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Diffstat (limited to 'boost/asio/detail/call_stack.hpp')
-rw-r--r-- | boost/asio/detail/call_stack.hpp | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/boost/asio/detail/call_stack.hpp b/boost/asio/detail/call_stack.hpp new file mode 100644 index 0000000000..db4cd1ed66 --- /dev/null +++ b/boost/asio/detail/call_stack.hpp @@ -0,0 +1,120 @@ +// +// detail/call_stack.hpp +// ~~~~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2012 Christopher M. Kohlhoff (chris at kohlhoff dot com) +// +// Distributed under the Boost Software License, Version 1.0. (See accompanying +// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) +// + +#ifndef BOOST_ASIO_DETAIL_CALL_STACK_HPP +#define BOOST_ASIO_DETAIL_CALL_STACK_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include <boost/asio/detail/config.hpp> +#include <boost/asio/detail/noncopyable.hpp> +#include <boost/asio/detail/tss_ptr.hpp> + +#include <boost/asio/detail/push_options.hpp> + +namespace boost { +namespace asio { +namespace detail { + +// Helper class to determine whether or not the current thread is inside an +// invocation of io_service::run() for a specified io_service object. +template <typename Key, typename Value = unsigned char> +class call_stack +{ +public: + // Context class automatically pushes the key/value pair on to the stack. + class context + : private noncopyable + { + public: + // Push the key on to the stack. + explicit context(Key* k) + : key_(k), + next_(call_stack<Key, Value>::top_) + { + value_ = reinterpret_cast<unsigned char*>(this); + call_stack<Key, Value>::top_ = this; + } + + // Push the key/value pair on to the stack. + context(Key* k, Value& v) + : key_(k), + value_(&v), + next_(call_stack<Key, Value>::top_) + { + call_stack<Key, Value>::top_ = this; + } + + // Pop the key/value pair from the stack. + ~context() + { + call_stack<Key, Value>::top_ = next_; + } + + // Find the next context with the same key. + Value* next_by_key() const + { + context* elem = next_; + while (elem) + { + if (elem->key_ == key_) + return elem->value_; + elem = elem->next_; + } + return 0; + } + + private: + friend class call_stack<Key, Value>; + + // The key associated with the context. + Key* key_; + + // The value associated with the context. + Value* value_; + + // The next element in the stack. + context* next_; + }; + + friend class context; + + // Determine whether the specified owner is on the stack. Returns address of + // key if present, 0 otherwise. + static Value* contains(Key* k) + { + context* elem = top_; + while (elem) + { + if (elem->key_ == k) + return elem->value_; + elem = elem->next_; + } + return 0; + } + +private: + // The top of the stack of calls for the current thread. + static tss_ptr<context> top_; +}; + +template <typename Key, typename Value> +tss_ptr<typename call_stack<Key, Value>::context> +call_stack<Key, Value>::top_; + +} // namespace detail +} // namespace asio +} // namespace boost + +#include <boost/asio/detail/pop_options.hpp> + +#endif // BOOST_ASIO_DETAIL_CALL_STACK_HPP |