cpython/Include/import.h
Benjamin Peterson 0df35a93a2 Merged revisions 74841 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

........
  r74841 | thomas.wouters | 2009-09-16 14:55:54 -0500 (Wed, 16 Sep 2009) | 23 lines


  Fix issue #1590864, multiple threads and fork() can cause deadlocks, by
  acquiring the import lock around fork() calls. This prevents other threads
  from having that lock while the fork happens, and is the recommended way of
  dealing with such issues. There are two other locks we care about, the GIL
  and the Thread Local Storage lock. The GIL is obviously held when calling
  Python functions like os.fork(), and the TLS lock is explicitly reallocated
  instead, while also deleting now-orphaned TLS data.

  This only fixes calls to os.fork(), not extension modules or embedding
  programs calling C's fork() directly. Solving that requires a new set of API
  functions, and possibly a rewrite of the Python/thread_*.c mess. Add a
  warning explaining the problem to the documentation in the mean time.

  This also changes behaviour a little on AIX. Before, AIX (but only AIX) was
  getting the import lock reallocated, seemingly to avoid this very same
  problem. This is not the right approach, because the import lock is a
  re-entrant one, and reallocating would do the wrong thing when forking while
  holding the import lock.

  Will backport to 2.6, minus the tiny AIX behaviour change.
........
2009-10-04 20:32:25 +00:00

72 lines
2.2 KiB
C

/* Module definition and import interface */
#ifndef Py_IMPORT_H
#define Py_IMPORT_H
#ifdef __cplusplus
extern "C" {
#endif
PyAPI_FUNC(long) PyImport_GetMagicNumber(void);
PyAPI_FUNC(PyObject *) PyImport_ExecCodeModule(char *name, PyObject *co);
PyAPI_FUNC(PyObject *) PyImport_ExecCodeModuleEx(
char *name, PyObject *co, char *pathname);
PyAPI_FUNC(PyObject *) PyImport_GetModuleDict(void);
PyAPI_FUNC(PyObject *) PyImport_AddModule(const char *name);
PyAPI_FUNC(PyObject *) PyImport_ImportModule(const char *name);
PyAPI_FUNC(PyObject *) PyImport_ImportModuleNoBlock(const char *);
PyAPI_FUNC(PyObject *) PyImport_ImportModuleLevel(char *name,
PyObject *globals, PyObject *locals, PyObject *fromlist, int level);
#define PyImport_ImportModuleEx(n, g, l, f) \
PyImport_ImportModuleLevel(n, g, l, f, -1)
PyAPI_FUNC(PyObject *) PyImport_GetImporter(PyObject *path);
PyAPI_FUNC(PyObject *) PyImport_Import(PyObject *name);
PyAPI_FUNC(PyObject *) PyImport_ReloadModule(PyObject *m);
PyAPI_FUNC(void) PyImport_Cleanup(void);
PyAPI_FUNC(int) PyImport_ImportFrozenModule(char *);
#ifdef WITH_THREAD
PyAPI_FUNC(void) _PyImport_AcquireLock(void);
PyAPI_FUNC(int) _PyImport_ReleaseLock(void);
#else
#define _PyImport_AcquireLock()
#define _PyImport_ReleaseLock() 1
#endif
PyAPI_FUNC(struct filedescr *) _PyImport_FindModule(
const char *, PyObject *, char *, size_t, FILE **, PyObject **);
PyAPI_FUNC(int) _PyImport_IsScript(struct filedescr *);
PyAPI_FUNC(void) _PyImport_ReInitLock(void);
PyAPI_FUNC(PyObject *)_PyImport_FindExtension(char *, char *);
PyAPI_FUNC(int)_PyImport_FixupExtension(PyObject*, char *, char *);
struct _inittab {
char *name;
PyObject* (*initfunc)(void);
};
PyAPI_DATA(PyTypeObject) PyNullImporter_Type;
PyAPI_DATA(struct _inittab *) PyImport_Inittab;
PyAPI_FUNC(int) PyImport_AppendInittab(const char *name, PyObject* (*initfunc)(void));
PyAPI_FUNC(int) PyImport_ExtendInittab(struct _inittab *newtab);
struct _frozen {
char *name;
unsigned char *code;
int size;
};
/* Embedding apps may change this pointer to point to their favorite
collection of frozen modules: */
PyAPI_DATA(struct _frozen *) PyImport_FrozenModules;
#ifdef __cplusplus
}
#endif
#endif /* !Py_IMPORT_H */