base/services/camera/libcameraservice/CameraService.cpp
status_t startPreview() // hardware frameworks/base/services/camera/libcameraservice/CameraHardwareInterface.h
mDevice->ops->start_preview(mDevice); // HAL start_preview HAL_camera_device_start_preview. device/magiclab/common/libcamera/SecCameraHWInterface_zoom.cppOK,関数呼び出しはここまででhardware内の具体的なデバイス関数を呼び出すアプリケーションの流れが完了する.HALの実現とは、上記の各関数を実現することである.協力させるだけです
作者:joseph_lee
出典:joseh_lee 2633のブログ--http://www.cnblogs.com/joseph-linux