1 /*
2 * Copyright (C) 2010 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 "MessageQueue-JNI"
18
19 #include <nativehelper/JNIHelp.h>
20 #include <android_runtime/AndroidRuntime.h>
21
22 #include <utils/Looper.h>
23 #include <utils/Log.h>
24 #include "android_os_MessageQueue.h"
25
26 #include "core_jni_helpers.h"
27
28 namespace android {
29
30 static struct {
31 jfieldID mPtr; // native object attached to the DVM MessageQueue
32 jmethodID dispatchEvents;
33 } gMessageQueueClassInfo;
34
35 // Must be kept in sync with the constants in Looper.FileDescriptorCallback
36 static const int CALLBACK_EVENT_INPUT = 1 << 0;
37 static const int CALLBACK_EVENT_OUTPUT = 1 << 1;
38 static const int CALLBACK_EVENT_ERROR = 1 << 2;
39
40
41 class NativeMessageQueue : public MessageQueue, public LooperCallback {
42 public:
43 NativeMessageQueue();
44 virtual ~NativeMessageQueue();
45
46 virtual void raiseException(JNIEnv* env, const char* msg, jthrowable exceptionObj);
47
48 void pollOnce(JNIEnv* env, jobject obj, int timeoutMillis);
49 void wake();
50 void setFileDescriptorEvents(int fd, int events);
51
52 virtual int handleEvent(int fd, int events, void* data);
53
54 private:
55 JNIEnv* mPollEnv;
56 jobject mPollObj;
57 jthrowable mExceptionObj;
58 };
59
60
MessageQueue()61 MessageQueue::MessageQueue() {
62 }
63
~MessageQueue()64 MessageQueue::~MessageQueue() {
65 }
66
raiseAndClearException(JNIEnv * env,const char * msg)67 bool MessageQueue::raiseAndClearException(JNIEnv* env, const char* msg) {
68 if (env->ExceptionCheck()) {
69 jthrowable exceptionObj = env->ExceptionOccurred();
70 env->ExceptionClear();
71 raiseException(env, msg, exceptionObj);
72 env->DeleteLocalRef(exceptionObj);
73 return true;
74 }
75 return false;
76 }
77
NativeMessageQueue()78 NativeMessageQueue::NativeMessageQueue() :
79 mPollEnv(NULL), mPollObj(NULL), mExceptionObj(NULL) {
80 mLooper = Looper::getForThread();
81 if (mLooper == NULL) {
82 mLooper = new Looper(false);
83 Looper::setForThread(mLooper);
84 }
85 }
86
~NativeMessageQueue()87 NativeMessageQueue::~NativeMessageQueue() {
88 }
89
raiseException(JNIEnv * env,const char * msg,jthrowable exceptionObj)90 void NativeMessageQueue::raiseException(JNIEnv* env, const char* msg, jthrowable exceptionObj) {
91 if (exceptionObj) {
92 if (mPollEnv == env) {
93 if (mExceptionObj) {
94 env->DeleteLocalRef(mExceptionObj);
95 }
96 mExceptionObj = jthrowable(env->NewLocalRef(exceptionObj));
97 ALOGE("Exception in MessageQueue callback: %s", msg);
98 jniLogException(env, ANDROID_LOG_ERROR, LOG_TAG, exceptionObj);
99 } else {
100 ALOGE("Exception: %s", msg);
101 jniLogException(env, ANDROID_LOG_ERROR, LOG_TAG, exceptionObj);
102 LOG_ALWAYS_FATAL("raiseException() was called when not in a callback, exiting.");
103 }
104 }
105 }
106
pollOnce(JNIEnv * env,jobject pollObj,int timeoutMillis)107 void NativeMessageQueue::pollOnce(JNIEnv* env, jobject pollObj, int timeoutMillis) {
108 mPollEnv = env;
109 mPollObj = pollObj;
110 mLooper->pollOnce(timeoutMillis);
111 mPollObj = NULL;
112 mPollEnv = NULL;
113
114 if (mExceptionObj) {
115 env->Throw(mExceptionObj);
116 env->DeleteLocalRef(mExceptionObj);
117 mExceptionObj = NULL;
118 }
119 }
120
wake()121 void NativeMessageQueue::wake() {
122 mLooper->wake();
123 }
124
setFileDescriptorEvents(int fd,int events)125 void NativeMessageQueue::setFileDescriptorEvents(int fd, int events) {
126 if (events) {
127 int looperEvents = 0;
128 if (events & CALLBACK_EVENT_INPUT) {
129 looperEvents |= Looper::EVENT_INPUT;
130 }
131 if (events & CALLBACK_EVENT_OUTPUT) {
132 looperEvents |= Looper::EVENT_OUTPUT;
133 }
134 mLooper->addFd(fd, Looper::POLL_CALLBACK, looperEvents, this,
135 reinterpret_cast<void*>(events));
136 } else {
137 mLooper->removeFd(fd);
138 }
139 }
140
handleEvent(int fd,int looperEvents,void * data)141 int NativeMessageQueue::handleEvent(int fd, int looperEvents, void* data) {
142 int events = 0;
143 if (looperEvents & Looper::EVENT_INPUT) {
144 events |= CALLBACK_EVENT_INPUT;
145 }
146 if (looperEvents & Looper::EVENT_OUTPUT) {
147 events |= CALLBACK_EVENT_OUTPUT;
148 }
149 if (looperEvents & (Looper::EVENT_ERROR | Looper::EVENT_HANGUP | Looper::EVENT_INVALID)) {
150 events |= CALLBACK_EVENT_ERROR;
151 }
152 int oldWatchedEvents = reinterpret_cast<intptr_t>(data);
153 int newWatchedEvents = mPollEnv->CallIntMethod(mPollObj,
154 gMessageQueueClassInfo.dispatchEvents, fd, events);
155 if (!newWatchedEvents) {
156 return 0; // unregister the fd
157 }
158 if (newWatchedEvents != oldWatchedEvents) {
159 setFileDescriptorEvents(fd, newWatchedEvents);
160 }
161 return 1;
162 }
163
164
165 // ----------------------------------------------------------------------------
166
android_os_MessageQueue_getMessageQueue(JNIEnv * env,jobject messageQueueObj)167 sp<MessageQueue> android_os_MessageQueue_getMessageQueue(JNIEnv* env, jobject messageQueueObj) {
168 jlong ptr = env->GetLongField(messageQueueObj, gMessageQueueClassInfo.mPtr);
169 return reinterpret_cast<NativeMessageQueue*>(ptr);
170 }
171
android_os_MessageQueue_nativeInit(JNIEnv * env,jclass clazz)172 static jlong android_os_MessageQueue_nativeInit(JNIEnv* env, jclass clazz) {
173 NativeMessageQueue* nativeMessageQueue = new NativeMessageQueue();
174 if (!nativeMessageQueue) {
175 jniThrowRuntimeException(env, "Unable to allocate native queue");
176 return 0;
177 }
178
179 nativeMessageQueue->incStrong(env);
180 return reinterpret_cast<jlong>(nativeMessageQueue);
181 }
182
android_os_MessageQueue_nativeDestroy(JNIEnv * env,jclass clazz,jlong ptr)183 static void android_os_MessageQueue_nativeDestroy(JNIEnv* env, jclass clazz, jlong ptr) {
184 NativeMessageQueue* nativeMessageQueue = reinterpret_cast<NativeMessageQueue*>(ptr);
185 nativeMessageQueue->decStrong(env);
186 }
187
android_os_MessageQueue_nativePollOnce(JNIEnv * env,jobject obj,jlong ptr,jint timeoutMillis)188 static void android_os_MessageQueue_nativePollOnce(JNIEnv* env, jobject obj,
189 jlong ptr, jint timeoutMillis) {
190 NativeMessageQueue* nativeMessageQueue = reinterpret_cast<NativeMessageQueue*>(ptr);
191 nativeMessageQueue->pollOnce(env, obj, timeoutMillis);
192 }
193
android_os_MessageQueue_nativeWake(JNIEnv * env,jclass clazz,jlong ptr)194 static void android_os_MessageQueue_nativeWake(JNIEnv* env, jclass clazz, jlong ptr) {
195 NativeMessageQueue* nativeMessageQueue = reinterpret_cast<NativeMessageQueue*>(ptr);
196 nativeMessageQueue->wake();
197 }
198
android_os_MessageQueue_nativeIsPolling(JNIEnv * env,jclass clazz,jlong ptr)199 static jboolean android_os_MessageQueue_nativeIsPolling(JNIEnv* env, jclass clazz, jlong ptr) {
200 NativeMessageQueue* nativeMessageQueue = reinterpret_cast<NativeMessageQueue*>(ptr);
201 return nativeMessageQueue->getLooper()->isPolling();
202 }
203
android_os_MessageQueue_nativeSetFileDescriptorEvents(JNIEnv * env,jclass clazz,jlong ptr,jint fd,jint events)204 static void android_os_MessageQueue_nativeSetFileDescriptorEvents(JNIEnv* env, jclass clazz,
205 jlong ptr, jint fd, jint events) {
206 NativeMessageQueue* nativeMessageQueue = reinterpret_cast<NativeMessageQueue*>(ptr);
207 nativeMessageQueue->setFileDescriptorEvents(fd, events);
208 }
209
210 // ----------------------------------------------------------------------------
211
212 static const JNINativeMethod gMessageQueueMethods[] = {
213 /* name, signature, funcPtr */
214 { "nativeInit", "()J", (void*)android_os_MessageQueue_nativeInit },
215 { "nativeDestroy", "(J)V", (void*)android_os_MessageQueue_nativeDestroy },
216 { "nativePollOnce", "(JI)V", (void*)android_os_MessageQueue_nativePollOnce },
217 { "nativeWake", "(J)V", (void*)android_os_MessageQueue_nativeWake },
218 { "nativeIsPolling", "(J)Z", (void*)android_os_MessageQueue_nativeIsPolling },
219 { "nativeSetFileDescriptorEvents", "(JII)V",
220 (void*)android_os_MessageQueue_nativeSetFileDescriptorEvents },
221 };
222
register_android_os_MessageQueue(JNIEnv * env)223 int register_android_os_MessageQueue(JNIEnv* env) {
224 int res = RegisterMethodsOrDie(env, "android/os/MessageQueue", gMessageQueueMethods,
225 NELEM(gMessageQueueMethods));
226
227 jclass clazz = FindClassOrDie(env, "android/os/MessageQueue");
228 gMessageQueueClassInfo.mPtr = GetFieldIDOrDie(env, clazz, "mPtr", "J");
229 gMessageQueueClassInfo.dispatchEvents = GetMethodIDOrDie(env, clazz,
230 "dispatchEvents", "(II)I");
231
232 return res;
233 }
234
235 } // namespace android
236