upload android base code part6

android/system/core/libutils/misc.cpp

@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2005 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 "misc"
+
+#include <utils/misc.h>
+
+#include <pthread.h>
+
+#include <utils/Log.h>
+#include <utils/Vector.h>
+
+#if defined(__ANDROID__)
+#include <dlfcn.h>
+#include <vndksupport/linker.h>
+#endif
+
+extern "C" void do_report_sysprop_change();
+
+using namespace android;
+
+namespace android {
+
+struct sysprop_change_callback_info {
+    sysprop_change_callback callback;
+    int priority;
+};
+
+#if !defined(_WIN32)
+static pthread_mutex_t gSyspropMutex = PTHREAD_MUTEX_INITIALIZER;
+static Vector<sysprop_change_callback_info>* gSyspropList = NULL;
+#endif
+
+void add_sysprop_change_callback(sysprop_change_callback cb, int priority) {
+#if !defined(_WIN32)
+    pthread_mutex_lock(&gSyspropMutex);
+    if (gSyspropList == NULL) {
+        gSyspropList = new Vector<sysprop_change_callback_info>();
+    }
+    sysprop_change_callback_info info;
+    info.callback = cb;
+    info.priority = priority;
+    bool added = false;
+    for (size_t i=0; i<gSyspropList->size(); i++) {
+        if (priority >= gSyspropList->itemAt(i).priority) {
+            gSyspropList->insertAt(info, i);
+            added = true;
+            break;
+        }
+    }
+    if (!added) {
+        gSyspropList->add(info);
+    }
+    pthread_mutex_unlock(&gSyspropMutex);
+#endif
+}
+
+#if defined(__ANDROID__)
+void (*get_report_sysprop_change_func())() {
+    void (*func)() = nullptr;
+    void* handle = android_load_sphal_library("libutils.so", RTLD_NOW);
+    if (handle != nullptr) {
+        func = reinterpret_cast<decltype(func)>(dlsym(handle, "do_report_sysprop_change"));
+    }
+
+    return func;
+}
+#endif
+
+void report_sysprop_change() {
+    do_report_sysprop_change();
+
+#if defined(__ANDROID__)
+    // libutils.so is double loaded; from the default namespace and from the
+    // 'sphal' namespace. Redirect the sysprop change event to the other instance
+    // of libutils.so loaded in the 'sphal' namespace so that listeners attached
+    // to that instance is also notified with this event.
+    static auto func = get_report_sysprop_change_func();
+    if (func != nullptr) {
+        (*func)();
+    }
+#endif
+}
+
+};  // namespace android
+
+void do_report_sysprop_change() {
+#if !defined(_WIN32)
+    pthread_mutex_lock(&gSyspropMutex);
+    Vector<sysprop_change_callback_info> listeners;
+    if (gSyspropList != NULL) {
+        listeners = *gSyspropList;
+    }
+    pthread_mutex_unlock(&gSyspropMutex);
+
+    //ALOGI("Reporting sysprop change to %d listeners", listeners.size());
+    for (size_t i=0; i<listeners.size(); i++) {
+        listeners[i].callback();
+    }
+#endif
+}