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Convert obstacks away from Glib memory allocator
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Jeffrey Kegler authored and Jeffrey Kegler committed Mar 21, 2012
1 parent 28e110d commit 0c53f4c
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Showing 3 changed files with 14 additions and 141 deletions.
2 changes: 0 additions & 2 deletions r2/libmarpa/dev/marpa.w
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Expand Up @@ -12854,8 +12854,6 @@ Small allocations needed for the lifetime of the grammar
are allocated on these as the grammar object is built.
All these allocations are are conveniently and quickly deallocated when
the grammar's obstack is destroyed along with its parent grammar.
@d obstack_chunk_alloc g_malloc
@d obstack_chunk_free g_free

@*0 Why the obstacks are renamed.
Regretfully, I realized I simply could not simply include the
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115 changes: 10 additions & 105 deletions r2/libmarpa/dev/marpa_obs.c
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Expand Up @@ -24,27 +24,10 @@
#endif

# include "marpa_obs.h"

/* NOTE BEFORE MODIFYING THIS FILE: This version number must be
incremented whenever callers compiled using an old obstack.h can no
longer properly call the functions in this obstack.c. */

/* WHY A SPECIAL MARPA VERSION? I am happy to rely on the local versions
of the glibc and glib libraries, and sanquine about facing the portability
consequences. But obstacks fall into a twilight zone, and I was forced
for reasons described below, to make my own copy
to be compiled with libmarpa. I was initially reluctant to do this,
but as development has proceeded, this has proved to be the right
choice.
*/
extern void (*marpa_out_of_memory)(void);

/* NOTES FOR THE MARPA MODIFICATIONS --
I read the previous note as saying the version numbers should be kept
in sync between the .h and the .c. In Marpa's case, these files are
an integral part of the package, so it's not so much of an issue but
it is a good idea.
Marpa has its own copy of the obstack code because
the GNU original had a number of complications which caused Marpa
problems, and which added no value in the Marpa context.
Expand All @@ -70,16 +53,6 @@
*/

/* ORIGINAL COMMENT:
Comment out all this code if we are using the GNU C Library, and are not
actually compiling the library itself, and the installed library
supports the same library interface we do. This code is part of the GNU
C Library, but also included in many other GNU distributions. Compiling
and linking in this code is a waste when using the GNU C library
(especially if it is a shared library). Rather than having every GNU
program understand `configure --with-gnu-libc' and omit the object
files, it is simpler to just do this in the source for each such file. */

#include <stdio.h> /* Random thing to get __GNU_LIBRARY__. */

#include <stddef.h>
Expand Down Expand Up @@ -122,39 +95,16 @@ enum

# include <stdlib.h>

/* Define a macro that either calls functions with the traditional malloc/free
calling interface, or calls functions with the mmalloc/mfree interface
(that adds an extra first argument), based on the state of use_extra_arg.
For free, do not use ?:, since some compilers, like the MIPS compilers,
do not allow (expr) ? void : void. */

# define CALL_CHUNKFUN(h, size) \
(((h) -> use_extra_arg) \
? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
: (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size)))

# define CALL_FREEFUN(h, old_chunk) \
do { \
if ((h) -> use_extra_arg) \
(*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
else \
(*(void (*) (void *)) (h)->freefun) ((old_chunk)); \
} while (0)


/* Initialize an obstack H for use. Specify chunk size SIZE (0 means default).
Objects start on multiples of ALIGNMENT (0 means use default).
CHUNKFUN is the function to use to allocate chunks,
and FREEFUN the function to free them.
Return nonzero if successful, calls obstack_alloc_failed_handler if
allocation fails. */

int
_marpa_obs_begin (struct obstack *h,
int size, int alignment,
void *(*chunkfun) (long),
void (*freefun) (void *))
int size, int alignment)
{
register struct _obstack_chunk *chunk; /* points to new chunk */

Expand All @@ -177,60 +127,13 @@ _marpa_obs_begin (struct obstack *h,
size = 4096 - extra;
}

h->chunkfun = (struct _obstack_chunk * (*)(void *, long)) chunkfun;
h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
h->chunk_size = size;
h->alignment_mask = alignment - 1;
h->use_extra_arg = 0;

chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
/* if (!chunk) (*obstack_alloc_failed_handler) (); */
h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents,
alignment - 1);
h->chunk_limit = chunk->limit
= (char *) chunk + h->chunk_size;
chunk->prev = 0;
/* The initial chunk now contains no empty object. */
h->maybe_empty_object = 0;
h->alloc_failed = 0;
return 1;
}

int
_marpa_obs_begin_1 (struct obstack *h, int size, int alignment,
void *(*chunkfun) (void *, long),
void (*freefun) (void *, void *),
void *arg)
{
register struct _obstack_chunk *chunk; /* points to new chunk */

if (alignment == 0)
alignment = DEFAULT_ALIGNMENT;
if (size == 0)
/* Default size is what GNU malloc can fit in a 4096-byte block. */
{
/* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
Use the values for range checking, because if range checking is off,
the extra bytes won't be missed terribly, but if range checking is on
and we used a larger request, a whole extra 4096 bytes would be
allocated.
These number are irrelevant to the new GNU malloc. I suspect it is
less sensitive to the size of the request. */
int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
+ 4 + DEFAULT_ROUNDING - 1)
& ~(DEFAULT_ROUNDING - 1));
size = 4096 - extra;
}

h->chunkfun = (struct _obstack_chunk * (*)(void *,long)) chunkfun;
h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
h->chunk_size = size;
h->alignment_mask = alignment - 1;
h->extra_arg = arg;
h->use_extra_arg = 1;

chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
chunk = h->chunk = malloc(h -> chunk_size);
if (!chunk) (*marpa_out_of_memory)();
/* chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size); */
/* if (!chunk) (*obstack_alloc_failed_handler) (); */
h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents,
alignment - 1);
Expand Down Expand Up @@ -266,7 +169,9 @@ _marpa_obs_newchunk (struct obstack *h, int length)
new_size = h->chunk_size;

/* Allocate and initialize the new chunk. */
new_chunk = CALL_CHUNKFUN (h, new_size);
new_chunk = malloc( new_size);
if (!new_chunk) (*marpa_out_of_memory)();
/* new_chunk = CALL_CHUNKFUN (h, new_size); */
/* if (!new_chunk) (*obstack_alloc_failed_handler) (); */
h->chunk = new_chunk;
new_chunk->prev = old_chunk;
Expand Down Expand Up @@ -305,7 +210,7 @@ _marpa_obs_newchunk (struct obstack *h, int length)
h->alignment_mask)))
{
new_chunk->prev = old_chunk->prev;
CALL_FREEFUN (h, old_chunk);
free( old_chunk);
}

h->object_base = object_base;
Expand Down Expand Up @@ -360,7 +265,7 @@ marpa_obs_free (struct obstack *h, void *obj)
while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj))
{
plp = lp->prev;
CALL_FREEFUN (h, lp);
free( lp);
lp = plp;
/* If we switch chunks, we can't tell whether the new current
chunk contains an empty object, so assume that it may. */
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38 changes: 4 additions & 34 deletions r2/libmarpa/dev/marpa_obs.h
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Expand Up @@ -164,8 +164,6 @@ struct obstack /* control current object in current chunk */
/* These prototypes vary based on `use_extra_arg', and we use
casts to the prototypeless function type in all assignments,
but having prototypes here quiets -Wstrict-prototypes. */
struct _obstack_chunk *(*chunkfun) (void *, long);
void (*freefun) (void *, struct _obstack_chunk *);
void *extra_arg; /* first arg for chunk alloc/dealloc funcs */
unsigned use_extra_arg:1; /* chunk alloc/dealloc funcs take extra arg */
unsigned maybe_empty_object:1;/* There is a possibility that the current
Expand All @@ -182,15 +180,9 @@ struct obstack /* control current object in current chunk */
extern void _marpa_obs_newchunk (struct obstack *, int);
#define _obstack_newchunk _marpa_obs_newchunk

extern int _marpa_obs_begin (struct obstack *, int, int,
void *(*) (long), void (*) (void *));
extern int _marpa_obs_begin (struct obstack *, int, int);
#define _obstack_begin _marpa_obs_begin

extern int _marpa_obs_begin_1 (struct obstack *, int, int,
void *(*) (void *, long),
void (*) (void *, void *), void *);
#define _obstack_begin_1 _marpa_obs_begin_1

extern int _marpa_obs_memory_used (struct obstack *);
#define _obstack_memory_used _marpa_obs_memory_used

Expand All @@ -215,31 +207,9 @@ void marpa_obs_free (struct obstack *__obstack, void *__block);
#define obstack_alignment_mask(h) ((h)->alignment_mask)

/* To prevent prototype warnings provide complete argument list. */
#define obstack_init(h) \
_obstack_begin ((h), 0, 0, \
(void *(*) (long)) obstack_chunk_alloc, \
(void (*) (void *)) obstack_chunk_free)

#define obstack_begin(h, size) \
_obstack_begin ((h), (size), 0, \
(void *(*) (long)) obstack_chunk_alloc, \
(void (*) (void *)) obstack_chunk_free)

#define obstack_specify_allocation(h, size, alignment, chunkfun, freefun) \
_obstack_begin ((h), (size), (alignment), \
(void *(*) (long)) (chunkfun), \
(void (*) (void *)) (freefun))

#define obstack_specify_allocation_with_arg(h, size, alignment, chunkfun, freefun, arg) \
_obstack_begin_1 ((h), (size), (alignment), \
(void *(*) (void *, long)) (chunkfun), \
(void (*) (void *, void *)) (freefun), (arg))

#define obstack_chunkfun(h, newchunkfun) \
((h) -> chunkfun = (struct _obstack_chunk *(*)(void *, long)) (newchunkfun))

#define obstack_freefun(h, newfreefun) \
((h) -> freefun = (void (*)(void *, struct _obstack_chunk *)) (newfreefun))
#define obstack_init(h) _obstack_begin ((h), 0, 0)

#define obstack_begin(h, size) _obstack_begin ((h), (size), 0)

#define obstack_1grow_fast(h,achar) (*((h)->next_free)++ = (achar))

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