X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/cb8c69ffa2625f5d14255ede0a59d9ab964bffab..b5858ae65676a0304a843e25d13d11df789106b6:/src/xbt/mmalloc/mrealloc.c diff --git a/src/xbt/mmalloc/mrealloc.c b/src/xbt/mmalloc/mrealloc.c index 0e03a922e2..dfd03b81b0 100644 --- a/src/xbt/mmalloc/mrealloc.c +++ b/src/xbt/mmalloc/mrealloc.c @@ -1,36 +1,31 @@ -/* Change the size of a block allocated by `mmalloc'. - Copyright 1990, 1991 Free Software Foundation - Written May 1989 by Mike Haertel. */ +/* Change the size of a block allocated by `mmalloc'. */ -/* Copyright (c) 2010. The SimGrid Team. +/* Copyright (c) 2010-2014. The SimGrid Team. * All rights reserved. */ /* This program is free software; you can redistribute it and/or modify it * under the terms of the license (GNU LGPL) which comes with this package. */ +/* Copyright 1990, 1991 Free Software Foundation + Written May 1989 by Mike Haertel. */ + #include /* Prototypes for memcpy, memmove, memset, etc */ #include /* abort */ #include "mmprivate.h" -/* Resize the given region to the new size, returning a pointer - to the (possibly moved) region. This is optimized for speed; - some benchmarks seem to indicate that greater compactness is - achieved by unconditionally allocating and copying to a - new region. This module has incestuous knowledge of the - internals of both mfree and mmalloc. */ +/* Resize the given region to the new size, returning a pointer to the (possibly moved) region. This is optimized for + * speed; some benchmarks seem to indicate that greater compactness is achieved by unconditionally allocating and + * copying to a new region. This module has incestuous knowledge of the internals of both mfree and mmalloc. */ void *mrealloc(xbt_mheap_t mdp, void *ptr, size_t size) { void *result; - int type; - size_t block, blocks, oldlimit; + size_t blocks; - /* Only keep real realloc and hidden malloc and free to the relevant functions */ + /* Only keep real realloc, and reroute hidden malloc and free to the relevant functions */ if (size == 0) { - fprintf(stderr,"free from realloc..."); mfree(mdp, ptr); - fprintf(stderr,"done\n"); return mmalloc(mdp, 0); } else if (ptr == NULL) { return mmalloc(mdp, size); @@ -39,89 +34,123 @@ void *mrealloc(xbt_mheap_t mdp, void *ptr, size_t size) //printf("(%s)realloc %p to %d...",xbt_thread_self_name(),ptr,(int)size); if ((char *) ptr < (char *) mdp->heapbase || BLOCK(ptr) > mdp->heapsize) { - printf - ("FIXME. Ouch, this pointer is not mine, refusing to proceed (another solution would be to malloc it instead of reallocing it, see source code)\n"); + printf("FIXME. Ouch, this pointer is not mine, refusing to proceed (another solution would be to malloc " + "it instead of reallocing it, see source code)\n"); result = mmalloc(mdp, size); abort(); return result; } - block = BLOCK(ptr); + size_t requested_size = size; // The amount of memory requested by user, for real + + /* Work even if the user was stupid enough to ask a ridicullously small block (even 0-length), + * ie return a valid block that can be realloced and freed. + * glibc malloc does not use this trick but return a constant pointer, but we need to enlist the free fragments later on. + */ + if (size < SMALLEST_POSSIBLE_MALLOC) + size = SMALLEST_POSSIBLE_MALLOC; - type = mdp->heapinfo[block].type; - if (type<0) - THROWF(arg_error,0,"Asked realloc a fragment comming from a *free* block. I'm puzzled."); + size_t block = BLOCK(ptr); + + int type = mdp->heapinfo[block].type; switch (type) { - case 0: + case MMALLOC_TYPE_HEAPINFO: + fprintf(stderr, "Asked realloc a fragment coming from a heapinfo block. I'm confused.\n"); + abort(); + break; + + case MMALLOC_TYPE_FREE: + fprintf(stderr, "Asked realloc a fragment coming from a *free* block. I'm puzzled.\n"); + abort(); + break; + + case MMALLOC_TYPE_UNFRAGMENTED: /* Maybe reallocate a large block to a small fragment. */ if (size <= BLOCKSIZE / 2) { // Full block -> Fragment; no need to optimize for time result = mmalloc(mdp, size); if (result != NULL) { // useless (mmalloc never returns NULL), but harmless - memcpy(result, ptr, size); + memcpy(result, ptr, requested_size); mfree(mdp, ptr); return (result); } } - /* The new size is a large allocation as well; - see if we can hold it in place. */ + /* Full blocks -> Full blocks; see if we can hold it in place. */ blocks = BLOCKIFY(size); if (blocks < mdp->heapinfo[block].busy_block.size) { - int it; + int it; /* The new size is smaller; return excess memory to the free list. */ //printf("(%s) return excess memory...",xbt_thread_self_name()); - for (it= block+blocks; it< mdp->heapinfo[block].busy_block.size ; it++) - mdp->heapinfo[it].type = 0; - mdp->heapinfo[block + blocks].busy_block.size - = mdp->heapinfo[block].busy_block.size - blocks; - mdp->heapinfo[block].busy_block.size = blocks; - mdp->heapinfo[block].busy_block.busy_size = size; + for (it= block+blocks; it< mdp->heapinfo[block].busy_block.size ; it++){ + mdp->heapinfo[it].type = MMALLOC_TYPE_UNFRAGMENTED; // FIXME that should be useless, type should already be 0 here + mdp->heapinfo[it].busy_block.ignore = 0; + mdp->heapinfo[it].busy_block.size = 0; + mdp->heapinfo[it].busy_block.busy_size = 0; + } + mdp->heapinfo[block + blocks].busy_block.size = mdp->heapinfo[block].busy_block.size - blocks; mfree(mdp, ADDRESS(block + blocks)); + + mdp->heapinfo[block].busy_block.size = blocks; + mdp->heapinfo[block].busy_block.busy_size = requested_size; + mdp->heapinfo[block].busy_block.ignore = 0; + result = ptr; } else if (blocks == mdp->heapinfo[block].busy_block.size) { - /* No size change necessary. */ + + /* No block size change necessary; only update the requested size */ result = ptr; + mdp->heapinfo[block].busy_block.busy_size = requested_size; + mdp->heapinfo[block].busy_block.ignore = 0; + } else { /* Won't fit, so allocate a new region that will. - Free the old region first in case there is sufficient - adjacent free space to grow without moving. */ + Free the old region first in case there is sufficient adjacent free space to grow without moving. + This trick mandates using a specific version of mmalloc that does not memset the memory to 0 after + action for obvious reasons. */ blocks = mdp->heapinfo[block].busy_block.size; /* Prevent free from actually returning memory to the system. */ - oldlimit = mdp->heaplimit; + size_t oldlimit = mdp->heaplimit; mdp->heaplimit = 0; mfree(mdp, ptr); mdp->heaplimit = oldlimit; - result = mmalloc(mdp, size); - if (result == NULL) { - mmalloc(mdp, blocks * BLOCKSIZE); - return (NULL); - } + + result = mmalloc_no_memset(mdp, requested_size); + //fprintf(stderr,"remalloc(%zu)~>%p\n",requested_size,result); + if (ptr != result) memmove(result, ptr, blocks * BLOCKSIZE); + /* FIXME: we should memset the end of the recently area */ } break; - default: - /* Old size is a fragment; type is logarithm - to base two of the fragment size. */ + default: /* Fragment -> ??; type=logarithm to base two of the fragment size. */ + + if (type < 0) { + fprintf(stderr, "Unkown mmalloc block type.\n"); + abort(); + } + if (size > (size_t) (1 << (type - 1)) && size <= (size_t) (1 << type)) { /* The new size is the same kind of fragment. */ //printf("(%s) new size is same kind of fragment...",xbt_thread_self_name()); + result = ptr; - } else { + int frag_nb = RESIDUAL(result, BLOCKSIZE) >> type; + mdp->heapinfo[block].busy_frag.frag_size[frag_nb] = requested_size; + mdp->heapinfo[block].busy_frag.ignore[frag_nb] = 0; + + } else { /* fragment -> Either other fragment, or block */ /* The new size is different; allocate a new space, and copy the lesser of the new size and the old. */ //printf("(%s) new size is different...",xbt_thread_self_name()); - result = mmalloc(mdp, size); - if (result == NULL) - return (NULL); + result = mmalloc(mdp, requested_size); - memcpy(result, ptr, MIN(size, (size_t) 1 << type)); + memcpy(result, ptr, MIN(requested_size, (size_t) 1 << type)); mfree(mdp, ptr); } break;