task.h

00001 /******************************************************************************
00002 The MIT License(MIT)
00003 
00004 Embedded Template Library.
00005 https://github.com/ETLCPP/etl
00006 http://www.etlcpp.com
00007 
00008 Copyright(c) 2017 jwellbelove
00009 
00010 Permission is hereby granted, free of charge, to any person obtaining a copy
00011 of this software and associated documentation files(the "Software"), to deal
00012 in the Software without restriction, including without limitation the rights
00013 to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
00014 copies of the Software, and to permit persons to whom the Software is
00015 furnished to do so, subject to the following conditions :
00016 
00017 The above copyright notice and this permission notice shall be included in all
00018 copies or substantial portions of the Software.
00019 
00020 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00021 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00022 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
00023 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00024 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00025 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
00026 SOFTWARE.
00027 ******************************************************************************/
00028 
00029 #ifndef __ETL_TASK__
00030 #define __ETL_TASK__
00031 
00032 #include <stdint.h>
00033 
00034 #include "platform.h "
00035 #include "error_handler.h "
00036 #include "exception.h "
00037 
00038 #undef ETL_FILE
00039 #define ETL_FILE "37"
00040 
00041 namespace etl
00042 {
00043   //***************************************************************************
00044   /// Base exception class for task.
00045   //***************************************************************************
00046   class task_exception : public etl::exception
00047   {
00048   public:
00049 
00050     task_exception(string_type reason_, string_type file_name_, numeric_type line_number_)
00051       : etl::exception(reason_, file_name_, line_number_)
00052     {
00053     }
00054   };
00055 
00056   typedef uint_least8_t task_priority_t;
00057 
00058   //***************************************************************************
00059   /// Scheduler.
00060   //***************************************************************************
00061   class task
00062   {
00063   public:
00064 
00065     //*******************************************
00066     /// Constructor.
00067     //*******************************************
00068     task(task_priority_t priority)
00069       : task_running(true),
00070         task_priority(priority)
00071     {
00072     }
00073 
00074     //*******************************************
00075     /// Destructor.
00076     //*******************************************
00077     virtual ~task()
00078     {
00079     }
00080 
00081     //*******************************************
00082     /// Called to check if the task has work.
00083     /// Returns a score as to the amount of work it has to do.
00084     //*******************************************
00085     virtual uint32_t task_request_work() const = 0;
00086 
00087     //*******************************************
00088     /// Called to get the task to do work.
00089     //*******************************************
00090     virtual void task_process_work() = 0;
00091 
00092     //*******************************************
00093     /// Set the running state for the task.
00094     //*******************************************
00095     void set_task_running(bool task_running_)
00096     {
00097       task_running = task_running_;
00098     }
00099 
00100     //*******************************************
00101     /// Get the running state for the task.
00102     //*******************************************
00103     bool task_is_running() const
00104     {
00105       return task_running;
00106     }
00107 
00108     //*******************************************
00109     /// Get the priority of the task.
00110     /// Higher value = higher priority.
00111     //*******************************************
00112     etl::task_priority_t get_task_priority() const
00113     {
00114       return task_priority;
00115     }
00116 
00117   private:
00118 
00119     bool task_running;
00120     etl::task_priority_t task_priority;
00121   };
00122 }
00123 
00124 #undef ETL_FILE
00125 
00126 #endif
00127