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      1 /*
      2  * Copyright (C) 2005 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 "misc"
     18 
     19 //
     20 // Miscellaneous utility functions.
     21 //
     22 #include <utils/misc.h>
     23 #include <utils/Log.h>
     24 
     25 #include <sys/stat.h>
     26 #include <string.h>
     27 #include <errno.h>
     28 #include <stdio.h>
     29 
     30 #if defined(HAVE_PTHREADS)
     31 # include <pthread.h>
     32 #endif
     33 
     34 #include <utils/Vector.h>
     35 
     36 using namespace android;
     37 
     38 namespace android {
     39 
     40 struct sysprop_change_callback_info {
     41     sysprop_change_callback callback;
     42     int priority;
     43 };
     44 
     45 #if defined(HAVE_PTHREADS)
     46 static pthread_mutex_t gSyspropMutex = PTHREAD_MUTEX_INITIALIZER;
     47 static Vector<sysprop_change_callback_info>* gSyspropList = NULL;
     48 #endif
     49 
     50 void add_sysprop_change_callback(sysprop_change_callback cb, int priority) {
     51 #if defined(HAVE_PTHREADS)
     52     pthread_mutex_lock(&gSyspropMutex);
     53     if (gSyspropList == NULL) {
     54         gSyspropList = new Vector<sysprop_change_callback_info>();
     55     }
     56     sysprop_change_callback_info info;
     57     info.callback = cb;
     58     info.priority = priority;
     59     bool added = false;
     60     for (size_t i=0; i<gSyspropList->size(); i++) {
     61         if (priority >= gSyspropList->itemAt(i).priority) {
     62             gSyspropList->insertAt(info, i);
     63             added = true;
     64             break;
     65         }
     66     }
     67     if (!added) {
     68         gSyspropList->add(info);
     69     }
     70     pthread_mutex_unlock(&gSyspropMutex);
     71 #endif
     72 }
     73 
     74 void report_sysprop_change() {
     75 #if defined(HAVE_PTHREADS)
     76     pthread_mutex_lock(&gSyspropMutex);
     77     Vector<sysprop_change_callback_info> listeners;
     78     if (gSyspropList != NULL) {
     79         listeners = *gSyspropList;
     80     }
     81     pthread_mutex_unlock(&gSyspropMutex);
     82 
     83     //ALOGI("Reporting sysprop change to %d listeners", listeners.size());
     84     for (size_t i=0; i<listeners.size(); i++) {
     85         listeners[i].callback();
     86     }
     87 #endif
     88 }
     89 
     90 }; // namespace android
     91