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#include <utils/misc.h>
20
21#include <pthread.h>
22
23#include <utils/Log.h>
24#include <utils/Vector.h>
25
26#if defined(__ANDROID__)
27#include <dlfcn.h>
28#include <vndksupport/linker.h>
29#endif
30
31extern "C" void do_report_sysprop_change();
32
33using namespace android;
34
35namespace android {
36
37struct sysprop_change_callback_info {
38    sysprop_change_callback callback;
39    int priority;
40};
41
42#if !defined(_WIN32)
43static pthread_mutex_t gSyspropMutex = PTHREAD_MUTEX_INITIALIZER;
44static Vector<sysprop_change_callback_info>* gSyspropList = NULL;
45#endif
46
47void add_sysprop_change_callback(sysprop_change_callback cb, int priority) {
48#if !defined(_WIN32)
49    pthread_mutex_lock(&gSyspropMutex);
50    if (gSyspropList == NULL) {
51        gSyspropList = new Vector<sysprop_change_callback_info>();
52    }
53    sysprop_change_callback_info info;
54    info.callback = cb;
55    info.priority = priority;
56    bool added = false;
57    for (size_t i=0; i<gSyspropList->size(); i++) {
58        if (priority >= gSyspropList->itemAt(i).priority) {
59            gSyspropList->insertAt(info, i);
60            added = true;
61            break;
62        }
63    }
64    if (!added) {
65        gSyspropList->add(info);
66    }
67    pthread_mutex_unlock(&gSyspropMutex);
68#endif
69}
70
71#if defined(__ANDROID__)
72void (*get_report_sysprop_change_func())() {
73    void (*func)() = nullptr;
74    void* handle = android_load_sphal_library("libutils.so", RTLD_NOW);
75    if (handle != nullptr) {
76        func = reinterpret_cast<decltype(func)>(dlsym(handle, "do_report_sysprop_change"));
77    }
78
79    return func;
80}
81#endif
82
83void report_sysprop_change() {
84    do_report_sysprop_change();
85
86#if defined(__ANDROID__)
87    // libutils.so is double loaded; from the default namespace and from the
88    // 'sphal' namespace. Redirect the sysprop change event to the other instance
89    // of libutils.so loaded in the 'sphal' namespace so that listeners attached
90    // to that instance is also notified with this event.
91    static auto func = get_report_sysprop_change_func();
92    if (func != nullptr) {
93        (*func)();
94    }
95#endif
96}
97
98};  // namespace android
99
100void do_report_sysprop_change() {
101#if !defined(_WIN32)
102    pthread_mutex_lock(&gSyspropMutex);
103    Vector<sysprop_change_callback_info> listeners;
104    if (gSyspropList != NULL) {
105        listeners = *gSyspropList;
106    }
107    pthread_mutex_unlock(&gSyspropMutex);
108
109    //ALOGI("Reporting sysprop change to %d listeners", listeners.size());
110    for (size_t i=0; i<listeners.size(); i++) {
111        listeners[i].callback();
112    }
113#endif
114}
115