build DPsim as a Python module

Source/CMakeLists.txt

 cmake_minimum_required(VERSION 3.0)
 project(DPsim)
 
+# needed so CIMParser and arabica (which are first compiled into static libs)
+# can be included in the .so
+set(CMAKE_CXX_FLAGS "-fPIC")
+
 # library configuration etc.
 if(IS_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/../Libraries/eigen)
 	set(EIGEN3_INCLUDE_DIR ../Libraries/eigen)
@@ -11,32 +15,19 @@ endif()
 find_package(PythonLibs)
 
 if(WIN32)
+	set(MODNAME "dpsim.dll")
 	set(ARABICA_XML_BACKEND USE_MSXML)
 else()
+	set(MODNAME "dpsim.so")
 	set(LIBS "-lrt -lvillas-ext")
 endif()
 
 include_directories(${EIGEN3_INCLUDE_DIR} ${PYTHON_INCLUDE_DIRS})
 add_subdirectory(CIM-XML-Parser)
 
-# static library target for everything but main (otherwise, CMake compiles all
-# object files again for each test)
-file(GLOB SOURCES *.cpp Components/*.cpp Examples/*.cpp)
-set(SOURCES_NOMAIN ${SOURCES})
-file(GLOB MAIN_FULLPATH DPsimMain.cpp)
-list(REMOVE_ITEM SOURCES_NOMAIN ${MAIN_FULLPATH})
-add_library(DPsim STATIC ${SOURCES_NOMAIN})
-target_link_libraries(DPsim CIMParser)
-
-# actual executable
-add_executable(DPSolver ${MAIN_FULLPATH})
-target_link_libraries(DPSolver DPsim CIMParser pthread ${PYTHON_LIBRARIES} ${LIBS})
+file(GLOB SOURCES *.cpp Components/*.cpp)
+add_library(dpsim SHARED ${SOURCES})
+target_link_libraries(dpsim CIMParser pthread ${PYTHON_LIBRARIES} ${LIBS})
+execute_process(COMMAND python -c "import sysconfig; print(sysconfig.get_path('platlib'), end='')" OUTPUT_VARIABLE PYTHON_PKGPATH)
+install(FILES build/libdpsim.so DESTINATION ${PYTHON_PKGPATH} RENAME ${MODNAME})
 
-# tests
-file(GLOB TESTS Tests/*.cpp)
-foreach(TEST ${TESTS})
-    string(REGEX MATCH "[^/]*$" TEST_SHORT ${TEST})
-    string(REPLACE ".cpp" "" TEST_BIN ${TEST_SHORT})
-    add_executable(${TEST_BIN} ${TEST})
-    target_link_libraries(${TEST_BIN} DPsim CIMParser ${LIBS})
-endforeach()

Source/DPsimMain.cpp

-#include <Python.h>
-
-#include <condition_variable>
-#include <iostream>
-#include <mutex>
-#include <string>
-#include <thread>
-
-#include "CIMReader.h"
-#include "PyComponent.h"
-#include "PySimulation.h"
-#include "Simulation.h"
-#include "ShmemInterface.h"
-
-using namespace DPsim;
-
-void usage() {
-	std::cerr << "usage: DPsolver [OPTIONS] [PYTHON_FILE...]" << std::endl
-	  << "Possible options:" << std::endl
-	  << "  -b/--batch:               don't show an interactive prompt after reading files" << std::endl
-	  << "  -h/--help:                show this help and exit" << std::endl
-	  << "  -i/--interface OBJ_NAME:  prefix for the names of the shmem objects used for communication (default: /dpsim)" << std::endl
-	  << "  -n/--node NODE_ID:        RDF id of the node where the interfacing voltage/current source should be placed" << std::endl
-	  << "  -r/--realtime:            enable realtime simulation " << std::endl
-	  << "  -s/--split INDEX:         index of this instance for distributed simulation (0 or 1)" << std::endl
-	  << "Remaining arguments are treated as Python files and executed in order." << std::endl;
-}
-
-bool parseFloat(const char *s, double *d) {
-	char *end;
-	*d = std::strtod(s, &end);
-	return (end != s && !*end);
-}
-
-bool parseInt(const char *s, int *i) {
-	char *end;
-	*i = strtol(s, &end, 0);
-	return (end != s && !*end);
-}
-
-static PyMethodDef pyModuleMethods[] = {
-	{"load_cim", pyLoadCim, METH_VARARGS, "Load a network from CIM file(s)."},
-	{0}
-};
-
-static PyModuleDef dpsimModule = {
-	PyModuleDef_HEAD_INIT, "dpsim", NULL, -1, pyModuleMethods,
-	NULL, NULL, NULL, NULL
-};
-
-static PyObject* PyInit_dpsim(void) {
-	PyObject* m;
-
-	if (PyType_Ready(&PyComponentType) < 0)
-		return nullptr;
-	if (PyType_Ready(&PySimulationType) < 0)
-		return nullptr;
-
-	m = PyModule_Create(&dpsimModule);
-	if (!m)
-		return nullptr;
-
-	Py_INCREF(&PySimulationType);
-	PyModule_AddObject(m, "Simulation", (PyObject*) &PySimulationType);
-	Py_INCREF(&PyComponentType);
-	PyModule_AddObject(m, "Component", (PyObject*) &PyComponentType);
-	return m;
-}
-
-// TODO: that many platform-dependent ifdefs inside main are kind of ugly
-int cimMain(int argc, const char* argv[]) {
-	bool rt = false, batch = false;
-	int i, split = -1;
-	std::string interfaceBase = "/dpsim";
-	std::string splitNode = "";
-	std::string outName, inName, logName("log.txt"), llogName("lvector.csv"), rlogName("rvector.csv");
-#ifdef __linux__
-	ShmemInterface *intf = nullptr;
-#endif
-
-	// Parse arguments
-	for (i = 1; i < argc; i++) {
-		if (!strcmp(argv[i], "-b") || !strcmp(argv[i], "--batch")) {
-			batch = true;
-		} else if (!strcmp(argv[i], "-h") || !strcmp(argv[i], "--help")) {
-			usage();
-			return 0;
-		} else if (!strcmp(argv[i], "-i") || !strcmp(argv[i], "--interface")) {
-			if (i == argc-1) {
-				std::cerr << "Missing argument for -i/--interface; see 'DPsim --help' for usage" << std::endl;
-				return 1;
-			}
-			if (argv[++i][0] != '/') {
-				std::cerr << "Shmem interface object name must start with a '/'" << std::endl;
-				return 1;
-			}
-			interfaceBase = std::string(argv[i]);
-		} else if (!strcmp(argv[i], "-n") || !strcmp(argv[i], "--node")) {
-			if (i == argc-1) {
-				std::cerr << "Missing argument for -n/--node; see 'DPsim --help' for usage" << std::endl;
-				return 1;
-			}
-			splitNode = std::string(argv[++i]);
-		} else if (!strcmp(argv[i], "-r") || !strcmp(argv[i], "--realtime")) {
-			rt = true;
-		} else if (!strcmp(argv[i], "-s") || !strcmp(argv[i], "--split")) {
-			if (i == argc-1) {
-				std::cerr << "Missing argument for -s/--split; see 'DPsim --help' for usage" << std::endl;
-				return 1;
-			}
-			if (!parseInt(argv[++i], &split) || split < 0 || split > 1) {
-				std::cerr << "Invalid setting " << argv[i] << " for the split index" << std::endl;
-				return 1;
-			}
-		} else if (argv[i][0] == '-') {
-			std::cerr << "Unknown option " << argv[i] << " ; see 'DPsim --help' for usage" << std::endl;
-			return 1;
-		} else {
-			// remaining arguments treated as input files
-			break;
-		}
-	}
-#ifndef __linux__
-	if (split >= 0 || splitNode.length() != 0) {
-		std::cerr << "Distributed simulation not supported on this platform" << std::endl;
-		return 1;
-	} else if (rt) {
-		std::cerr << "Realtime simulation not supported on this platform" << std::endl;
-		return 1;
-	}
-#endif
-	if (split >= 0 || splitNode.length() != 0 || rt) {
-		std::cerr << "Realtime and distributed simulation currently not supported in combination with Python" << std::endl;
-		return 1;
-	}
-
-	// TODO: RT / shmem interface with python
-	/*
-#ifdef __linux__
-	// TODO: this is a simple, pretty much fixed setup. Make this more flexible / configurable
-	if (split >= 0) {
-		int node = reader.mapTopologicalNode(splitNode);
-		if (node < 0) {
-			std::cerr << "Invalid / missing split node" << std::endl;
-			return 1;
-		}
-		if (split == 0) {
-			outName = interfaceBase + ".0.out";
-			inName = interfaceBase + ".0.in";
-			intf = new ShmemInterface(outName.c_str(), inName.c_str());
-			ExternalVoltageSource *evs = new ExternalVoltageSource("v_int", node, 0, 0, 0, reader.getNumVoltageSources()+1);
-			intf->registerVoltageSource(evs, 0, 1);
-			intf->registerExportedCurrent(evs, 0, 1);
-			components.push_back(evs);
-			// TODO make log names configurable
-			logName = "cim0.log";
-			llogName = "lvector-cim0.csv";
-			rlogName = "rvector-cim0.csv";
-		} else {
-			outName = interfaceBase + ".1.out";
-			inName = interfaceBase + ".1.in";
-			intf = new ShmemInterface(outName.c_str(), inName.c_str());
-			ExternalCurrentSource *ecs = new ExternalCurrentSource("i_int", node, 0, 0, 0);
-			intf->registerCurrentSource(ecs, 0, 1);
-			intf->registerExportedVoltage(node, 0, 0, 1);
-			components.push_back(ecs);
-			logName = "cim1.log";
-			llogName = "lvector-cim1.csv";
-			rlogName = "rvector-cim1.csv";
-		}
-	}
-#endif
-	*/
-	
-	PyImport_AppendInittab("dpsim", &PyInit_dpsim);
-	Py_Initialize();
-	for (; i < argc; i++) {
-		FILE* f = fopen(argv[i], "r");
-		if (!f) {
-			std::cerr << "Failed to open ";
-			std::perror(argv[i]);
-			return 1;
-		}
-		PyRun_SimpleFile(f, argv[i]);
-		fclose(f);
-	}
-
-	if (!batch) {
-		while (std::cin.good() && Py_IsInitialized()) {
-			std::cout << "> ";
-			std::string line;
-			std::getline(std::cin, line);
-			PyRun_SimpleString(line.c_str());
-		}
-	}
-
-	/*
-#ifdef __linux__
-		if (intf)
-			sim.addExternalInterface(intf);
-
-		if (rt) {
-			sim.runRT(RTTimerFD, true, log, llog, rlog);
-		} else {
-			while (sim.step(log, llog, rlog))
-				sim.increaseByTimeStep();
-		}
-
-		if (intf)
-			delete intf;
-#endif
-	*/
-	return 0;
-}
-
-int main(int argc, const char* argv[]) {
-	return cimMain(argc, argv);
-}

Source/PyModule.cpp

+#include <Python.h>
+
+#include "PyComponent.h"
+#include "PyModule.h"
+#include "PySimulation.h"
+
+using namespace DPsim;
+
+PyMethodDef DPsim::pyModuleMethods[] = {
+	{"load_cim", pyLoadCim, METH_VARARGS, "Load a network from CIM file(s)."},
+	{0}
+};
+
+PyModuleDef DPsim::dpsimModule = {
+	PyModuleDef_HEAD_INIT, "dpsim", NULL, -1, pyModuleMethods,
+	NULL, NULL, NULL, NULL
+};
+
+extern "C" {
+	PyObject* PyInit_dpsim(void) {
+		PyObject* m;
+
+		if (PyType_Ready(&PyComponentType) < 0)
+			return nullptr;
+		if (PyType_Ready(&PySimulationType) < 0)
+			return nullptr;
+
+		m = PyModule_Create(&dpsimModule);
+		if (!m)
+			return nullptr;
+
+		Py_INCREF(&PySimulationType);
+		PyModule_AddObject(m, "Simulation", (PyObject*) &PySimulationType);
+		Py_INCREF(&PyComponentType);
+		PyModule_AddObject(m, "Component", (PyObject*) &PyComponentType);
+		return m;
+	}
+};
+

Source/PyModule.h

+#ifndef PYMODULE_H
+#define PYMODULE_H
+
+#include <Python.h>
+
+namespace DPsim {
+	extern PyMethodDef pyModuleMethods[];
+
+	extern PyModuleDef dpsimModule;
+
+};
+
+// Has to be declared as extern C and without a namespace, because  the linker
+// otherwise mangles the name so the Python interpreter can't find this function.
+extern "C" {
+	extern PyObject* PyInit_dpsim(void);
+};
+#endif