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/* Copyright 2006 The Android Open Source Project */
/* A wrapper file for dlmalloc.c that compiles in the
* mspace_*() functions, which provide an interface for
* creating multiple heaps.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdint.h>
#include <sys/ioctl.h>
/* It's a pain getting the mallinfo stuff to work
* with Linux, OSX, and klibc, so just turn it off
* for now.
* TODO: make mallinfo work
*/
#define NO_MALLINFO 1
/* Allow setting the maximum heap footprint.
*/
#define USE_MAX_ALLOWED_FOOTPRINT 1
/* Don't try to trim memory.
* TODO: support this.
*/
#define MORECORE_CANNOT_TRIM 1
/* Use mmap()d anonymous memory to guarantee
* that an mspace is contiguous.
*
* create_mspace() won't work right if this is
* defined, so hide the definition of it and
* break any users at build time.
*/
#define USE_CONTIGUOUS_MSPACES 1
#if USE_CONTIGUOUS_MSPACES
/* This combination of settings forces sys_alloc()
* to always use MORECORE(). It won't expect the
* results to be contiguous, but we'll guarantee
* that they are.
*/
#define HAVE_MMAP 0
#define HAVE_MORECORE 1
#define MORECORE_CONTIGUOUS 0
/* m is always the appropriate local when MORECORE() is called. */
#define MORECORE(S) contiguous_mspace_morecore(m, S)
#define create_mspace HIDDEN_create_mspace_HIDDEN
#define destroy_mspace HIDDEN_destroy_mspace_HIDDEN
typedef struct malloc_state *mstate0;
static void *contiguous_mspace_morecore(mstate0 m, ssize_t nb);
#endif /* USE_CONTIGUOUS_MSPACES */
#define MSPACES 1
#define ONLY_MSPACES 1
#include "dlmalloc.c"
#ifndef PAGESIZE
#define PAGESIZE mparams.page_size
#endif
#define ALIGN_UP(p, alignment) \
(((uintptr_t)(p) + (alignment)-1) & ~((alignment)-1))
/* A direct copy of dlmalloc_usable_size(),
* which isn't compiled in when ONLY_MSPACES is set.
* The mspace parameter isn't actually necessary,
* but we include it to be consistent with the
* rest of the mspace_*() functions.
*/
size_t mspace_usable_size(mspace _unused, const void* mem) {
if (mem != 0) {
const mchunkptr p = mem2chunk(mem);
if (cinuse(p))
return chunksize(p) - overhead_for(p);
}
return 0;
}
#if USE_CONTIGUOUS_MSPACES
#include <sys/mman.h>
#include <limits.h>
#define CONTIG_STATE_MAGIC 0xf00dd00d
struct mspace_contig_state {
unsigned int magic;
char *brk;
char *top;
mspace m;
};
static void *contiguous_mspace_morecore(mstate m, ssize_t nb) {
struct mspace_contig_state *cs;
char *oldbrk;
const unsigned int pagesize = PAGESIZE;
cs = (struct mspace_contig_state *)((uintptr_t)m & ~(pagesize-1));
assert(cs->magic == CONTIG_STATE_MAGIC);
assert(cs->m == m);
assert(nb >= 0); //xxx deal with the trim case
oldbrk = cs->brk;
if (nb > 0) {
/* Break to the first page boundary that satisfies the request.
*/
char *newbrk = (char *)ALIGN_UP(oldbrk + nb, pagesize);
if (newbrk > cs->top)
return CMFAIL;
/* Update the protection on the underlying memory.
* Pages we've given to dlmalloc are read/write, and
* pages we haven't are not accessable (read or write
* will cause a seg fault).
*/
if (mprotect(cs, newbrk - (char *)cs, PROT_READ | PROT_WRITE) < 0)
return CMFAIL;
if (newbrk != cs->top) {
if (mprotect(newbrk, cs->top - newbrk, PROT_NONE) < 0)
return CMFAIL;
}
cs->brk = newbrk;
/* Make sure that dlmalloc will merge this block with the
* initial block that was passed to create_mspace_with_base().
* We don't care about extern vs. non-extern, so just clear it.
*/
m->seg.sflags &= ~EXTERN_BIT;
}
return oldbrk;
}
mspace create_contiguous_mspace_with_base(size_t starting_capacity,
size_t max_capacity, int locked, void *base) {
struct mspace_contig_state *cs;
unsigned int pagesize;
mstate m;
init_mparams();
pagesize = PAGESIZE;
assert(starting_capacity <= max_capacity);
assert(((uintptr_t)base & (pagesize-1)) == 0);
assert(((uintptr_t)max_capacity & (pagesize-1)) == 0);
starting_capacity = (size_t)ALIGN_UP(starting_capacity, pagesize);
/* Make the first page read/write. dlmalloc needs to use that page.
*/
if (mprotect(base, starting_capacity, PROT_READ | PROT_WRITE) < 0) {
goto error;
}
/* Create the mspace, pointing to the memory given.
*/
m = create_mspace_with_base((char *)base + sizeof(*cs), starting_capacity,
locked);
if (m == (mspace)0) {
goto error;
}
/* Make sure that m is in the same page as base.
*/
assert(((uintptr_t)m & (uintptr_t)~(pagesize-1)) == (uintptr_t)base);
/* Use some space for the information that our MORECORE needs.
*/
cs = (struct mspace_contig_state *)base;
/* Find out exactly how much of the memory the mspace
* is using.
*/
cs->brk = m->seg.base + m->seg.size;
cs->top = (char *)base + max_capacity;
assert((char *)base <= cs->brk);
assert(cs->brk <= cs->top);
/* Prevent access to the memory we haven't handed out yet.
*/
if (cs->brk != cs->top) {
/* mprotect() requires page-aligned arguments, but it's possible
* for cs->brk not to be page-aligned at this point.
*/
char *prot_brk = (char *)ALIGN_UP(cs->brk, pagesize);
if ((mprotect(base, prot_brk - (char *)base, PROT_READ | PROT_WRITE) < 0) ||
(mprotect(prot_brk, cs->top - prot_brk, PROT_NONE) < 0)) {
goto error;
}
}
cs->m = m;
cs->magic = CONTIG_STATE_MAGIC;
return (mspace)m;
error:
return (mspace)0;
}
size_t destroy_contiguous_mspace(mspace msp) {
mstate ms = (mstate)msp;
if (ok_magic(ms)) {
struct mspace_contig_state *cs;
size_t length;
const unsigned int pagesize = PAGESIZE;
cs = (struct mspace_contig_state *)((uintptr_t)ms & ~(pagesize-1));
assert(cs->magic == CONTIG_STATE_MAGIC);
assert(cs->m == ms);
length = cs->top - (char *)cs;
if (munmap((char *)cs, length) != 0)
return length;
}
else {
USAGE_ERROR_ACTION(ms, ms);
}
return 0;
}
void *contiguous_mspace_sbrk0(mspace msp) {
struct mspace_contig_state *cs;
mstate ms;
const unsigned int pagesize = PAGESIZE;
ms = (mstate)msp;
cs = (struct mspace_contig_state *)((uintptr_t)ms & ~(pagesize-1));
assert(cs->magic == CONTIG_STATE_MAGIC);
assert(cs->m == ms);
return cs->brk;
}
#endif /* USE_CONTIGUOUS_MSPACES */