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Diffstat (limited to 'qpid/cpp/src/qpid/sys/DeletionManager.h')
-rw-r--r-- | qpid/cpp/src/qpid/sys/DeletionManager.h | 138 |
1 files changed, 0 insertions, 138 deletions
diff --git a/qpid/cpp/src/qpid/sys/DeletionManager.h b/qpid/cpp/src/qpid/sys/DeletionManager.h deleted file mode 100644 index 43154eb98e..0000000000 --- a/qpid/cpp/src/qpid/sys/DeletionManager.h +++ /dev/null @@ -1,138 +0,0 @@ -#ifndef _sys_DeletionManager_h -#define _sys_DeletionManager_h - -/* - * - * 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 <vector> -#include <algorithm> -#include <boost/shared_ptr.hpp> - -namespace qpid { -namespace sys { - -struct deleter -{ - template <typename T> - void operator()(T* ptr){ delete ptr;} -}; - -/** - * DeletionManager keeps track of handles that need to be deleted but may still be - * in use by one of the threads concurrently. - * - * The mode of operation is like this: - * - When we want to delete but we might still be using the handle we - * * Transfer ownership of the handle to this class - * * Mark the handle as (potentially) in use by every thread - * - Then subsequently at points where the thread code knows it isn't - * using any handles it declares that it is using no handles - * - When the last thread declares no use of a handle it automatically - * gets deleted by the shared_ptr implementation - * - * The class only has static members and data and so can only be used once for - * any particular handle type - */ -template <typename H> -class DeletionManager -{ -public: - // Mark every thread as using the handle - it will be deleted - // below after every thread marks the handle as unused - static void markForDeletion(H* handle) { - allThreadsStatuses.addHandle(shared_ptr(handle)); - } - - // Mark this thread is not using any handle - - // handles get deleted here when no one else - // is using them either - static void markAllUnusedInThisThread() { - static __thread ThreadStatus* threadStatus = 0; - - // Thread local vars can't be dynamically constructed so we need - // to check whether we've made it yet and construct it if not - // (no locking necessary for the check as it's thread local!) - if (!threadStatus) { - threadStatus = new ThreadStatus; - allThreadsStatuses.addThreadStatus(threadStatus); - } - - ScopedLock<Mutex> l(threadStatus->lock); - - // The actual deletions will happen here when all the shared_ptr - // ref counts hit 0 (that is when every thread marks the handle unused) - threadStatus->handles.clear(); - } - -private: - typedef boost::shared_ptr<H> shared_ptr; - - // In theory we know that we never need more handles than the number of - // threads runnning so we could use a fixed size array. However at this point - // in the code we don't have easy access to this information. - struct ThreadStatus - { - Mutex lock; - std::vector<shared_ptr> handles; - }; - - class AllThreadsStatuses - { - Mutex lock; - std::vector<ThreadStatus*> statuses; - - struct handleAdder - { - shared_ptr handle; - - handleAdder(shared_ptr h): handle(h) {} - - void operator()(ThreadStatus* ptr) { - ScopedLock<Mutex> l(ptr->lock); - ptr->handles.push_back(handle); - } - }; - - public: - // Need this to be able to do static initialisation - explicit AllThreadsStatuses(int) {} - - ~AllThreadsStatuses() { - ScopedLock<Mutex> l(lock); - std::for_each(statuses.begin(), statuses.end(), deleter()); - } - - void addThreadStatus(ThreadStatus* t) { - ScopedLock<Mutex> l(lock); - statuses.push_back(t); - } - - void addHandle(shared_ptr h) { - ScopedLock<Mutex> l(lock); - std::for_each(statuses.begin(), statuses.end(), handleAdder(h)); - } - }; - - static AllThreadsStatuses allThreadsStatuses; -}; - -}} -#endif // _sys_DeletionManager_h |