xref: /petsc/src/sys/python/pythonsys.c (revision 49a6f2e5440bbcbd382a01c535bb68c01842b385)
1 #include <petsc/private/petscimpl.h>       /*I "petscsys.h" I*/
2 
3 /* ---------------------------------------------------------------- */
4 
5 #if !defined(PETSC_PYTHON_EXE)
6 #define PETSC_PYTHON_EXE "python"
7 #endif
8 
9 static PetscErrorCode PetscPythonFindExecutable(char pythonexe[PETSC_MAX_PATH_LEN])
10 {
11   PetscBool      flag;
12   PetscErrorCode ierr;
13 
14   PetscFunctionBegin;
15   /* get the path for the Python interpreter executable */
16   ierr = PetscStrncpy(pythonexe,PETSC_PYTHON_EXE,PETSC_MAX_PATH_LEN);CHKERRQ(ierr);
17   ierr = PetscOptionsGetString(NULL,NULL,"-python",pythonexe,PETSC_MAX_PATH_LEN,&flag);CHKERRQ(ierr);
18   if (!flag || pythonexe[0]==0) {
19     ierr = PetscStrncpy(pythonexe,PETSC_PYTHON_EXE,PETSC_MAX_PATH_LEN);CHKERRQ(ierr);
20   }
21   PetscFunctionReturn(0);
22 }
23 
24 /*
25     Python does not appear to have a universal way to indicate the location of Python dynamic library so try several possibilities
26 */
27 static PetscErrorCode PetscPythonFindLibraryName(const char pythonexe[PETSC_MAX_PATH_LEN],const char attempt[PETSC_MAX_PATH_LEN],char pythonlib[PETSC_MAX_PATH_LEN],PetscBool *found)
28 {
29   char           command[2*PETSC_MAX_PATH_LEN];
30   FILE           *fp = NULL;
31   char           *eol;
32   PetscErrorCode ierr;
33 
34   PetscFunctionBegin;
35   /* call Python to find out the name of the Python dynamic library */
36   ierr = PetscStrncpy(command,pythonexe,PETSC_MAX_PATH_LEN);CHKERRQ(ierr);
37   ierr = PetscStrcat(command," ");CHKERRQ(ierr);
38   ierr = PetscStrcat(command,attempt);CHKERRQ(ierr);
39 #if defined(PETSC_HAVE_POPEN)
40   ierr = PetscPOpen(PETSC_COMM_SELF,NULL,command,"r",&fp);CHKERRQ(ierr);
41   if (!fgets(pythonlib,PETSC_MAX_PATH_LEN,fp)) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Python: bad output from executable: %s",pythonexe);
42   ierr = PetscPClose(PETSC_COMM_SELF,fp);CHKERRQ(ierr);
43 #else
44   SETERRQ(PETSC_COMM_SELF,1,"Python: Aborted due to missing popen()");
45 #endif
46   /* remove newlines */
47   ierr = PetscStrchr(pythonlib,'\n',&eol);CHKERRQ(ierr);
48   if (eol) eol[0] = 0;
49   ierr = PetscTestFile(pythonlib,'r',found);CHKERRQ(ierr);
50   PetscFunctionReturn(0);
51 }
52 
53 
54 static PetscErrorCode PetscPythonFindLibrary(const char pythonexe[PETSC_MAX_PATH_LEN],char pythonlib[PETSC_MAX_PATH_LEN])
55 {
56   const char     cmdline1[] = "-c 'from distutils import sysconfig; print(sysconfig.get_config_var(\"LIBPYTHON\"))'";
57   const char     cmdline2[] = "-c 'import os;from distutils import sysconfig; print(os.path.join(sysconfig.get_config_var(\"LIBPL\"),sysconfig.get_config_var(\"LDLIBRARY\")))'";
58   const char     cmdline3[] = "-c 'import os;from distutils import sysconfig; print(os.path.join(sysconfig.get_config_var(\"LIBDIR\"),sysconfig.get_config_var(\"LDLIBRARY\")))'";
59   PetscBool      found = PETSC_FALSE;
60   PetscErrorCode ierr;
61 
62   PetscFunctionBegin;
63 #if defined(PETSC_PYTHON_LIB)
64   ierr = PetscStrcpy(pythonlib,PETSC_PYTHON_LIB);CHKERRQ(ierr);
65   PetscFunctionReturn(0);
66 #endif
67 
68   ierr = PetscPythonFindLibraryName(pythonexe,cmdline1,pythonlib,&found);CHKERRQ(ierr);
69   if (!found) {
70     ierr = PetscPythonFindLibraryName(pythonexe,cmdline2,pythonlib,&found);CHKERRQ(ierr);
71   }
72   if (!found) {
73     ierr = PetscPythonFindLibraryName(pythonexe,cmdline3,pythonlib,&found);CHKERRQ(ierr);
74   }
75   ierr = PetscInfo2(0,"Python library  %s found %d\n",pythonlib,found);CHKERRQ(ierr);
76   PetscFunctionReturn(0);
77 }
78 
79 /* ---------------------------------------------------------------- */
80 
81 typedef struct _Py_object_t PyObject; /* fake definition */
82 
83 static PyObject* Py_None = 0;
84 
85 static const char* (*Py_GetVersion)(void);
86 
87 static int       (*Py_IsInitialized)(void);
88 static void      (*Py_InitializeEx)(int);
89 static void      (*Py_Finalize)(void);
90 
91 static void      (*PySys_SetArgv)(int,void*);
92 static PyObject* (*PySys_GetObject)(const char*);
93 static PyObject* (*PyObject_CallMethod)(PyObject*,const char*, const char*, ...);
94 static PyObject* (*PyImport_ImportModule)(const char*);
95 
96 static void      (*Py_IncRef)(PyObject*);
97 static void      (*Py_DecRef)(PyObject*);
98 
99 static void      (*PyErr_Clear)(void);
100 static PyObject* (*PyErr_Occurred)(void);
101 static void      (*PyErr_Fetch)(PyObject**,PyObject**,PyObject**);
102 static void      (*PyErr_NormalizeException)(PyObject**,PyObject**, PyObject**);
103 static void      (*PyErr_Display)(PyObject*,PyObject*,PyObject*);
104 static void      (*PyErr_Restore)(PyObject*,PyObject*,PyObject*);
105 
106 
107 #define PetscDLPyLibOpen(libname) \
108   PetscDLLibraryAppend(PETSC_COMM_SELF,&PetscDLLibrariesLoaded,libname)
109 #define PetscDLPyLibSym(symbol, value) \
110   PetscDLLibrarySym(PETSC_COMM_SELF,&PetscDLLibrariesLoaded,NULL,symbol,(void**)value)
111 #define PetscDLPyLibClose(comm) \
112   do { } while (0)
113 
114 static PetscErrorCode PetscPythonLoadLibrary(const char pythonlib[])
115 {
116   PetscErrorCode ierr;
117 
118   PetscFunctionBegin;
119   /* open the Python dynamic library */
120   ierr = PetscDLPyLibOpen(pythonlib);CHKERRQ(ierr);
121   ierr = PetscInfo1(0,"Python: loaded dynamic library %s\n", pythonlib);CHKERRQ(ierr);
122   /* look required symbols from the Python C-API */
123   ierr = PetscDLPyLibSym("_Py_NoneStruct"        , &Py_None               );CHKERRQ(ierr);
124   ierr = PetscDLPyLibSym("Py_GetVersion"         , &Py_GetVersion         );CHKERRQ(ierr);
125   ierr = PetscDLPyLibSym("Py_IsInitialized"      , &Py_IsInitialized      );CHKERRQ(ierr);
126   ierr = PetscDLPyLibSym("Py_InitializeEx"       , &Py_InitializeEx       );CHKERRQ(ierr);
127   ierr = PetscDLPyLibSym("Py_Finalize"           , &Py_Finalize           );CHKERRQ(ierr);
128   ierr = PetscDLPyLibSym("PySys_GetObject"       , &PySys_GetObject       );CHKERRQ(ierr);
129   ierr = PetscDLPyLibSym("PySys_SetArgv"         , &PySys_SetArgv         );CHKERRQ(ierr);
130   ierr = PetscDLPyLibSym("PyObject_CallMethod"   , &PyObject_CallMethod   );CHKERRQ(ierr);
131   ierr = PetscDLPyLibSym("PyImport_ImportModule" , &PyImport_ImportModule );CHKERRQ(ierr);
132   ierr = PetscDLPyLibSym("Py_IncRef"             , &Py_IncRef             );CHKERRQ(ierr);
133   ierr = PetscDLPyLibSym("Py_DecRef"             , &Py_DecRef             );CHKERRQ(ierr);
134   ierr = PetscDLPyLibSym("PyErr_Clear"           , &PyErr_Clear           );CHKERRQ(ierr);
135   ierr = PetscDLPyLibSym("PyErr_Occurred"        , &PyErr_Occurred        );CHKERRQ(ierr);
136   ierr = PetscDLPyLibSym("PyErr_Fetch"             , &PyErr_Fetch             );CHKERRQ(ierr);
137   ierr = PetscDLPyLibSym("PyErr_NormalizeException", &PyErr_NormalizeException);CHKERRQ(ierr);
138   ierr = PetscDLPyLibSym("PyErr_Display",            &PyErr_Display           );CHKERRQ(ierr);
139   ierr = PetscDLPyLibSym("PyErr_Restore",            &PyErr_Restore           );CHKERRQ(ierr);
140   /* XXX TODO: check that ALL symbols were there !!! */
141   if (!Py_None)          SETERRQ1(PETSC_COMM_SELF,1,"Python: failed to load symbols from Python dynamic library %s",pythonlib);
142   if (!Py_GetVersion)    SETERRQ1(PETSC_COMM_SELF,1,"Python: failed to load symbols from Python dynamic library %s",pythonlib);
143   if (!Py_IsInitialized) SETERRQ1(PETSC_COMM_SELF,1,"Python: failed to load symbols from Python dynamic library %s",pythonlib);
144   if (!Py_InitializeEx)  SETERRQ1(PETSC_COMM_SELF,1,"Python: failed to load symbols from Python dynamic library %s",pythonlib);
145   if (!Py_Finalize)      SETERRQ1(PETSC_COMM_SELF,1,"Python: failed to load symbols from Python dynamic library %s",pythonlib);
146   ierr = PetscInfo1(0,"Python: all required symbols loaded from Python dynamic library %s\n",pythonlib);CHKERRQ(ierr);
147   PetscFunctionReturn(0);
148 }
149 
150 /* ---------------------------------------------------------------- */
151 
152 static char      PetscPythonExe[PETSC_MAX_PATH_LEN] = { 0 };
153 static char      PetscPythonLib[PETSC_MAX_PATH_LEN] = { 0 };
154 static PetscBool PetscBeganPython = PETSC_FALSE;
155 
156 /*@C
157   PetscPythonFinalize - Finalize Python.
158 
159   Level: intermediate
160 
161 .keywords: Python
162 @*/
163 PetscErrorCode  PetscPythonFinalize(void)
164 {
165   PetscFunctionBegin;
166   if (PetscBeganPython) { if (Py_IsInitialized()) Py_Finalize(); }
167   PetscBeganPython = PETSC_FALSE;
168   PetscFunctionReturn(0);
169 }
170 
171 /*@C
172   PetscPythonInitialize - Initialize Python and import petsc4py.
173 
174    Input Parameter:
175 +  pyexe - path to the Python interpreter executable, or NULL.
176 -  pylib - full path to the Python dynamic library, or NULL.
177 
178   Level: intermediate
179 
180 .keywords: Python
181 
182 @*/
183 PetscErrorCode  PetscPythonInitialize(const char pyexe[],const char pylib[])
184 {
185   PyObject       *module = 0;
186   PetscErrorCode ierr;
187 
188   PetscFunctionBegin;
189   if (PetscBeganPython) PetscFunctionReturn(0);
190   /* Python executable */
191   if (pyexe && pyexe[0] != 0) {
192     ierr = PetscStrncpy(PetscPythonExe,pyexe,sizeof(PetscPythonExe));CHKERRQ(ierr);
193   } else {
194     ierr = PetscPythonFindExecutable(PetscPythonExe);CHKERRQ(ierr);
195   }
196   /* Python dynamic library */
197   if (pylib && pylib[0] != 0) {
198     ierr = PetscStrncpy(PetscPythonLib,pylib,sizeof(PetscPythonLib));CHKERRQ(ierr);
199   } else {
200     ierr = PetscPythonFindLibrary(PetscPythonExe,PetscPythonLib);CHKERRQ(ierr);
201   }
202   /* dynamically load Python library */
203   ierr = PetscPythonLoadLibrary(PetscPythonLib);CHKERRQ(ierr);
204   /* initialize Python */
205   PetscBeganPython = PETSC_FALSE;
206   if (!Py_IsInitialized()) {
207     static PetscBool registered = PETSC_FALSE;
208     const char       *py_version;
209     PyObject         *sys_path;
210     char             path[PETSC_MAX_PATH_LEN] = { 0 };
211 
212     /* initialize Python */
213     Py_InitializeEx(0); /* 0: do not install signal handlers */
214     /*  build 'sys.argv' list */
215     py_version = Py_GetVersion();
216     if (py_version[0] == '2') {
217       int argc = 0; char *argv[1] = {NULL};
218       PySys_SetArgv(argc,argv);
219     }
220     if (py_version[0] == '3') {
221       int argc = 0; wchar_t *argv[1] = {NULL};
222       PySys_SetArgv(argc,argv);
223     }
224     /* add PETSC_LIB_DIR in front of 'sys.path' */
225     sys_path = PySys_GetObject("path");
226     if (sys_path) {
227       ierr = PetscStrreplace(PETSC_COMM_SELF,"${PETSC_LIB_DIR}",path,sizeof(path));CHKERRQ(ierr);
228       Py_DecRef(PyObject_CallMethod(sys_path,"insert","is",(int)0,(char*)path));
229     }
230     /* register finalizer */
231     if (!registered) {
232       ierr = PetscRegisterFinalize(PetscPythonFinalize);CHKERRQ(ierr);
233       registered = PETSC_TRUE;
234     }
235     PetscBeganPython = PETSC_TRUE;
236   }
237   /* import 'petsc4py.PETSc' module */
238   module = PyImport_ImportModule("petsc4py.PETSc");
239   if (module) {
240     ierr = PetscInfo(0,"Python: successfully imported  module 'petsc4py.PETSc'\n");CHKERRQ(ierr);
241 
242     Py_DecRef(module); module = 0;
243   } else {
244     PetscPythonPrintError();
245     SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Python: could not import module 'petsc4py.PETSc', perhaps your PYTHONPATH does not contain it\n");
246   }
247   PetscFunctionReturn(0);
248 }
249 
250 /*@C
251   PetscPythonPrintError - Print Python errors.
252 
253   Level: developer
254 
255 .keywords: Python
256 
257 @*/
258 PetscErrorCode  PetscPythonPrintError(void)
259 {
260   PyObject *exc=0, *val=0, *tb=0;
261 
262   PetscFunctionBegin;
263   if (!PetscBeganPython) PetscFunctionReturn(0);
264   if (!PyErr_Occurred()) PetscFunctionReturn(0);
265   PyErr_Fetch(&exc,&val,&tb);
266   PyErr_NormalizeException(&exc,&val,&tb);
267   PyErr_Display(exc ? exc : Py_None,
268                 val ? val : Py_None,
269                 tb  ? tb  : Py_None);
270   PyErr_Restore(exc,val,tb);
271   PetscFunctionReturn(0);
272 }
273 
274 /* ---------------------------------------------------------------- */
275 
276 PETSC_EXTERN PetscErrorCode (*PetscPythonMonitorSet_C)(PetscObject,const char[]);
277 PetscErrorCode (*PetscPythonMonitorSet_C)(PetscObject,const char[]) = NULL;
278 
279 /*@C
280   PetscPythonMonitorSet - Set Python monitor
281 
282   Level: developer
283 
284 .keywords: Python
285 
286 @*/
287 PetscErrorCode PetscPythonMonitorSet(PetscObject obj, const char url[])
288 {
289   PetscErrorCode ierr;
290 
291   PetscFunctionBegin;
292   PetscValidHeader(obj,1);
293   PetscValidCharPointer(url,2);
294   if (!PetscPythonMonitorSet_C) {
295     ierr = PetscPythonInitialize(NULL,NULL);CHKERRQ(ierr);
296     if (!PetscPythonMonitorSet_C) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"Couldn't initialize Python support for monitors");
297   }
298   ierr = PetscPythonMonitorSet_C(obj,url);CHKERRQ(ierr);
299   PetscFunctionReturn(0);
300 }
301 
302 /* ---------------------------------------------------------------- */
303