TLA  Line data    Source code

       1                 : //
       2                 : // Copyright (c) 2026 Michael Vandeberg
       3                 : //
       4                 : // Distributed under the Boost Software License, Version 1.0. (See accompanying
       5                 : // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
       6                 : //
       7                 : // Official repository: https://github.com/cppalliance/corosio
       8                 : //
       9                 : 
      10                 : #ifndef BOOST_COROSIO_DETAIL_CONDITIONALLY_ENABLED_EVENT_HPP
      11                 : #define BOOST_COROSIO_DETAIL_CONDITIONALLY_ENABLED_EVENT_HPP
      12                 : 
      13                 : #include <boost/corosio/detail/conditionally_enabled_mutex.hpp>
      14                 : 
      15                 : #include <chrono>
      16                 : #include <condition_variable>
      17                 : 
      18                 : namespace boost::corosio::detail {
      19                 : 
      20                 : /* Condition variable wrapper that becomes a no-op when disabled.
      21                 : 
      22                 :    When enabled, notify/wait delegate to an underlying
      23                 :    std::condition_variable. When disabled, all operations
      24                 :    are no-ops. The wait paths are unreachable in
      25                 :    single-threaded mode because the task sentinel prevents
      26                 :    the empty-queue state in do_one().
      27                 : */
      28                 : class conditionally_enabled_event
      29                 : {
      30                 :     std::condition_variable cond_;
      31                 :     bool enabled_;
      32                 : 
      33                 : public:
      34 HIT         515 :     explicit conditionally_enabled_event(bool enabled = true) noexcept
      35             515 :         : enabled_(enabled)
      36                 :     {
      37             515 :     }
      38                 : 
      39                 :     conditionally_enabled_event(conditionally_enabled_event const&)            = delete;
      40                 :     conditionally_enabled_event& operator=(conditionally_enabled_event const&) = delete;
      41                 : 
      42 MIS           0 :     void set_enabled(bool v) noexcept
      43                 :     {
      44               0 :         enabled_ = v;
      45               0 :     }
      46                 : 
      47               0 :     void notify_one()
      48                 :     {
      49               0 :         if (enabled_)
      50               0 :             cond_.notify_one();
      51               0 :     }
      52                 : 
      53 HIT         889 :     void notify_all()
      54                 :     {
      55             889 :         if (enabled_)
      56             889 :             cond_.notify_all();
      57             889 :     }
      58                 : 
      59 MIS           0 :     void wait(conditionally_enabled_mutex::scoped_lock& lock)
      60                 :     {
      61               0 :         if (enabled_)
      62               0 :             cond_.wait(lock.underlying());
      63               0 :     }
      64                 : 
      65                 :     template<class Rep, class Period>
      66               0 :     void wait_for(
      67                 :         conditionally_enabled_mutex::scoped_lock& lock,
      68                 :         std::chrono::duration<Rep, Period> const& d)
      69                 :     {
      70               0 :         if (enabled_)
      71               0 :             cond_.wait_for(lock.underlying(), d);
      72               0 :     }
      73                 : };
      74                 : 
      75                 : } // namespace boost::corosio::detail
      76                 : 
      77                 : #endif // BOOST_COROSIO_DETAIL_CONDITIONALLY_ENABLED_EVENT_HPP