Getting started

Once you have installed the WRENCH library, following the instructions on the installation page, you are ready to create a WRENCH simulator. Information on what can be simulated and how to do it are provided in the WRENCH 101 and WRENCH 102 pages. This page is only about the logistics of setting up a simulator project.

Using the WRENCH initialization tool

The wrench-init tool is a project generator built with WRENCH, which creates a simple project structure as follows:

project-folder/
├── CMakeLists.txt
├── CMakeModules
│   └── FindSimGrid.cmake
├── src/
│   ├── SimpleSimulator.cpp
│   ├── SimpleStandardJobScheduler.cpp
│   ├── SimpleStandardJobScheduler.h
│   ├── SimpleWMS.cpp
│   └── SimpleWMS.h 
├── test/
├── doc/
├── build/
└── data/
    └── platform-files/
        └── hosts.xml

The simplesimulator.cpp source file contains the class representing the simulator (either cloud or batch). simplestandardjobscheduler.h and simplestandardjobscheduler.cpp contain a simple implementation for a wrench::StandardJobScheduler; simplewms.h and simplewms.cpp denote the implementation of a simple workflow management system. Example platform and workflow files are also generated into the data folder. These files provide the minimum necessary implementation for a WRENCH-enabled simulator.

The wrench-init tool only requires a single argument, the name of the folder where the project skeleton will be generated:

$ wrench-init <project_folder>

Additional options supported by the tool can be found by using the wrench-init --help command.

Creating a CMakeLists.txt file by hand

Alternately, you can do a manual setup, i.e., create your own Cmake project. Below is an example of a CMakeLists.txt file that can be used as a basic template:

cmake_minimum_required(version 3.2)
message(status "cmake version ${cmake_major_version}.${cmake_minor_version}.${cmake_patch_version}")
 
project(your_project_name)
 
add_definitions("-wall -wno-unused-variable -wno-unused-private-field")
 
set(cmake_cxx_standard 11)
 
# include directories for dependencies and wrench libraries
include_directories(src/ /usr/local/include /usr/local/include/wrench)
 
# source files
set(source_files
        src/main.cpp
        )
 
# test files
set(test_files
        )
 
# wrench library and dependencies
find_library(wrench_library names wrench)
find_library(simgrid_library names simgrid)
find_library(pugixml_library names pugixml)
find_library(gtest_library names gtest)
 
# generating the executable
add_executable(my-executable ${source_files})
target_link_libraries(my-executable 
                        ${wrench_library} 
                        ${simgrid_library} 
                        ${pugixml_library} 
                     )
 
install(targets my-executable destination bin)
 
# generating unit tests
add_executable(unit_tests exclude_from_all 
                 ${source_files} 
                 ${test_files}
               )
target_link_libraries(unit_tests 
                        ${gtest_library} wrench -lpthread -lm
                      )

Example WRENCH simulators

The examples in the examples directory provide good starting points for developing your own simulators. Typing make in the top-level directory compiles the examples in the examples directory.

Let us run the examples/basic-examples/bare-metal-bag-of-tasks by navigating to that directory and typing:

./wrench-example-bare-metal-bag-of-tasks 6 ./two_hosts.xml --wrench-no-logs --log=custom_wms.threshold=info

You should see some output in the terminal. The output in white is produced by the simulator implemented with the WRENCH user API. The output in green is produced by the workflow management system implemented with the WRENCH developer API.

Although you can inspect the codes of the examples on your own, we highly recommend that you go through the WRENCH 101 and WRENCH 102 pages first. These pages make direct references to the examples, a description of which is available in examples/README.md in the WRENCH distribution.

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