diff options
author | Guido van Rossum <guido@python.org> | 2000-05-03 23:44:39 (GMT) |
---|---|---|
committer | Guido van Rossum <guido@python.org> | 2000-05-03 23:44:39 (GMT) |
commit | b18618dab7b6b85bb05b084693706e59211fa180 (patch) | |
tree | 785d51f6677da8366be2ad4b4296a62f53161276 /Include/mymalloc.h | |
parent | 2808b744e8d94459f189e1d89c97072d6a1f53b6 (diff) | |
download | cpython-b18618dab7b6b85bb05b084693706e59211fa180.zip cpython-b18618dab7b6b85bb05b084693706e59211fa180.tar.gz cpython-b18618dab7b6b85bb05b084693706e59211fa180.tar.bz2 |
Vladimir Marangozov's long-awaited malloc restructuring.
For more comments, read the patches@python.org archives.
For documentation read the comments in mymalloc.h and objimpl.h.
(This is not exactly what Vladimir posted to the patches list; I've
made a few changes, and Vladimir sent me a fix in private email for a
problem that only occurs in debug mode. I'm also holding back on his
change to main.c, which seems unnecessary to me.)
Diffstat (limited to 'Include/mymalloc.h')
-rw-r--r-- | Include/mymalloc.h | 133 |
1 files changed, 107 insertions, 26 deletions
diff --git a/Include/mymalloc.h b/Include/mymalloc.h index 558af9d..df3113b 100644 --- a/Include/mymalloc.h +++ b/Include/mymalloc.h @@ -57,6 +57,8 @@ PERFORMANCE OF THIS SOFTWARE. #include <stdlib.h> #endif +#include "myproto.h" + #ifdef __cplusplus /* Move this down here since some C++ #include's don't like to be included inside an extern "C" */ @@ -67,12 +69,8 @@ extern "C" { #pragma lib_export on #endif -/* The following should never be necessary */ -#ifdef NEED_TO_DECLARE_MALLOC_AND_FRIEND -extern ANY *malloc Py_PROTO((size_t)); -extern ANY *calloc Py_PROTO((size_t, size_t)); -extern ANY *realloc Py_PROTO((ANY *, size_t)); -extern void free Py_PROTO((ANY *)); /* XXX sometimes int on Unix old systems */ +#ifndef DL_IMPORT /* declarations for DLL import */ +#define DL_IMPORT(RTYPE) RTYPE #endif #ifndef NULL @@ -87,34 +85,117 @@ extern void free Py_PROTO((ANY *)); /* XXX sometimes int on Unix old systems */ #define _PyMem_EXTRA 0 #endif -#define PyMem_NEW(type, n) \ - ( (type *) malloc(_PyMem_EXTRA + (n) * sizeof(type)) ) -#define PyMem_RESIZE(p, type, n) \ - if ((p) == NULL) \ - (p) = (type *) malloc(_PyMem_EXTRA + (n) * sizeof(type)); \ - else \ - (p) = (type *) realloc((ANY *)(p), \ - _PyMem_EXTRA + (n) * sizeof(type)) -#define PyMem_DEL(p) free((ANY *)p) -#define PyMem_XDEL(p) if ((p) == NULL) ; else PyMem_DEL(p) +/* + * Core memory allocator + * ===================== + */ +/* To make sure the interpreter is user-malloc friendly, all memory + APIs are implemented on top of this one. -/* Two sets of function wrappers around malloc and friends; useful if - you need to be sure that you are using the same memory allocator as - Python. Note that the wrappers make sure that allocating 0 bytes - returns a non-NULL pointer, even if the underlying malloc doesn't. - The Python interpreter continues to use PyMem_NEW etc. */ + The PyCore_* macros can be defined to make the interpreter use a + custom allocator. Note that they are for internal use only. Both + the core and extension modules should use the PyMem_* API. */ + +#ifndef PyCore_MALLOC_FUNC +#undef PyCore_REALLOC_FUNC +#undef PyCore_FREE_FUNC +#define PyCore_MALLOC_FUNC malloc +#define PyCore_REALLOC_FUNC realloc +#define PyCore_FREE_FUNC free +#endif + +#ifndef PyCore_MALLOC_PROTO +#undef PyCore_REALLOC_PROTO +#undef PyCore_FREE_PROTO +#define PyCore_MALLOC_PROTO Py_PROTO((size_t)) +#define PyCore_REALLOC_PROTO Py_PROTO((ANY *, size_t)) +#define PyCore_FREE_PROTO Py_PROTO((ANY *)) +#endif + +#ifdef NEED_TO_DECLARE_MALLOC_AND_FRIEND +extern ANY *PyCore_MALLOC_FUNC PyCore_MALLOC_PROTO; +extern ANY *PyCore_REALLOC_FUNC PyCore_REALLOC_PROTO; +extern void PyCore_FREE_FUNC PyCore_FREE_PROTO; +#endif + +#ifndef PyCore_MALLOC +#undef PyCore_REALLOC +#undef PyCore_FREE +#define PyCore_MALLOC(n) PyCore_MALLOC_FUNC(n) +#define PyCore_REALLOC(p, n) PyCore_REALLOC_FUNC((p), (n)) +#define PyCore_FREE(p) PyCore_FREE_FUNC(p) +#endif -/* These wrappers around malloc call PyErr_NoMemory() on failure */ -extern DL_IMPORT(ANY *) Py_Malloc Py_PROTO((size_t)); -extern DL_IMPORT(ANY *) Py_Realloc Py_PROTO((ANY *, size_t)); -extern DL_IMPORT(void) Py_Free Py_PROTO((ANY *)); +/* BEWARE: -/* These wrappers around malloc *don't* call anything on failure */ + Each interface exports both functions and macros. Extension modules + should normally use the functions for ensuring binary compatibility + of the user's code across Python versions. Subsequently, if the + Python runtime switches to its own malloc (different from standard + malloc), no recompilation is required for the extensions. + + The macro versions trade compatibility for speed. They can be used + whenever there is a performance problem, but their use implies + recompilation of the code for each new Python release. The Python + core uses the macros because it *is* compiled on every upgrade. + This might not be the case with 3rd party extensions in a custom + setup (for example, a customer does not always have access to the + source of 3rd party deliverables). You have been warned! */ + +/* + * Raw memory interface + * ==================== + */ + +/* Functions */ + +/* Function wrappers around PyCore_MALLOC and friends; useful if you + need to be sure that you are using the same memory allocator as + Python. Note that the wrappers make sure that allocating 0 bytes + returns a non-NULL pointer, even if the underlying malloc + doesn't. Returned pointers must be checked for NULL explicitly. + No action is performed on failure. */ extern DL_IMPORT(ANY *) PyMem_Malloc Py_PROTO((size_t)); extern DL_IMPORT(ANY *) PyMem_Realloc Py_PROTO((ANY *, size_t)); extern DL_IMPORT(void) PyMem_Free Py_PROTO((ANY *)); +/* Starting from Python 1.6, the wrappers Py_{Malloc,Realloc,Free} are + no longer supported. They used to call PyErr_NoMemory() on failure. */ + +/* Macros */ +#define PyMem_MALLOC(n) PyCore_MALLOC(n) +#define PyMem_REALLOC(p, n) PyCore_REALLOC((ANY *)(p), (n)) +#define PyMem_FREE(p) PyCore_FREE((ANY *)(p)) + +/* + * Type-oriented memory interface + * ============================== + */ + +/* Functions */ +#define PyMem_New(type, n) \ + ( (type *) PyMem_Malloc((n) * sizeof(type)) ) +#define PyMem_Resize(p, type, n) \ + ( (p) = (type *) PyMem_Realloc((n) * sizeof(type)) ) +#define PyMem_Del(p) PyMem_Free(p) + +/* Macros */ +#define PyMem_NEW(type, n) \ + ( (type *) PyMem_MALLOC(_PyMem_EXTRA + (n) * sizeof(type)) ) +#define PyMem_RESIZE(p, type, n) \ + if ((p) == NULL) \ + (p) = (type *)(PyMem_MALLOC( \ + _PyMem_EXTRA + (n) * sizeof(type))); \ + else \ + (p) = (type *)(PyMem_REALLOC((p), \ + _PyMem_EXTRA + (n) * sizeof(type))) +#define PyMem_DEL(p) PyMem_FREE(p) + +/* PyMem_XDEL is deprecated. To avoid the call when p is NULL, + it is recommended to write the test explicitly in the code. + Note that according to ANSI C, free(NULL) has no effect. */ + #ifdef __cplusplus } #endif |