Actual source code: pythonsys.c

petsc-3.8.4 2018-03-24
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  1:  #include <petsc/private/petscimpl.h>

  3: /* ---------------------------------------------------------------- */

  5: #if !defined(PETSC_PYTHON_EXE)
  6: #define PETSC_PYTHON_EXE "python"
  7: #endif

  9: static PetscErrorCode PetscPythonFindExecutable(char pythonexe[PETSC_MAX_PATH_LEN])
 10: {
 11:   PetscBool      flag;

 15:   /* get the path for the Python interpreter executable */
 16:   PetscStrncpy(pythonexe,PETSC_PYTHON_EXE,PETSC_MAX_PATH_LEN);
 17:   PetscOptionsGetString(NULL,NULL,"-python",pythonexe,PETSC_MAX_PATH_LEN,&flag);
 18:   if (!flag || pythonexe[0]==0) {
 19:     PetscStrncpy(pythonexe,PETSC_PYTHON_EXE,PETSC_MAX_PATH_LEN);
 20:   }
 21:   return(0);
 22: }

 24: static PetscErrorCode PetscPythonFindLibrary(char pythonexe[PETSC_MAX_PATH_LEN],char pythonlib[PETSC_MAX_PATH_LEN])
 25: {
 26:   const char     cmdline[] = "-c 'import sys; print(sys.exec_prefix); print(sys.version[:3])'";
 27:   char           command[PETSC_MAX_PATH_LEN+1+sizeof(cmdline)+1];
 28:   char           prefix[PETSC_MAX_PATH_LEN],version[8],sep[2]={PETSC_DIR_SEPARATOR, 0},*eol;
 29:   FILE           *fp = NULL;
 30:   char           path[PETSC_MAX_PATH_LEN+1];
 31:   PetscBool      found = PETSC_FALSE;

 35: #if defined(PETSC_PYTHON_LIB)
 36:   PetscStrcpy(pythonlib,PETSC_PYTHON_LIB);
 37:   return(0);
 38: #endif

 40:   /* call Python to find out the name of the Python dynamic library */
 41:   PetscStrncpy(command,pythonexe,PETSC_MAX_PATH_LEN);
 42:   PetscStrcat(command," ");
 43:   PetscStrcat(command,cmdline);
 44: #if defined(PETSC_HAVE_POPEN)
 45:   PetscPOpen(PETSC_COMM_SELF,NULL,command,"r",&fp);
 46:   if (!fgets(prefix,sizeof(prefix),fp)) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Python: bad output from executable: %s",pythonexe);
 47:   if (!fgets(version,sizeof(version),fp)) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Python: bad output from executable: %s",pythonexe);
 48:   PetscPClose(PETSC_COMM_SELF,fp,NULL);
 49: #else
 50:   SETERRQ(PETSC_COMM_SELF,1,"Python: Aborted due to missing popen()");
 51: #endif
 52:   /* remove newlines */
 53:   PetscStrchr(prefix,'\n',&eol);
 54:   if (eol) eol[0] = 0;
 55:   PetscStrchr(version,'\n',&eol);
 56:   if (eol) eol[0] = 0;

 58:   /* test for $prefix/lib64/libpythonX.X[.so]*/
 59:   PetscStrcpy(pythonlib,prefix);
 60:   PetscStrcat(pythonlib,sep);
 61:   PetscStrcat(pythonlib,"lib64");
 62:   PetscTestDirectory(pythonlib,'r',&found);
 63:   if (found) {
 64:     PetscStrcat(pythonlib,sep);
 65:     PetscStrcat(pythonlib,"libpython");
 66:     PetscStrcat(pythonlib,version);
 67:     PetscDLLibraryRetrieve(PETSC_COMM_SELF,pythonlib,path,PETSC_MAX_PATH_LEN,&found);
 68:     if (found) return(0);
 69:   }

 71:   /* test for $prefix/lib/libpythonX.X[.so]*/
 72:   PetscStrcpy(pythonlib,prefix);
 73:   PetscStrcat(pythonlib,sep);
 74:   PetscStrcat(pythonlib,"lib");
 75:   PetscTestDirectory(pythonlib,'r',&found);
 76:   if (found) {
 77:     PetscStrcat(pythonlib,sep);
 78:     PetscStrcat(pythonlib,"libpython");
 79:     PetscStrcat(pythonlib,version);
 80:     PetscDLLibraryRetrieve(PETSC_COMM_SELF,pythonlib,path,PETSC_MAX_PATH_LEN,&found);
 81:     if (found) return(0);
 82:   }

 84:   /* nothing good found */
 85:   PetscMemzero(pythonlib,PETSC_MAX_PATH_LEN);
 86:   PetscInfo(0,"Python dynamic library not found\n");
 87:   return(0);
 88: }

 90: /* ---------------------------------------------------------------- */

 92: typedef struct _Py_object_t PyObject; /* fake definition */

 94: static PyObject* Py_None = 0;

 96: static const char* (*Py_GetVersion)(void);

 98: static int       (*Py_IsInitialized)(void);
 99: static void      (*Py_InitializeEx)(int);
100: static void      (*Py_Finalize)(void);

102: static void      (*PySys_SetArgv)(int,char**);
103: static PyObject* (*PySys_GetObject)(const char*);
104: static PyObject* (*PyObject_CallMethod)(PyObject*,const char*, const char*, ...);
105: static PyObject* (*PyImport_ImportModule)(const char*);

107: static void      (*Py_IncRef)(PyObject*);
108: static void      (*Py_DecRef)(PyObject*);

110: static void      (*PyErr_Clear)(void);
111: static PyObject* (*PyErr_Occurred)(void);
112: static void      (*PyErr_Fetch)(PyObject**,PyObject**,PyObject**);
113: static void      (*PyErr_NormalizeException)(PyObject**,PyObject**, PyObject**);
114: static void      (*PyErr_Display)(PyObject*,PyObject*,PyObject*);
115: static void      (*PyErr_Restore)(PyObject*,PyObject*,PyObject*);


118: #define PetscDLPyLibOpen(libname) \
119:   PetscDLLibraryAppend(PETSC_COMM_SELF,&PetscDLLibrariesLoaded,libname)
120: #define PetscDLPyLibSym(symbol, value) \
121:   PetscDLLibrarySym(PETSC_COMM_SELF,&PetscDLLibrariesLoaded,NULL,symbol,(void**)value)
122: #define PetscDLPyLibClose(comm) \
123:   do { } while (0)

125: static PetscErrorCode PetscPythonLoadLibrary(const char pythonlib[])
126: {

130:   /* open the Python dynamic library */
131:   PetscDLPyLibOpen(pythonlib);
132:   PetscInfo1(0,"Python: loaded dynamic library %s\n", pythonlib);
133:   /* look required symbols from the Python C-API */
134:   PetscDLPyLibSym("_Py_NoneStruct"        , &Py_None               );
135:   PetscDLPyLibSym("Py_GetVersion"         , &Py_GetVersion         );
136:   PetscDLPyLibSym("Py_IsInitialized"      , &Py_IsInitialized      );
137:   PetscDLPyLibSym("Py_InitializeEx"       , &Py_InitializeEx       );
138:   PetscDLPyLibSym("Py_Finalize"           , &Py_Finalize           );
139:   PetscDLPyLibSym("PySys_GetObject"       , &PySys_GetObject       );
140:   PetscDLPyLibSym("PySys_SetArgv"         , &PySys_SetArgv         );
141:   PetscDLPyLibSym("PyObject_CallMethod"   , &PyObject_CallMethod   );
142:   PetscDLPyLibSym("PyImport_ImportModule" , &PyImport_ImportModule );
143:   PetscDLPyLibSym("Py_IncRef"             , &Py_IncRef             );
144:   PetscDLPyLibSym("Py_DecRef"             , &Py_DecRef             );
145:   PetscDLPyLibSym("PyErr_Clear"           , &PyErr_Clear           );
146:   PetscDLPyLibSym("PyErr_Occurred"        , &PyErr_Occurred        );
147:   PetscDLPyLibSym("PyErr_Fetch"             , &PyErr_Fetch             );
148:   PetscDLPyLibSym("PyErr_NormalizeException", &PyErr_NormalizeException);
149:   PetscDLPyLibSym("PyErr_Display",            &PyErr_Display           );
150:   PetscDLPyLibSym("PyErr_Restore",            &PyErr_Restore           );
151:   /* XXX TODO: check that ALL symbols were there !!! */
152:   if (!Py_None)          SETERRQ(PETSC_COMM_SELF,1,"Python: failed to load symbols from dynamic library");
153:   if (!Py_GetVersion)    SETERRQ(PETSC_COMM_SELF,1,"Python: failed to load symbols from dynamic library");
154:   if (!Py_IsInitialized) SETERRQ(PETSC_COMM_SELF,1,"Python: failed to load symbols from dynamic library");
155:   if (!Py_InitializeEx)  SETERRQ(PETSC_COMM_SELF,1,"Python: failed to load symbols from dynamic library");
156:   if (!Py_Finalize)      SETERRQ(PETSC_COMM_SELF,1,"Python: failed to load symbols from dynamic library");
157:   PetscInfo(0,"Python: all required symbols loaded from Python dynamic library\n");
158:   return(0);
159: }

161: /* ---------------------------------------------------------------- */

163: static char      PetscPythonExe[PETSC_MAX_PATH_LEN] = { 0 };
164: static char      PetscPythonLib[PETSC_MAX_PATH_LEN] = { 0 };
165: static PetscBool PetscBeganPython = PETSC_FALSE;

167: /*@C
168:   PetscPythonFinalize - Finalize Python.

170:   Level: intermediate

172: .keywords: Python
173: @*/
174: PetscErrorCode  PetscPythonFinalize(void)
175: {
177:   if (PetscBeganPython) { if (Py_IsInitialized()) Py_Finalize(); }
178:   PetscBeganPython = PETSC_FALSE;
179:   return(0);
180: }

182: /*@C
183:   PetscPythonInitialize - Initialize Python and import petsc4py.

185:    Input Parameter:
186: +  pyexe - path to the Python interpreter executable, or NULL.
187: -  pylib - full path to the Python dynamic library, or NULL.

189:   Level: intermediate

191: .keywords: Python

193: @*/
194: PetscErrorCode  PetscPythonInitialize(const char pyexe[],const char pylib[])
195: {
196:   PyObject       *module = 0;

200:   if (PetscBeganPython) return(0);
201:   /* Python executable */
202:   if (pyexe && pyexe[0] != 0) {
203:     PetscStrncpy(PetscPythonExe,pyexe,sizeof(PetscPythonExe));
204:   } else {
205:     PetscPythonFindExecutable(PetscPythonExe);
206:   }
207:   /* Python dynamic library */
208:   if (pylib && pylib[0] != 0) {
209:     PetscStrncpy(PetscPythonLib,pylib,sizeof(PetscPythonLib));
210:   } else {
211:     PetscPythonFindLibrary(PetscPythonExe,PetscPythonLib);
212:   }
213:   /* dynamically load Python library */
214:   PetscPythonLoadLibrary(PetscPythonLib);
215:   /* initialize Python */
216:   PetscBeganPython = PETSC_FALSE;
217:   if (!Py_IsInitialized()) {
218:     static PetscBool registered = PETSC_FALSE;
219:     const char       *py_version;
220:     PyObject         *sys_path;
221:     char             path[PETSC_MAX_PATH_LEN] = { 0 };

223:     /* initialize Python */
224:     Py_InitializeEx(0); /* 0: do not install signal handlers */
225:     /*  build 'sys.argv' list */
226:     py_version = Py_GetVersion();
227:     if (py_version[0] == '2') {
228:       int argc = 0; char **argv = 0;
229:       PetscGetArgs(&argc,&argv);
230:       PySys_SetArgv(argc,argv);
231:     }
232:     if (py_version[0] == '3') {
233:       /* XXX 'argv' is type 'wchar_t**' */
234:       PySys_SetArgv(0,NULL);
235:     }
236:     /* add PETSC_LIB_DIR in front of 'sys.path' */
237:     sys_path = PySys_GetObject("path");
238:     if (sys_path) {
239:       PetscStrreplace(PETSC_COMM_SELF,"${PETSC_LIB_DIR}",path,sizeof(path));
240:       Py_DecRef(PyObject_CallMethod(sys_path,"insert","is",(int)0,(char*)path));
241:     }
242:     /* register finalizer */
243:     if (!registered) {
244:       PetscRegisterFinalize(PetscPythonFinalize);

246:       registered = PETSC_TRUE;
247:     }
248:     PetscBeganPython = PETSC_TRUE;
249:   }
250:   /* import 'petsc4py.PETSc' module */
251:   module = PyImport_ImportModule("petsc4py.PETSc");
252:   if (module) {
253:     PetscInfo(0,"Python: successfully imported  module 'petsc4py.PETSc'\n");

255:     Py_DecRef(module); module = 0;
256:   } else {
257:     PetscPythonPrintError();
258:     SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Python: could not import module 'petsc4py.PETSc', perhaps your PYTHONPATH does not contain it\n");
259:   }
260:   return(0);
261: }

263: /*@C
264:   PetscPythonPrintError - Print Python errors.

266:   Level: developer

268: .keywords: Python

270: @*/
271: PetscErrorCode  PetscPythonPrintError(void)
272: {
273:   PyObject *exc=0, *val=0, *tb=0;

276:   if (!PetscBeganPython) return(0);
277:   if (!PyErr_Occurred()) return(0);
278:   PyErr_Fetch(&exc,&val,&tb);
279:   PyErr_NormalizeException(&exc,&val,&tb);
280:   PyErr_Display(exc ? exc : Py_None,
281:                 val ? val : Py_None,
282:                 tb  ? tb  : Py_None);
283:   PyErr_Restore(exc,val,tb);
284:   return(0);
285: }

287: /* ---------------------------------------------------------------- */

289: PETSC_EXTERN PetscErrorCode (*PetscPythonMonitorSet_C)(PetscObject,const char[]);
290: PetscErrorCode (*PetscPythonMonitorSet_C)(PetscObject,const char[]) = NULL;

292: /*@C
293:   PetscPythonMonitorSet - Set Python monitor

295:   Level: developer

297: .keywords: Python

299: @*/
300: PetscErrorCode PetscPythonMonitorSet(PetscObject obj, const char url[])
301: {

307:   if (!PetscPythonMonitorSet_C) {
308:     PetscPythonInitialize(NULL,NULL);
309:     if (!PetscPythonMonitorSet_C) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"Couldn't initialize Python support for monitors");
310:   }
311:   PetscPythonMonitorSet_C(obj,url);
312:   return(0);
313: }

315: /* ---------------------------------------------------------------- */