Add a new camera open API that allows taking the ownership.

The purpose is to let face unlock always get the camera
successfully. What happened was the camera applications may
have opened the camera in onResume under the lock screen.
This API lets face unlock take the camera from the camera
application. A new permission will be added, so other
applicatoins won't be able to take the camera from the face
unlock.

bug:5584464

Change-Id: Ib3d9dcbc2161815b68db42327dc01148453704c6

7 files changed, 143 insertions, 42 deletions

diff --git a/camera/Camera.cpp b/camera/Camera.cpp
index d43cb0b..b81fe86 100644
--- a/camera/Camera.cpp
+++ b/camera/Camera.cpp
@@ -116,13 +116,13 @@ status_t Camera::getCameraInfo(int cameraId,
     return cs->getCameraInfo(cameraId, cameraInfo);
 }
 
-sp<Camera> Camera::connect(int cameraId)
+sp<Camera> Camera::connect(int cameraId, bool force, bool keep)
 {
     ALOGV("connect");
     sp<Camera> c = new Camera();
     const sp<ICameraService>& cs = getCameraService();
     if (cs != 0) {
-        c->mCamera = cs->connect(c, cameraId);
+        c->mCamera = cs->connect(c, cameraId, force, keep);
     }
     if (c->mCamera != 0) {
         c->mCamera->asBinder()->linkToDeath(c);
diff --git a/camera/ICameraService.cpp b/camera/ICameraService.cpp
index 85f1a29..c74298a 100644
--- a/camera/ICameraService.cpp
+++ b/camera/ICameraService.cpp
@@ -56,12 +56,15 @@ public:
     }
 
     // connect to camera service
-    virtual sp<ICamera> connect(const sp<ICameraClient>& cameraClient, int cameraId)
+    virtual sp<ICamera> connect(const sp<ICameraClient>& cameraClient, int cameraId,
+                                bool force, bool keep)
     {
         Parcel data, reply;
         data.writeInterfaceToken(ICameraService::getInterfaceDescriptor());
         data.writeStrongBinder(cameraClient->asBinder());
         data.writeInt32(cameraId);
+        data.writeInt32(force);
+        data.writeInt32(keep);
         remote()->transact(BnCameraService::CONNECT, data, &reply);
         return interface_cast<ICamera>(reply.readStrongBinder());
     }
@@ -93,7 +96,10 @@ status_t BnCameraService::onTransact(
         case CONNECT: {
             CHECK_INTERFACE(ICameraService, data, reply);
             sp<ICameraClient> cameraClient = interface_cast<ICameraClient>(data.readStrongBinder());
-            sp<ICamera> camera = connect(cameraClient, data.readInt32());
+            const int cameraId = data.readInt32();
+            const int force = data.readInt32();
+            const int keep = data.readInt32();
+            sp<ICamera> camera = connect(cameraClient, cameraId, force, keep);
             reply->writeStrongBinder(camera->asBinder());
             return NO_ERROR;
         } break;
@@ -105,4 +111,3 @@ status_t BnCameraService::onTransact(
 // ----------------------------------------------------------------------------
 
 }; // namespace android
-
diff --git a/include/camera/Camera.h b/include/camera/Camera.h
index 234e165..3fedea0 100644
--- a/include/camera/Camera.h
+++ b/include/camera/Camera.h
@@ -72,7 +72,7 @@ public:
     static  int32_t     getNumberOfCameras();
     static  status_t    getCameraInfo(int cameraId,
                                       struct CameraInfo* cameraInfo);
-    static  sp<Camera>  connect(int cameraId);
+    static  sp<Camera>  connect(int cameraId, bool force, bool keep);
             virtual     ~Camera();
             void        init();
 
diff --git a/include/camera/ICameraService.h b/include/camera/ICameraService.h
index 7d70c1e..97e3169 100644
--- a/include/camera/ICameraService.h
+++ b/include/camera/ICameraService.h
@@ -42,7 +42,7 @@ public:
     virtual status_t        getCameraInfo(int cameraId,
                                           struct CameraInfo* cameraInfo) = 0;
     virtual sp<ICamera>     connect(const sp<ICameraClient>& cameraClient,
-                                    int cameraId) = 0;
+                                    int cameraId, bool force, bool keep) = 0;
 };
 
 // ----------------------------------------------------------------------------
diff --git a/media/libstagefright/CameraSource.cpp b/media/libstagefright/CameraSource.cpp
index 2df5528..0d67800 100755
--- a/media/libstagefright/CameraSource.cpp
+++ b/media/libstagefright/CameraSource.cpp
@@ -182,7 +182,7 @@ status_t CameraSource::isCameraAvailable(
     int32_t cameraId) {
 
     if (camera == 0) {
-        mCamera = Camera::connect(cameraId);
+        mCamera = Camera::connect(cameraId, false, false);
         if (mCamera == 0) return -EBUSY;
         mCameraFlags &= ~FLAGS_HOT_CAMERA;
     } else {
diff --git a/services/camera/libcameraservice/CameraService.cpp b/services/camera/libcameraservice/CameraService.cpp
index adf1d49..22836e3 100644
--- a/services/camera/libcameraservice/CameraService.cpp
+++ b/services/camera/libcameraservice/CameraService.cpp
@@ -21,6 +21,7 @@
 #include <stdio.h>
 #include <sys/types.h>
 #include <pthread.h>
+#include <time.h>
 
 #include <binder/IPCThreadState.h>
 #include <binder/IServiceManager.h>
@@ -33,6 +34,7 @@
 #include <hardware/hardware.h>
 #include <media/AudioSystem.h>
 #include <media/mediaplayer.h>
+#include <utils/Condition.h>
 #include <utils/Errors.h>
 #include <utils/Log.h>
 #include <utils/String16.h>
@@ -42,6 +44,8 @@
 
 namespace android {
 
+#define WAIT_RELEASE_TIMEOUT 250 // 250ms
+
 // ----------------------------------------------------------------------------
 // Logging support -- this is for debugging only
 // Use "adb shell dumpsys media.camera -v 1" to change it.
@@ -64,6 +68,13 @@ static int getCallingUid() {
     return IPCThreadState::self()->getCallingUid();
 }
 
+static long long getTimeInMs() {
+    struct timeval t;
+    t.tv_sec = t.tv_usec = 0;
+    gettimeofday(&t, NULL);
+    return t.tv_sec * 1000LL + t.tv_usec / 1000;
+}
+
 // ----------------------------------------------------------------------------
 
 // This is ugly and only safe if we never re-create the CameraService, but
@@ -131,7 +142,7 @@ status_t CameraService::getCameraInfo(int cameraId,
 }
 
 sp<ICamera> CameraService::connect(
-        const sp<ICameraClient>& cameraClient, int cameraId) {
+        const sp<ICameraClient>& cameraClient, int cameraId, bool force, bool keep) {
     int callingPid = getCallingPid();
     sp<CameraHardwareInterface> hardware = NULL;
 
@@ -157,27 +168,73 @@ sp<ICamera> CameraService::connect(
         return NULL;
     }
 
+    if (keep && !checkCallingPermission(String16("android.permission.KEEP_CAMERA"))) {
+        ALOGE("connect X (pid %d) rejected (no KEEP_CAMERA permission).", 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 {
-                ALOGW("CameraService::connect X (pid %d) rejected (existing client).",
-                    callingPid);
-                return NULL;
-            }
+    // Check if there is an existing client.
+    client = mClient[cameraId].promote();
+    if (client != 0 &&
+            cameraClient->asBinder() == client->getCameraClient()->asBinder()) {
+        LOG1("connect X (pid %d) (the same client)", callingPid);
+        return client;
+    }
+
+    if (!force) {
+        if (mClient[cameraId].promote() != 0) {
+            ALOGW("connect X (pid %d) rejected (existing client).", callingPid);
+            return NULL;
         }
         mClient[cameraId].clear();
-    }
+        if (mBusy[cameraId]) {
+            ALOGW("connect X (pid %d) rejected (camera %d is still busy).",
+                  callingPid, cameraId);
+            return NULL;
+        }
+    } else { // force == true
+        int i = 0;
+        long long start_time = getTimeInMs();
+        while (i < mNumberOfCameras) {
+            if (getTimeInMs() - start_time >= 3000LL) {
+                ALOGE("connect X (pid %d) rejected (timeout 3s)", callingPid);
+                return NULL;
+            }
 
-    if (mBusy[cameraId]) {
-        ALOGW("CameraService::connect X (pid %d) rejected"
-             " (camera %d is still busy).", callingPid, cameraId);
-        return NULL;
+            client = mClient[i].promote();
+            if (client != 0) {
+                if (client->keep()) {
+                    ALOGW("connect X (pid %d) rejected (existing client wants to keeps the camera)",
+                          callingPid);
+                    return NULL;
+                } else {
+                    ALOGW("New client (pid %d, id=%d). Disconnect the existing client (id=%d).",
+                         callingPid, cameraId, i);
+                    // Do not hold mServiceLock because disconnect will try to get it.
+                    mServiceLock.unlock();
+                    client->notifyCallback(CAMERA_MSG_ERROR, CAMERA_ERROR_RELEASED, 0, &i);
+                    client->waitRelease(WAIT_RELEASE_TIMEOUT);
+                    client->disconnectInternal(false);
+                    mServiceLock.lock();
+                    // Restart from the first client because a new client may have connected
+                    // when mServiceLock is unlocked.
+                    i = 0;
+                    continue;
+                }
+            }
+
+            if (mBusy[i]) {
+                // Give the client a chance to release the hardware.
+                mServiceLock.unlock();
+                usleep(10 * 1000);
+                mServiceLock.lock();
+                i = 0; // Restart from the first client
+                continue;
+            }
+
+            i++;
+        }
     }
 
     struct camera_info info;
@@ -195,9 +252,15 @@ sp<ICamera> CameraService::connect(
         return NULL;
     }
 
-    client = new Client(this, cameraClient, hardware, cameraId, info.facing, callingPid);
+    client = new Client(this, cameraClient, hardware, cameraId, info.facing,
+                        callingPid, keep);
+    // We need to clear the hardware here. After the destructor of mServiceLock
+    // finishes, a new client may connect and disconnect this client. If this
+    // reference is not cleared, the destructor of CameraHardwareInterface
+    // cannot run. The new client will not be able to connect.
+    hardware.clear();
     mClient[cameraId] = client;
-    LOG1("CameraService::connect X");
+    LOG1("CameraService::connect X (id %d)", cameraId);
     return client;
 }
 
@@ -331,9 +394,9 @@ void CameraService::playSound(sound_kind kind) {
 CameraService::Client::Client(const sp<CameraService>& cameraService,
         const sp<ICameraClient>& cameraClient,
         const sp<CameraHardwareInterface>& hardware,
-        int cameraId, int cameraFacing, int clientPid) {
+        int cameraId, int cameraFacing, int clientPid, bool keep) {
     int callingPid = getCallingPid();
-    LOG1("Client::Client E (pid %d)", callingPid);
+    LOG1("Client::Client E (pid %d, id %d)", callingPid, cameraId);
 
     mCameraService = cameraService;
     mCameraClient = cameraClient;
@@ -341,6 +404,7 @@ CameraService::Client::Client(const sp<CameraService>& cameraService,
     mCameraId = cameraId;
     mCameraFacing = cameraFacing;
     mClientPid = clientPid;
+    mKeep = keep;
     mMsgEnabled = 0;
     mSurface = 0;
     mPreviewWindow = 0;
@@ -359,7 +423,7 @@ CameraService::Client::Client(const sp<CameraService>& cameraService,
     mPlayShutterSound = true;
     cameraService->setCameraBusy(cameraId);
     cameraService->loadSound();
-    LOG1("Client::Client X (pid %d)", callingPid);
+    LOG1("Client::Client X (pid %d, id %d)", callingPid, cameraId);
 }
 
 // tear down the client
@@ -468,18 +532,24 @@ static void disconnectWindow(const sp<ANativeWindow>& window) {
 }
 
 void CameraService::Client::disconnect() {
+    disconnectInternal(true);
+}
+
+void CameraService::Client::disconnectInternal(bool needCheckPid) {
     int callingPid = getCallingPid();
-    LOG1("disconnect E (pid %d)", callingPid);
+    LOG1("disconnectInternal E (pid %d)", callingPid);
     Mutex::Autolock lock(mLock);
 
-    if (checkPid() != NO_ERROR) {
-        ALOGW("different client - don't disconnect");
-        return;
-    }
+    if (needCheckPid) {
+        if (checkPid() != NO_ERROR) {
+            ALOGW("different client - don't disconnect");
+            return;
+        }
 
-    if (mClientPid <= 0) {
-        LOG1("camera is unlocked (mClientPid = %d), don't tear down hardware", mClientPid);
-        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
@@ -506,8 +576,16 @@ void CameraService::Client::disconnect() {
 
     mCameraService->removeClient(mCameraClient);
     mCameraService->setCameraFree(mCameraId);
+    mReleaseCondition.signal();
+
+    LOG1("disconnectInternal X (pid %d)", callingPid);
+}
 
-    LOG1("disconnect X (pid %d)", callingPid);
+void CameraService::Client::waitRelease(int ms) {
+    Mutex::Autolock lock(mLock);
+    if (mHardware != 0) {
+        mReleaseCondition.waitRelative(mLock, ms * 1000000);
+    }
 }
 
 // ----------------------------------------------------------------------------
@@ -874,6 +952,9 @@ status_t CameraService::Client::sendCommand(int32_t cmd, int32_t arg1, int32_t a
         return OK;
     } else if (cmd == CAMERA_CMD_PLAY_RECORDING_SOUND) {
         mCameraService->playSound(SOUND_RECORDING);
+    } else if (cmd == CAMERA_CMD_PING) {
+        // If mHardware is 0, checkPidAndHardware will return error.
+        return OK;
     }
 
     return mHardware->sendCommand(cmd, arg1, arg2);
@@ -1217,6 +1298,10 @@ int CameraService::Client::getOrientation(int degrees, bool mirror) {
     return -1;
 }
 
+// Whether the client wants to keep the camera from taking
+bool CameraService::Client::keep() const {
+    return mKeep;
+}
 
 // ----------------------------------------------------------------------------
 
diff --git a/services/camera/libcameraservice/CameraService.h b/services/camera/libcameraservice/CameraService.h
index bad41f5..457c79b 100644
--- a/services/camera/libcameraservice/CameraService.h
+++ b/services/camera/libcameraservice/CameraService.h
@@ -46,7 +46,8 @@ public:
     virtual int32_t     getNumberOfCameras();
     virtual status_t    getCameraInfo(int cameraId,
                                       struct CameraInfo* cameraInfo);
-    virtual sp<ICamera> connect(const sp<ICameraClient>& cameraClient, int cameraId);
+    virtual sp<ICamera> connect(const sp<ICameraClient>& cameraClient, int cameraId,
+                                bool force, bool keep);
     virtual void        removeClient(const sp<ICameraClient>& cameraClient);
     virtual sp<Client>  getClientById(int cameraId);
 
@@ -114,7 +115,8 @@ private:
                                        const sp<CameraHardwareInterface>& hardware,
                                        int cameraId,
                                        int cameraFacing,
-                                       int clientPid);
+                                       int clientPid,
+                                       bool keep);
                                 ~Client();
 
         // return our camera client
@@ -172,12 +174,19 @@ private:
                                     const sp<IBinder>& binder,
                                     const sp<ANativeWindow>& window);
 
+        void                    disconnectInternal(bool needCheckPid);
+        bool                    keep() const;
+        void                    waitRelease(int ms);
+
+
         // 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;
+        // Client wants to keep the camera from taking by other clients.
+        bool                            mKeep;
         sp<CameraHardwareInterface>     mHardware;       // cleared after disconnect()
         int                             mPreviewCallbackFlag;
         int                             mOrientation;     // Current display orientation
@@ -185,6 +194,8 @@ private:
 
         // Ensures atomicity among the public methods
         mutable Mutex                   mLock;
+        // This will get notified when the hardware is released.
+        Condition                       mReleaseCondition;
         // This is a binder of Surface or SurfaceTexture.
         sp<IBinder>                     mSurface;
         sp<ANativeWindow>               mPreviewWindow;