xref: /petsc/src/sys/python/pythonsys.c (revision 702f9f58dc9dd5d9c7e1ff0579a0e93079772d47)
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 'import os;from distutils import sysconfig; print(os.path.join(sysconfig.get_config_var(\"LIBDIR\"),sysconfig.get_config_var(\"LDLIBRARY\")))'";
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 'from distutils import sysconfig; print(sysconfig.get_config_var(\"LIBPYTHON\"))'";
59 
60   PetscBool      found = PETSC_FALSE;
61   PetscErrorCode ierr;
62 
63   PetscFunctionBegin;
64 #if defined(PETSC_PYTHON_LIB)
65   ierr = PetscStrcpy(pythonlib,PETSC_PYTHON_LIB);CHKERRQ(ierr);
66   PetscFunctionReturn(0);
67 #endif
68 
69   ierr = PetscPythonFindLibraryName(pythonexe,cmdline1,pythonlib,&found);CHKERRQ(ierr);
70   if (!found) {
71     ierr = PetscPythonFindLibraryName(pythonexe,cmdline2,pythonlib,&found);CHKERRQ(ierr);
72   }
73   if (!found) {
74     ierr = PetscPythonFindLibraryName(pythonexe,cmdline3,pythonlib,&found);CHKERRQ(ierr);
75   }
76   ierr = PetscInfo2(0,"Python library  %s found %d\n",pythonlib,found);CHKERRQ(ierr);
77   PetscFunctionReturn(0);
78 }
79 
80 /* ---------------------------------------------------------------- */
81 
82 typedef struct _Py_object_t PyObject; /* fake definition */
83 
84 static PyObject* Py_None = 0;
85 
86 static const char* (*Py_GetVersion)(void);
87 
88 static int       (*Py_IsInitialized)(void);
89 static void      (*Py_InitializeEx)(int);
90 static void      (*Py_Finalize)(void);
91 
92 static void      (*PySys_SetArgv)(int,void*);
93 static PyObject* (*PySys_GetObject)(const char*);
94 static PyObject* (*PyObject_CallMethod)(PyObject*,const char*, const char*, ...);
95 static PyObject* (*PyImport_ImportModule)(const char*);
96 
97 static void      (*Py_IncRef)(PyObject*);
98 static void      (*Py_DecRef)(PyObject*);
99 
100 static void      (*PyErr_Clear)(void);
101 static PyObject* (*PyErr_Occurred)(void);
102 static void      (*PyErr_Fetch)(PyObject**,PyObject**,PyObject**);
103 static void      (*PyErr_NormalizeException)(PyObject**,PyObject**, PyObject**);
104 static void      (*PyErr_Display)(PyObject*,PyObject*,PyObject*);
105 static void      (*PyErr_Restore)(PyObject*,PyObject*,PyObject*);
106 
107 
108 #define PetscDLPyLibOpen(libname) \
109   PetscDLLibraryAppend(PETSC_COMM_SELF,&PetscDLLibrariesLoaded,libname)
110 #define PetscDLPyLibSym(symbol, value) \
111   PetscDLLibrarySym(PETSC_COMM_SELF,&PetscDLLibrariesLoaded,NULL,symbol,(void**)value)
112 #define PetscDLPyLibClose(comm) \
113   do { } while (0)
114 
115 static PetscErrorCode PetscPythonLoadLibrary(const char pythonlib[])
116 {
117   PetscErrorCode ierr;
118 
119   PetscFunctionBegin;
120   /* open the Python dynamic library */
121   ierr = PetscDLPyLibOpen(pythonlib);CHKERRQ(ierr);
122   ierr = PetscInfo1(0,"Python: loaded dynamic library %s\n", pythonlib);CHKERRQ(ierr);
123   /* look required symbols from the Python C-API */
124   ierr = PetscDLPyLibSym("_Py_NoneStruct"        , &Py_None               );CHKERRQ(ierr);
125   ierr = PetscDLPyLibSym("Py_GetVersion"         , &Py_GetVersion         );CHKERRQ(ierr);
126   ierr = PetscDLPyLibSym("Py_IsInitialized"      , &Py_IsInitialized      );CHKERRQ(ierr);
127   ierr = PetscDLPyLibSym("Py_InitializeEx"       , &Py_InitializeEx       );CHKERRQ(ierr);
128   ierr = PetscDLPyLibSym("Py_Finalize"           , &Py_Finalize           );CHKERRQ(ierr);
129   ierr = PetscDLPyLibSym("PySys_GetObject"       , &PySys_GetObject       );CHKERRQ(ierr);
130   ierr = PetscDLPyLibSym("PySys_SetArgv"         , &PySys_SetArgv         );CHKERRQ(ierr);
131   ierr = PetscDLPyLibSym("PyObject_CallMethod"   , &PyObject_CallMethod   );CHKERRQ(ierr);
132   ierr = PetscDLPyLibSym("PyImport_ImportModule" , &PyImport_ImportModule );CHKERRQ(ierr);
133   ierr = PetscDLPyLibSym("Py_IncRef"             , &Py_IncRef             );CHKERRQ(ierr);
134   ierr = PetscDLPyLibSym("Py_DecRef"             , &Py_DecRef             );CHKERRQ(ierr);
135   ierr = PetscDLPyLibSym("PyErr_Clear"           , &PyErr_Clear           );CHKERRQ(ierr);
136   ierr = PetscDLPyLibSym("PyErr_Occurred"        , &PyErr_Occurred        );CHKERRQ(ierr);
137   ierr = PetscDLPyLibSym("PyErr_Fetch"             , &PyErr_Fetch             );CHKERRQ(ierr);
138   ierr = PetscDLPyLibSym("PyErr_NormalizeException", &PyErr_NormalizeException);CHKERRQ(ierr);
139   ierr = PetscDLPyLibSym("PyErr_Display",            &PyErr_Display           );CHKERRQ(ierr);
140   ierr = PetscDLPyLibSym("PyErr_Restore",            &PyErr_Restore           );CHKERRQ(ierr);
141   /* XXX TODO: check that ALL symbols were there !!! */
142   if (!Py_None)          SETERRQ1(PETSC_COMM_SELF,1,"Python: failed to load symbols from Python dynamic library %s",pythonlib);
143   if (!Py_GetVersion)    SETERRQ1(PETSC_COMM_SELF,1,"Python: failed to load symbols from Python dynamic library %s",pythonlib);
144   if (!Py_IsInitialized) SETERRQ1(PETSC_COMM_SELF,1,"Python: failed to load symbols from Python dynamic library %s",pythonlib);
145   if (!Py_InitializeEx)  SETERRQ1(PETSC_COMM_SELF,1,"Python: failed to load symbols from Python dynamic library %s",pythonlib);
146   if (!Py_Finalize)      SETERRQ1(PETSC_COMM_SELF,1,"Python: failed to load symbols from Python dynamic library %s",pythonlib);
147   ierr = PetscInfo1(0,"Python: all required symbols loaded from Python dynamic library %s\n",pythonlib);CHKERRQ(ierr);
148   PetscFunctionReturn(0);
149 }
150 
151 /* ---------------------------------------------------------------- */
152 
153 static char      PetscPythonExe[PETSC_MAX_PATH_LEN] = { 0 };
154 static char      PetscPythonLib[PETSC_MAX_PATH_LEN] = { 0 };
155 static PetscBool PetscBeganPython = PETSC_FALSE;
156 
157 /*@C
158   PetscPythonFinalize - Finalize Python.
159 
160   Level: intermediate
161 
162 .keywords: Python
163 @*/
164 PetscErrorCode  PetscPythonFinalize(void)
165 {
166   PetscFunctionBegin;
167   if (PetscBeganPython) { if (Py_IsInitialized()) Py_Finalize(); }
168   PetscBeganPython = PETSC_FALSE;
169   PetscFunctionReturn(0);
170 }
171 
172 /*@C
173   PetscPythonInitialize - Initialize Python and import petsc4py.
174 
175    Input Parameter:
176 +  pyexe - path to the Python interpreter executable, or NULL.
177 -  pylib - full path to the Python dynamic library, or NULL.
178 
179   Level: intermediate
180 
181 .keywords: Python
182 
183 @*/
184 PetscErrorCode  PetscPythonInitialize(const char pyexe[],const char pylib[])
185 {
186   PyObject       *module = 0;
187   PetscErrorCode ierr;
188 
189   PetscFunctionBegin;
190   if (PetscBeganPython) PetscFunctionReturn(0);
191   /* Python executable */
192   if (pyexe && pyexe[0] != 0) {
193     ierr = PetscStrncpy(PetscPythonExe,pyexe,sizeof(PetscPythonExe));CHKERRQ(ierr);
194   } else {
195     ierr = PetscPythonFindExecutable(PetscPythonExe);CHKERRQ(ierr);
196   }
197   /* Python dynamic library */
198   if (pylib && pylib[0] != 0) {
199     ierr = PetscStrncpy(PetscPythonLib,pylib,sizeof(PetscPythonLib));CHKERRQ(ierr);
200   } else {
201     ierr = PetscPythonFindLibrary(PetscPythonExe,PetscPythonLib);CHKERRQ(ierr);
202   }
203   /* dynamically load Python library */
204   ierr = PetscPythonLoadLibrary(PetscPythonLib);CHKERRQ(ierr);
205   /* initialize Python */
206   PetscBeganPython = PETSC_FALSE;
207   if (!Py_IsInitialized()) {
208     static PetscBool registered = PETSC_FALSE;
209     const char       *py_version;
210     PyObject         *sys_path;
211     char             path[PETSC_MAX_PATH_LEN] = { 0 };
212 
213     /* initialize Python */
214     Py_InitializeEx(0); /* 0: do not install signal handlers */
215     /*  build 'sys.argv' list */
216     py_version = Py_GetVersion();
217     if (py_version[0] == '2') {
218       int argc = 0; char *argv[1] = {NULL};
219       PySys_SetArgv(argc,argv);
220     }
221     if (py_version[0] == '3') {
222       int argc = 0; wchar_t *argv[1] = {NULL};
223       PySys_SetArgv(argc,argv);
224     }
225     /* add PETSC_LIB_DIR in front of 'sys.path' */
226     sys_path = PySys_GetObject("path");
227     if (sys_path) {
228       ierr = PetscStrreplace(PETSC_COMM_SELF,"${PETSC_LIB_DIR}",path,sizeof(path));CHKERRQ(ierr);
229       Py_DecRef(PyObject_CallMethod(sys_path,"insert","is",(int)0,(char*)path));
230     }
231     /* register finalizer */
232     if (!registered) {
233       ierr = PetscRegisterFinalize(PetscPythonFinalize);CHKERRQ(ierr);
234       registered = PETSC_TRUE;
235     }
236     PetscBeganPython = PETSC_TRUE;
237   }
238   /* import 'petsc4py.PETSc' module */
239   module = PyImport_ImportModule("petsc4py.PETSc");
240   if (module) {
241     ierr = PetscInfo(0,"Python: successfully imported  module 'petsc4py.PETSc'\n");CHKERRQ(ierr);
242 
243     Py_DecRef(module); module = 0;
244   } else {
245     PetscPythonPrintError();
246     SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Python: could not import module 'petsc4py.PETSc', perhaps your PYTHONPATH does not contain it\n");
247   }
248   PetscFunctionReturn(0);
249 }
250 
251 /*@C
252   PetscPythonPrintError - Print Python errors.
253 
254   Level: developer
255 
256 .keywords: Python
257 
258 @*/
259 PetscErrorCode  PetscPythonPrintError(void)
260 {
261   PyObject *exc=0, *val=0, *tb=0;
262 
263   PetscFunctionBegin;
264   if (!PetscBeganPython) PetscFunctionReturn(0);
265   if (!PyErr_Occurred()) PetscFunctionReturn(0);
266   PyErr_Fetch(&exc,&val,&tb);
267   PyErr_NormalizeException(&exc,&val,&tb);
268   PyErr_Display(exc ? exc : Py_None,
269                 val ? val : Py_None,
270                 tb  ? tb  : Py_None);
271   PyErr_Restore(exc,val,tb);
272   PetscFunctionReturn(0);
273 }
274 
275 /* ---------------------------------------------------------------- */
276 
277 PETSC_EXTERN PetscErrorCode (*PetscPythonMonitorSet_C)(PetscObject,const char[]);
278 PetscErrorCode (*PetscPythonMonitorSet_C)(PetscObject,const char[]) = NULL;
279 
280 /*@C
281   PetscPythonMonitorSet - Set Python monitor
282 
283   Level: developer
284 
285 .keywords: Python
286 
287 @*/
288 PetscErrorCode PetscPythonMonitorSet(PetscObject obj, const char url[])
289 {
290   PetscErrorCode ierr;
291 
292   PetscFunctionBegin;
293   PetscValidHeader(obj,1);
294   PetscValidCharPointer(url,2);
295   if (!PetscPythonMonitorSet_C) {
296     ierr = PetscPythonInitialize(NULL,NULL);CHKERRQ(ierr);
297     if (!PetscPythonMonitorSet_C) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"Couldn't initialize Python support for monitors");
298   }
299   ierr = PetscPythonMonitorSet_C(obj,url);CHKERRQ(ierr);
300   PetscFunctionReturn(0);
301 }
302 
303 /* ---------------------------------------------------------------- */
304