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/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define LOG_TAG "UEventObserver"
//#define LOG_NDEBUG 0
#include "utils/Log.h"
#include "hardware_legacy/uevent.h"
#include "jni.h"
#include "JNIHelp.h"
#include "core_jni_helpers.h"
#include <utils/Mutex.h>
#include <utils/Vector.h>
#include <utils/String8.h>
#include <ScopedUtfChars.h>
namespace android {
static Mutex gMatchesMutex;
static Vector<String8> gMatches;
static void nativeSetup(JNIEnv *env, jclass clazz) {
if (!uevent_init()) {
jniThrowException(env, "java/lang/RuntimeException",
"Unable to open socket for UEventObserver");
}
}
static bool isMatch(const char* buffer, size_t length) {
AutoMutex _l(gMatchesMutex);
for (size_t i = 0; i < gMatches.size(); i++) {
const String8& match = gMatches.itemAt(i);
// Consider all zero-delimited fields of the buffer.
const char* field = buffer;
const char* end = buffer + length + 1;
do {
if (strstr(field, match.string())) {
ALOGV("Matched uevent message with pattern: %s", match.string());
return true;
}
field += strlen(field) + 1;
} while (field != end);
}
return false;
}
static jstring nativeWaitForNextEvent(JNIEnv *env, jclass clazz) {
char buffer[1024];
for (;;) {
int length = uevent_next_event(buffer, sizeof(buffer) - 1);
if (length <= 0) {
return NULL;
}
buffer[length] = '\0';
ALOGV("Received uevent message: %s", buffer);
if (isMatch(buffer, length)) {
// Assume the message is ASCII.
jchar message[length];
for (int i = 0; i < length; i++) {
message[i] = buffer[i];
}
return env->NewString(message, length);
}
}
}
static void nativeAddMatch(JNIEnv* env, jclass clazz, jstring matchStr) {
ScopedUtfChars match(env, matchStr);
AutoMutex _l(gMatchesMutex);
gMatches.add(String8(match.c_str()));
}
static void nativeRemoveMatch(JNIEnv* env, jclass clazz, jstring matchStr) {
ScopedUtfChars match(env, matchStr);
AutoMutex _l(gMatchesMutex);
for (size_t i = 0; i < gMatches.size(); i++) {
if (gMatches.itemAt(i) == match.c_str()) {
gMatches.removeAt(i);
break; // only remove first occurrence
}
}
}
static const JNINativeMethod gMethods[] = {
{ "nativeSetup", "()V",
(void *)nativeSetup },
{ "nativeWaitForNextEvent", "()Ljava/lang/String;",
(void *)nativeWaitForNextEvent },
{ "nativeAddMatch", "(Ljava/lang/String;)V",
(void *)nativeAddMatch },
{ "nativeRemoveMatch", "(Ljava/lang/String;)V",
(void *)nativeRemoveMatch },
};
int register_android_os_UEventObserver(JNIEnv *env)
{
FindClassOrDie(env, "android/os/UEventObserver");
return RegisterMethodsOrDie(env, "android/os/UEventObserver", gMethods, NELEM(gMethods));
}
} // namespace android
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