Swapped the order of setup and do_iteration in initialize function

src/cosim/algorithm/fixed_step_algorithm.cpp

@@ -151,13 +151,6 @@ class fixed_step_algorithm::impl
 
     void initialize()
     {
-        for (auto& s : simulators_) {
-            pool_.submit([&] {
-                s.second.sim->setup(startTime_, stopTime_, std::nullopt);
-            });
-        }
-        pool_.wait_for_tasks_to_finish();
-
         // Run N iterations of the simulators' and functions' step/calculation
         // procedures, where N is the number of simulators in the system,
         // to propagate initial values.
@@ -171,6 +164,14 @@ class fixed_step_algorithm::impl
             calculate_and_transfer();
         }
 
+        for (auto& s : simulators_) {
+            pool_.submit([&] {
+                s.second.sim->setup(startTime_, stopTime_, std::nullopt);
+            });
+        }
+        pool_.wait_for_tasks_to_finish();
+
+
         for (auto& s : simulators_) {
             pool_.submit([&] {
                 s.second.sim->start_simulation();

tests/CMakeLists.txt

@@ -13,6 +13,7 @@ set(tests
     "scenario_manager_test"
     "synchronized_xy_series_test"
     "config_end_time_test"
+    "state_init_test"
 )
 
 set(unittests

tests/data/msmi/OspSystemStructure_StateInitExample.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<OspSystemStructure xmlns="http://opensimulationplatform.com/MSMI/OSPSystemStructure" version="0.1">
+    <StartTime>0.0</StartTime>
+    <BaseStepSize>0.01</BaseStepSize>
+    <Algorithm>fixedStep</Algorithm>
+    <Simulators>
+        <Simulator name="example" source="../fmi2/StateInitExample.fmu">
+            <InitialValues>
+                <InitialValue variable="Parameters.Integrator1_x0">
+                    <Real value="10" />
+                </InitialValue>
+            </InitialValues>
+        </Simulator>
+    </Simulators>
+    <Connections>
+    </Connections>
+</OspSystemStructure>

tests/state_init_test.cpp

@@ -0,0 +1,53 @@
+#include <cosim/algorithm/fixed_step_algorithm.hpp>
+#include <cosim/osp_config_parser.hpp>
+#include <cosim/observer/file_observer.hpp>
+#include <cosim/exception.hpp>
+#include <cosim/execution.hpp>
+#include <cosim/function/linear_transformation.hpp>
+#include <cosim/observer/last_value_observer.hpp>
+#include <cosim/system_structure.hpp>
+#include <algorithm>
+#include <iostream>
+
+#define REQUIRE(test) \
+    if (!(test)) throw std::runtime_error("Requirement not satisfied: " #test)
+
+int main()
+{
+    try {
+        const auto testDataDir = std::getenv("TEST_DATA_DIR");
+        REQUIRE(!!testDataDir);
+
+        cosim::filesystem::path configPath = testDataDir;
+
+        auto resolver = cosim::default_model_uri_resolver();
+        const auto config = cosim::load_osp_config(configPath / "msmi" / "OspSystemStructure_StateInitExample.xml", *resolver);
+
+        auto execution = cosim::execution(
+            config.start_time,
+            std::make_shared<cosim::fixed_step_algorithm>(config.step_size));
+
+        const auto entityMaps = cosim::inject_system_structure(
+            execution, config.system_structure, config.initial_values);
+        auto lvObserver = std::make_shared<cosim::last_value_observer>();
+
+        execution.add_observer(lvObserver);
+        execution.simulate_until(cosim::to_time_point(0.1));
+
+        auto sim = entityMaps.simulators.at("example"); 
+        const cosim::value_reference inRef = 2;
+        const cosim::value_reference outRef = 3;
+
+        double initialValue = 0.0;
+        double outputValue = 0.0;
+        lvObserver->get_real(sim, gsl::make_span(&inRef, 1), gsl::make_span(&initialValue, 1));
+        lvObserver->get_real(sim, gsl::make_span(&outRef, 1), gsl::make_span(&outputValue, 1));
+
+        REQUIRE(initialValue == 1.0);
+        REQUIRE(std::fabs(outputValue - 10.1) < 1.0e-9);
+
+    } catch (const std::exception& e) {
+        std::cerr << "Error: " << e.what() << std::endl;
+        return 1;
+    }
+}