//////////////////////////////////////// // WARNING!: pos_realloc has error!. FIX UP! //////////////////////////////////////// Void_t* pos_int_realloc(char *name, mstate av, mchunkptr oldp, INTERNAL_SIZE_T oldsize, INTERNAL_SIZE_T nb) { mchunkptr newp; /* chunk to return */ INTERNAL_SIZE_T newsize; /* its size */ Void_t* newmem; /* corresponding user mem */ mchunkptr next; /* next contiguous chunk after oldp */ mchunkptr remainder; /* extra space at end of newp */ unsigned long remainder_size; /* its size */ mchunkptr bck; /* misc temp for linking */ mchunkptr fwd; /* misc temp for linking */ unsigned long copysize; /* bytes to copy */ unsigned int ncopies; /* INTERNAL_SIZE_T words to copy */ INTERNAL_SIZE_T* s; /* copy source */ INTERNAL_SIZE_T* d; /* copy destination */ const char *errstr = NULL; /* oldmem size */ /*if (oldp->size <= 2 * SIZE_SZ || oldsize >= av->system_mem) { errstr = "realloc(): invalid old size"; errout: malloc_printerr (check_action, errstr, chunk2mem(oldp)); return NULL; }*/ next = chunk_at_offset(oldp, oldsize); INTERNAL_SIZE_T nextsize = chunksize(next); /*if (next->size <= 2 * SIZE_SZ || nextsize >= av->system_mem) { errstr = "realloc(): invalid next size"; goto errout; }*/ //old size 보다 작을 경우 if ((unsigned long)(oldsize) >= (unsigned long)(nb)) { /* already big enough; split below */ newp = oldp; newsize = oldsize; } //old size 보다 클 경우 else { /* Try to expand forward into next chunk; split off remainder below */ if (!inuse(next) && (unsigned long)(newsize = oldsize + nextsize) >= (unsigned long)(nb)) { newp = oldp; unlink(next, bck, fwd); } /* allocate, copy, free */ else { newmem = pos_int_malloc(name, av, nb - MALLOC_ALIGN_MASK); if (newmem == 0) return 0; /* propagate failure */ newp = mem2chunk(newmem); newsize = chunksize(newp); /* Avoid copy if newp is next chunk after oldp. */ if (newp == next) { newsize += oldsize; newp = oldp; } else { /* Unroll copy of <= 36 bytes (72 if 8byte sizes) We know that contents have an odd number of INTERNAL_SIZE_T-sized words; minimally 3. */ copysize = oldsize - SIZE_SZ; s = (INTERNAL_SIZE_T*)(chunk2mem(oldp)); d = (INTERNAL_SIZE_T*)(newmem); ncopies = copysize / sizeof(INTERNAL_SIZE_T); if (ncopies > 9) memcpy(d, s, copysize); else { *(d+0) = *(s+0); *(d+1) = *(s+1); *(d+2) = *(s+2); if (ncopies > 4) { *(d+3) = *(s+3); *(d+4) = *(s+4); if (ncopies > 6) { *(d+5) = *(s+5); *(d+6) = *(s+6); if (ncopies > 8) { *(d+7) = *(s+7); *(d+8) = *(s+8); } } } } pos_int_free(name, av, oldp, 1); return chunk2mem(newp); } } } /* If possible, free extra space in old or extended chunk */ remainder_size = newsize - nb; if (remainder_size < MINSIZE) { /* not enough extra to split off */ set_head_size(newp, newsize); set_inuse_bit_at_offset(newp, newsize); } else { /* split remainder */ remainder = chunk_at_offset(newp, nb); if (chunk_is_last(newp)) set_head(remainder, remainder_size | LAST_CHUNK | PREV_INUSE); else set_head(remainder, remainder_size | PREV_INUSE); // set PREV_INUSE flag.. if (chunk_is_first(newp)) set_head(newp, nb | FIRST_CHUNK | PREV_INUSE); else set_head(newp, nb | PREV_INUSE); //set_head_size(newp, nb); //set_head(remainder, remainder_size | PREV_INUSE |(av != &main_arena ? NON_MAIN_ARENA : 0)); /* Mark remainder as inuse so free() won't complain */ set_inuse_bit_at_offset(remainder, remainder_size); pos_int_free(name, av, remainder, 1); } return chunk2mem(newp); }
/* ------------------------------ realloc ------------------------------ */ void* ulibc_realloc(void* oldmem, size_t bytes) { mstate av; size_t nb; /* padded request size */ mchunkptr oldp; /* chunk corresponding to oldmem */ size_t oldsize; /* its size */ mchunkptr newp; /* chunk to return */ size_t newsize; /* its size */ void* newmem; /* corresponding user mem */ mchunkptr next; /* next contiguous chunk after oldp */ mchunkptr remainder; /* extra space at end of newp */ unsigned long remainder_size; /* its size */ mchunkptr bck; /* misc temp for linking */ mchunkptr fwd; /* misc temp for linking */ unsigned long copysize; /* bytes to copy */ unsigned int ncopies; /* size_t words to copy */ size_t* s; /* copy source */ size_t* d; /* copy destination */ void *retval; /* Check for special cases. */ if (! oldmem) return ulibc_malloc(bytes); if (! bytes) { ulibc_free (oldmem); return NULL; } av = get_malloc_state(); checked_request2size(bytes, nb); oldp = mem2chunk(oldmem); oldsize = chunksize(oldp); check_inuse_chunk(oldp); if (!chunk_is_mmapped(oldp)) { if ((unsigned long)(oldsize) >= (unsigned long)(nb)) { /* already big enough; split below */ newp = oldp; newsize = oldsize; } else { next = chunk_at_offset(oldp, oldsize); /* Try to expand forward into top */ if (next == av->top && (unsigned long)(newsize = oldsize + chunksize(next)) >= (unsigned long)(nb + MINSIZE)) { set_head_size(oldp, nb); av->top = chunk_at_offset(oldp, nb); set_head(av->top, (newsize - nb) | PREV_INUSE); retval = chunk2mem(oldp); goto DONE; } /* Try to expand forward into next chunk; split off remainder below */ else if (next != av->top && !inuse(next) && (unsigned long)(newsize = oldsize + chunksize(next)) >= (unsigned long)(nb)) { newp = oldp; unlink(next, bck, fwd); } /* allocate, copy, free */ else { newmem = malloc(nb - MALLOC_ALIGN_MASK); if (newmem == 0) { retval = 0; /* propagate failure */ goto DONE; } newp = mem2chunk(newmem); newsize = chunksize(newp); /* Avoid copy if newp is next chunk after oldp. */ if (newp == next) { newsize += oldsize; newp = oldp; } else { /* Unroll copy of <= 36 bytes (72 if 8byte sizes) We know that contents have an odd number of size_t-sized words; minimally 3. */ copysize = oldsize - (sizeof(size_t)); s = (size_t*)(oldmem); d = (size_t*)(newmem); ncopies = copysize / sizeof(size_t); assert(ncopies >= 3); if (ncopies > 9) memcpy(d, s, copysize); else { *(d+0) = *(s+0); *(d+1) = *(s+1); *(d+2) = *(s+2); if (ncopies > 4) { *(d+3) = *(s+3); *(d+4) = *(s+4); if (ncopies > 6) { *(d+5) = *(s+5); *(d+6) = *(s+6); if (ncopies > 8) { *(d+7) = *(s+7); *(d+8) = *(s+8); } } } } ulibc_free(oldmem); check_inuse_chunk(newp); retval = chunk2mem(newp); goto DONE; } } } /* If possible, free extra space in old or extended chunk */ assert((unsigned long)(newsize) >= (unsigned long)(nb)); remainder_size = newsize - nb; if (remainder_size < MINSIZE) { /* not enough extra to split off */ set_head_size(newp, newsize); set_inuse_bit_at_offset(newp, newsize); } else { /* split remainder */ remainder = chunk_at_offset(newp, nb); set_head_size(newp, nb); set_head(remainder, remainder_size | PREV_INUSE); /* Mark remainder as inuse so free() won't complain */ set_inuse_bit_at_offset(remainder, remainder_size); ulibc_free(chunk2mem(remainder)); } check_inuse_chunk(newp); retval = chunk2mem(newp); goto DONE; } /* Handle mmap cases */ else { size_t offset = oldp->prev_size; size_t pagemask = av->pagesize - 1; char *cp; unsigned long sum; /* Note the extra (sizeof(size_t)) overhead */ newsize = (nb + offset + (sizeof(size_t)) + pagemask) & ~pagemask; /* don't need to remap if still within same page */ if (oldsize == newsize - offset) { retval = oldmem; goto DONE; } cp = (char*)mremap((char*)oldp - offset, oldsize + offset, newsize, 1); if (cp != (char*)MORECORE_FAILURE) { newp = (mchunkptr)(cp + offset); set_head(newp, (newsize - offset)|IS_MMAPPED); assert(aligned_OK(chunk2mem(newp))); assert((newp->prev_size == offset)); /* update statistics */ sum = av->mmapped_mem += newsize - oldsize; if (sum > (unsigned long)(av->max_mmapped_mem)) av->max_mmapped_mem = sum; sum += av->sbrked_mem; if (sum > (unsigned long)(av->max_total_mem)) av->max_total_mem = sum; retval = chunk2mem(newp); goto DONE; } /* Note the extra (sizeof(size_t)) overhead. */ if ((unsigned long)(oldsize) >= (unsigned long)(nb + (sizeof(size_t)))) newmem = oldmem; /* do nothing */ else { /* Must alloc, copy, free. */ newmem = malloc(nb - MALLOC_ALIGN_MASK); if (newmem != 0) { memcpy(newmem, oldmem, oldsize - 2*(sizeof(size_t))); ulibc_free(oldmem); } } retval = newmem; } DONE: return retval; }