| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you 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. |
| #include "kudu/util/threadlocal.h" |
| |
| #include <pthread.h> |
| |
| #include <memory> |
| #include <ostream> |
| |
| #include <glog/logging.h> |
| |
| #include "kudu/gutil/once.h" |
| #include "kudu/util/errno.h" |
| |
| namespace kudu { |
| namespace threadlocal { |
| namespace internal { |
| |
| // One key used by the entire process to attach destructors on thread exit. |
| static pthread_key_t destructors_key; |
| |
| // The above key must only be initialized once per process. |
| static GoogleOnceType once = GOOGLE_ONCE_INIT; |
| |
| namespace { |
| |
| // List of destructors for all thread locals instantiated on a given thread. |
| struct PerThreadDestructorList { |
| void (*destructor)(void*); |
| void* arg; |
| PerThreadDestructorList* next; |
| }; |
| |
| } // anonymous namespace |
| |
| // Call all the destructors associated with all THREAD_LOCAL instances in this |
| // thread. |
| static void InvokeDestructors(void* t) { |
| PerThreadDestructorList* d = reinterpret_cast<PerThreadDestructorList*>(t); |
| while (d != nullptr) { |
| d->destructor(d->arg); |
| PerThreadDestructorList* next = d->next; |
| delete d; |
| d = next; |
| } |
| } |
| |
| // This key must be initialized only once. |
| static void CreateKey() { |
| int ret = pthread_key_create(&destructors_key, &InvokeDestructors); |
| // Linux supports up to 1024 keys, we will use only one for all thread locals. |
| CHECK_EQ(0, ret) << "pthread_key_create() failed, cannot add destructor to thread: " |
| << "error " << ret << ": " << ErrnoToString(ret); |
| } |
| |
| // Adds a destructor to the list. |
| void AddDestructor(void (*destructor)(void*), void* arg) { |
| GoogleOnceInit(&once, &CreateKey); |
| |
| // Returns NULL if nothing is set yet. |
| std::unique_ptr<PerThreadDestructorList> p(new PerThreadDestructorList()); |
| p->destructor = destructor; |
| p->arg = arg; |
| p->next = reinterpret_cast<PerThreadDestructorList*>(pthread_getspecific(destructors_key)); |
| int ret = pthread_setspecific(destructors_key, p.release()); |
| // The only time this check should fail is if we are out of memory, or if |
| // somehow key creation failed, which should be caught by the above CHECK. |
| CHECK_EQ(0, ret) << "pthread_setspecific() failed, cannot update destructor list: " |
| << "error " << ret << ": " << ErrnoToString(ret); |
| } |
| |
| } // namespace internal |
| } // namespace threadlocal |
| } // namespace kudu |