android_hardware_location_ActivityRecognitionHardware.cpp revision 3b0224dc3c2e7ffb93dc56970395003d0e387545 
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
29static activity_recognition_module_t* sModule = NULL;
30static activity_recognition_device_t* sDevice = NULL;
31
32static jobject sCallbacksObject = NULL;
33static jmethodID sOnActivityChanged = NULL;
34
35
36static 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
46static 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
64static 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 */
80static 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
126activity_recognition_callback_procs_t sCallbacks {
127    activity_callback,
128};
129
130/**
131 * Initializes the ActivityRecognitionHardware class from the native side.
132 */
133static 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 */
166static 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 */
183static 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 */
198static 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 */
208static 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 */
243static 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 */
259static 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 */
273static int flush(JNIEnv* env, jobject obj) {
274    return sDevice->flush(sDevice);
275}
276
277
278static 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 */
293int register_android_hardware_location_ActivityRecognitionHardware(JNIEnv* env) {
294    return jniRegisterNativeMethods(
295            env,
296            "android/hardware/location/ActivityRecognitionHardware",
297            sMethods,
298            NELEM(sMethods));
299}
300