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/* enable mremap on GNU/Linux */
#ifdef __linux__
# define _GNU_SOURCE
#endif
/* enable the POSIX prototypes of mmap/munmap on Solaris */
#ifdef __sun
# if __STDC_VERSION__ >= 199901L
# define _XOPEN_SOURCE 600
# else
# define _XOPEN_SOURCE 500
# endif
#endif
#include "emman.h"
#include <ecb.h>
#include <string.h>
#ifndef _WIN32
# include <unistd.h>
#endif
#if _POSIX_MAPPED_FILES > 0
# define USE_MMAP 1
# include <sys/mman.h>
# ifndef MAP_FAILED
# define MAP_FAILED ((void *)-1)
# endif
# ifndef MAP_ANONYMOUS
# ifdef MAP_ANON
# define MAP_ANONYMOUS MAP_ANON
# else
# undef USE_MMAP
# endif
# endif
# include <limits.h>
# ifndef PAGESIZE
static uint32_t pagesize;
# define BOOT_PAGESIZE if (!pagesize) pagesize = sysconf (_SC_PAGESIZE)
# define PAGESIZE pagesize
# else
# define BOOT_PAGESIZE
# endif
#else
# define PAGESIZE 1
# define BOOT_PAGESIZE
#endif
size_t
chunk_round (size_t size)
{
BOOT_PAGESIZE;
return (size + (PAGESIZE - 1)) & ~(size_t)(PAGESIZE - 1);
}
size_t
chunk_fit (size_t header, size_t element_size, size_t max_increase)
{
uint32_t fill, maximum_fill = 0;
size_t minimum_size;
max_increase += header + element_size;
BOOT_PAGESIZE;
do
{
header += element_size;
fill = (uint32_t)header & (PAGESIZE - 1);
if (fill >= maximum_fill)
{
maximum_fill = fill + 16; /* size increase results in at least 16 bytes improvement */
minimum_size = header;
}
}
while (header < max_increase);
return minimum_size;
}
void *
chunk_alloc (size_t size, int populate)
{
#if USE_MMAP
void *ptr = MAP_FAILED;
#ifdef MAP_POPULATE
if (populate & 1)
ptr = mmap (0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE, -1, 0);
#endif
if (ptr == MAP_FAILED)
ptr = mmap (0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (ptr == MAP_FAILED)
return 0;
return ptr;
#else
return malloc (size);
#endif
}
void *
chunk_realloc (void *ptr, size_t old_size, size_t new_size)
{
#if USE_MMAP
#ifdef MREMAP_MAYMOVE /* requires _GNU_SOURCE */
void *ptr2 = mremap (ptr, old_size, new_size, MREMAP_MAYMOVE);
if (ptr2 == MAP_FAILED)
return 0;
return ptr2;
#else
void *ptr2 = chunk_alloc (new_size, 0);
if (!ptr2)
return ptr2;
/* TODO: prepopulate old_size pages instead of faulting them in */
memcpy (ptr2, ptr, old_size);
munmap (ptr, old_size);
return ptr2;
#endif
#else
return realloc (ptr, new_size);
#endif
}
void
chunk_free (void *ptr, size_t size)
{
#if USE_MMAP
/* we assume the OS never mmaps at address 0 */
if (ptr)
munmap (ptr, size);
#else
return free (ptr);
#endif
}
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