android_hardware_location_ActivityRecognitionHardware.cpp revision a4fa3b5aa53cf677b623fe346c585cb8a0c1ce26 
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        return;
98    }
99
100    jclass event_class =
101            env->FindClass("android/hardware/location/ActivityRecognitionHardware$Event");
102    jmethodID event_ctor = env->GetMethodID(event_class, "<init>", "()V");
103    jfieldID activity_field = env->GetFieldID(event_class, "activity", "I");
104    jfieldID type_field = env->GetFieldID(event_class, "type", "I");
105    jfieldID timestamp_field = env->GetFieldID(event_class, "timestamp", "J");
106
107    jobjectArray events_array = env->NewObjectArray(count, event_class, NULL);
108    for (int i = 0; i < count; ++i) {
109        const activity_event_t* event = &events[i];
110        jobject event_object = env->NewObject(event_class, event_ctor);
111        env->SetIntField(event_object, activity_field, event->activity);
112        env->SetIntField(event_object, type_field, event->event_type);
113        env->SetLongField(event_object, timestamp_field, event->timestamp);
114        env->SetObjectArrayElement(events_array, i, event_object);
115        env->DeleteLocalRef(event_object);
116    }
117
118    env->CallVoidMethod(sCallbacksObject, sOnActivityChanged, events_array);
119    check_and_clear_exceptions(env, __FUNCTION__);
120
121    // TODO: ideally we'd let the HAL register the callback thread only once
122    detach_thread();
123}
124
125activity_recognition_callback_procs_t sCallbacks {
126    activity_callback,
127};
128
129/**
130 * Initializes the ActivityRecognitionHardware class from the native side.
131 */
132static void class_init(JNIEnv* env, jclass clazz) {
133    // open the hardware module
134    int error = hw_get_module(
135            ACTIVITY_RECOGNITION_HARDWARE_MODULE_ID,
136            (const hw_module_t**) &sModule);
137    if (error != 0) {
138        ALOGE("Error hw_get_module: %d", error);
139        return;
140    }
141
142    error = activity_recognition_open(&sModule->common, &sDevice);
143    if (error != 0) {
144        ALOGE("Error opening device: %d", error);
145        return;
146    }
147
148    // get references to the Java provided methods
149    sOnActivityChanged = env->GetMethodID(
150            clazz,
151            "onActivityChanged",
152            "([Landroid/hardware/location/ActivityRecognitionHardware$Event;)V");
153    if (sOnActivityChanged == NULL) {
154        ALOGE("Error obtaining ActivityChanged callback.");
155        return;
156    }
157
158    // register callbacks
159    sDevice->register_activity_callback(sDevice, &sCallbacks);
160}
161
162/**
163 * Initializes and connect the callbacks handlers in the HAL.
164 */
165static void initialize(JNIEnv* env, jobject obj) {
166    if (sCallbacksObject == NULL) {
167        sCallbacksObject = env->NewGlobalRef(obj);
168    } else {
169        ALOGD("Callbacks Object was already initialized.");
170    }
171
172    if (sDevice != NULL) {
173        sDevice->register_activity_callback(sDevice, &sCallbacks);
174    } else {
175        ALOGD("ActivityRecognition device not found during initialization.");
176    }
177}
178
179/**
180 * De-initializes the ActivityRecognitionHardware from the native side.
181 */
182static void release(JNIEnv* env, jobject obj) {
183    if (sDevice == NULL) {
184        return;
185    }
186
187    int error = activity_recognition_close(sDevice);
188    if (error != 0) {
189        ALOGE("Error closing device: %d", error);
190        return;
191    }
192}
193
194/**
195 * Returns true if ActivityRecognition HAL is supported, false otherwise.
196 */
197static jboolean is_supported(JNIEnv* env, jclass clazz) {
198    if (sModule != NULL && sDevice != NULL ) {
199        return JNI_TRUE;
200    }
201    return JNI_FALSE;
202}
203
204/**
205 * Gets an array representing the supported activities.
206 */
207static jobjectArray get_supported_activities(JNIEnv* env, jobject obj) {
208    if (sModule == NULL) {
209        return NULL;
210    }
211
212    char const* const* list = NULL;
213    int list_size = sModule->get_supported_activities_list(sModule, &list);
214    if (list_size <= 0 || list == NULL) {
215        return NULL;
216    }
217
218    jclass string_class = env->FindClass("java/lang/String;");
219    if (string_class == NULL) {
220        ALOGE("Unable to find String class for supported activities.");
221        return NULL;
222    }
223
224    jobjectArray string_array = env->NewObjectArray(list_size, string_class, NULL);
225    if (string_array == NULL) {
226        ALOGE("Unable to create string array for supported activities.");
227        return NULL;
228    }
229
230    for (int i = 0; i < list_size; ++i) {
231        const char* string_ptr = const_cast<const char*>(list[i]);
232        jsize string_length = strlen(string_ptr);
233        jstring string = env->NewString((const jchar*) string_ptr, string_length);
234        env->SetObjectArrayElement(string_array, i, string);
235
236        // log debugging information in case we need to try to trace issues with the strings
237        if (string_length) {
238            ALOGD("Invalid activity (index=%d) name size: %d", i, string_length);
239        }
240    }
241
242    return string_array;
243}
244
245/**
246 * Enables a given activity event to be actively monitored.
247 */
248static int enable_activity_event(
249        JNIEnv* env,
250        jobject obj,
251        jint activity_handle,
252        jint event_type,
253        jlong report_latency_ns) {
254    return sDevice->enable_activity_event(
255            sDevice,
256            (uint32_t) activity_handle,
257            (uint32_t) event_type,
258            report_latency_ns);
259}
260
261/**
262 * Disables a given activity event from being actively monitored.
263 */
264static int disable_activity_event(
265        JNIEnv* env,
266        jobject obj,
267        jint activity_handle,
268        jint event_type) {
269    return sDevice->disable_activity_event(
270            sDevice,
271            (uint32_t) activity_handle,
272            (uint32_t) event_type);
273}
274
275/**
276 * Request flush for al batch buffers.
277 */
278static int flush(JNIEnv* env, jobject obj) {
279    return sDevice->flush(sDevice);
280}
281
282
283static JNINativeMethod sMethods[] = {
284    // {"name", "signature", (void*) functionPointer },
285    { "nativeClassInit", "()V", (void*) class_init },
286    { "nativeInitialize", "()V", (void*) initialize },
287    { "nativeRelease", "()V", (void*) release },
288    { "nativeIsSupported", "()Z", (void*) is_supported },
289    { "nativeGetSupportedActivities", "()[Ljava/lang/String;", (void*) get_supported_activities },
290    { "nativeEnableActivityEvent", "(IIJ)I", (void*) enable_activity_event },
291    { "nativeDisableActivityEvent", "(II)I", (void*) disable_activity_event },
292    { "nativeFlush", "()I", (void*) flush },
293};
294
295/**
296 * Registration method invoked in JNI load.
297 */
298int register_android_hardware_location_ActivityRecognitionHardware(JNIEnv* env) {
299    return jniRegisterNativeMethods(
300            env,
301            "android/hardware/location/ActivityRecognitionHardware",
302            sMethods,
303            NELEM(sMethods));
304}
305