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 "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 namespace android {
27
28 static struct {
29 jfieldID mPtr; // native object attached to the DVM MessageQueue
30 } gMessageQueueClassInfo;
31
32
33 class NativeMessageQueue : public MessageQueue {
34 public:
35 NativeMessageQueue();
36 virtual ~NativeMessageQueue();
37
38 virtual void raiseException(JNIEnv* env, const char* msg, jthrowable exceptionObj);
39
40 void pollOnce(JNIEnv* env, int timeoutMillis);
41
42 void wake();
43
44 private:
45 bool mInCallback;
46 jthrowable mExceptionObj;
47 };
48
49
MessageQueue()50 MessageQueue::MessageQueue() {
51 }
52
~MessageQueue()53 MessageQueue::~MessageQueue() {
54 }
55
raiseAndClearException(JNIEnv * env,const char * msg)56 bool MessageQueue::raiseAndClearException(JNIEnv* env, const char* msg) {
57 jthrowable exceptionObj = env->ExceptionOccurred();
58 if (exceptionObj) {
59 env->ExceptionClear();
60 raiseException(env, msg, exceptionObj);
61 env->DeleteLocalRef(exceptionObj);
62 return true;
63 }
64 return false;
65 }
66
NativeMessageQueue()67 NativeMessageQueue::NativeMessageQueue() : mInCallback(false), mExceptionObj(NULL) {
68 mLooper = Looper::getForThread();
69 if (mLooper == NULL) {
70 mLooper = new Looper(false);
71 Looper::setForThread(mLooper);
72 }
73 }
74
~NativeMessageQueue()75 NativeMessageQueue::~NativeMessageQueue() {
76 }
77
raiseException(JNIEnv * env,const char * msg,jthrowable exceptionObj)78 void NativeMessageQueue::raiseException(JNIEnv* env, const char* msg, jthrowable exceptionObj) {
79 if (exceptionObj) {
80 if (mInCallback) {
81 if (mExceptionObj) {
82 env->DeleteLocalRef(mExceptionObj);
83 }
84 mExceptionObj = jthrowable(env->NewLocalRef(exceptionObj));
85 ALOGE("Exception in MessageQueue callback: %s", msg);
86 jniLogException(env, ANDROID_LOG_ERROR, LOG_TAG, exceptionObj);
87 } else {
88 ALOGE("Exception: %s", msg);
89 jniLogException(env, ANDROID_LOG_ERROR, LOG_TAG, exceptionObj);
90 LOG_ALWAYS_FATAL("raiseException() was called when not in a callback, exiting.");
91 }
92 }
93 }
94
pollOnce(JNIEnv * env,int timeoutMillis)95 void NativeMessageQueue::pollOnce(JNIEnv* env, int timeoutMillis) {
96 mInCallback = true;
97 mLooper->pollOnce(timeoutMillis);
98 mInCallback = false;
99 if (mExceptionObj) {
100 env->Throw(mExceptionObj);
101 env->DeleteLocalRef(mExceptionObj);
102 mExceptionObj = NULL;
103 }
104 }
105
wake()106 void NativeMessageQueue::wake() {
107 mLooper->wake();
108 }
109
110 // ----------------------------------------------------------------------------
111
android_os_MessageQueue_getMessageQueue(JNIEnv * env,jobject messageQueueObj)112 sp<MessageQueue> android_os_MessageQueue_getMessageQueue(JNIEnv* env, jobject messageQueueObj) {
113 jint intPtr = env->GetIntField(messageQueueObj, gMessageQueueClassInfo.mPtr);
114 return reinterpret_cast<NativeMessageQueue*>(intPtr);
115 }
116
android_os_MessageQueue_nativeInit(JNIEnv * env,jclass clazz)117 static jint android_os_MessageQueue_nativeInit(JNIEnv* env, jclass clazz) {
118 NativeMessageQueue* nativeMessageQueue = new NativeMessageQueue();
119 if (!nativeMessageQueue) {
120 jniThrowRuntimeException(env, "Unable to allocate native queue");
121 return 0;
122 }
123
124 nativeMessageQueue->incStrong(env);
125 return reinterpret_cast<jint>(nativeMessageQueue);
126 }
127
android_os_MessageQueue_nativeDestroy(JNIEnv * env,jclass clazz,jint ptr)128 static void android_os_MessageQueue_nativeDestroy(JNIEnv* env, jclass clazz, jint ptr) {
129 NativeMessageQueue* nativeMessageQueue = reinterpret_cast<NativeMessageQueue*>(ptr);
130 nativeMessageQueue->decStrong(env);
131 }
132
android_os_MessageQueue_nativePollOnce(JNIEnv * env,jclass clazz,jint ptr,jint timeoutMillis)133 static void android_os_MessageQueue_nativePollOnce(JNIEnv* env, jclass clazz,
134 jint ptr, jint timeoutMillis) {
135 NativeMessageQueue* nativeMessageQueue = reinterpret_cast<NativeMessageQueue*>(ptr);
136 nativeMessageQueue->pollOnce(env, timeoutMillis);
137 }
138
android_os_MessageQueue_nativeWake(JNIEnv * env,jclass clazz,jint ptr)139 static void android_os_MessageQueue_nativeWake(JNIEnv* env, jclass clazz, jint ptr) {
140 NativeMessageQueue* nativeMessageQueue = reinterpret_cast<NativeMessageQueue*>(ptr);
141 return nativeMessageQueue->wake();
142 }
143
144 // ----------------------------------------------------------------------------
145
146 static JNINativeMethod gMessageQueueMethods[] = {
147 /* name, signature, funcPtr */
148 { "nativeInit", "()I", (void*)android_os_MessageQueue_nativeInit },
149 { "nativeDestroy", "(I)V", (void*)android_os_MessageQueue_nativeDestroy },
150 { "nativePollOnce", "(II)V", (void*)android_os_MessageQueue_nativePollOnce },
151 { "nativeWake", "(I)V", (void*)android_os_MessageQueue_nativeWake }
152 };
153
154 #define FIND_CLASS(var, className) \
155 var = env->FindClass(className); \
156 LOG_FATAL_IF(! var, "Unable to find class " className);
157
158 #define GET_FIELD_ID(var, clazz, fieldName, fieldDescriptor) \
159 var = env->GetFieldID(clazz, fieldName, fieldDescriptor); \
160 LOG_FATAL_IF(! var, "Unable to find field " fieldName);
161
register_android_os_MessageQueue(JNIEnv * env)162 int register_android_os_MessageQueue(JNIEnv* env) {
163 int res = jniRegisterNativeMethods(env, "android/os/MessageQueue",
164 gMessageQueueMethods, NELEM(gMessageQueueMethods));
165 LOG_FATAL_IF(res < 0, "Unable to register native methods.");
166
167 jclass clazz;
168 FIND_CLASS(clazz, "android/os/MessageQueue");
169
170 GET_FIELD_ID(gMessageQueueClassInfo.mPtr, clazz,
171 "mPtr", "I");
172
173 return 0;
174 }
175
176 } // namespace android
177