retronetworking
/
freeswitch
13
0
Fork 0
Code Pull Requests Releases Activity
freeswitch/libs/libks/src/mpool.c

1769 lines
41 KiB
C
Raw Blame History

/*
* Memory pool routines.
*
* Copyright 1996 by Gray Watson.
*
* This file is part of the mpool package.
*
* Permission to use, copy, modify, and distribute this software for
* any purpose and without fee is hereby granted, provided that the
* above copyright notice and this permission notice appear in all
* copies, and that the name of Gray Watson not be used in advertising
* or publicity pertaining to distribution of the document or software
* without specific, written prior permission.
*
* Gray Watson makes no representations about the suitability of the
* software described herein for any purpose. It is provided "as is"
* without express or implied warranty.
*
* The author may be reached via http://256.com/gray/
*
* $Id: mpool.c,v 1.5 2006/05/31 20:28:31 gray Exp $
*/
/*
* Memory-pool allocation routines. I got sick of the GNU mmalloc
* library which was close to what we needed but did not exactly do
* what I wanted.
*
* The following uses mmap from /dev/zero. It allows a number of
* allocations to be made inside of a memory pool then with a clear or
* close the pool can be reset without any memory fragmentation and
* growth problems.
*/
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#ifdef DMALLOC
#include "dmalloc.h"
#endif
#define MPOOL_MAIN
#include "mpool.h"
#include "mpool_loc.h"
#ifdef __GNUC__
#ident "$Id: mpool.c,v 1.5 2006/05/31 20:28:31 gray Exp $"
#else
static char *rcs_id = "$Id: mpool.c,v 1.5 2006/05/31 20:28:31 gray Exp $";
#endif
/* version */
static char *version = "mpool library version 2.1.0";
/* local variables */
static int enabled_b = 0; /* lib initialized? */
static unsigned int min_bit_free_next = 0; /* min size of next pnt */
static unsigned int min_bit_free_size = 0; /* min size of next + size */
static unsigned long bit_array[MAX_BITS + 1]; /* size -> bit */
/****************************** local utilities ******************************/
/*
* static void startup
*
* DESCRIPTION:
*
* Perform any library level initialization.
*
* RETURNS:
*
* None.
*
* ARGUMENTS:
*
* None.
*/
static void startup(void)
{
int bit_c;
unsigned long size = 1;
if (enabled_b) {
return;
}
/* allocate our free bit array list */
for (bit_c = 0; bit_c <= MAX_BITS; bit_c++) {
bit_array[bit_c] = size;
/*
* Note our minimum number of bits that can store a pointer. This
* is smallest address that we can have a linked list for.
*/
if (min_bit_free_next == 0 && size >= sizeof(void *)) {
min_bit_free_next = bit_c;
}
/*
* Note our minimum number of bits that can store a pointer and
* the size of the block.
*/
if (min_bit_free_size == 0 && size >= sizeof(mpool_free_t)) {
min_bit_free_size = bit_c;
}
size *= 2;
}
enabled_b = 1;
}
/*
* static int size_to_bits
*
* DESCRIPTION:
*
* Calculate the number of bits in a size.
*
* RETURNS:
*
* Number of bits.
*
* ARGUMENTS:
*
* size -> Size of memory of which to calculate the number of bits.
*/
static int size_to_bits(const unsigned long size)
{
int bit_c = 0;
for (bit_c = 0; bit_c <= MAX_BITS; bit_c++) {
if (size <= bit_array[bit_c]) {
break;
}
}
return bit_c;
}
/*
* static int size_to_free_bits
*
* DESCRIPTION:
*
* Calculate the number of bits in a size going on the free list.
*
* RETURNS:
*
* Number of bits.
*
* ARGUMENTS:
*
* size -> Size of memory of which to calculate the number of bits.
*/
static int size_to_free_bits(const unsigned long size)
{
int bit_c = 0;
if (size == 0) {
return 0;
}
for (bit_c = 0; bit_c <= MAX_BITS; bit_c++) {
if (size < bit_array[bit_c]) {
break;
}
}
return bit_c - 1;
}
/*
* static int bits_to_size
*
* DESCRIPTION:
*
* Calculate the size represented by a number of bits.
*
* RETURNS:
*
* Number of bits.
*
* ARGUMENTS:
*
* bit_n -> Number of bits
*/
static unsigned long bits_to_size(const int bit_n)
{
if (bit_n > MAX_BITS) {
return bit_array[MAX_BITS];
}
else {
return bit_array[bit_n];
}
}
/*
* static void *alloc_pages
*
* DESCRIPTION:
*
* Allocate space for a number of memory pages in the memory pool.
*
* RETURNS:
*
* Success - New pages of memory
*
* Failure - NULL
*
* ARGUMENTS:
*
* mp_p <-> Pointer to our memory pool.
*
* page_n -> Number of pages to alloc.
*
* error_p <- Pointer to integer which, if not NULL, will be set with
* a mpool error code.
*/
static void *alloc_pages(mpool_t *mp_p, const unsigned int page_n,
int *error_p)
{
void *mem, *fill_mem;
unsigned long size, fill;
int state;
/* are we over our max-pages? */
if (mp_p->mp_max_pages > 0 && mp_p->mp_page_c >= mp_p->mp_max_pages) {
SET_POINTER(error_p, MPOOL_ERROR_NO_PAGES);
return NULL;
}
size = SIZE_OF_PAGES(mp_p, page_n);
#ifdef DEBUG
(void)printf("allocating %u pages or %lu bytes\n", page_n, size);
#endif
if (BIT_IS_SET(mp_p->mp_flags, MPOOL_FLAG_USE_SBRK)) {
mem = sbrk(size);
if (mem == (void *)-1) {
SET_POINTER(error_p, MPOOL_ERROR_NO_MEM);
return NULL;
}
fill = (unsigned long)mem % mp_p->mp_page_size;
if (fill > 0) {
fill = mp_p->mp_page_size - fill;
fill_mem = sbrk(fill);
if (fill_mem == (void *)-1) {
SET_POINTER(error_p, MPOOL_ERROR_NO_MEM);
return NULL;
}
if ((char *)fill_mem != (char *)mem + size) {
SET_POINTER(error_p, MPOOL_ERROR_SBRK_CONTIG);
return NULL;
}
mem = (char *)mem + fill;
}
}
else {
state = MAP_PRIVATE;
#ifdef MAP_FILE
state |= MAP_FILE;
#endif
#ifdef MAP_VARIABLE
state |= MAP_VARIABLE;
#endif
/* mmap from /dev/zero */
mem = mmap((caddr_t)mp_p->mp_addr, size, PROT_READ | PROT_WRITE, state,
mp_p->mp_fd, mp_p->mp_top);
if (mem == (void *)MAP_FAILED) {
if (errno == ENOMEM) {
SET_POINTER(error_p, MPOOL_ERROR_NO_MEM);
}
else {
SET_POINTER(error_p, MPOOL_ERROR_MMAP);
}
return NULL;
}
mp_p->mp_top += size;
if (mp_p->mp_addr != NULL) {
mp_p->mp_addr = (char *)mp_p->mp_addr + size;
}
}
mp_p->mp_page_c += page_n;
SET_POINTER(error_p, MPOOL_ERROR_NONE);
return mem;
}
/*
* static int free_pages
*
* DESCRIPTION:
*
* Free previously allocated pages of memory.
*
* RETURNS:
*
* Success - MPOOL_ERROR_NONE
*
* Failure - Mpool error code
*
* ARGUMENTS:
*
* pages <-> Pointer to memory pages that we are freeing.
*
* size -> Size of the block that we are freeing.
*
* sbrk_b -> Set to one if the pages were allocated with sbrk else mmap.
*/
static int free_pages(void *pages, const unsigned long size,
const int sbrk_b)
{
if (! sbrk_b) {
(void)munmap((caddr_t)pages, size);
}
return MPOOL_ERROR_NONE;
}
/*
* static int check_magic
*
* DESCRIPTION:
*
* Check for the existance of the magic ID in a memory pointer.
*
* RETURNS:
*
* Success - MPOOL_ERROR_NONE
*
* Failure - Mpool error code
*
* ARGUMENTS:
*
* addr -> Address inside of the block that we are tryign to locate.
*
* size -> Size of the block.
*/
static int check_magic(const void *addr, const unsigned long size)
{
const unsigned char *mem_p;
/* set our starting point */
mem_p = (unsigned char *)addr + size;
if (*mem_p == FENCE_MAGIC0 && *(mem_p + 1) == FENCE_MAGIC1) {
return MPOOL_ERROR_NONE;
}
else {
return MPOOL_ERROR_PNT_OVER;
}
}
/*
* static void write_magic
*
* DESCRIPTION:
*
* Write the magic ID to the address.
*
* RETURNS:
*
* None.
*
* ARGUMENTS:
*
* addr -> Address where to write the magic.
*/
static void write_magic(const void *addr)
{
*(unsigned char *)addr = FENCE_MAGIC0;
*((unsigned char *)addr + 1) = FENCE_MAGIC1;
}
/*
* static void free_pointer
*
* DESCRIPTION:
*
* Moved a pointer into our free lists.
*
* RETURNS:
*
* Success - MPOOL_ERROR_NONE
*
* Failure - Mpool error code
*
* ARGUMENTS:
*
* mp_p <-> Pointer to the memory pool.
*
* addr <-> Address where to write the magic. We may write a next
* pointer to it.
*
* size -> Size of the address space.
*/
static int free_pointer(mpool_t *mp_p, void *addr,
const unsigned long size)
{
unsigned int bit_n;
unsigned long real_size;
mpool_free_t free_pnt;
#ifdef DEBUG
(void)printf("freeing a block at %lx of %lu bytes\n", (long)addr, size);
#endif
if (size == 0) {
return MPOOL_ERROR_NONE;
}
/*
* if the user size is larger then can fit in an entire block then
* we change the size
*/
if (size > MAX_BLOCK_USER_MEMORY(mp_p)) {
real_size = SIZE_OF_PAGES(mp_p, PAGES_IN_SIZE(mp_p, size)) -
sizeof(mpool_block_t);
}
else {
real_size = size;
}
/*
* We use a specific free bits calculation here because if we are
* freeing 10 bytes then we will be putting it into the 8-byte free
* list and not the 16 byte list. size_to_bits(10) will return 4
* instead of 3.
*/
bit_n = size_to_free_bits(real_size);
/*
* Minimal error checking. We could go all the way through the
* list however this might be prohibitive.
*/
if (mp_p->mp_free[bit_n] == addr) {
return MPOOL_ERROR_IS_FREE;
}
/* add the freed pointer to the free list */
if (bit_n < min_bit_free_next) {
/*
* Yes we know this will lose 99% of the allocations but what else
* can we do? No space for a next pointer.
*/
if (mp_p->mp_free[bit_n] == NULL) {
mp_p->mp_free[bit_n] = addr;
}
}
else if (bit_n < min_bit_free_size) {
/* we copy, not assign, to maintain the free list */
memcpy(addr, mp_p->mp_free + bit_n, sizeof(void *));
mp_p->mp_free[bit_n] = addr;
}
else {
/* setup our free list structure */
free_pnt.mf_next_p = mp_p->mp_free[bit_n];
free_pnt.mf_size = real_size;
/* we copy the structure in since we don't know about alignment */
memcpy(addr, &free_pnt, sizeof(free_pnt));
mp_p->mp_free[bit_n] = addr;
}
return MPOOL_ERROR_NONE;
}
/*
* static int split_block
*
* DESCRIPTION:
*
* When freeing space in a multi-block chunk we have to create new
* blocks out of the upper areas being freed.
*
* RETURNS:
*
* Success - MPOOL_ERROR_NONE
*
* Failure - Mpool error code
*
* ARGUMENTS:
*
* mp_p <-> Pointer to the memory pool.
*
* free_addr -> Address that we are freeing.
*
* size -> Size of the space that we are taking from address.
*/
static int split_block(mpool_t *mp_p, void *free_addr,
const unsigned long size)
{
mpool_block_t *block_p, *new_block_p;
int ret, page_n;
void *end_p;
/*
* 1st we find the block pointer from our free addr. At this point
* the pointer must be the 1st one in the block if it is spans
* multiple blocks.
*/
block_p = (mpool_block_t *)((char *)free_addr - sizeof(mpool_block_t));
if (block_p->mb_magic != BLOCK_MAGIC
|| block_p->mb_magic2 != BLOCK_MAGIC) {
return MPOOL_ERROR_POOL_OVER;
}
page_n = PAGES_IN_SIZE(mp_p, size);
/* we are creating a new block structure for the 2nd ... */
new_block_p = (mpool_block_t *)((char *)block_p +
SIZE_OF_PAGES(mp_p, page_n));
new_block_p->mb_magic = BLOCK_MAGIC;
/* New bounds is 1st block bounds. The 1st block's is reset below. */
new_block_p->mb_bounds_p = block_p->mb_bounds_p;
/* Continue the linked list. The 1st block will point to us below. */
new_block_p->mb_next_p = block_p->mb_next_p;
new_block_p->mb_magic2 = BLOCK_MAGIC;
/* bounds for the 1st block are reset to the 1st page only */
block_p->mb_bounds_p = (char *)new_block_p;
/* the next block pointer for the 1st block is now the new one */
block_p->mb_next_p = new_block_p;
/* only free the space in the 1st block if it is only 1 block in size */
if (page_n == 1) {
/* now free the rest of the 1st block block */
end_p = (char *)free_addr + size;
ret = free_pointer(mp_p, end_p,
(char *)block_p->mb_bounds_p - (char *)end_p);
if (ret != MPOOL_ERROR_NONE) {
return ret;
}
}
/* now free the rest of the block */
ret = free_pointer(mp_p, FIRST_ADDR_IN_BLOCK(new_block_p),
MEMORY_IN_BLOCK(new_block_p));
if (ret != MPOOL_ERROR_NONE) {
return ret;
}
return MPOOL_ERROR_NONE;
}
/*
* static void *get_space
*
* DESCRIPTION:
*
* Moved a pointer into our free lists.
*
* RETURNS:
*
* Success - New address that we can use.
*
* Failure - NULL
*
* ARGUMENTS:
*
* mp_p <-> Pointer to the memory pool.
*
* byte_size -> Size of the address space that we need.
*
* error_p <- Pointer to integer which, if not NULL, will be set with
* a mpool error code.
*/
static void *get_space(mpool_t *mp_p, const unsigned long byte_size,
int *error_p)
{
mpool_block_t *block_p;
mpool_free_t free_pnt;
int ret;
unsigned long size;
unsigned int bit_c, page_n, left;
void *free_addr = NULL, *free_end;
size = byte_size;
while ((size & (sizeof(void *) - 1)) > 0) {
size++;
}
/*
* First we check the free lists looking for something with enough
* pages. Maybe we should only look X bits higher in the list.
*
* XXX: this is where we'd do the best fit. We'd look for the
* closest match. We then could put the rest of the allocation that
* we did not use in a lower free list. Have a define which states
* how deep in the free list to go to find the closest match.
*/
for (bit_c = size_to_bits(size); bit_c <= MAX_BITS; bit_c++) {
if (mp_p->mp_free[bit_c] != NULL) {
free_addr = mp_p->mp_free[bit_c];
break;
}
}
/*
* If we haven't allocated any blocks or if the last block doesn't
* have enough memory then we need a new block.
*/
if (bit_c > MAX_BITS) {
/* we need to allocate more space */
page_n = PAGES_IN_SIZE(mp_p, size);
/* now we try and get the pages we need/want */
block_p = alloc_pages(mp_p, page_n, error_p);
if (block_p == NULL) {
/* error_p set in alloc_pages */
return NULL;
}
/* init the block header */
block_p->mb_magic = BLOCK_MAGIC;
block_p->mb_bounds_p = (char *)block_p + SIZE_OF_PAGES(mp_p, page_n);
block_p->mb_next_p = mp_p->mp_first_p;
block_p->mb_magic2 = BLOCK_MAGIC;
/*
* We insert it into the front of the queue. We could add it to
* the end but there is not much use.
*/
mp_p->mp_first_p = block_p;
if (mp_p->mp_last_p == NULL) {
mp_p->mp_last_p = block_p;
}
free_addr = FIRST_ADDR_IN_BLOCK(block_p);
#ifdef DEBUG
(void)printf("had to allocate space for %lx of %lu bytes\n",
(long)free_addr, size);
#endif
free_end = (char *)free_addr + size;
left = (char *)block_p->mb_bounds_p - (char *)free_end;
}
else {
if (bit_c < min_bit_free_next) {
mp_p->mp_free[bit_c] = NULL;
/* calculate the number of left over bytes */
left = bits_to_size(bit_c) - size;
}
else if (bit_c < min_bit_free_next) {
/* grab the next pointer from the freed address into our list */
memcpy(mp_p->mp_free + bit_c, free_addr, sizeof(void *));
/* calculate the number of left over bytes */
left = bits_to_size(bit_c) - size;
}
else {
/* grab the free structure from the address */
memcpy(&free_pnt, free_addr, sizeof(free_pnt));
mp_p->mp_free[bit_c] = free_pnt.mf_next_p;
/* are we are splitting up a multiblock chunk into fewer blocks? */
if (PAGES_IN_SIZE(mp_p, free_pnt.mf_size) > PAGES_IN_SIZE(mp_p, size)) {
ret = split_block(mp_p, free_addr, size);
if (ret != MPOOL_ERROR_NONE) {
SET_POINTER(error_p, ret);
return NULL;
}
/* left over memory was taken care of in split_block */
left = 0;
}
else {
/* calculate the number of left over bytes */
left = free_pnt.mf_size - size;
}
}
#ifdef DEBUG
(void)printf("found a free block at %lx of %lu bytes\n",
(long)free_addr, left + size);
#endif
free_end = (char *)free_addr + size;
}
/*
* If we have memory left over then we free it so someone else can
* use it. We do not free the space if we just allocated a
* multi-block chunk because we need to have every allocation easily
* find the start of the block. Every user address % page-size
* should take us to the start of the block.
*/
if (left > 0 && size <= MAX_BLOCK_USER_MEMORY(mp_p)) {
/* free the rest of the block */
ret = free_pointer(mp_p, free_end, left);
if (ret != MPOOL_ERROR_NONE) {
SET_POINTER(error_p, ret);
return NULL;
}
}
/* update our bounds */
if (free_addr > mp_p->mp_bounds_p) {
mp_p->mp_bounds_p = free_addr;
}
else if (free_addr < mp_p->mp_min_p) {
mp_p->mp_min_p = free_addr;
}
return free_addr;
}
/*
* static void *alloc_mem
*
* DESCRIPTION:
*
* Allocate space for bytes inside of an already open memory pool.
*
* RETURNS:
*
* Success - Pointer to the address to use.
*
* Failure - NULL
*
* ARGUMENTS:
*
* mp_p <-> Pointer to the memory pool. If NULL then it will do a
* normal malloc.
*
* byte_size -> Number of bytes to allocate in the pool. Must be >0.
*
* error_p <- Pointer to integer which, if not NULL, will be set with
* a mpool error code.
*/
static void *alloc_mem(mpool_t *mp_p, const unsigned long byte_size,
int *error_p)
{
unsigned long size, fence;
void *addr;
/* make sure we have enough bytes */
if (byte_size < MIN_ALLOCATION) {
size = MIN_ALLOCATION;
}
else {
size = byte_size;
}
if (BIT_IS_SET(mp_p->mp_flags, MPOOL_FLAG_NO_FREE)) {
fence = 0;
}
else {
fence = FENCE_SIZE;
}
/* get our free space + the space for the fence post */
addr = get_space(mp_p, size + fence, error_p);
if (addr == NULL) {
/* error_p set in get_space */
return NULL;
}
if (! BIT_IS_SET(mp_p->mp_flags, MPOOL_FLAG_NO_FREE)) {
write_magic((char *)addr + size);
}
/* maintain our stats */
mp_p->mp_alloc_c++;
mp_p->mp_user_alloc += size;
if (mp_p->mp_user_alloc > mp_p->mp_max_alloc) {
mp_p->mp_max_alloc = mp_p->mp_user_alloc;
}
SET_POINTER(error_p, MPOOL_ERROR_NONE);
return addr;
}
/*
* static int free_mem
*
* DESCRIPTION:
*
* Free an address from a memory pool.
*
* RETURNS:
*
* Success - MPOOL_ERROR_NONE
*
* Failure - Mpool error code
*
* ARGUMENTS:
*
* mp_p <-> Pointer to the memory pool. If NULL then it will do a
* normal free.
*
* addr <-> Address to free.
*
* size -> Size of the address being freed.
*/
static int free_mem(mpool_t *mp_p, void *addr, const unsigned long size)
{
unsigned long old_size, fence;
int ret;
mpool_block_t *block_p;
/*
* If the size is larger than a block then the allocation must be at
* the front of the block.
*/
if (size > MAX_BLOCK_USER_MEMORY(mp_p)) {
block_p = (mpool_block_t *)((char *)addr - sizeof(mpool_block_t));
if (block_p->mb_magic != BLOCK_MAGIC
|| block_p->mb_magic2 != BLOCK_MAGIC) {
return MPOOL_ERROR_POOL_OVER;
}
}
/* make sure we have enough bytes */
if (size < MIN_ALLOCATION) {
old_size = MIN_ALLOCATION;
}
else {
old_size = size;
}
/* if we are packing the pool smaller */
if (BIT_IS_SET(mp_p->mp_flags, MPOOL_FLAG_NO_FREE)) {
fence = 0;
}
else {
/* find the user's magic numbers if they were written */
ret = check_magic(addr, old_size);
if (ret != MPOOL_ERROR_NONE) {
return ret;
}
fence = FENCE_SIZE;
}
/* now we free the pointer */
ret = free_pointer(mp_p, addr, old_size + fence);
if (ret != MPOOL_ERROR_NONE) {
return ret;
}
mp_p->mp_user_alloc -= old_size;
/* adjust our stats */
mp_p->mp_alloc_c--;
return MPOOL_ERROR_NONE;
}
/***************************** exported routines *****************************/
/*
* mpool_t *mpool_open
*
* DESCRIPTION:
*
* Open/allocate a new memory pool.
*
* RETURNS:
*
* Success - Pool pointer which must be passed to mpool_close to
* deallocate.
*
* Failure - NULL
*
* ARGUMENTS:
*
* flags -> Flags to set attributes of the memory pool. See the top
* of mpool.h.
*
* page_size -> Set the internal memory page-size. This must be a
* multiple of the getpagesize() value. Set to 0 for the default.
*
* start_addr -> Starting address to try and allocate memory pools.
* This is ignored if the MPOOL_FLAG_USE_SBRK is enabled.
*
* error_p <- Pointer to integer which, if not NULL, will be set with
* a mpool error code.
*/
mpool_t *mpool_open(const unsigned int flags, const unsigned int page_size,
void *start_addr, int *error_p)
{
mpool_block_t *block_p;
int page_n, ret;
mpool_t mp, *mp_p;
void *free_addr;
if (! enabled_b) {
startup();
}
/* zero our temp struct */
memset(&mp, 0, sizeof(mp));
mp.mp_magic = MPOOL_MAGIC;
mp.mp_flags = flags;
mp.mp_alloc_c = 0;
mp.mp_user_alloc = 0;
mp.mp_max_alloc = 0;
mp.mp_page_c = 0;
/* mp.mp_page_size set below */
/* mp.mp_blocks_bit_n set below */
/* mp.mp_fd set below */
/* mp.mp_top set below */
/* mp.mp_addr set below */
mp.mp_log_func = NULL;
mp.mp_min_p = NULL;
mp.mp_bounds_p = NULL;
mp.mp_first_p = NULL;
mp.mp_last_p = NULL;
mp.mp_magic2 = MPOOL_MAGIC;
/* get and sanity check our page size */
if (page_size > 0) {
mp.mp_page_size = page_size;
if (mp.mp_page_size % getpagesize() != 0) {
SET_POINTER(error_p, MPOOL_ERROR_ARG_INVALID);
return NULL;
}
}
else {
mp.mp_page_size = getpagesize() * DEFAULT_PAGE_MULT;
if (mp.mp_page_size % 1024 != 0) {
SET_POINTER(error_p, MPOOL_ERROR_PAGE_SIZE);
return NULL;
}
}
if (BIT_IS_SET(flags, MPOOL_FLAG_USE_SBRK)) {
mp.mp_fd = -1;
mp.mp_addr = NULL;
mp.mp_top = 0;
}
else {
/* open dev-zero for our mmaping */
mp.mp_fd = open("/dev/zero", O_RDWR, 0);
if (mp.mp_fd < 0) {
SET_POINTER(error_p, MPOOL_ERROR_OPEN_ZERO);
return NULL;
}
mp.mp_addr = start_addr;
/* we start at the front of the file */
mp.mp_top = 0;
}
/*
* Find out how many pages we need for our mpool structure.
*
* NOTE: this adds possibly unneeded space for mpool_block_t which
* may not be in this block.
*/
page_n = PAGES_IN_SIZE(&mp, sizeof(mpool_t));
/* now allocate us space for the actual struct */
mp_p = alloc_pages(&mp, page_n, error_p);
if (mp_p == NULL) {
if (mp.mp_fd >= 0) {
(void)close(mp.mp_fd);
mp.mp_fd = -1;
}
return NULL;
}
/*
* NOTE: we do not normally free the rest of the block here because
* we want to lesson the chance of an allocation overwriting the
* main structure.
*/
if (BIT_IS_SET(flags, MPOOL_FLAG_HEAVY_PACKING)) {
/* we add a block header to the front of the block */
block_p = (mpool_block_t *)mp_p;
/* init the block header */
block_p->mb_magic = BLOCK_MAGIC;
block_p->mb_bounds_p = (char *)block_p + SIZE_OF_PAGES(&mp, page_n);
block_p->mb_next_p = NULL;
block_p->mb_magic2 = BLOCK_MAGIC;
/* the mpool pointer is then the 2nd thing in the block */
mp_p = FIRST_ADDR_IN_BLOCK(block_p);
free_addr = (char *)mp_p + sizeof(mpool_t);
/* free the rest of the block */
ret = free_pointer(&mp, free_addr,
(char *)block_p->mb_bounds_p - (char *)free_addr);
if (ret != MPOOL_ERROR_NONE) {
if (mp.mp_fd >= 0) {
(void)close(mp.mp_fd);
mp.mp_fd = -1;
}
/* NOTE: after this line mp_p will be invalid */
(void)free_pages(block_p, SIZE_OF_PAGES(&mp, page_n),
BIT_IS_SET(flags, MPOOL_FLAG_USE_SBRK));
SET_POINTER(error_p, ret);
return NULL;
}
/*
* NOTE: if we are HEAVY_PACKING then the 1st block with the mpool
* header is not on the block linked list.
*/
/* now copy our tmp structure into our new memory area */
memcpy(mp_p, &mp, sizeof(mpool_t));
/* we setup min/max to our current address which is as good as any */
mp_p->mp_min_p = block_p;
mp_p->mp_bounds_p = block_p->mb_bounds_p;
}
else {
/* now copy our tmp structure into our new memory area */
memcpy(mp_p, &mp, sizeof(mpool_t));
/* we setup min/max to our current address which is as good as any */
mp_p->mp_min_p = mp_p;
mp_p->mp_bounds_p = (char *)mp_p + SIZE_OF_PAGES(mp_p, page_n);
}
SET_POINTER(error_p, MPOOL_ERROR_NONE);
return mp_p;
}
/*
* int mpool_close
*
* DESCRIPTION:
*
* Close/free a memory allocation pool previously opened with
* mpool_open.
*
* RETURNS:
*
* Success - MPOOL_ERROR_NONE
*
* Failure - Mpool error code
*
* ARGUMENTS:
*
* mp_p <-> Pointer to our memory pool.
*/
int mpool_close(mpool_t *mp_p)
{
mpool_block_t *block_p, *next_p;
void *addr;
unsigned long size;
int ret, final = MPOOL_ERROR_NONE;
/* special case, just return no-error */
if (mp_p == NULL) {
return MPOOL_ERROR_ARG_NULL;
}
if (mp_p->mp_magic != MPOOL_MAGIC) {
return MPOOL_ERROR_PNT;
}
if (mp_p->mp_magic2 != MPOOL_MAGIC) {
return MPOOL_ERROR_POOL_OVER;
}
if (mp_p->mp_log_func != NULL) {
mp_p->mp_log_func(mp_p, MPOOL_FUNC_CLOSE, 0, 0, NULL, NULL, 0);
}
/*
* NOTE: if we are HEAVY_PACKING then the 1st block with the mpool
* header is not on the linked list.
*/
/* free/invalidate the blocks */
for (block_p = mp_p->mp_first_p; block_p != NULL; block_p = next_p) {
if (block_p->mb_magic != BLOCK_MAGIC
|| block_p->mb_magic2 != BLOCK_MAGIC) {
final = MPOOL_ERROR_POOL_OVER;
break;
}
block_p->mb_magic = 0;
block_p->mb_magic2 = 0;
/* record the next pointer because it might be invalidated below */
next_p = block_p->mb_next_p;
ret = free_pages(block_p, (char *)block_p->mb_bounds_p - (char *)block_p,
BIT_IS_SET(mp_p->mp_flags, MPOOL_FLAG_USE_SBRK));
if (ret != MPOOL_ERROR_NONE) {
final = ret;
}
}
/* close /dev/zero if necessary */
if (mp_p->mp_fd >= 0) {
(void)close(mp_p->mp_fd);
mp_p->mp_fd = -1;
}
/* invalidate the mpool before we ditch it */
mp_p->mp_magic = 0;
mp_p->mp_magic2 = 0;
/* last we munmap the mpool pointer itself */
if (! BIT_IS_SET(mp_p->mp_flags, MPOOL_FLAG_USE_SBRK)) {
/* if we are heavy packing then we need to free the 1st block later */
if (BIT_IS_SET(mp_p->mp_flags, MPOOL_FLAG_HEAVY_PACKING)) {
addr = (char *)mp_p - sizeof(mpool_block_t);
}
else {
addr = mp_p;
}
size = SIZE_OF_PAGES(mp_p, PAGES_IN_SIZE(mp_p, sizeof(mpool_t)));
(void)munmap((caddr_t)addr, size);
}
return final;
}
/*
* int mpool_clear
*
* DESCRIPTION:
*
* Wipe an opened memory pool clean so we can start again.
*
* RETURNS:
*
* Success - MPOOL_ERROR_NONE
*
* Failure - Mpool error code
*
* ARGUMENTS:
*
* mp_p <-> Pointer to our memory pool.
*/
int mpool_clear(mpool_t *mp_p)
{
mpool_block_t *block_p;
int final = MPOOL_ERROR_NONE, bit_n, ret;
void *first_p;
/* special case, just return no-error */
if (mp_p == NULL) {
return MPOOL_ERROR_ARG_NULL;
}
if (mp_p->mp_magic != MPOOL_MAGIC) {
return MPOOL_ERROR_PNT;
}
if (mp_p->mp_magic2 != MPOOL_MAGIC) {
return MPOOL_ERROR_POOL_OVER;
}
if (mp_p->mp_log_func != NULL) {
mp_p->mp_log_func(mp_p, MPOOL_FUNC_CLEAR, 0, 0, NULL, NULL, 0);
}
/* reset all of our free lists */
for (bit_n = 0; bit_n <= MAX_BITS; bit_n++) {
mp_p->mp_free[bit_n] = NULL;
}
/* free the blocks */
for (block_p = mp_p->mp_first_p;
block_p != NULL;
block_p = block_p->mb_next_p) {
if (block_p->mb_magic != BLOCK_MAGIC
|| block_p->mb_magic2 != BLOCK_MAGIC) {
final = MPOOL_ERROR_POOL_OVER;
break;
}
first_p = FIRST_ADDR_IN_BLOCK(block_p);
/* free the memory */
ret = free_pointer(mp_p, first_p, MEMORY_IN_BLOCK(block_p));
if (ret != MPOOL_ERROR_NONE) {
final = ret;
}
}
return final;
}
/*
* void *mpool_alloc
*
* DESCRIPTION:
*
* Allocate space for bytes inside of an already open memory pool.
*
* RETURNS:
*
* Success - Pointer to the address to use.
*
* Failure - NULL
*
* ARGUMENTS:
*
* mp_p <-> Pointer to the memory pool. If NULL then it will do a
* normal malloc.
*
* byte_size -> Number of bytes to allocate in the pool. Must be >0.
*
* error_p <- Pointer to integer which, if not NULL, will be set with
* a mpool error code.
*/
void *mpool_alloc(mpool_t *mp_p, const unsigned long byte_size,
int *error_p)
{
void *addr;
if (mp_p == NULL) {
/* special case -- do a normal malloc */
addr = (void *)malloc(byte_size);
if (addr == NULL) {
SET_POINTER(error_p, MPOOL_ERROR_ALLOC);
return NULL;
}
else {
SET_POINTER(error_p, MPOOL_ERROR_NONE);
return addr;
}
}
if (mp_p->mp_magic != MPOOL_MAGIC) {
SET_POINTER(error_p, MPOOL_ERROR_PNT);
return NULL;
}
if (mp_p->mp_magic2 != MPOOL_MAGIC) {
SET_POINTER(error_p, MPOOL_ERROR_POOL_OVER);
return NULL;
}
if (byte_size == 0) {
SET_POINTER(error_p, MPOOL_ERROR_ARG_INVALID);
return NULL;
}
addr = alloc_mem(mp_p, byte_size, error_p);
if (mp_p->mp_log_func != NULL) {
mp_p->mp_log_func(mp_p, MPOOL_FUNC_ALLOC, byte_size, 0, addr, NULL, 0);
}
return addr;
}
/*
* void *mpool_calloc
*
* DESCRIPTION:
*
* Allocate space for elements of bytes in the memory pool and zero
* the space afterwards.
*
* RETURNS:
*
* Success - Pointer to the address to use.
*
* Failure - NULL
*
* ARGUMENTS:
*
* mp_p <-> Pointer to the memory pool. If NULL then it will do a
* normal calloc.
*
* ele_n -> Number of elements to allocate.
*
* ele_size -> Number of bytes per element being allocated.
*
* error_p <- Pointer to integer which, if not NULL, will be set with
* a mpool error code.
*/
void *mpool_calloc(mpool_t *mp_p, const unsigned long ele_n,
const unsigned long ele_size, int *error_p)
{
void *addr;
unsigned long byte_size;
if (mp_p == NULL) {
/* special case -- do a normal calloc */
addr = (void *)calloc(ele_n, ele_size);
if (addr == NULL) {
SET_POINTER(error_p, MPOOL_ERROR_ALLOC);
return NULL;
}
else {
SET_POINTER(error_p, MPOOL_ERROR_NONE);
return addr;
}
}
if (mp_p->mp_magic != MPOOL_MAGIC) {
SET_POINTER(error_p, MPOOL_ERROR_PNT);
return NULL;
}
if (mp_p->mp_magic2 != MPOOL_MAGIC) {
SET_POINTER(error_p, MPOOL_ERROR_POOL_OVER);
return NULL;
}
if (ele_n == 0 || ele_size == 0) {
SET_POINTER(error_p, MPOOL_ERROR_ARG_INVALID);
return NULL;
}
byte_size = ele_n * ele_size;
addr = alloc_mem(mp_p, byte_size, error_p);
if (addr != NULL) {
memset(addr, 0, byte_size);
}
if (mp_p->mp_log_func != NULL) {
mp_p->mp_log_func(mp_p, MPOOL_FUNC_CALLOC, ele_size, ele_n, addr, NULL, 0);
}
/* NOTE: error_p set above */
return addr;
}
/*
* int mpool_free
*
* DESCRIPTION:
*
* Free an address from a memory pool.
*
* RETURNS:
*
* Success - MPOOL_ERROR_NONE
*
* Failure - Mpool error code
*
* ARGUMENTS:
*
* mp_p <-> Pointer to the memory pool. If NULL then it will do a
* normal free.
*
* addr <-> Address to free.
*
* size -> Size of the address being freed.
*/
int mpool_free(mpool_t *mp_p, void *addr, const unsigned long size)
{
if (mp_p == NULL) {
/* special case -- do a normal free */
free(addr);
return MPOOL_ERROR_NONE;
}
if (mp_p->mp_magic != MPOOL_MAGIC) {
return MPOOL_ERROR_PNT;
}
if (mp_p->mp_magic2 != MPOOL_MAGIC) {
return MPOOL_ERROR_POOL_OVER;
}
if (mp_p->mp_log_func != NULL) {
mp_p->mp_log_func(mp_p, MPOOL_FUNC_FREE, size, 0, NULL, addr, 0);
}
if (addr == NULL) {
return MPOOL_ERROR_ARG_NULL;
}
if (size == 0) {
return MPOOL_ERROR_ARG_INVALID;
}
return free_mem(mp_p, addr, size);
}
/*
* void *mpool_resize
*
* DESCRIPTION:
*
* Reallocate an address in a mmeory pool to a new size. This is
* different from realloc in that it needs the old address' size. If
* you don't have it then you need to allocate new space, copy the
* data, and free the old pointer yourself.
*
* RETURNS:
*
* Success - Pointer to the address to use.
*
* Failure - NULL
*
* ARGUMENTS:
*
* mp_p <-> Pointer to the memory pool. If NULL then it will do a
* normal realloc.
*
* old_addr -> Previously allocated address.
*
* old_byte_size -> Size of the old address. Must be known, cannot be
* 0.
*
* new_byte_size -> New size of the allocation.
*
* error_p <- Pointer to integer which, if not NULL, will be set with
* a mpool error code.
*/
void *mpool_resize(mpool_t *mp_p, void *old_addr,
const unsigned long old_byte_size,
const unsigned long new_byte_size,
int *error_p)
{
unsigned long copy_size, new_size, old_size, fence;
void *new_addr;
mpool_block_t *block_p;
int ret;
if (mp_p == NULL) {
/* special case -- do a normal realloc */
new_addr = (void *)realloc(old_addr, new_byte_size);
if (new_addr == NULL) {
SET_POINTER(error_p, MPOOL_ERROR_ALLOC);
return NULL;
}
else {
SET_POINTER(error_p, MPOOL_ERROR_NONE);
return new_addr;
}
}
if (mp_p->mp_magic != MPOOL_MAGIC) {
SET_POINTER(error_p, MPOOL_ERROR_PNT);
return NULL;
}
if (mp_p->mp_magic2 != MPOOL_MAGIC) {
SET_POINTER(error_p, MPOOL_ERROR_POOL_OVER);
return NULL;
}
if (old_addr == NULL) {
SET_POINTER(error_p, MPOOL_ERROR_ARG_NULL);
return NULL;
}
if (old_byte_size == 0) {
SET_POINTER(error_p, MPOOL_ERROR_ARG_INVALID);
return NULL;
}
/*
* If the size is larger than a block then the allocation must be at
* the front of the block.
*/
if (old_byte_size > MAX_BLOCK_USER_MEMORY(mp_p)) {
block_p = (mpool_block_t *)((char *)old_addr - sizeof(mpool_block_t));
if (block_p->mb_magic != BLOCK_MAGIC
|| block_p->mb_magic2 != BLOCK_MAGIC) {
SET_POINTER(error_p, MPOOL_ERROR_POOL_OVER);
return NULL;
}
}
/* make sure we have enough bytes */
if (old_byte_size < MIN_ALLOCATION) {
old_size = MIN_ALLOCATION;
}
else {
old_size = old_byte_size;
}
/* verify that the size matches exactly if we can */
if (BIT_IS_SET(mp_p->mp_flags, MPOOL_FLAG_NO_FREE)) {
fence = 0;
}
else if (old_size > 0) {
ret = check_magic(old_addr, old_size);
if (ret != MPOOL_ERROR_NONE) {
SET_POINTER(error_p, ret);
return NULL;
}
fence = FENCE_SIZE;
}
/* make sure we have enough bytes */
if (new_byte_size < MIN_ALLOCATION) {
new_size = MIN_ALLOCATION;
}
else {
new_size = new_byte_size;
}
/*
* NOTE: we could here see if the size is the same or less and then
* use the current memory and free the space above. This is harder
* than it sounds if we are changing the block size of the
* allocation.
*/
/* we need to get another address */
new_addr = alloc_mem(mp_p, new_byte_size, error_p);
if (new_addr == NULL) {
/* error_p set in mpool_alloc */
return NULL;
}
if (new_byte_size > old_byte_size) {
copy_size = old_byte_size;
}
else {
copy_size = new_byte_size;
}
memcpy(new_addr, old_addr, copy_size);
/* free the old address */
ret = free_mem(mp_p, old_addr, old_byte_size);
if (ret != MPOOL_ERROR_NONE) {
/* if the old free failed, try and free the new address */
(void)free_mem(mp_p, new_addr, new_byte_size);
SET_POINTER(error_p, ret);
return NULL;
}
if (mp_p->mp_log_func != NULL) {
mp_p->mp_log_func(mp_p, MPOOL_FUNC_RESIZE, new_byte_size,
0, new_addr, old_addr, old_byte_size);
}
SET_POINTER(error_p, MPOOL_ERROR_NONE);
return new_addr;
}
/*
* int mpool_stats
*
* DESCRIPTION:
*
* Return stats from the memory pool.
*
* RETURNS:
*
* Success - MPOOL_ERROR_NONE
*
* Failure - Mpool error code
*
* ARGUMENTS:
*
* mp_p -> Pointer to the memory pool.
*
* page_size_p <- Pointer to an unsigned integer which, if not NULL,
* will be set to the page-size of the pool.
*
* num_alloced_p <- Pointer to an unsigned long which, if not NULL,
* will be set to the number of pointers currently allocated in pool.
*
* user_alloced_p <- Pointer to an unsigned long which, if not NULL,
* will be set to the number of user bytes allocated in this pool.
*
* max_alloced_p <- Pointer to an unsigned long which, if not NULL,
* will be set to the maximum number of user bytes that have been
* allocated in this pool.
*
* tot_alloced_p <- Pointer to an unsigned long which, if not NULL,
* will be set to the total amount of space (including administrative
* overhead) used by the pool.
*/
int mpool_stats(const mpool_t *mp_p, unsigned int *page_size_p,
unsigned long *num_alloced_p,
unsigned long *user_alloced_p,
unsigned long *max_alloced_p,
unsigned long *tot_alloced_p)
{
if (mp_p == NULL) {
return MPOOL_ERROR_ARG_NULL;
}
if (mp_p->mp_magic != MPOOL_MAGIC) {
return MPOOL_ERROR_PNT;
}
if (mp_p->mp_magic2 != MPOOL_MAGIC) {
return MPOOL_ERROR_POOL_OVER;
}
SET_POINTER(page_size_p, mp_p->mp_page_size);
SET_POINTER(num_alloced_p, mp_p->mp_alloc_c);
SET_POINTER(user_alloced_p, mp_p->mp_user_alloc);
SET_POINTER(max_alloced_p, mp_p->mp_max_alloc);
SET_POINTER(tot_alloced_p, SIZE_OF_PAGES(mp_p, mp_p->mp_page_c));
return MPOOL_ERROR_NONE;
}
/*
* int mpool_set_log_func
*
* DESCRIPTION:
*
* Set a logging callback function to be called whenever there was a
* memory transaction. See mpool_log_func_t.
*
* RETURNS:
*
* Success - MPOOL_ERROR_NONE
*
* Failure - Mpool error code
*
* ARGUMENTS:
*
* mp_p <-> Pointer to the memory pool.
*
* log_func -> Log function (defined in mpool.h) which will be called
* with each mpool transaction.
*/
int mpool_set_log_func(mpool_t *mp_p, mpool_log_func_t log_func)
{
if (mp_p == NULL) {
return MPOOL_ERROR_ARG_NULL;
}
if (mp_p->mp_magic != MPOOL_MAGIC) {
return MPOOL_ERROR_PNT;
}
if (mp_p->mp_magic2 != MPOOL_MAGIC) {
return MPOOL_ERROR_POOL_OVER;
}
mp_p->mp_log_func = log_func;
return MPOOL_ERROR_NONE;
}
/*
* int mpool_set_max_pages
*
* DESCRIPTION:
*
* Set the maximum number of pages that the library will use. Once it
* hits the limit it will return MPOOL_ERROR_NO_PAGES.
*
* NOTE: if the MPOOL_FLAG_HEAVY_PACKING is set then this max-pages
* value will include the page with the mpool header structure in it.
* If the flag is _not_ set then the max-pages will not include this
* first page.
*
* RETURNS:
*
* Success - MPOOL_ERROR_NONE
*
* Failure - Mpool error code
*
* ARGUMENTS:
*
* mp_p <-> Pointer to the memory pool.
*
* max_pages -> Maximum number of pages used by the library.
*/
int mpool_set_max_pages(mpool_t *mp_p, const unsigned int max_pages)
{
if (mp_p == NULL) {
return MPOOL_ERROR_ARG_NULL;
}
if (mp_p->mp_magic != MPOOL_MAGIC) {
return MPOOL_ERROR_PNT;
}
if (mp_p->mp_magic2 != MPOOL_MAGIC) {
return MPOOL_ERROR_POOL_OVER;
}
if (BIT_IS_SET(mp_p->mp_flags, MPOOL_FLAG_HEAVY_PACKING)) {
mp_p->mp_max_pages = max_pages;
}
else {
/*
* If we are not heavy-packing the pool then we don't count the
* 1st page allocated which holds the mpool header structure.
*/
mp_p->mp_max_pages = max_pages + 1;
}
return MPOOL_ERROR_NONE;
}
/*
* const char *mpool_strerror
*
* DESCRIPTION:
*
* Return the corresponding string for the error number.
*
* RETURNS:
*
* Success - String equivalient of the error.
*
* Failure - String "invalid error code"
*
* ARGUMENTS:
*
* error -> Error number that we are converting.
*/
const char *mpool_strerror(const int error)
{
switch (error) {
case MPOOL_ERROR_NONE:
return "no error";
break;
case MPOOL_ERROR_ARG_NULL:
return "function argument is null";
break;
case MPOOL_ERROR_ARG_INVALID:
return "function argument is invalid";
break;
case MPOOL_ERROR_PNT:
return "invalid mpool pointer";
break;
case MPOOL_ERROR_POOL_OVER:
return "mpool structure was overwritten";
break;
case MPOOL_ERROR_PAGE_SIZE:
return "could not get system page-size";
break;
case MPOOL_ERROR_OPEN_ZERO:
return "could not open /dev/zero";
break;
case MPOOL_ERROR_NO_MEM:
return "no memory available";
break;
case MPOOL_ERROR_MMAP:
return "problems with mmap";
break;
case MPOOL_ERROR_SIZE:
return "error processing requested size";
break;
case MPOOL_ERROR_TOO_BIG:
return "allocation exceeds pool max size";
break;
case MPOOL_ERROR_MEM:
return "invalid memory address";
break;
case MPOOL_ERROR_MEM_OVER:
return "memory lower bounds overwritten";
break;
case MPOOL_ERROR_NOT_FOUND:
return "memory block not found in pool";
break;
case MPOOL_ERROR_IS_FREE:
return "memory address has already been freed";
break;
case MPOOL_ERROR_BLOCK_STAT:
return "invalid internal block status";
break;
case MPOOL_ERROR_FREE_ADDR:
return "invalid internal free address";
break;
case MPOOL_ERROR_SBRK_CONTIG:
return "sbrk did not return contiguous memory";
break;
case MPOOL_ERROR_NO_PAGES:
return "no available pages left in pool";
break;
case MPOOL_ERROR_ALLOC:
return "system alloc function failed";
break;
case MPOOL_ERROR_PNT_OVER:
return "user pointer admin space overwritten";
break;
default:
break;
}
return "invalid error code";
}
View Git Blame Copy Permalink