Actual source code: pythonsys.c

petsc-3.7.3 2016-08-01
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  1: #include <petsc/private/petscimpl.h>       /*I "petscsys.h" I*/

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

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

 11: static PetscErrorCode PetscPythonFindExecutable(char pythonexe[PETSC_MAX_PATH_LEN])
 12: {
 13:   PetscBool      flag;

 17:   /* get the path for the Python interpreter executable */
 18:   PetscStrncpy(pythonexe,PETSC_PYTHON_EXE,PETSC_MAX_PATH_LEN);
 19:   PetscOptionsGetString(NULL,NULL,"-python",pythonexe,PETSC_MAX_PATH_LEN,&flag);
 20:   if (!flag || pythonexe[0]==0) {
 21:     PetscStrncpy(pythonexe,PETSC_PYTHON_EXE,PETSC_MAX_PATH_LEN);
 22:   }
 23:   return(0);
 24: }

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

 39: #if defined(PETSC_PYTHON_LIB)
 40:   PetscStrcpy(pythonlib,PETSC_PYTHON_LIB);
 41:   return(0);
 42: #endif

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

 62:   /* test for $prefix/lib64/libpythonX.X[.so]*/
 63:   PetscStrcpy(pythonlib,prefix);
 64:   PetscStrcat(pythonlib,sep);
 65:   PetscStrcat(pythonlib,"lib64");
 66:   PetscTestDirectory(pythonlib,'r',&found);
 67:   if (found) {
 68:     PetscStrcat(pythonlib,sep);
 69:     PetscStrcat(pythonlib,"libpython");
 70:     PetscStrcat(pythonlib,version);
 71:     PetscDLLibraryRetrieve(PETSC_COMM_SELF,pythonlib,path,PETSC_MAX_PATH_LEN,&found);
 72:     if (found) return(0);
 73:   }

 75:   /* test for $prefix/lib/libpythonX.X[.so]*/
 76:   PetscStrcpy(pythonlib,prefix);
 77:   PetscStrcat(pythonlib,sep);
 78:   PetscStrcat(pythonlib,"lib");
 79:   PetscTestDirectory(pythonlib,'r',&found);
 80:   if (found) {
 81:     PetscStrcat(pythonlib,sep);
 82:     PetscStrcat(pythonlib,"libpython");
 83:     PetscStrcat(pythonlib,version);
 84:     PetscDLLibraryRetrieve(PETSC_COMM_SELF,pythonlib,path,PETSC_MAX_PATH_LEN,&found);
 85:     if (found) return(0);
 86:   }

 88:   /* nothing good found */
 89:   PetscMemzero(pythonlib,PETSC_MAX_PATH_LEN);
 90:   PetscInfo(0,"Python dynamic library not found\n");
 91:   return(0);
 92: }

 94: /* ---------------------------------------------------------------- */

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

 98: static PyObject* Py_None = 0;

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

102: static int       (*Py_IsInitialized)(void);
103: static void      (*Py_InitializeEx)(int);
104: static void      (*Py_Finalize)(void);

106: static void      (*PySys_SetArgv)(int,char**);
107: static PyObject* (*PySys_GetObject)(const char*);
108: static PyObject* (*PyObject_CallMethod)(PyObject*,const char*, const char*, ...);
109: static PyObject* (*PyImport_ImportModule)(const char*);

111: static void      (*Py_IncRef)(PyObject*);
112: static void      (*Py_DecRef)(PyObject*);

114: static void      (*PyErr_Clear)(void);
115: static PyObject* (*PyErr_Occurred)(void);
116: static void      (*PyErr_Fetch)(PyObject**,PyObject**,PyObject**);
117: static void      (*PyErr_NormalizeException)(PyObject**,PyObject**, PyObject**);
118: static void      (*PyErr_Display)(PyObject*,PyObject*,PyObject*);
119: static void      (*PyErr_Restore)(PyObject*,PyObject*,PyObject*);


122: #define PetscDLPyLibOpen(libname) \
123:   PetscDLLibraryAppend(PETSC_COMM_SELF,&PetscDLLibrariesLoaded,libname)
124: #define PetscDLPyLibSym(symbol, value) \
125:   PetscDLLibrarySym(PETSC_COMM_SELF,&PetscDLLibrariesLoaded,NULL,symbol,(void**)value)
126: #define PetscDLPyLibClose(comm) \
127:   do { } while (0)

131: static PetscErrorCode PetscPythonLoadLibrary(const char pythonlib[])
132: {

136:   /* open the Python dynamic library */
137:   PetscDLPyLibOpen(pythonlib);
138:   PetscInfo1(0,"Python: loaded dynamic library %s\n", pythonlib);
139:   /* look required symbols from the Python C-API */
140:   PetscDLPyLibSym("_Py_NoneStruct"        , &Py_None               );
141:   PetscDLPyLibSym("Py_GetVersion"         , &Py_GetVersion         );
142:   PetscDLPyLibSym("Py_IsInitialized"      , &Py_IsInitialized      );
143:   PetscDLPyLibSym("Py_InitializeEx"       , &Py_InitializeEx       );
144:   PetscDLPyLibSym("Py_Finalize"           , &Py_Finalize           );
145:   PetscDLPyLibSym("PySys_GetObject"       , &PySys_GetObject       );
146:   PetscDLPyLibSym("PySys_SetArgv"         , &PySys_SetArgv         );
147:   PetscDLPyLibSym("PyObject_CallMethod"   , &PyObject_CallMethod   );
148:   PetscDLPyLibSym("PyImport_ImportModule" , &PyImport_ImportModule );
149:   PetscDLPyLibSym("Py_IncRef"             , &Py_IncRef             );
150:   PetscDLPyLibSym("Py_DecRef"             , &Py_DecRef             );
151:   PetscDLPyLibSym("PyErr_Clear"           , &PyErr_Clear           );
152:   PetscDLPyLibSym("PyErr_Occurred"        , &PyErr_Occurred        );
153:   PetscDLPyLibSym("PyErr_Fetch"             , &PyErr_Fetch             );
154:   PetscDLPyLibSym("PyErr_NormalizeException", &PyErr_NormalizeException);
155:   PetscDLPyLibSym("PyErr_Display",            &PyErr_Display           );
156:   PetscDLPyLibSym("PyErr_Restore",            &PyErr_Restore           );
157:   /* XXX TODO: check that ALL symbols were there !!! */
158:   if (!Py_None)          SETERRQ(PETSC_COMM_SELF,1,"Python: failed to load symbols from dynamic library");
159:   if (!Py_GetVersion)    SETERRQ(PETSC_COMM_SELF,1,"Python: failed to load symbols from dynamic library");
160:   if (!Py_IsInitialized) SETERRQ(PETSC_COMM_SELF,1,"Python: failed to load symbols from dynamic library");
161:   if (!Py_InitializeEx)  SETERRQ(PETSC_COMM_SELF,1,"Python: failed to load symbols from dynamic library");
162:   if (!Py_Finalize)      SETERRQ(PETSC_COMM_SELF,1,"Python: failed to load symbols from dynamic library");
163:   PetscInfo(0,"Python: all required symbols loaded from Python dynamic library\n");
164:   return(0);
165: }

167: /* ---------------------------------------------------------------- */

169: static char      PetscPythonExe[PETSC_MAX_PATH_LEN] = { 0 };
170: static char      PetscPythonLib[PETSC_MAX_PATH_LEN] = { 0 };
171: static PetscBool PetscBeganPython = PETSC_FALSE;

175: /*@C
176:   PetscPythonFinalize - Finalize Python.

178:   Level: intermediate

180: .keywords: Python
181: @*/
182: PetscErrorCode  PetscPythonFinalize(void)
183: {
185:   if (PetscBeganPython) { if (Py_IsInitialized()) Py_Finalize(); }
186:   PetscBeganPython = PETSC_FALSE;
187:   return(0);
188: }

192: /*@C
193:   PetscPythonInitialize - Initialize Python and import petsc4py.

195:    Input Parameter:
196: +  pyexe - path to the Python interpreter executable, or NULL.
197: -  pylib - full path to the Python dynamic library, or NULL.

199:   Level: intermediate

201: .keywords: Python

203: @*/
204: PetscErrorCode  PetscPythonInitialize(const char pyexe[],const char pylib[])
205: {
206:   PyObject       *module = 0;

210:   if (PetscBeganPython) return(0);
211:   /* Python executable */
212:   if (pyexe && pyexe[0] != 0) {
213:     PetscStrncpy(PetscPythonExe,pyexe,sizeof(PetscPythonExe));
214:   } else {
215:     PetscPythonFindExecutable(PetscPythonExe);
216:   }
217:   /* Python dynamic library */
218:   if (pylib && pylib[0] != 0) {
219:     PetscStrncpy(PetscPythonLib,pylib,sizeof(PetscPythonLib));
220:   } else {
221:     PetscPythonFindLibrary(PetscPythonExe,PetscPythonLib);
222:   }
223:   /* dynamically load Python library */
224:   PetscPythonLoadLibrary(PetscPythonLib);
225:   /* initialize Python */
226:   PetscBeganPython = PETSC_FALSE;
227:   if (!Py_IsInitialized()) {
228:     static PetscBool registered = PETSC_FALSE;
229:     const char       *py_version;
230:     PyObject         *sys_path;
231:     char             path[PETSC_MAX_PATH_LEN] = { 0 };

233:     /* initialize Python */
234:     Py_InitializeEx(0); /* 0: do not install signal handlers */
235:     /*  build 'sys.argv' list */
236:     py_version = Py_GetVersion();
237:     if (py_version[0] == '2') {
238:       int argc = 0; char **argv = 0;
239:       PetscGetArgs(&argc,&argv);
240:       PySys_SetArgv(argc,argv);
241:     }
242:     if (py_version[0] == '3') {
243:       /* XXX 'argv' is type 'wchar_t**' */
244:       PySys_SetArgv(0,NULL);
245:     }
246:     /* add PETSC_LIB_DIR in front of 'sys.path' */
247:     sys_path = PySys_GetObject("path");
248:     if (sys_path) {
249:       PetscStrreplace(PETSC_COMM_SELF,"${PETSC_LIB_DIR}",path,sizeof(path));
250:       Py_DecRef(PyObject_CallMethod(sys_path,"insert","is",(int)0,(char*)path));
251:     }
252:     /* register finalizer */
253:     if (!registered) {
254:       PetscRegisterFinalize(PetscPythonFinalize);

256:       registered = PETSC_TRUE;
257:     }
258:     PetscBeganPython = PETSC_TRUE;
259:   }
260:   /* import 'petsc4py.PETSc' module */
261:   module = PyImport_ImportModule("petsc4py.PETSc");
262:   if (module) {
263:     PetscInfo(0,"Python: successfully imported  module 'petsc4py.PETSc'\n");

265:     Py_DecRef(module); module = 0;
266:   } else {
267:     PetscPythonPrintError();
268:     SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Python: could not import module 'petsc4py.PETSc', perhaps your PYTHONPATH does not contain it\n");
269:   }
270:   return(0);
271: }

275: /*@C
276:   PetscPythonPrintError - Print Python errors.

278:   Level: developer

280: .keywords: Python

282: @*/
283: PetscErrorCode  PetscPythonPrintError(void)
284: {
285:   PyObject *exc=0, *val=0, *tb=0;

288:   if (!PetscBeganPython) return(0);
289:   if (!PyErr_Occurred()) return(0);
290:   PyErr_Fetch(&exc,&val,&tb);
291:   PyErr_NormalizeException(&exc,&val,&tb);
292:   PyErr_Display(exc ? exc : Py_None,
293:                 val ? val : Py_None,
294:                 tb  ? tb  : Py_None);
295:   PyErr_Restore(exc,val,tb);
296:   return(0);
297: }

299: /* ---------------------------------------------------------------- */

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

306: /*@C
307:   PetscPythonMonitorSet - Set Python monitor

309:   Level: developer

311: .keywords: Python

313: @*/
314: PetscErrorCode PetscPythonMonitorSet(PetscObject obj, const char url[])
315: {

321:   if (!PetscPythonMonitorSet_C) {
322:     PetscPythonInitialize(NULL,NULL);
323:     if (!PetscPythonMonitorSet_C) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"Couldn't initialize Python support for monitors");
324:   }
325:   PetscPythonMonitorSet_C(obj,url);
326:   return(0);
327: }

329: /* ---------------------------------------------------------------- */