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__) && !defined(__ANDROID_RECOVERY__)
27 #include <dlfcn.h>
28 #include <vndksupport/linker.h>
29 #endif
30
31 extern "C" void do_report_sysprop_change();
32
33 using namespace android;
34
35 namespace android {
36
37 struct sysprop_change_callback_info {
38 sysprop_change_callback callback;
39 int priority;
40 };
41
42 #if !defined(_WIN32)
43 static pthread_mutex_t gSyspropMutex = PTHREAD_MUTEX_INITIALIZER;
44 static Vector<sysprop_change_callback_info>* gSyspropList = nullptr;
45 #endif
46
47 #if !defined(_WIN32)
add_sysprop_change_callback(sysprop_change_callback cb,int priority)48 void add_sysprop_change_callback(sysprop_change_callback cb, int priority) {
49 pthread_mutex_lock(&gSyspropMutex);
50 if (gSyspropList == nullptr) {
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 }
69 #else
add_sysprop_change_callback(sysprop_change_callback,int)70 void add_sysprop_change_callback(sysprop_change_callback, int) {}
71 #endif
72
73 #if defined(__ANDROID__) && !defined(__ANDROID_RECOVERY__)
get_report_sysprop_change_func()74 void (*get_report_sysprop_change_func())() {
75 void (*func)() = nullptr;
76 void* handle = android_load_sphal_library("libutils.so", RTLD_NOW);
77 if (handle != nullptr) {
78 func = reinterpret_cast<decltype(func)>(dlsym(handle, "do_report_sysprop_change"));
79 }
80
81 return func;
82 }
83 #endif
84
report_sysprop_change()85 void report_sysprop_change() {
86 do_report_sysprop_change();
87
88 #if defined(__ANDROID__) && !defined(__ANDROID_RECOVERY__)
89 // libutils.so is double loaded; from the default namespace and from the
90 // 'sphal' namespace. Redirect the sysprop change event to the other instance
91 // of libutils.so loaded in the 'sphal' namespace so that listeners attached
92 // to that instance is also notified with this event.
93 static auto func = get_report_sysprop_change_func();
94 if (func != nullptr) {
95 (*func)();
96 }
97 #endif
98 }
99
100 }; // namespace android
101
do_report_sysprop_change()102 void do_report_sysprop_change() {
103 #if !defined(_WIN32)
104 pthread_mutex_lock(&gSyspropMutex);
105 Vector<sysprop_change_callback_info> listeners;
106 if (gSyspropList != nullptr) {
107 listeners = *gSyspropList;
108 }
109 pthread_mutex_unlock(&gSyspropMutex);
110
111 //ALOGI("Reporting sysprop change to %d listeners", listeners.size());
112 for (size_t i=0; i<listeners.size(); i++) {
113 listeners[i].callback();
114 }
115 #endif
116 }
117