Initial Commit

include/asio/detail/conditionally_enabled_event.hpp

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+//
+// detail/conditionally_enabled_event.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2025 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_CONDITIONALLY_ENABLED_EVENT_HPP
+#define ASIO_DETAIL_CONDITIONALLY_ENABLED_EVENT_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/conditionally_enabled_mutex.hpp"
+#include "asio/detail/event.hpp"
+#include "asio/detail/noncopyable.hpp"
+#include "asio/detail/null_event.hpp"
+#include "asio/detail/scoped_lock.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+// Mutex adapter used to conditionally enable or disable locking.
+class conditionally_enabled_event
+  : private noncopyable
+{
+public:
+  // Constructor.
+  conditionally_enabled_event()
+  {
+  }
+
+  // Destructor.
+  ~conditionally_enabled_event()
+  {
+  }
+
+  // Signal the event. (Retained for backward compatibility.)
+  void signal(conditionally_enabled_mutex::scoped_lock& lock)
+  {
+    if (lock.mutex_.enabled_)
+      event_.signal(lock);
+  }
+
+  // Signal all waiters.
+  void signal_all(conditionally_enabled_mutex::scoped_lock& lock)
+  {
+    if (lock.mutex_.enabled_)
+      event_.signal_all(lock);
+  }
+
+  // Unlock the mutex and signal one waiter.
+  void unlock_and_signal_one(
+      conditionally_enabled_mutex::scoped_lock& lock)
+  {
+    if (lock.mutex_.enabled_)
+      event_.unlock_and_signal_one(lock);
+  }
+
+  // Unlock the mutex and signal one waiter who may destroy us.
+  void unlock_and_signal_one_for_destruction(
+      conditionally_enabled_mutex::scoped_lock& lock)
+  {
+    if (lock.mutex_.enabled_)
+      event_.unlock_and_signal_one(lock);
+  }
+
+  // If there's a waiter, unlock the mutex and signal it.
+  bool maybe_unlock_and_signal_one(
+      conditionally_enabled_mutex::scoped_lock& lock)
+  {
+    if (lock.mutex_.enabled_)
+      return event_.maybe_unlock_and_signal_one(lock);
+    else
+      return false;
+  }
+
+  // Reset the event.
+  void clear(conditionally_enabled_mutex::scoped_lock& lock)
+  {
+    if (lock.mutex_.enabled_)
+      event_.clear(lock);
+  }
+
+  // Wait for the event to become signalled.
+  void wait(conditionally_enabled_mutex::scoped_lock& lock)
+  {
+    if (lock.mutex_.enabled_)
+      event_.wait(lock);
+    else
+      null_event().wait(lock);
+  }
+
+  // Timed wait for the event to become signalled.
+  bool wait_for_usec(
+      conditionally_enabled_mutex::scoped_lock& lock, long usec)
+  {
+    if (lock.mutex_.enabled_)
+      return event_.wait_for_usec(lock, usec);
+    else
+      return null_event().wait_for_usec(lock, usec);
+  }
+
+private:
+  asio::detail::event event_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_CONDITIONALLY_ENABLED_EVENT_HPP