[NETD-BPF#1] Move libnetdutils to frameworks/libs/net/...

libnetdutils is referenced by netd.c and TrafficController.cpp, which
are going to be mainlined. Therefore, move libnetdutils to a common
place where both mainline module and platform code (Netd) can refer to.

Bug: 202086915
Test: build; flash; cd system/netd; atest
Ignore-AOSP-First: the netd change(same topic) would not automerge from
aosp.
No-Typo-Check: Clean code move with no other changes.
BYPASS_INCLUSIVE_LANGUAGE_REASON=Clean code move with no other changes.
Change-Id: I645bfe35f6543149c9a9f894cd4158d27a481abe

staticlibs/netd/libnetdutils/include/netdutils/ThreadUtil.h

@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+#ifndef NETDUTILS_THREADUTIL_H
+#define NETDUTILS_THREADUTIL_H
+
+#include <pthread.h>
+#include <memory>
+
+#include <android-base/logging.h>
+
+namespace android {
+namespace netdutils {
+
+struct scoped_pthread_attr {
+    scoped_pthread_attr() { pthread_attr_init(&attr); }
+    ~scoped_pthread_attr() { pthread_attr_destroy(&attr); }
+
+    int detach() { return -pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); }
+
+    pthread_attr_t attr;
+};
+
+inline void setThreadName(std::string name) {
+    // MAX_TASK_COMM_LEN=16 is not exported by bionic.
+    const size_t MAX_TASK_COMM_LEN = 16;
+
+    // Crop name to 16 bytes including the NUL byte, as required by pthread_setname_np()
+    if (name.size() >= MAX_TASK_COMM_LEN) name.resize(MAX_TASK_COMM_LEN - 1);
+
+    if (int ret = pthread_setname_np(pthread_self(), name.c_str()); ret != 0) {
+        LOG(WARNING) << "Unable to set thread name to " << name << ": " << strerror(ret);
+    }
+}
+
+template <typename T>
+inline void* runAndDelete(void* obj) {
+    std::unique_ptr<T> handler(reinterpret_cast<T*>(obj));
+    setThreadName(handler->threadName().c_str());
+    handler->run();
+    return nullptr;
+}
+
+template <typename T>
+inline int threadLaunch(T* obj) {
+    if (obj == nullptr) {
+        return -EINVAL;
+    }
+
+    scoped_pthread_attr scoped_attr;
+
+    int rval = scoped_attr.detach();
+    if (rval != 0) {
+        return rval;
+    }
+
+    pthread_t thread;
+    rval = pthread_create(&thread, &scoped_attr.attr, &runAndDelete<T>, obj);
+    if (rval != 0) {
+        LOG(WARNING) << __func__ << ": pthread_create failed: " << rval;
+        return -rval;
+    }
+
+    return rval;
+}
+
+}  // namespace netdutils
+}  // namespace android
+
+#endif  // NETDUTILS_THREADUTIL_H