Model Instance Management
-------------------------

OpenDA contains a number of filters that requires multiple instances of a model to be run. The EFDC is not designed to be run for multiple instances. Therefor, the OpenDA compatible EFDC shared library implements the required functionality is added in a number of Fortran source files. 

The original EFDC files (with some small alterations) are located in /model_efdc_dll/native/efdc_fortran_dll/original_efdc_files/. All the additional files are located in /model_efdc_dll/native/efdc_fortran_dll/openDA_wrapper/.

Additional functionality can be split in the following categories:

- Communication between OpenDA (Java implementation for the EFDC model ) and EFDC shared library:

    openDA_wrapper.f90

 - Data exchange with Exchange Items 

    (for information see exchange_items.txt)

 - Model instance mananagement

    openDA_wrapper.f90
        function get_model_instance(instance_dir) result(ret_val)
        function save_instance(instance) result(ret_val)
        function restore_instance(instance) result(ret_val)
        function store_current_instance_restart_files() result (ret_val)
        function select_instance_from_restart_files(instance) result (ret_val)

    model_state.f90
    model_aser_time_series.f90
    model_cser_time_series.f90
    model_pser_time_series.f90
    model_qser_time_series.f90

 - Time bookkeeping

    OpenDA asks the model for run period, which is defined in TOX_EVENT.INP and other time related quantities.

    openDA_wrapper.f90
        function get_reference_year(instance) result(ret_val)
        function get_start_time(instance, start_time) result(ret_val)
        function get_end_time(instance, end_time) result(ret_val)
        function get_delta_t(delta_t) result(ret_val)
        function get_reference_period(reference_period) result(ret_val)
        function get_current_time(instance, current_time) result(ret_val)

 - Compute (integrating over time)

    model_make_time_step.f90
    openDA_wrapper.f90
        function compute(instance, from_time_stamp, to_time_stamp) result(ret_val)

 - EFDC init and end subroutines (originaly part of EFDC.for)

    model_init.f90
    model_init_1.for
    model_init_2.for
    model_init_3.for
    model_end.f90
    openDA_wrapper.f90
        function init(parent_directory, template_directory) result(ret_val)
        function finish(instance) result(ret_val)
        subroutine destroy()