mirror of https://github.com/python/cpython
63 lines
2.6 KiB
C
63 lines
2.6 KiB
C
/* An arena-like memory interface for the compiler.
|
|
*/
|
|
|
|
#ifndef Py_PYARENA_H
|
|
#define Py_PYARENA_H
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
typedef struct _arena PyArena;
|
|
|
|
/* PyArena_New() and PyArena_Free() create a new arena and free it,
|
|
respectively. Once an arena has been created, it can be used
|
|
to allocate memory via PyArena_Malloc(). Pointers to PyObject can
|
|
also be registered with the arena via PyArena_AddPyObject(), and the
|
|
arena will ensure that the PyObjects stay alive at least until
|
|
PyArena_Free() is called. When an arena is freed, all the memory it
|
|
allocated is freed, the arena releases internal references to registered
|
|
PyObject*, and none of its pointers are valid.
|
|
XXX (tim) What does "none of its pointers are valid" mean? Does it
|
|
XXX mean that pointers previously obtained via PyArena_Malloc() are
|
|
XXX no longer valid? (That's clearly true, but not sure that's what
|
|
XXX the text is trying to say.)
|
|
|
|
PyArena_New() returns an arena pointer. On error, it
|
|
returns a negative number and sets an exception.
|
|
XXX (tim): Not true. On error, PyArena_New() actually returns NULL,
|
|
XXX and looks like it may or may not set an exception (e.g., if the
|
|
XXX internal PyList_New(0) returns NULL, PyArena_New() passes that on
|
|
XXX and an exception is set; OTOH, if the internal
|
|
XXX block_new(DEFAULT_BLOCK_SIZE) returns NULL, that's passed on but
|
|
XXX an exception is not set in that case).
|
|
*/
|
|
PyAPI_FUNC(PyArena *) PyArena_New(void);
|
|
PyAPI_FUNC(void) PyArena_Free(PyArena *);
|
|
|
|
/* Mostly like malloc(), return the address of a block of memory spanning
|
|
* `size` bytes, or return NULL (without setting an exception) if enough
|
|
* new memory can't be obtained. Unlike malloc(0), PyArena_Malloc() with
|
|
* size=0 does not guarantee to return a unique pointer (the pointer
|
|
* returned may equal one or more other pointers obtained from
|
|
* PyArena_Malloc()).
|
|
* Note that pointers obtained via PyArena_Malloc() must never be passed to
|
|
* the system free() or realloc(), or to any of Python's similar memory-
|
|
* management functions. PyArena_Malloc()-obtained pointers remain valid
|
|
* until PyArena_Free(ar) is called, at which point all pointers obtained
|
|
* from the arena `ar` become invalid simultaneously.
|
|
*/
|
|
PyAPI_FUNC(void *) PyArena_Malloc(PyArena *, size_t size);
|
|
|
|
/* This routine isn't a proper arena allocation routine. It takes
|
|
* a PyObject* and records it so that it can be DECREFed when the
|
|
* arena is freed.
|
|
*/
|
|
PyAPI_FUNC(int) PyArena_AddPyObject(PyArena *, PyObject *);
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* !Py_PYARENA_H */
|