.. _program_listing_file_include_rclcpp_guard_condition.hpp:

Program Listing for File guard_condition.hpp
============================================

|exhale_lsh| :ref:`Return to documentation for file <file_include_rclcpp_guard_condition.hpp>` (``include/rclcpp/guard_condition.hpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   // Copyright 2020 Open Source Robotics Foundation, Inc.
   //
   // Licensed under the Apache License, Version 2.0 (the "License");
   // you may not use this file except in compliance with the License.
   // You may obtain a copy of the License at
   //
   //     http://www.apache.org/licenses/LICENSE-2.0
   //
   // Unless required by applicable law or agreed to in writing, software
   // distributed under the License is distributed on an "AS IS" BASIS,
   // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   // See the License for the specific language governing permissions and
   // limitations under the License.
   
   #ifndef RCLCPP__GUARD_CONDITION_HPP_
   #define RCLCPP__GUARD_CONDITION_HPP_
   
   #include <atomic>
   
   #include "rcl/guard_condition.h"
   
   #include "rclcpp/context.hpp"
   #include "rclcpp/contexts/default_context.hpp"
   #include "rclcpp/macros.hpp"
   #include "rclcpp/visibility_control.hpp"
   
   namespace rclcpp
   {
   
   class GuardCondition
   {
   public:
     RCLCPP_SMART_PTR_DEFINITIONS_NOT_COPYABLE(GuardCondition)
   
     // TODO(wjwwood): support custom allocator, maybe restrict to polymorphic allocator
   
     RCLCPP_PUBLIC
     explicit GuardCondition(
       const rclcpp::Context::SharedPtr & context =
       rclcpp::contexts::get_global_default_context(),
       rcl_guard_condition_options_t guard_condition_options =
       rcl_guard_condition_get_default_options());
   
     RCLCPP_PUBLIC
     virtual
     ~GuardCondition();
   
     RCLCPP_PUBLIC
     rcl_guard_condition_t &
     get_rcl_guard_condition();
   
     RCLCPP_PUBLIC
     const rcl_guard_condition_t &
     get_rcl_guard_condition() const;
   
   
     RCLCPP_PUBLIC
     void
     trigger();
   
   
     RCLCPP_PUBLIC
     bool
     exchange_in_use_by_wait_set_state(bool in_use_state);
   
   
     RCLCPP_PUBLIC
     void
     add_to_wait_set(rcl_wait_set_t & wait_set);
   
   
     RCLCPP_PUBLIC
     void
     set_on_trigger_callback(std::function<void(size_t)> callback);
   
   protected:
     rcl_guard_condition_t rcl_guard_condition_;
     std::atomic<bool> in_use_by_wait_set_{false};
     std::recursive_mutex reentrant_mutex_;
     std::function<void(size_t)> on_trigger_callback_{nullptr};
     size_t unread_count_{0};
     // the type of wait_set_ is actually rcl_wait_set_t *, but it's never
     // dereferenced, only compared to, so make it void * to avoid accidental use
     void * wait_set_{nullptr};
   };
   
   }  // namespace rclcpp
   
   #endif  // RCLCPP__GUARD_CONDITION_HPP_