summaryrefslogtreecommitdiff
path: root/src/third_party/boost-1.60.0/boost/asio/strand.hpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/third_party/boost-1.60.0/boost/asio/strand.hpp')
-rw-r--r--src/third_party/boost-1.60.0/boost/asio/strand.hpp254
1 files changed, 254 insertions, 0 deletions
diff --git a/src/third_party/boost-1.60.0/boost/asio/strand.hpp b/src/third_party/boost-1.60.0/boost/asio/strand.hpp
new file mode 100644
index 00000000000..8c6d94509b7
--- /dev/null
+++ b/src/third_party/boost-1.60.0/boost/asio/strand.hpp
@@ -0,0 +1,254 @@
+//
+// strand.hpp
+// ~~~~~~~~~~
+//
+// Copyright (c) 2003-2015 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_STRAND_HPP
+#define BOOST_ASIO_STRAND_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/async_result.hpp>
+#include <boost/asio/detail/handler_type_requirements.hpp>
+#include <boost/asio/detail/strand_service.hpp>
+#include <boost/asio/detail/wrapped_handler.hpp>
+#include <boost/asio/io_service.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+
+/// Provides serialised handler execution.
+/**
+ * The io_service::strand class provides the ability to post and dispatch
+ * handlers with the guarantee that none of those handlers will execute
+ * concurrently.
+ *
+ * @par Order of handler invocation
+ * Given:
+ *
+ * @li a strand object @c s
+ *
+ * @li an object @c a meeting completion handler requirements
+ *
+ * @li an object @c a1 which is an arbitrary copy of @c a made by the
+ * implementation
+ *
+ * @li an object @c b meeting completion handler requirements
+ *
+ * @li an object @c b1 which is an arbitrary copy of @c b made by the
+ * implementation
+ *
+ * if any of the following conditions are true:
+ *
+ * @li @c s.post(a) happens-before @c s.post(b)
+ *
+ * @li @c s.post(a) happens-before @c s.dispatch(b), where the latter is
+ * performed outside the strand
+ *
+ * @li @c s.dispatch(a) happens-before @c s.post(b), where the former is
+ * performed outside the strand
+ *
+ * @li @c s.dispatch(a) happens-before @c s.dispatch(b), where both are
+ * performed outside the strand
+ *
+ * then @c asio_handler_invoke(a1, &a1) happens-before
+ * @c asio_handler_invoke(b1, &b1).
+ *
+ * Note that in the following case:
+ * @code async_op_1(..., s.wrap(a));
+ * async_op_2(..., s.wrap(b)); @endcode
+ * the completion of the first async operation will perform @c s.dispatch(a),
+ * and the second will perform @c s.dispatch(b), but the order in which those
+ * are performed is unspecified. That is, you cannot state whether one
+ * happens-before the other. Therefore none of the above conditions are met and
+ * no ordering guarantee is made.
+ *
+ * @note The implementation makes no guarantee that handlers posted or
+ * dispatched through different @c strand objects will be invoked concurrently.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Safe.
+ *
+ * @par Concepts:
+ * Dispatcher.
+ */
+class io_service::strand
+{
+public:
+ /// Constructor.
+ /**
+ * Constructs the strand.
+ *
+ * @param io_service The io_service object that the strand will use to
+ * dispatch handlers that are ready to be run.
+ */
+ explicit strand(boost::asio::io_service& io_service)
+ : service_(boost::asio::use_service<
+ boost::asio::detail::strand_service>(io_service))
+ {
+ service_.construct(impl_);
+ }
+
+ /// Destructor.
+ /**
+ * Destroys a strand.
+ *
+ * Handlers posted through the strand that have not yet been invoked will
+ * still be dispatched in a way that meets the guarantee of non-concurrency.
+ */
+ ~strand()
+ {
+ }
+
+ /// Get the io_service associated with the strand.
+ /**
+ * This function may be used to obtain the io_service object that the strand
+ * uses to dispatch handlers for asynchronous operations.
+ *
+ * @return A reference to the io_service object that the strand will use to
+ * dispatch handlers. Ownership is not transferred to the caller.
+ */
+ boost::asio::io_service& get_io_service()
+ {
+ return service_.get_io_service();
+ }
+
+ /// Request the strand to invoke the given handler.
+ /**
+ * This function is used to ask the strand to execute the given handler.
+ *
+ * The strand object guarantees that handlers posted or dispatched through
+ * the strand will not be executed concurrently. The handler may be executed
+ * inside this function if the guarantee can be met. If this function is
+ * called from within a handler that was posted or dispatched through the same
+ * strand, then the new handler will be executed immediately.
+ *
+ * The strand's guarantee is in addition to the guarantee provided by the
+ * underlying io_service. The io_service guarantees that the handler will only
+ * be called in a thread in which the io_service's run member function is
+ * currently being invoked.
+ *
+ * @param handler The handler to be called. The strand will make a copy of the
+ * handler object as required. The function signature of the handler must be:
+ * @code void handler(); @endcode
+ */
+ template <typename CompletionHandler>
+ BOOST_ASIO_INITFN_RESULT_TYPE(CompletionHandler, void ())
+ dispatch(BOOST_ASIO_MOVE_ARG(CompletionHandler) handler)
+ {
+ // If you get an error on the following line it means that your handler does
+ // not meet the documented type requirements for a CompletionHandler.
+ BOOST_ASIO_COMPLETION_HANDLER_CHECK(CompletionHandler, handler) type_check;
+
+ detail::async_result_init<
+ CompletionHandler, void ()> init(
+ BOOST_ASIO_MOVE_CAST(CompletionHandler)(handler));
+
+ service_.dispatch(impl_, init.handler);
+
+ return init.result.get();
+ }
+
+ /// Request the strand to invoke the given handler and return
+ /// immediately.
+ /**
+ * This function is used to ask the strand to execute the given handler, but
+ * without allowing the strand to call the handler from inside this function.
+ *
+ * The strand object guarantees that handlers posted or dispatched through
+ * the strand will not be executed concurrently. The strand's guarantee is in
+ * addition to the guarantee provided by the underlying io_service. The
+ * io_service guarantees that the handler will only be called in a thread in
+ * which the io_service's run member function is currently being invoked.
+ *
+ * @param handler The handler to be called. The strand will make a copy of the
+ * handler object as required. The function signature of the handler must be:
+ * @code void handler(); @endcode
+ */
+ template <typename CompletionHandler>
+ BOOST_ASIO_INITFN_RESULT_TYPE(CompletionHandler, void ())
+ post(BOOST_ASIO_MOVE_ARG(CompletionHandler) handler)
+ {
+ // If you get an error on the following line it means that your handler does
+ // not meet the documented type requirements for a CompletionHandler.
+ BOOST_ASIO_COMPLETION_HANDLER_CHECK(CompletionHandler, handler) type_check;
+
+ detail::async_result_init<
+ CompletionHandler, void ()> init(
+ BOOST_ASIO_MOVE_CAST(CompletionHandler)(handler));
+
+ service_.post(impl_, init.handler);
+
+ return init.result.get();
+ }
+
+ /// Create a new handler that automatically dispatches the wrapped handler
+ /// on the strand.
+ /**
+ * This function is used to create a new handler function object that, when
+ * invoked, will automatically pass the wrapped handler to the strand's
+ * dispatch function.
+ *
+ * @param handler The handler to be wrapped. The strand will make a copy of
+ * the handler object as required. The function signature of the handler must
+ * be: @code void handler(A1 a1, ... An an); @endcode
+ *
+ * @return A function object that, when invoked, passes the wrapped handler to
+ * the strand's dispatch function. Given a function object with the signature:
+ * @code R f(A1 a1, ... An an); @endcode
+ * If this function object is passed to the wrap function like so:
+ * @code strand.wrap(f); @endcode
+ * then the return value is a function object with the signature
+ * @code void g(A1 a1, ... An an); @endcode
+ * that, when invoked, executes code equivalent to:
+ * @code strand.dispatch(boost::bind(f, a1, ... an)); @endcode
+ */
+ template <typename Handler>
+#if defined(GENERATING_DOCUMENTATION)
+ unspecified
+#else
+ detail::wrapped_handler<strand, Handler, detail::is_continuation_if_running>
+#endif
+ wrap(Handler handler)
+ {
+ return detail::wrapped_handler<io_service::strand, Handler,
+ detail::is_continuation_if_running>(*this, handler);
+ }
+
+ /// Determine whether the strand is running in the current thread.
+ /**
+ * @return @c true if the current thread is executing a handler that was
+ * submitted to the strand using post(), dispatch() or wrap(). Otherwise
+ * returns @c false.
+ */
+ bool running_in_this_thread() const
+ {
+ return service_.running_in_this_thread(impl_);
+ }
+
+private:
+ boost::asio::detail::strand_service& service_;
+ boost::asio::detail::strand_service::implementation_type impl_;
+};
+
+/// (Deprecated: Use boost::asio::io_service::strand.) Typedef for backwards
+/// compatibility.
+typedef boost::asio::io_service::strand strand;
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_STRAND_HPP