1570af302Sopenharmony_ci#define _GNU_SOURCE 2570af302Sopenharmony_ci#include <stdlib.h> 3570af302Sopenharmony_ci#include <sys/mman.h> 4570af302Sopenharmony_ci#include <string.h> 5570af302Sopenharmony_ci#include "meta.h" 6570af302Sopenharmony_ci 7570af302Sopenharmony_civoid *realloc(void *p, size_t n) 8570af302Sopenharmony_ci{ 9570af302Sopenharmony_ci if (!p) return malloc(n); 10570af302Sopenharmony_ci if (size_overflows(n)) return 0; 11570af302Sopenharmony_ci 12570af302Sopenharmony_ci struct meta *g = get_meta(p); 13570af302Sopenharmony_ci int idx = get_slot_index(p); 14570af302Sopenharmony_ci size_t stride = get_stride(g); 15570af302Sopenharmony_ci unsigned char *start = g->mem->storage + stride*idx; 16570af302Sopenharmony_ci unsigned char *end = start + stride - IB; 17570af302Sopenharmony_ci size_t old_size = get_nominal_size(p, end); 18570af302Sopenharmony_ci size_t avail_size = end-(unsigned char *)p; 19570af302Sopenharmony_ci void *new; 20570af302Sopenharmony_ci 21570af302Sopenharmony_ci // only resize in-place if size class matches 22570af302Sopenharmony_ci if (n <= avail_size && n<MMAP_THRESHOLD 23570af302Sopenharmony_ci && size_to_class(n)+1 >= g->sizeclass) { 24570af302Sopenharmony_ci set_size(p, end, n); 25570af302Sopenharmony_ci return p; 26570af302Sopenharmony_ci } 27570af302Sopenharmony_ci 28570af302Sopenharmony_ci // use mremap if old and new size are both mmap-worthy 29570af302Sopenharmony_ci if (g->sizeclass>=48 && n>=MMAP_THRESHOLD) { 30570af302Sopenharmony_ci assert(g->sizeclass==63); 31570af302Sopenharmony_ci size_t base = (unsigned char *)p-start; 32570af302Sopenharmony_ci size_t needed = (n + base + UNIT + IB + 4095) & -4096; 33570af302Sopenharmony_ci new = g->maplen*4096UL == needed ? g->mem : 34570af302Sopenharmony_ci mremap(g->mem, g->maplen*4096UL, needed, MREMAP_MAYMOVE); 35570af302Sopenharmony_ci if (new!=MAP_FAILED) { 36570af302Sopenharmony_ci g->mem = new; 37570af302Sopenharmony_ci g->maplen = needed/4096; 38570af302Sopenharmony_ci p = g->mem->storage + base; 39570af302Sopenharmony_ci end = g->mem->storage + (needed - UNIT) - IB; 40570af302Sopenharmony_ci *end = 0; 41570af302Sopenharmony_ci set_size(p, end, n); 42570af302Sopenharmony_ci return p; 43570af302Sopenharmony_ci } 44570af302Sopenharmony_ci } 45570af302Sopenharmony_ci 46570af302Sopenharmony_ci new = malloc(n); 47570af302Sopenharmony_ci if (!new) return 0; 48570af302Sopenharmony_ci memcpy(new, p, n < old_size ? n : old_size); 49570af302Sopenharmony_ci free(p); 50570af302Sopenharmony_ci return new; 51570af302Sopenharmony_ci} 52