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Simplify malloc initialization

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Singificantly reduce the code needed at malloc initialization.  In
the process getpagesize is simplified by always initializing
GLRO(dl_pagesize).
This commit is contained in:
Ulrich Drepper
2011-09-10 21:47:36 -04:00
parent 22a8918713
commit 02d46fc4b9
8 changed files with 65 additions and 98 deletions
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69
malloc/malloc.c
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@@ -170,7 +170,6 @@
Compilation Environment options:
HAVE_MREMAP 0 unless linux defined
malloc_getpagesize derived from system #includes, or 4096 if not
Changing default word sizes:
@@ -226,6 +225,8 @@
#include <bits/wordsize.h>
#include <sys/sysinfo.h>
#include <ldsodefs.h>
#ifdef __cplusplus
extern "C" {
#endif
@@ -454,7 +455,6 @@ __malloc_assert (const char *assertion, const char *file, unsigned int line,
#define public_iCOMALLOc __libc_independent_comalloc
#define public_gET_STATe __malloc_get_state
#define public_sET_STATe __malloc_set_state
#define malloc_getpagesize __getpagesize()
#define open __open
#define mmap __mmap
#define munmap __munmap
@@ -588,24 +588,6 @@ void *(*__morecore)(ptrdiff_t) = __default_morecore;
#endif /* HAVE_MREMAP */
/*
The system page size. To the extent possible, this malloc manages
memory from the system in page-size units. Note that this value is
cached during initialization into a field of malloc_state. So even
if malloc_getpagesize is a function, it is only called once.
The following mechanics for getpagesize were adapted from bsd/gnu
getpagesize.h. If none of the system-probes here apply, a value of
4096 is used, which should be OK: If they don't apply, then using
the actual value probably doesn't impact performance.
*/
#ifndef malloc_getpagesize
# include <unistd.h>
# define malloc_getpagesize sysconf(_SC_PAGE_SIZE)
#endif
/*
This version of malloc supports the standard SVID/XPG mallinfo
routine that returns a struct containing usage properties and
@@ -1878,9 +1860,6 @@ struct malloc_par {
dynamic behavior. */
int no_dyn_threshold;
/* Cache malloc_getpagesize */
unsigned int pagesize;
/* Statistics */
INTERNAL_SIZE_T mmapped_mem;
/*INTERNAL_SIZE_T sbrked_mem;*/
@@ -1898,11 +1877,25 @@ struct malloc_par {
before using. This malloc relies on the property that malloc_state
is initialized to all zeroes (as is true of C statics). */
static struct malloc_state main_arena;
static struct malloc_state main_arena =
{
.mutex = MUTEX_INITIALIZER,
.next = &main_arena
};
/* There is only one instance of the malloc parameters. */
static struct malloc_par mp_;
static struct malloc_par mp_ =
{
.top_pad = DEFAULT_TOP_PAD,
.n_mmaps_max = DEFAULT_MMAP_MAX,
.mmap_threshold = DEFAULT_MMAP_THRESHOLD,
.trim_threshold = DEFAULT_TRIM_THRESHOLD,
#ifdef PER_THREAD
# define NARENAS_FROM_NCORES(n) ((n) * (sizeof(long) == 4 ? 2 : 8))
.arena_test = NARENAS_FROM_NCORES (1)
#endif
};
#ifdef PER_THREAD
@@ -2070,7 +2063,7 @@ static void do_check_chunk(mstate av, mchunkptr p)
assert(((char*)p) < min_address || ((char*)p) >= max_address);
}
/* chunk is page-aligned */
assert(((p->prev_size + sz) & (mp_.pagesize-1)) == 0);
assert(((p->prev_size + sz) & (GLRO(dl_pagesize)-1)) == 0);
/* mem is aligned */
assert(aligned_OK(chunk2mem(p)));
}
@@ -2231,7 +2224,7 @@ static void do_check_malloc_state(mstate av)
return;
/* pagesize is a power of 2 */
assert((mp_.pagesize & (mp_.pagesize-1)) == 0);
assert((GLRO(dl_pagesize) & (GLRO(dl_pagesize)-1)) == 0);
/* A contiguous main_arena is consistent with sbrk_base. */
if (av == &main_arena && contiguous(av))
@@ -2389,7 +2382,7 @@ static void* sYSMALLOc(INTERNAL_SIZE_T nb, mstate av)
unsigned long sum; /* for updating stats */
size_t pagemask = mp_.pagesize - 1;
size_t pagemask = GLRO(dl_pagesize) - 1;
bool tried_mmap = false;
@@ -2804,7 +2797,7 @@ static int sYSTRIm(size_t pad, mstate av)
char* new_brk; /* address returned by post-check sbrk call */
size_t pagesz;
pagesz = mp_.pagesize;
pagesz = GLRO(dl_pagesize);
top_size = chunksize(av->top);
/* Release in pagesize units, keeping at least one page */
@@ -2867,7 +2860,7 @@ munmap_chunk(mchunkptr p)
page size. But gcc does not recognize the optimization possibility
(in the moment at least) so we combine the two values into one before
the bit test. */
if (__builtin_expect (((block | total_size) & (mp_.pagesize - 1)) != 0, 0))
if (__builtin_expect (((block | total_size) & (GLRO(dl_pagesize) - 1)) != 0, 0))
{
malloc_printerr (check_action, "munmap_chunk(): invalid pointer",
chunk2mem (p));
@@ -2889,13 +2882,13 @@ static mchunkptr
internal_function
mremap_chunk(mchunkptr p, size_t new_size)
{
size_t page_mask = mp_.pagesize - 1;
size_t page_mask = GLRO(dl_pagesize) - 1;
INTERNAL_SIZE_T offset = p->prev_size;
INTERNAL_SIZE_T size = chunksize(p);
char *cp;
assert (chunk_is_mmapped(p));
assert(((size + offset) & (mp_.pagesize-1)) == 0);
assert(((size + offset) & (GLRO(dl_pagesize)-1)) == 0);
/* Note the extra SIZE_SZ overhead as in mmap_chunk(). */
new_size = (new_size + offset + SIZE_SZ + page_mask) & ~page_mask;
@@ -3157,7 +3150,7 @@ public_vALLOc(size_t bytes)
if(__malloc_initialized < 0)
ptmalloc_init ();
size_t pagesz = mp_.pagesize;
size_t pagesz = GLRO(dl_pagesize);
__malloc_ptr_t (*hook) __MALLOC_PMT ((size_t, size_t,
__const __malloc_ptr_t)) =
@@ -3201,8 +3194,8 @@ public_pVALLOc(size_t bytes)
if(__malloc_initialized < 0)
ptmalloc_init ();
size_t pagesz = mp_.pagesize;
size_t page_mask = mp_.pagesize - 1;
size_t pagesz = GLRO(dl_pagesize);
size_t page_mask = GLRO(dl_pagesize) - 1;
size_t rounded_bytes = (bytes + page_mask) & ~(page_mask);
__malloc_ptr_t (*hook) __MALLOC_PMT ((size_t, size_t,
@@ -4582,7 +4575,7 @@ _int_valloc(mstate av, size_t bytes)
{
/* Ensure initialization/consolidation */
if (have_fastchunks(av)) malloc_consolidate(av);
return _int_memalign(av, mp_.pagesize, bytes);
return _int_memalign(av, GLRO(dl_pagesize), bytes);
}
/*
@@ -4597,7 +4590,7 @@ _int_pvalloc(mstate av, size_t bytes)
/* Ensure initialization/consolidation */
if (have_fastchunks(av)) malloc_consolidate(av);
pagesz = mp_.pagesize;
pagesz = GLRO(dl_pagesize);
return _int_memalign(av, pagesz, (bytes + pagesz - 1) & ~(pagesz - 1));
}
@@ -4611,7 +4604,7 @@ static int mTRIm(mstate av, size_t pad)
/* Ensure initialization/consolidation */
malloc_consolidate (av);
const size_t ps = mp_.pagesize;
const size_t ps = GLRO(dl_pagesize);
int psindex = bin_index (ps);
const size_t psm1 = ps - 1;