diff options
Diffstat (limited to 'source/luametatex/source/luacore/lua54/src/lmem.c')
-rw-r--r-- | source/luametatex/source/luacore/lua54/src/lmem.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/source/luametatex/source/luacore/lua54/src/lmem.c b/source/luametatex/source/luacore/lua54/src/lmem.c new file mode 100644 index 000000000..9029d588c --- /dev/null +++ b/source/luametatex/source/luacore/lua54/src/lmem.c @@ -0,0 +1,201 @@ +/* +** $Id: lmem.c $ +** Interface to Memory Manager +** See Copyright Notice in lua.h +*/ + +#define lmem_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <stddef.h> + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lgc.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" + + +#if defined(EMERGENCYGCTESTS) +/* +** First allocation will fail whenever not building initial state. +** (This fail will trigger 'tryagain' and a full GC cycle at every +** allocation.) +*/ +static void *firsttry (global_State *g, void *block, size_t os, size_t ns) { + if (completestate(g) && ns > 0) /* frees never fail */ + return NULL; /* fail */ + else /* normal allocation */ + return (*g->frealloc)(g->ud, block, os, ns); +} +#else +#define firsttry(g,block,os,ns) ((*g->frealloc)(g->ud, block, os, ns)) +#endif + + + + + +/* +** About the realloc function: +** void *frealloc (void *ud, void *ptr, size_t osize, size_t nsize); +** ('osize' is the old size, 'nsize' is the new size) +** +** - frealloc(ud, p, x, 0) frees the block 'p' and returns NULL. +** Particularly, frealloc(ud, NULL, 0, 0) does nothing, +** which is equivalent to free(NULL) in ISO C. +** +** - frealloc(ud, NULL, x, s) creates a new block of size 's' +** (no matter 'x'). Returns NULL if it cannot create the new block. +** +** - otherwise, frealloc(ud, b, x, y) reallocates the block 'b' from +** size 'x' to size 'y'. Returns NULL if it cannot reallocate the +** block to the new size. +*/ + + + + +/* +** {================================================================== +** Functions to allocate/deallocate arrays for the Parser +** =================================================================== +*/ + +/* +** Minimum size for arrays during parsing, to avoid overhead of +** reallocating to size 1, then 2, and then 4. All these arrays +** will be reallocated to exact sizes or erased when parsing ends. +*/ +#define MINSIZEARRAY 4 + + +void *luaM_growaux_ (lua_State *L, void *block, int nelems, int *psize, + int size_elems, int limit, const char *what) { + void *newblock; + int size = *psize; + if (nelems + 1 <= size) /* does one extra element still fit? */ + return block; /* nothing to be done */ + if (size >= limit / 2) { /* cannot double it? */ + if (l_unlikely(size >= limit)) /* cannot grow even a little? */ + luaG_runerror(L, "too many %s (limit is %d)", what, limit); + size = limit; /* still have at least one free place */ + } + else { + size *= 2; + if (size < MINSIZEARRAY) + size = MINSIZEARRAY; /* minimum size */ + } + lua_assert(nelems + 1 <= size && size <= limit); + /* 'limit' ensures that multiplication will not overflow */ + newblock = luaM_saferealloc_(L, block, cast_sizet(*psize) * size_elems, + cast_sizet(size) * size_elems); + *psize = size; /* update only when everything else is OK */ + return newblock; +} + + +/* +** In prototypes, the size of the array is also its number of +** elements (to save memory). So, if it cannot shrink an array +** to its number of elements, the only option is to raise an +** error. +*/ +void *luaM_shrinkvector_ (lua_State *L, void *block, int *size, + int final_n, int size_elem) { + void *newblock; + size_t oldsize = cast_sizet((*size) * size_elem); + size_t newsize = cast_sizet(final_n * size_elem); + lua_assert(newsize <= oldsize); + newblock = luaM_saferealloc_(L, block, oldsize, newsize); + *size = final_n; + return newblock; +} + +/* }================================================================== */ + + +l_noret luaM_toobig (lua_State *L) { + luaG_runerror(L, "memory allocation error: block too big"); +} + + +/* +** Free memory +*/ +void luaM_free_ (lua_State *L, void *block, size_t osize) { + global_State *g = G(L); + lua_assert((osize == 0) == (block == NULL)); + (*g->frealloc)(g->ud, block, osize, 0); + g->GCdebt -= osize; +} + + +/* +** In case of allocation fail, this function will do an emergency +** collection to free some memory and then try the allocation again. +** The GC should not be called while state is not fully built, as the +** collector is not yet fully initialized. Also, it should not be called +** when 'gcstopem' is true, because then the interpreter is in the +** middle of a collection step. +*/ +static void *tryagain (lua_State *L, void *block, + size_t osize, size_t nsize) { + global_State *g = G(L); + if (completestate(g) && !g->gcstopem) { + luaC_fullgc(L, 1); /* try to free some memory... */ + return (*g->frealloc)(g->ud, block, osize, nsize); /* try again */ + } + else return NULL; /* cannot free any memory without a full state */ +} + + +/* +** Generic allocation routine. +*/ +void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) { + void *newblock; + global_State *g = G(L); + lua_assert((osize == 0) == (block == NULL)); + newblock = firsttry(g, block, osize, nsize); + if (l_unlikely(newblock == NULL && nsize > 0)) { + newblock = tryagain(L, block, osize, nsize); + if (newblock == NULL) /* still no memory? */ + return NULL; /* do not update 'GCdebt' */ + } + lua_assert((nsize == 0) == (newblock == NULL)); + g->GCdebt = (g->GCdebt + nsize) - osize; + return newblock; +} + + +void *luaM_saferealloc_ (lua_State *L, void *block, size_t osize, + size_t nsize) { + void *newblock = luaM_realloc_(L, block, osize, nsize); + if (l_unlikely(newblock == NULL && nsize > 0)) /* allocation failed? */ + luaM_error(L); + return newblock; +} + + +void *luaM_malloc_ (lua_State *L, size_t size, int tag) { + if (size == 0) + return NULL; /* that's all */ + else { + global_State *g = G(L); + void *newblock = firsttry(g, NULL, tag, size); + if (l_unlikely(newblock == NULL)) { + newblock = tryagain(L, NULL, tag, size); + if (newblock == NULL) + luaM_error(L); + } + g->GCdebt += size; + return newblock; + } +} |