+++ /dev/null
-/* Memory allocator `malloc'. */
-
-/* Copyright (c) 2010-2021. 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, 1992 Free Software Foundation
-
- Written May 1989 by Mike Haertel.
- Heavily modified Mar 1992 by Fred Fish for mmap'd version. */
-
-#include <string.h> /* Prototypes for memcpy, memmove, memset, etc */
-#include <stdio.h>
-#include "mmprivate.h"
-
-/* Prototypes for local functions */
-
-static void initialize(xbt_mheap_t mdp);
-static void *register_morecore(xbt_mheap_t mdp, size_t size);
-static void *align(xbt_mheap_t mdp, size_t size);
-
-/* Allocation aligned on block boundary.
- *
- * It never returns NULL, but dies verbosely on error.
- */
-static void *align(struct mdesc *mdp, size_t size)
-{
- void *result;
- unsigned long int adj;
-
- result = mmorecore(mdp, size);
-
- /* if this reservation does not fill up the last block of our resa,
- * complete the reservation by also asking for the full latest block.
- *
- * Also, the returned block is aligned to the end of block (but I've
- * no fucking idea of why, actually -- http://abstrusegoose.com/432 --
- * but not doing so seems to lead to issues).
- */
- adj = RESIDUAL(result, BLOCKSIZE);
- if (adj != 0) {
- adj = BLOCKSIZE - adj;
- mmorecore(mdp, adj);
- result = (char *) result + adj;
- }
- return (result);
-}
-
-/** Initialize heapinfo about the heapinfo pages :)
- *
- */
-static void initialize_heapinfo_heapinfo(const s_xbt_mheap_t* mdp)
-{
- // Update heapinfo about the heapinfo pages (!):
- xbt_assert((uintptr_t) mdp->heapinfo % BLOCKSIZE == 0);
- size_t block = BLOCK(mdp->heapinfo);
- size_t nblocks = mdp->heapsize * sizeof(malloc_info) / BLOCKSIZE;
- // Mark them as free:
- for (size_t j=0; j!=nblocks; ++j) {
- mdp->heapinfo[block+j].type = MMALLOC_TYPE_FREE;
- mdp->heapinfo[block+j].free_block.size = 0;
- mdp->heapinfo[block+j].free_block.next = 0;
- mdp->heapinfo[block+j].free_block.prev = 0;
- }
- mdp->heapinfo[block].free_block.size = nblocks;
-}
-
-/* Finish the initialization of the mheap. If we want to inline it
- * properly, we need to make the align function publicly visible, too */
-static void initialize(xbt_mheap_t mdp)
-{
- // Update mdp meta-data:
- mdp->heapsize = HEAP / BLOCKSIZE;
- mdp->heapinfo = (malloc_info *)
- align(mdp, mdp->heapsize * sizeof(malloc_info));
- mdp->heapbase = (void *) mdp->heapinfo;
- mdp->flags |= MMALLOC_INITIALIZED;
-
- // Update root heapinfo:
- memset((void *) mdp->heapinfo, 0, mdp->heapsize * sizeof(malloc_info));
- mdp->heapinfo[0].type = MMALLOC_TYPE_FREE;
- mdp->heapinfo[0].free_block.size = 0;
- mdp->heapinfo[0].free_block.next = mdp->heapinfo[0].free_block.prev = 0;
- mdp->heapindex = 0;
-
- initialize_heapinfo_heapinfo(mdp);
-
- for (int i = 0; i < BLOCKLOG; i++) {
- malloc_info mi; /* to compute the offset of the swag hook */
- xbt_swag_init(&(mdp->fraghead[i]), xbt_swag_offset(mi, freehook));
- }
-}
-
-static inline void update_hook(void **a, size_t offset)
-{
- if (*a)
- *a = (char*)*a + offset;
-}
-
-/* Get neatly aligned memory from the low level layers, and register it
- * into the heap info table as necessary. */
-static void *register_morecore(struct mdesc *mdp, size_t size)
-{
- void* result = align(mdp, size); // Never returns NULL
-
- /* Check if we need to grow the info table (in a multiplicative manner) */
- if ((size_t) BLOCK((char *) result + size) > mdp->heapsize) {
- size_t newsize = mdp->heapsize;
- while ((size_t) BLOCK((char *) result + size) > newsize)
- newsize *= 2;
-
- /* Copy old info into new location */
- malloc_info* oldinfo = mdp->heapinfo;
- malloc_info* newinfo = (malloc_info*)align(mdp, newsize * sizeof(malloc_info));
- memcpy(newinfo, oldinfo, mdp->heapsize * sizeof(malloc_info));
-
- /* Initialize the new blockinfo : */
- memset((char*) newinfo + mdp->heapsize * sizeof(malloc_info), 0,
- (newsize - mdp->heapsize)* sizeof(malloc_info));
-
- /* Update the swag of busy blocks containing free fragments by applying the offset to all swag_hooks. Yeah. My hand is right in the fan and I still type */
- size_t offset=((char*)newinfo)-((char*)oldinfo);
-
- for (int i = 1 /*first element of heapinfo describes the mdesc area*/; i < mdp->heaplimit; i++) {
- update_hook(&newinfo[i].freehook.next, offset);
- update_hook(&newinfo[i].freehook.prev, offset);
- }
- // also update the starting points of the swag
- for (int i = 0; i < BLOCKLOG; i++) {
- update_hook(&mdp->fraghead[i].head, offset);
- update_hook(&mdp->fraghead[i].tail, offset);
- }
- mdp->heapinfo = newinfo;
-
- /* mark the space previously occupied by the block info as free by first marking it
- * as occupied in the regular way, and then freing it */
- for (int it = 0; it < BLOCKIFY(mdp->heapsize * sizeof(malloc_info)); it++) {
- newinfo[BLOCK(oldinfo)+it].type = MMALLOC_TYPE_UNFRAGMENTED;
- newinfo[BLOCK(oldinfo)+it].busy_block.ignore = 0;
- }
-
- newinfo[BLOCK(oldinfo)].busy_block.size = BLOCKIFY(mdp->heapsize * sizeof(malloc_info));
- newinfo[BLOCK(oldinfo)].busy_block.busy_size = size;
- mfree(mdp, (void *) oldinfo);
- mdp->heapsize = newsize;
-
- initialize_heapinfo_heapinfo(mdp);
- }
-
- mdp->heaplimit = BLOCK((char *) result + size);
- return (result);
-}
-
-/* Allocate memory from the heap. */
-void *mmalloc(xbt_mheap_t mdp, size_t size) {
- void *res= mmalloc_no_memset(mdp,size);
- if (mdp->options & XBT_MHEAP_OPTION_MEMSET) {
- memset(res,0,size);
- }
- return res;
-}
-
-static void mmalloc_mark_used(xbt_mheap_t mdp, size_t block, size_t nblocks, size_t requested_size)
-{
- for (int it = 0; it < nblocks; it++) {
- mdp->heapinfo[block + it].type = MMALLOC_TYPE_UNFRAGMENTED;
- mdp->heapinfo[block + it].busy_block.busy_size = 0;
- mdp->heapinfo[block + it].busy_block.ignore = 0;
- mdp->heapinfo[block + it].busy_block.size = 0;
- }
- mdp->heapinfo[block].busy_block.size = nblocks;
- mdp->heapinfo[block].busy_block.busy_size = requested_size;
- mdp->heapstats.chunks_used++;
- mdp->heapstats.bytes_used += nblocks * BLOCKSIZE;
-}
-
-/* Splitting mmalloc this way is mandated by a trick in mrealloc, that gives
- back the memory of big blocks to the system before reallocating them: we don't
- want to loose the beginning of the area when this happens */
-void *mmalloc_no_memset(xbt_mheap_t mdp, size_t size)
-{
- void *result;
- size_t block;
-
- 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 ridiculously 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;
-
- if (!(mdp->flags & MMALLOC_INITIALIZED))
- initialize(mdp);
-
- /* Determine the allocation policy based on the request size. */
- if (size <= BLOCKSIZE / 2) {
- /* Small allocation to receive a fragment of a block.
- Determine the logarithm to base two of the fragment size. */
- size_t log = 1;
- --size;
- while ((size /= 2) != 0) {
- ++log;
- }
-
- /* Look in the fragment lists for a free fragment of the desired size. */
- if (xbt_swag_size(&mdp->fraghead[log])>0) {
- /* There are free fragments of this size; Get one of them and prepare to return it.
- Update the block's nfree and if no other free fragment, get out of the swag. */
-
- /* search a fragment that I could return as a result */
- malloc_info *candidate_info = xbt_swag_getFirst(&mdp->fraghead[log]);
- size_t candidate_block = (candidate_info - &(mdp->heapinfo[0]));
- size_t candidate_frag;
- for (candidate_frag=0;candidate_frag<(size_t) (BLOCKSIZE >> log);candidate_frag++)
- if (candidate_info->busy_frag.frag_size[candidate_frag] == -1)
- break;
- xbt_assert(candidate_frag < (size_t) (BLOCKSIZE >> log),
- "Block %zu was registered as containing free fragments of type %zu, but I can't find any",candidate_block,log);
-
- result = (void*) (((char*)ADDRESS(candidate_block)) + (candidate_frag << log));
-
- /* Remove this fragment from the list of free guys */
- candidate_info->busy_frag.nfree--;
- if (candidate_info->busy_frag.nfree == 0) {
- xbt_swag_remove(candidate_info,&mdp->fraghead[log]);
- }
-
- /* Update our metadata about this fragment */
- candidate_info->busy_frag.frag_size[candidate_frag] = requested_size;
- candidate_info->busy_frag.ignore[candidate_frag] = 0;
-
- /* Update the statistics. */
- mdp -> heapstats.chunks_used++;
- mdp -> heapstats.bytes_used += 1 << log;
- mdp -> heapstats.chunks_free--;
- mdp -> heapstats.bytes_free -= 1 << log;
-
- } else {
- /* No free fragments of the desired size, so get a new block
- and break it into fragments, returning the first. */
-
- result = mmalloc(mdp, BLOCKSIZE); // does not return NULL
- block = BLOCK(result);
-
- mdp->heapinfo[block].type = (int)log;
- /* Link all fragments but the first as free, and add the block to the swag of blocks containing free frags */
- size_t i;
- for (i = 1; i < (size_t) (BLOCKSIZE >> log); ++i) {
- mdp->heapinfo[block].busy_frag.frag_size[i] = -1;
- mdp->heapinfo[block].busy_frag.ignore[i] = 0;
- }
- mdp->heapinfo[block].busy_frag.nfree = i - 1;
- mdp->heapinfo[block].freehook.prev = NULL;
- mdp->heapinfo[block].freehook.next = NULL;
-
- xbt_swag_insert(&mdp->heapinfo[block], &(mdp->fraghead[log]));
-
- /* mark the fragment returned as busy */
- mdp->heapinfo[block].busy_frag.frag_size[0] = requested_size;
- mdp->heapinfo[block].busy_frag.ignore[0] = 0;
-
- /* update stats */
- mdp -> heapstats.chunks_free += (BLOCKSIZE >> log) - 1;
- mdp -> heapstats.bytes_free += BLOCKSIZE - (1 << log);
- mdp -> heapstats.bytes_used -= BLOCKSIZE - (1 << log);
- }
- } else {
- /* Large allocation to receive one or more blocks.
- Search the free list in a circle starting at the last place visited.
- If we loop completely around without finding a large enough
- space we will have to get more memory from the system. */
- size_t blocks = BLOCKIFY(size);
- size_t start = MALLOC_SEARCH_START;
- block = MALLOC_SEARCH_START;
- while (mdp->heapinfo[block].free_block.size < blocks) {
- if (mdp->heapinfo[block].type >=0) { // Don't trust xbt_die and friends in malloc-level library, you fool!
- fprintf(stderr,
- "Internal error: found a free block not marked as such (block=%zu type=%d). Please report this bug.\n",
- block, mdp->heapinfo[block].type);
- abort();
- }
-
- block = mdp->heapinfo[block].free_block.next;
- if (block == start) {
- /* Need to get more from the system. Check to see if
- the new core will be contiguous with the final free
- block; if so we don't need to get as much. */
- block = mdp->heapinfo[0].free_block.prev;
- size_t lastblocks = mdp->heapinfo[block].free_block.size;
- if (mdp->heaplimit != 0 &&
- block + lastblocks == mdp->heaplimit &&
- mmorecore(mdp, 0) == ADDRESS(block + lastblocks) &&
- (register_morecore(mdp, (blocks - lastblocks) * BLOCKSIZE)) != NULL) {
- /* Which block we are extending (the `final free
- block' referred to above) might have changed, if
- it got combined with a freed info table. */
- block = mdp->heapinfo[0].free_block.prev;
-
- mdp->heapinfo[block].free_block.size += (blocks - lastblocks);
- continue;
- }
- result = register_morecore(mdp, blocks * BLOCKSIZE);
-
- block = BLOCK(result);
- mmalloc_mark_used(mdp, block, blocks, requested_size);
-
- return result;
- }
- /* Need large block(s), but found some in the existing heap */
- }
-
- /* At this point we have found a suitable free list entry.
- Figure out how to remove what we need from the list. */
- result = ADDRESS(block);
- if (mdp->heapinfo[block].free_block.size > blocks) {
- /* The block we found has a bit left over,
- so relink the tail end back into the free list. */
- mdp->heapinfo[block + blocks].free_block.size
- = mdp->heapinfo[block].free_block.size - blocks;
- mdp->heapinfo[block + blocks].free_block.next
- = mdp->heapinfo[block].free_block.next;
- mdp->heapinfo[block + blocks].free_block.prev
- = mdp->heapinfo[block].free_block.prev;
- mdp->heapinfo[mdp->heapinfo[block].free_block.prev].free_block.next
- = mdp->heapinfo[mdp->heapinfo[block].free_block.next].free_block.prev
- = mdp->heapindex = block + blocks;
- } else {
- /* The block exactly matches our requirements,
- so just remove it from the list. */
- mdp->heapinfo[mdp->heapinfo[block].free_block.next].free_block.prev
- = mdp->heapinfo[block].free_block.prev;
- mdp->heapinfo[mdp->heapinfo[block].free_block.prev].free_block.next
- = mdp->heapindex = mdp->heapinfo[block].free_block.next;
- }
-
- mmalloc_mark_used(mdp, block, blocks, requested_size);
- mdp -> heapstats.bytes_free -= blocks * BLOCKSIZE;
-
- }
-
- return (result);
-}
