post.hpp 4.6 KB

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  1. //
  2. // post.hpp
  3. // ~~~~~~~~
  4. //
  5. // Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
  6. //
  7. // Distributed under the Boost Software License, Version 1.0. (See accompanying
  8. // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  9. //
  10. #ifndef BOOST_ASIO_POST_HPP
  11. #define BOOST_ASIO_POST_HPP
  12. #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  13. # pragma once
  14. #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  15. #include <boost/asio/detail/config.hpp>
  16. #include <boost/asio/async_result.hpp>
  17. #include <boost/asio/detail/type_traits.hpp>
  18. #include <boost/asio/execution_context.hpp>
  19. #include <boost/asio/is_executor.hpp>
  20. #include <boost/asio/detail/push_options.hpp>
  21. namespace boost {
  22. namespace asio {
  23. /// Submits a completion token or function object for execution.
  24. /**
  25. * This function submits an object for execution using the object's associated
  26. * executor. The function object is queued for execution, and is never called
  27. * from the current thread prior to returning from <tt>post()</tt>.
  28. *
  29. * The use of @c post(), rather than @ref defer(), indicates the caller's
  30. * preference that the function object be eagerly queued for execution.
  31. *
  32. * This function has the following effects:
  33. *
  34. * @li Constructs a function object handler of type @c Handler, initialized
  35. * with <tt>handler(forward<CompletionToken>(token))</tt>.
  36. *
  37. * @li Constructs an object @c result of type <tt>async_result<Handler></tt>,
  38. * initializing the object as <tt>result(handler)</tt>.
  39. *
  40. * @li Obtains the handler's associated executor object @c ex by performing
  41. * <tt>get_associated_executor(handler)</tt>.
  42. *
  43. * @li Obtains the handler's associated allocator object @c alloc by performing
  44. * <tt>get_associated_allocator(handler)</tt>.
  45. *
  46. * @li Performs <tt>ex.post(std::move(handler), alloc)</tt>.
  47. *
  48. * @li Returns <tt>result.get()</tt>.
  49. */
  50. template <BOOST_ASIO_COMPLETION_TOKEN_FOR(void()) CompletionToken>
  51. BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, void()) post(
  52. BOOST_ASIO_MOVE_ARG(CompletionToken) token);
  53. /// Submits a completion token or function object for execution.
  54. /**
  55. * This function submits an object for execution using the specified executor.
  56. * The function object is queued for execution, and is never called from the
  57. * current thread prior to returning from <tt>post()</tt>.
  58. *
  59. * The use of @c post(), rather than @ref defer(), indicates the caller's
  60. * preference that the function object be eagerly queued for execution.
  61. *
  62. * This function has the following effects:
  63. *
  64. * @li Constructs a function object handler of type @c Handler, initialized
  65. * with <tt>handler(forward<CompletionToken>(token))</tt>.
  66. *
  67. * @li Constructs an object @c result of type <tt>async_result<Handler></tt>,
  68. * initializing the object as <tt>result(handler)</tt>.
  69. *
  70. * @li Obtains the handler's associated executor object @c ex1 by performing
  71. * <tt>get_associated_executor(handler)</tt>.
  72. *
  73. * @li Creates a work object @c w by performing <tt>make_work(ex1)</tt>.
  74. *
  75. * @li Obtains the handler's associated allocator object @c alloc by performing
  76. * <tt>get_associated_allocator(handler)</tt>.
  77. *
  78. * @li Constructs a function object @c f with a function call operator that
  79. * performs <tt>ex1.dispatch(std::move(handler), alloc)</tt> followed by
  80. * <tt>w.reset()</tt>.
  81. *
  82. * @li Performs <tt>Executor(ex).post(std::move(f), alloc)</tt>.
  83. *
  84. * @li Returns <tt>result.get()</tt>.
  85. */
  86. template <typename Executor,
  87. BOOST_ASIO_COMPLETION_TOKEN_FOR(void()) CompletionToken
  88. BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(Executor)>
  89. BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, void()) post(
  90. const Executor& ex,
  91. BOOST_ASIO_MOVE_ARG(CompletionToken) token
  92. BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(Executor),
  93. typename enable_if<is_executor<Executor>::value>::type* = 0);
  94. /// Submits a completion token or function object for execution.
  95. /**
  96. * @returns <tt>post(ctx.get_executor(), forward<CompletionToken>(token))</tt>.
  97. */
  98. template <typename ExecutionContext,
  99. BOOST_ASIO_COMPLETION_TOKEN_FOR(void()) CompletionToken
  100. BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(
  101. typename ExecutionContext::executor_type)>
  102. BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, void()) post(
  103. ExecutionContext& ctx,
  104. BOOST_ASIO_MOVE_ARG(CompletionToken) token
  105. BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(
  106. typename ExecutionContext::executor_type),
  107. typename enable_if<is_convertible<
  108. ExecutionContext&, execution_context&>::value>::type* = 0);
  109. } // namespace asio
  110. } // namespace boost
  111. #include <boost/asio/detail/pop_options.hpp>
  112. #include <boost/asio/impl/post.hpp>
  113. #endif // BOOST_ASIO_POST_HPP