ceph/src/boost/libs/outcome/test/tests/coroutine-support.cpp

   1 /* Unit testing for outcomes
   2 (C) 2013-2022 Niall Douglas <http://www.nedproductions.biz/> (6 commits)
   3
   4
   5 Boost Software License - Version 1.0 - August 17th, 2003
   6
   7 Permission is hereby granted, free of charge, to any person or organization
   8 obtaining a copy of the software and accompanying documentation covered by
   9 this license (the "Software") to use, reproduce, display, distribute,
  10 execute, and transmit the Software, and to prepare derivative works of the
  11 Software, and to permit third-parties to whom the Software is furnished to
  12 do so, all subject to the following:
  13
  14 The copyright notices in the Software and this entire statement, including
  15 the above license grant, this restriction and the following disclaimer,
  16 must be included in all copies of the Software, in whole or in part, and
  17 all derivative works of the Software, unless such copies or derivative
  18 works are solely in the form of machine-executable object code generated by
  19 a source language processor.
  20
  21 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  22 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  23 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
  24 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
  25 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
  26 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  27 DEALINGS IN THE SOFTWARE.
  28 */
  29
  30 #include <boost/outcome/coroutine_support.hpp>
  31 #include <boost/outcome.hpp>
  32 #include <boost/outcome/try.hpp>
  33
  34 #if BOOST_OUTCOME_FOUND_COROUTINE_HEADER
  35
  36 #include <boost/test/unit_test.hpp>
  37 #include <boost/test/unit_test_monitor.hpp>
  38
  39 namespace coroutines
  40 {
  41   template <class T> using eager = BOOST_OUTCOME_V2_NAMESPACE::awaitables::eager<T>;
  42   template <class T> using lazy = BOOST_OUTCOME_V2_NAMESPACE::awaitables::lazy<T>;
  43   template <class T, class E = boost::system::error_code> using result = BOOST_OUTCOME_V2_NAMESPACE::result<T, E>;
  44
  45   inline eager<result<int>> eager_int(int x) { co_return x + 1; }
  46   inline lazy<result<int>> lazy_int(int x) { co_return x + 1; }
  47   inline eager<result<int>> eager_error() { co_return boost::system::errc::not_enough_memory; }
  48   inline lazy<result<int>> lazy_error() { co_return boost::system::errc::not_enough_memory; }
  49   inline eager<result<void>> eager_void() { co_return boost::system::errc::not_enough_memory; }
  50   inline lazy<result<void>> lazy_void() { co_return boost::system::errc::not_enough_memory; }
  51
  52   template <class U, class... Args> inline eager<result<std::string>> eager_coawait(U &&f, Args... args)
  53   {
  54     BOOST_OUTCOME_CO_TRYV2(auto &&, co_await f(args...));
  55     co_return "hi";
  56   }
  57   template <class U, class... Args> inline lazy<result<std::string>> lazy_coawait(U &&f, Args... args)
  58   {
  59     BOOST_OUTCOME_CO_TRYV2(auto &&, co_await f(args...));
  60     co_return "hi";
  61   }
  62
  63 #ifndef BOOST_NO_EXCEPTIONS
  64   struct custom_exception_type
  65   {
  66   };
  67   inline lazy<result<int, boost::exception_ptr>> result_exception(boost::exception_ptr e)
  68   {
  69     boost::rethrow_exception(e);
  70     co_return 5;
  71   }
  72
  73   inline lazy<BOOST_OUTCOME_V2_NAMESPACE::outcome<int>> outcome_exception(boost::exception_ptr e)
  74   {
  75     boost::rethrow_exception(e);
  76     co_return 5;
  77   }
  78 #endif
  79
  80   inline eager<int> eager_int2(int x) { co_return x + 1; }
  81   inline lazy<int> lazy_int2(int x) { co_return x + 1; }
  82   inline eager<void> eager_void2() { co_return; }
  83   inline lazy<void> lazy_void2() { co_return; }
  84 }  // namespace coroutines
  85
  86 BOOST_OUTCOME_AUTO_TEST_CASE(works_result_coroutine, "Tests that results are eager and lazy awaitable")
  87 {
  88   using namespace coroutines;
  89   auto ensure_coroutine_completed_immediately = [](auto t) {
  90     BOOST_CHECK(t.await_ready());  // must have eagerly evaluated
  91     return t.await_resume();       // fetch the value returned into the promise by the coroutine
  92   };
  93   auto ensure_coroutine_needs_resuming_once = [](auto t) {
  94     BOOST_CHECK(!t.await_ready());  // must not have eagerly evaluated
  95 #if BOOST_OUTCOME_HAVE_NOOP_COROUTINE
  96     t.await_suspend({}).resume();  // resume execution, which sets the promise
  97 #else
  98     t.await_suspend({});  // resume execution, which sets the promise
  99 #endif
 100     BOOST_CHECK(t.await_ready());  // must now be ready
 101     return t.await_resume();       // fetch the value returned into the promise by the coroutine
 102   };
 103
 104   // eager_int never suspends, sets promise immediately, must be able to retrieve immediately
 105   BOOST_CHECK(ensure_coroutine_completed_immediately(eager_int(5)).value() == 6);
 106   // lazy_int suspends before execution, needs resuming to set the promise
 107   BOOST_CHECK(ensure_coroutine_needs_resuming_once(lazy_int(5)).value() == 6);
 108   BOOST_CHECK(ensure_coroutine_completed_immediately(eager_error()).error() == boost::system::errc::not_enough_memory);
 109   BOOST_CHECK(ensure_coroutine_needs_resuming_once(lazy_error()).error() == boost::system::errc::not_enough_memory);
 110   BOOST_CHECK(ensure_coroutine_completed_immediately(eager_void()).error() == boost::system::errc::not_enough_memory);
 111   BOOST_CHECK(ensure_coroutine_needs_resuming_once(lazy_void()).error() == boost::system::errc::not_enough_memory);
 112
 113   // co_await eager_int realises it has already completed, does not suspend.
 114   BOOST_CHECK(ensure_coroutine_completed_immediately(eager_coawait(eager_int, 5)).value() == "hi");
 115   // co_await lazy_int resumes the suspended coroutine.
 116   BOOST_CHECK(ensure_coroutine_needs_resuming_once(lazy_coawait(lazy_int, 5)).value() == "hi");
 117
 118 #ifndef BOOST_NO_EXCEPTIONS
 119   auto e = boost::copy_exception(custom_exception_type());
 120   BOOST_CHECK_THROW(ensure_coroutine_needs_resuming_once(result_exception(e)).value(), custom_exception_type);
 121   BOOST_CHECK_THROW(ensure_coroutine_needs_resuming_once(outcome_exception(e)).value(), custom_exception_type);
 122 #endif
 123
 124   BOOST_CHECK(ensure_coroutine_completed_immediately(eager_int2(5)) == 6);
 125   BOOST_CHECK(ensure_coroutine_needs_resuming_once(lazy_int2(5)) == 6);
 126   ensure_coroutine_completed_immediately(eager_void2());
 127   ensure_coroutine_needs_resuming_once(lazy_void2());
 128 }
 129 #else
 130 int main(void)
 131 {
 132   return 0;
 133 }
 134 #endif