src/meta/palloc.c

#ifndef lint
static const char       RCSid[] = "$Id: palloc.c,v 1.2 2003/06/08 12:03:10 schorsch Exp $";
#endif
/*
 *   Limited dynamic storage allocator for primitives
 */


#define  FBSIZE  72             /* size of malloc call */


#include  "meta.h"


extern int  maxalloc;           /* number of prims to allocate */
int  nalloc = 0;                /* number allocated so far */

static PLIST  freelist = {NULL, NULL};


static int morefree(void);


PRIMITIVE *
palloc(void)            /* allocate a primitive */

{
    register PRIMITIVE  *p;

    if (maxalloc > 0 && nalloc >= maxalloc)
        return(NULL);

    if ((p = pop(&freelist)) == NULL) {
        if (morefree())
            p = pop(&freelist);
        else {
            sprintf(errmsg, "out of memory in palloc (nalloc = %d)", nalloc);
            error(SYSTEM, errmsg);
        }
    }

    nalloc++;
    return(p);
}


void
pfree(          /* free a primitive */
register PRIMITIVE  *p
)
{

 if (p->args != NULL) {
    freestr(p->args);
    p->args = NULL;
    } 
 push(p, &freelist);
 nalloc--;

 }


void
plfree(         /* free a primitive list */
register PLIST  *pl
)
{
    register PRIMITIVE  *p;
    
    for (p = pl->ptop; p != NULL; p = p->pnext) {
        if (p->args != NULL) {
           freestr(p->args);
           p->args = NULL;
           }
        nalloc--;
        }

    append(pl, &freelist);
    pl->ptop = pl->pbot = NULL;

}
    

static int
morefree(void)          /* get more free space */

{
 register PRIMITIVE  *p;
 register int  i;
 int rnu;

 if (maxalloc > 0 && (i = maxalloc-nalloc) < FBSIZE)
    rnu = i;
 else
    rnu = i = FBSIZE;

 p = (PRIMITIVE *)malloc((unsigned)i * sizeof(PRIMITIVE));

 if (p == NULL)
    return(0);

 while (i--) {
    p->args = NULL;
    push(p, &freelist);
    p++;
    }

 return(rnu);
 }
Revision:	1.3
Committed:	Mon Jul 21 22:30:18 2003 UTC (22 years, 3 months ago) by schorsch
Content type:	text/plain
Branch:	MAIN
Changes since 1.2:	+14 -13 lines
Log Message:	Eliminated copystruct() macro, which is unnecessary in ANSI. Reduced ambiguity warnings for nested if/if/else clauses.
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	schorsch	1.3	static const char RCSid[] = "$Id: palloc.c,v 1.2 2003/06/08 12:03:10 schorsch Exp $";
3	greg	1.1	#endif
4			/*
5			* Limited dynamic storage allocator for primitives
6			*/
7
8
9			#define FBSIZE 72 /* size of malloc call */
10
11
12			#include "meta.h"
13
14
15			extern int maxalloc; /* number of prims to allocate */
16			int nalloc = 0; /* number allocated so far */
17
18			static PLIST freelist = {NULL, NULL};
19
20
21	schorsch	1.2	static int morefree(void);
22	greg	1.1
23
24			PRIMITIVE *
25	schorsch	1.2	palloc(void) /* allocate a primitive */
26	greg	1.1
27			{
28	schorsch	1.3	register PRIMITIVE *p;
29	greg	1.1
30	schorsch	1.3	if (maxalloc > 0 && nalloc >= maxalloc)
31			return(NULL);
32	greg	1.1
33	schorsch	1.3	if ((p = pop(&freelist)) == NULL) {
34			if (morefree())
35			p = pop(&freelist);
36			else {
37			sprintf(errmsg, "out of memory in palloc (nalloc = %d)", nalloc);
38			error(SYSTEM, errmsg);
39			}
40			}
41	greg	1.1
42	schorsch	1.3	nalloc++;
43			return(p);
44	schorsch	1.2	}
45	greg	1.1
46
47
48	schorsch	1.2	void
49			pfree( /* free a primitive */
50			register PRIMITIVE *p
51			)
52	greg	1.1	{
53
54			if (p->args != NULL) {
55			freestr(p->args);
56			p->args = NULL;
57			}
58			push(p, &freelist);
59			nalloc--;
60
61			}
62
63
64
65	schorsch	1.2	void
66			plfree( /* free a primitive list */
67			register PLIST *pl
68			)
69	greg	1.1	{
70			register PRIMITIVE *p;
71
72			for (p = pl->ptop; p != NULL; p = p->pnext) {
73			if (p->args != NULL) {
74			freestr(p->args);
75			p->args = NULL;
76			}
77			nalloc--;
78			}
79
80			append(pl, &freelist);
81			pl->ptop = pl->pbot = NULL;
82
83			}
84
85
86
87			static int
88	schorsch	1.2	morefree(void) /* get more free space */
89	greg	1.1
90			{
91			register PRIMITIVE *p;
92			register int i;
93			int rnu;
94
95			if (maxalloc > 0 && (i = maxalloc-nalloc) < FBSIZE)
96			rnu = i;
97			else
98			rnu = i = FBSIZE;
99
100			p = (PRIMITIVE )malloc((unsigned)i sizeof(PRIMITIVE));
101
102			if (p == NULL)
103			return(0);
104
105			while (i--) {
106			p->args = NULL;
107			push(p, &freelist);
108			p++;
109			}
110
111			return(rnu);
112			}