diff options
Diffstat (limited to 'src/lmem.c')
-rw-r--r-- | src/lmem.c | 133 |
1 files changed, 80 insertions, 53 deletions
@@ -1,5 +1,5 @@ /* -** $Id: lmem.c,v 1.7 1998/06/29 22:03:06 roberto Exp $ +** $Id: lmem.c,v 1.17 1999/05/24 17:51:05 roberto Exp $ ** Interface to Memory Manager ** See Copyright Notice in lua.h */ @@ -12,41 +12,54 @@ #include "lua.h" +/* +** real ANSI systems do not need these tests; +** but some systems (Sun OS) are not that ANSI... +*/ +#ifdef OLD_ANSI +#define realloc(b,s) ((b) == NULL ? malloc(s) : (realloc)(b, s)) +#define free(b) if (b) (free)(b) +#endif + + +#define MINSIZE 8 /* minimum size for "growing" vectors */ + + -int luaM_growaux (void **block, unsigned long nelems, int size, - char *errormsg, unsigned long limit) -{ - if (nelems >= limit) - lua_error(errormsg); - nelems = (nelems == 0) ? 32 : nelems*2; - if (nelems > limit) - nelems = limit; - *block = luaM_realloc(*block, nelems*size); - return (int)nelems; + +static unsigned long power2 (unsigned long n) { + unsigned long p = MINSIZE; + while (p<=n) p<<=1; + return p; } +void *luaM_growaux (void *block, unsigned long nelems, int inc, int size, + char *errormsg, unsigned long limit) { + unsigned long newn = nelems+inc; + if (newn >= limit) lua_error(errormsg); + if ((newn ^ nelems) <= nelems || /* still the same power of 2 limit? */ + (nelems > 0 && newn < MINSIZE)) /* or block already is MINSIZE? */ + return block; /* do not need to reallocate */ + else /* it crossed a power of 2 boundary; grow to next power */ + return luaM_realloc(block, power2(newn)*size); +} + #ifndef DEBUG /* ** generic allocation routine. -** real ANSI systems do not need some of these tests, -** since realloc(NULL, s)==malloc(s) and realloc(b, 0)==free(b). -** But some systems (e.g. Sun OS) are not that ANSI... */ -void *luaM_realloc (void *block, unsigned long size) -{ +void *luaM_realloc (void *block, unsigned long size) { size_t s = (size_t)size; if (s != size) - lua_error("Allocation Error: Block too big"); + lua_error("memory allocation error: block too big"); if (size == 0) { - if (block) { - free(block); - } + free(block); /* block may be NULL, that is OK for free */ return NULL; } - block = block ? realloc(block, s) : malloc(s); + block = realloc(block, s); if (block == NULL) lua_error(memEM); return block; @@ -61,52 +74,66 @@ void *luaM_realloc (void *block, unsigned long size) #define HEADER (sizeof(double)) +#define MARKSIZE 16 #define MARK 55 + +#define blocksize(b) ((unsigned long *)((char *)(b) - HEADER)) + unsigned long numblocks = 0; unsigned long totalmem = 0; -static void *checkblock (void *block) -{ - unsigned long *b = (unsigned long *)((char *)block - HEADER); - unsigned long size = *b; - LUA_ASSERT(*(((char *)b)+size+HEADER) == MARK, - "corrupted block"); - numblocks--; - totalmem -= size; - return b; +static void *checkblock (void *block) { + if (block == NULL) + return NULL; + else { + unsigned long *b = blocksize(block); + unsigned long size = *b; + int i; + for (i=0;i<MARKSIZE;i++) + LUA_ASSERT(*(((char *)b)+HEADER+size+i) == MARK+i, "corrupted block"); + numblocks--; + totalmem -= size; + return b; + } } -void *luaM_realloc (void *block, unsigned long size) -{ - unsigned long realsize = HEADER+size+1; +static void freeblock (void *block) { + if (block) + memset(block, -1, *blocksize(block)); /* erase block */ + free(checkblock(block)); +} + + +void *luaM_realloc (void *block, unsigned long size) { + unsigned long realsize = HEADER+size+MARKSIZE; if (realsize != (size_t)realsize) - lua_error("Allocation Error: Block too big"); - if (size == 0) { /* ANSI dosen't need this, but some machines... */ - if (block) { - unsigned long *b = (unsigned long *)((char *)block - HEADER); - memset(block, -1, *b); /* erase block */ - block = checkblock(block); - free(block); - } + lua_error("memory allocation error: block too big"); + if (size == 0) { + freeblock(block); return NULL; } - if (block) { - block = checkblock(block); - block = (unsigned long *)realloc(block, realsize); + else { + char *newblock = malloc(realsize); + int i; + if (block) { + unsigned long oldsize = *blocksize(block); + if (oldsize > size) oldsize = size; + memcpy(newblock+HEADER, block, oldsize); + freeblock(block); /* erase (and check) old copy */ + } + if (newblock == NULL) + lua_error(memEM); + totalmem += size; + numblocks++; + *(unsigned long *)newblock = size; + for (i=0;i<MARKSIZE;i++) + *(newblock+HEADER+size+i) = MARK+i; + return newblock+HEADER; } - else - block = (unsigned long *)malloc(realsize); - if (block == NULL) - lua_error(memEM); - totalmem += size; - numblocks++; - *(unsigned long *)block = size; - *(((char *)block)+size+HEADER) = MARK; - return (unsigned long *)((char *)block+HEADER); } |