cosmopolitan/third_party/dlmalloc/dlrealloc.c

43 lines
1.0 KiB
C

#include "libc/str/str.h"
#include "libc/sysv/errfuns.h"
#include "third_party/dlmalloc/dlmalloc.h"
void *dlrealloc(void *oldmem, size_t bytes) {
void *mem = 0;
if (oldmem == 0) {
mem = dlmalloc(bytes);
} else if (bytes >= MAX_REQUEST) {
enomem();
} else if (bytes == 0) {
dlfree(oldmem);
} else {
size_t nb = request2size(bytes);
mchunkptr oldp = mem2chunk(oldmem);
#if !FOOTERS
mstate m = g_dlmalloc;
#else /* FOOTERS */
mstate m = get_mstate_for(oldp);
if (!ok_magic(m)) {
USAGE_ERROR_ACTION(m, oldmem);
return 0;
}
#endif /* FOOTERS */
if (!PREACTION(m)) {
mchunkptr newp = dlmalloc_try_realloc_chunk(m, oldp, nb, 1);
POSTACTION(m);
if (newp != 0) {
check_inuse_chunk(m, newp);
mem = chunk2mem(newp);
} else {
mem = dlmalloc(bytes);
if (mem != 0) {
size_t oc = chunksize(oldp) - overhead_for(oldp);
memcpy(mem, oldmem, (oc < bytes) ? oc : bytes);
dlfree(oldmem);
}
}
}
}
return mem;
}