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Diffstat (limited to 'lib/asio/detail/concurrency_hint.hpp')
| -rw-r--r-- | lib/asio/detail/concurrency_hint.hpp | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/lib/asio/detail/concurrency_hint.hpp b/lib/asio/detail/concurrency_hint.hpp new file mode 100644 index 0000000..229124d --- /dev/null +++ b/lib/asio/detail/concurrency_hint.hpp @@ -0,0 +1,94 @@ +// +// detail/concurrency_hint.hpp +// ~~~~~~~~~~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2018 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 ASIO_DETAIL_CONCURRENCY_HINT_HPP +#define ASIO_DETAIL_CONCURRENCY_HINT_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include "asio/detail/config.hpp" +#include "asio/detail/noncopyable.hpp" + +// The concurrency hint ID and mask are used to identify when a "well-known" +// concurrency hint value has been passed to the io_context. +#define ASIO_CONCURRENCY_HINT_ID 0xA5100000u +#define ASIO_CONCURRENCY_HINT_ID_MASK 0xFFFF0000u + +// If set, this bit indicates that the scheduler should perform locking. +#define ASIO_CONCURRENCY_HINT_LOCKING_SCHEDULER 0x1u + +// If set, this bit indicates that the reactor should perform locking when +// managing descriptor registrations. +#define ASIO_CONCURRENCY_HINT_LOCKING_REACTOR_REGISTRATION 0x2u + +// If set, this bit indicates that the reactor should perform locking for I/O. +#define ASIO_CONCURRENCY_HINT_LOCKING_REACTOR_IO 0x4u + +// Helper macro to determine if we have a special concurrency hint. +#define ASIO_CONCURRENCY_HINT_IS_SPECIAL(hint) \ + ((static_cast<unsigned>(hint) \ + & ASIO_CONCURRENCY_HINT_ID_MASK) \ + == ASIO_CONCURRENCY_HINT_ID) + +// Helper macro to determine if locking is enabled for a given facility. +#define ASIO_CONCURRENCY_HINT_IS_LOCKING(facility, hint) \ + (((static_cast<unsigned>(hint) \ + & (ASIO_CONCURRENCY_HINT_ID_MASK \ + | ASIO_CONCURRENCY_HINT_LOCKING_ ## facility)) \ + ^ ASIO_CONCURRENCY_HINT_ID) != 0) + +// This special concurrency hint disables locking in both the scheduler and +// reactor I/O. This hint has the following restrictions: +// +// - Care must be taken to ensure that all operations on the io_context and any +// of its associated I/O objects (such as sockets and timers) occur in only +// one thread at a time. +// +// - Asynchronous resolve operations fail with operation_not_supported. +// +// - If a signal_set is used with the io_context, signal_set objects cannot be +// used with any other io_context in the program. +#define ASIO_CONCURRENCY_HINT_UNSAFE \ + static_cast<int>(ASIO_CONCURRENCY_HINT_ID) + +// This special concurrency hint disables locking in the reactor I/O. This hint +// has the following restrictions: +// +// - Care must be taken to ensure that run functions on the io_context, and all +// operations on the io_context's associated I/O objects (such as sockets and +// timers), occur in only one thread at a time. +#define ASIO_CONCURRENCY_HINT_UNSAFE_IO \ + static_cast<int>(ASIO_CONCURRENCY_HINT_ID \ + | ASIO_CONCURRENCY_HINT_LOCKING_SCHEDULER \ + | ASIO_CONCURRENCY_HINT_LOCKING_REACTOR_REGISTRATION) + +// The special concurrency hint provides full thread safety. +#define ASIO_CONCURRENCY_HINT_SAFE \ + static_cast<int>(ASIO_CONCURRENCY_HINT_ID \ + | ASIO_CONCURRENCY_HINT_LOCKING_SCHEDULER \ + | ASIO_CONCURRENCY_HINT_LOCKING_REACTOR_REGISTRATION \ + | ASIO_CONCURRENCY_HINT_LOCKING_REACTOR_IO) + +// This #define may be overridden at compile time to specify a program-wide +// default concurrency hint, used by the zero-argument io_context constructor. +#if !defined(ASIO_CONCURRENCY_HINT_DEFAULT) +# define ASIO_CONCURRENCY_HINT_DEFAULT -1 +#endif // !defined(ASIO_CONCURRENCY_HINT_DEFAULT) + +// This #define may be overridden at compile time to specify a program-wide +// concurrency hint, used by the one-argument io_context constructor when +// passed a value of 1. +#if !defined(ASIO_CONCURRENCY_HINT_1) +# define ASIO_CONCURRENCY_HINT_1 1 +#endif // !defined(ASIO_CONCURRENCY_HINT_DEFAULT) + +#endif // ASIO_DETAIL_CONCURRENCY_HINT_HPP |