Home | History | Annotate | Download | only in jni 
      1 /*
      2  * Copyright 2014, The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *     http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #define LOG_TAG "ActivityRecognitionHardware"
     18 
     19 #include <jni.h>
     20 #include <JNIHelp.h>
     21 
     22 #include <android_runtime/AndroidRuntime.h>
     23 #include <android_runtime/Log.h>
     24 
     25 #include "activity_recognition.h"
     26 
     27 
     28 // keep base connection data from the HAL
     29 static activity_recognition_module_t* sModule = NULL;
     30 static activity_recognition_device_t* sDevice = NULL;
     31 
     32 static jobject sCallbacksObject = NULL;
     33 static jmethodID sOnActivityChanged = NULL;
     34 
     35 
     36 static void check_and_clear_exceptions(JNIEnv* env, const char* method_name) {
     37     if (!env->ExceptionCheck()) {
     38         return;
     39     }
     40 
     41     ALOGE("An exception was thrown by '%s'.", method_name);
     42     LOGE_EX(env);
     43     env->ExceptionClear();
     44 }
     45 
     46 static jint attach_thread(JNIEnv** env) {
     47     JavaVM* java_vm = android::AndroidRuntime::getJavaVM();
     48     assert(java_vm != NULL);
     49 
     50     JavaVMAttachArgs args = {
     51         JNI_VERSION_1_6,
     52         "ActivityRecognition HAL callback.",
     53         NULL /* group */
     54     };
     55 
     56     jint result = java_vm->AttachCurrentThread(env, &args);
     57     if (result != JNI_OK) {
     58         ALOGE("Attach to callback thread failed: %d", result);
     59     }
     60 
     61     return result;
     62 }
     63 
     64 static jint detach_thread() {
     65     JavaVM* java_vm = android::AndroidRuntime::getJavaVM();
     66     assert(java_vm != NULL);
     67 
     68     jint result = java_vm->DetachCurrentThread();
     69     if (result != JNI_OK) {
     70         ALOGE("Detach of callback thread failed: %d", result);
     71     }
     72 
     73     return result;
     74 }
     75 
     76 
     77 /**
     78  * Handle activity recognition events from HAL.
     79  */
     80 static void activity_callback(
     81         const activity_recognition_callback_procs_t* procs,
     82         const activity_event_t* events,
     83         int count) {
     84     if (sOnActivityChanged == NULL) {
     85         ALOGE("Dropping activity_callback because onActivityChanged handler is null.");
     86         return;
     87     }
     88 
     89     if (events == NULL || count <= 0) {
     90         ALOGE("Invalid activity_callback. Count: %d, Events: %p", count, events);
     91         return;
     92     }
     93 
     94     JNIEnv* env = NULL;
     95     int result = attach_thread(&env);
     96     if (result != JNI_OK) {
     97         ALOGE("Unable to attach thread with JNI.");
     98         return;
     99     }
    100 
    101     jclass event_class =
    102             env->FindClass("android/hardware/location/ActivityRecognitionHardware$Event");
    103     jmethodID event_ctor = env->GetMethodID(event_class, "<init>", "()V");
    104     jfieldID activity_field = env->GetFieldID(event_class, "activity", "I");
    105     jfieldID type_field = env->GetFieldID(event_class, "type", "I");
    106     jfieldID timestamp_field = env->GetFieldID(event_class, "timestamp", "J");
    107 
    108     jobjectArray events_array = env->NewObjectArray(count, event_class, NULL);
    109     for (int i = 0; i < count; ++i) {
    110         const activity_event_t* event = &events[i];
    111         jobject event_object = env->NewObject(event_class, event_ctor);
    112         env->SetIntField(event_object, activity_field, event->activity);
    113         env->SetIntField(event_object, type_field, event->event_type);
    114         env->SetLongField(event_object, timestamp_field, event->timestamp);
    115         env->SetObjectArrayElement(events_array, i, event_object);
    116         env->DeleteLocalRef(event_object);
    117     }
    118 
    119     env->CallVoidMethod(sCallbacksObject, sOnActivityChanged, events_array);
    120     check_and_clear_exceptions(env, __FUNCTION__);
    121 
    122     // TODO: ideally we'd let the HAL register the callback thread only once
    123     detach_thread();
    124 }
    125 
    126 activity_recognition_callback_procs_t sCallbacks {
    127     activity_callback,
    128 };
    129 
    130 /**
    131  * Initializes the ActivityRecognitionHardware class from the native side.
    132  */
    133 static void class_init(JNIEnv* env, jclass clazz) {
    134     // open the hardware module
    135     int error = hw_get_module(
    136             ACTIVITY_RECOGNITION_HARDWARE_MODULE_ID,
    137             (const hw_module_t**) &sModule);
    138     if (error != 0) {
    139         ALOGE("Error hw_get_module: %d", error);
    140         return;
    141     }
    142 
    143     error = activity_recognition_open(&sModule->common, &sDevice);
    144     if (error != 0) {
    145         ALOGE("Error opening device: %d", error);
    146         return;
    147     }
    148 
    149     // get references to the Java provided methods
    150     sOnActivityChanged = env->GetMethodID(
    151             clazz,
    152             "onActivityChanged",
    153             "([Landroid/hardware/location/ActivityRecognitionHardware$Event;)V");
    154     if (sOnActivityChanged == NULL) {
    155         ALOGE("Error obtaining ActivityChanged callback.");
    156         return;
    157     }
    158 
    159     // register callbacks
    160     sDevice->register_activity_callback(sDevice, &sCallbacks);
    161 }
    162 
    163 /**
    164  * Initializes and connect the callbacks handlers in the HAL.
    165  */
    166 static void initialize(JNIEnv* env, jobject obj) {
    167     if (sCallbacksObject == NULL) {
    168         sCallbacksObject = env->NewGlobalRef(obj);
    169     } else {
    170         ALOGD("Callbacks Object was already initialized.");
    171     }
    172 
    173     if (sDevice != NULL) {
    174         sDevice->register_activity_callback(sDevice, &sCallbacks);
    175     } else {
    176         ALOGD("ActivityRecognition device not found during initialization.");
    177     }
    178 }
    179 
    180 /**
    181  * De-initializes the ActivityRecognitionHardware from the native side.
    182  */
    183 static void release(JNIEnv* env, jobject obj) {
    184     if (sDevice == NULL) {
    185         return;
    186     }
    187 
    188     int error = activity_recognition_close(sDevice);
    189     if (error != 0) {
    190         ALOGE("Error closing device: %d", error);
    191         return;
    192     }
    193 }
    194 
    195 /**
    196  * Returns true if ActivityRecognition HAL is supported, false otherwise.
    197  */
    198 static jboolean is_supported(JNIEnv* env, jclass clazz) {
    199     if (sModule != NULL && sDevice != NULL ) {
    200         return JNI_TRUE;
    201     }
    202     return JNI_FALSE;
    203 }
    204 
    205 /**
    206  * Gets an array representing the supported activities.
    207  */
    208 static jobjectArray get_supported_activities(JNIEnv* env, jobject obj) {
    209     if (sModule == NULL) {
    210         return NULL;
    211     }
    212 
    213     char const* const* list = NULL;
    214     int list_size = sModule->get_supported_activities_list(sModule, &list);
    215     if (list_size <= 0 || list == NULL) {
    216         return NULL;
    217     }
    218 
    219     jclass string_class = env->FindClass("java/lang/String");
    220     if (string_class == NULL) {
    221         ALOGE("Unable to find String class for supported activities.");
    222         return NULL;
    223     }
    224 
    225     jobjectArray string_array = env->NewObjectArray(list_size, string_class, NULL);
    226     if (string_array == NULL) {
    227         ALOGE("Unable to create string array for supported activities.");
    228         return NULL;
    229     }
    230 
    231     for (int i = 0; i < list_size; ++i) {
    232         const char* string_ptr = const_cast<const char*>(list[i]);
    233         jstring string = env->NewStringUTF(string_ptr);
    234         env->SetObjectArrayElement(string_array, i, string);
    235     }
    236 
    237     return string_array;
    238 }
    239 
    240 /**
    241  * Enables a given activity event to be actively monitored.
    242  */
    243 static int enable_activity_event(
    244         JNIEnv* env,
    245         jobject obj,
    246         jint activity_handle,
    247         jint event_type,
    248         jlong report_latency_ns) {
    249     return sDevice->enable_activity_event(
    250             sDevice,
    251             (uint32_t) activity_handle,
    252             (uint32_t) event_type,
    253             report_latency_ns);
    254 }
    255 
    256 /**
    257  * Disables a given activity event from being actively monitored.
    258  */
    259 static int disable_activity_event(
    260         JNIEnv* env,
    261         jobject obj,
    262         jint activity_handle,
    263         jint event_type) {
    264     return sDevice->disable_activity_event(
    265             sDevice,
    266             (uint32_t) activity_handle,
    267             (uint32_t) event_type);
    268 }
    269 
    270 /**
    271  * Request flush for al batch buffers.
    272  */
    273 static int flush(JNIEnv* env, jobject obj) {
    274     return sDevice->flush(sDevice);
    275 }
    276 
    277 
    278 static JNINativeMethod sMethods[] = {
    279     // {"name", "signature", (void*) functionPointer },
    280     { "nativeClassInit", "()V", (void*) class_init },
    281     { "nativeInitialize", "()V", (void*) initialize },
    282     { "nativeRelease", "()V", (void*) release },
    283     { "nativeIsSupported", "()Z", (void*) is_supported },
    284     { "nativeGetSupportedActivities", "()[Ljava/lang/String;", (void*) get_supported_activities },
    285     { "nativeEnableActivityEvent", "(IIJ)I", (void*) enable_activity_event },
    286     { "nativeDisableActivityEvent", "(II)I", (void*) disable_activity_event },
    287     { "nativeFlush", "()I", (void*) flush },
    288 };
    289 
    290 /**
    291  * Registration method invoked in JNI load.
    292  */
    293 int register_android_hardware_location_ActivityRecognitionHardware(JNIEnv* env) {
    294     return jniRegisterNativeMethods(
    295             env,
    296             "android/hardware/location/ActivityRecognitionHardware",
    297             sMethods,
    298             NELEM(sMethods));
    299 }
    300