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NetBSD/dist/bind/lib/isc/memcluster.c

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/* $NetBSD: memcluster.c,v 1.1.1.1 1999/11/20 18:54:11 veego Exp $ */
/*
* Copyright (c) 1997,1999 by Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
* SOFTWARE.
*/
/* When this symbol is defined allocations via memget are made slightly
bigger and some debugging info stuck before and after the region given
back to the caller. */
/* #define DEBUGGING_MEMCLUSTER */
#if !defined(LINT) && !defined(CODECENTER)
static const char rcsid[] = "Id: memcluster.c,v 8.19 1999/10/13 17:11:22 vixie Exp";
#endif /* not lint */
#include "port_before.h"
#include <sys/types.h>
#include <sys/uio.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <isc/memcluster.h>
#include <isc/assertions.h>
#include "port_after.h"
#ifdef MEMCLUSTER_RECORD
#ifndef DEBUGGING_MEMCLUSTER
#define DEBUGGING_MEMCLUSTER
#endif
#endif
#define DEF_MAX_SIZE 1100
#define DEF_MEM_TARGET 4096
typedef u_int32_t fence_t;
typedef struct {
void * next;
#if defined(DEBUGGING_MEMCLUSTER)
#if defined(MEMCLUSTER_RECORD)
const char * file;
int line;
#endif
int size;
fence_t fencepost;
#endif
} memcluster_element;
#define SMALL_SIZE_LIMIT sizeof(memcluster_element)
#define P_SIZE sizeof(void *)
#define FRONT_FENCEPOST 0xfebafeba
#define BACK_FENCEPOST 0xabefabef
#define FENCEPOST_SIZE 4
#ifndef MEMCLUSTER_LITTLE_MALLOC
#define MEMCLUSTER_BIG_MALLOC 1
#define NUM_BASIC_BLOCKS 64
#endif
struct stats {
u_long gets;
u_long totalgets;
u_long blocks;
u_long freefrags;
};
/* Private data. */
static size_t max_size;
static size_t mem_target;
static size_t mem_target_half;
static size_t mem_target_fudge;
static memcluster_element ** freelists;
#ifdef MEMCLUSTER_RECORD
static memcluster_element ** activelists;
#endif
#ifdef MEMCLUSTER_BIG_MALLOC
static memcluster_element * basic_blocks;
#endif
static struct stats * stats;
/* Forward. */
static size_t quantize(size_t);
#if defined(DEBUGGING_MEMCLUSTER)
static void check(unsigned char *, int, size_t);
#endif
/* Public. */
int
meminit(size_t init_max_size, size_t target_size) {
#if defined(DEBUGGING_MEMCLUSTER)
INSIST(sizeof(fence_t) == FENCEPOST_SIZE);
#endif
if (freelists != NULL) {
errno = EEXIST;
return (-1);
}
if (init_max_size == 0)
max_size = DEF_MAX_SIZE;
else
max_size = init_max_size;
if (target_size == 0)
mem_target = DEF_MEM_TARGET;
else
mem_target = target_size;
mem_target_half = mem_target / 2;
mem_target_fudge = mem_target + mem_target / 4;
freelists = malloc(max_size * sizeof (memcluster_element *));
stats = malloc((max_size+1) * sizeof (struct stats));
if (freelists == NULL || stats == NULL) {
errno = ENOMEM;
return (-1);
}
memset(freelists, 0,
max_size * sizeof (memcluster_element *));
memset(stats, 0, (max_size + 1) * sizeof (struct stats));
#ifdef MEMCLUSTER_RECORD
activelists = malloc((max_size + 1) * sizeof (memcluster_element *));
if (activelists == NULL) {
errno = ENOMEM;
return (-1);
}
memset(activelists, 0,
(max_size + 1) * sizeof (memcluster_element *));
#endif
#ifdef MEMCLUSTER_BIG_MALLOC
basic_blocks = NULL;
#endif
return (0);
}
void *
__memget(size_t size) {
return (__memget_record(size, NULL, 0));
}
void *
__memget_record(size_t size, const char *file, int line) {
size_t new_size = quantize(size);
#if defined(DEBUGGING_MEMCLUSTER)
memcluster_element *e;
char *p;
fence_t fp = BACK_FENCEPOST;
#endif
void *ret;
if (freelists == NULL)
if (meminit(0, 0) == -1)
return (NULL);
if (size == 0) {
errno = EINVAL;
return (NULL);
}
if (size >= max_size || new_size >= max_size) {
/* memget() was called on something beyond our upper limit. */
stats[max_size].gets++;
stats[max_size].totalgets++;
#if defined(DEBUGGING_MEMCLUSTER)
e = malloc(new_size);
if (e == NULL) {
errno = ENOMEM;
return (NULL);
}
e->next = NULL;
e->size = size;
#ifdef MEMCLUSTER_RECORD
e->file = file;
e->line = line;
e->next = activelists[max_size];
activelists[max_size] = e;
#endif
e->fencepost = FRONT_FENCEPOST;
p = (char *)e + sizeof *e + size;
memcpy(p, &fp, sizeof fp);
return ((char *)e + sizeof *e);
#else
return (malloc(size));
#endif
}
/*
* If there are no blocks in the free list for this size, get a chunk
* of memory and then break it up into "new_size"-sized blocks, adding
* them to the free list.
*/
if (freelists[new_size] == NULL) {
int i, frags;
size_t total_size;
void *new;
char *curr, *next;
#ifdef MEMCLUSTER_BIG_MALLOC
if (basic_blocks == NULL) {
new = malloc(NUM_BASIC_BLOCKS * mem_target);
if (new == NULL) {
errno = ENOMEM;
return (NULL);
}
curr = new;
next = curr + mem_target;
for (i = 0; i < (NUM_BASIC_BLOCKS - 1); i++) {
((memcluster_element *)curr)->next = next;
curr = next;
next += mem_target;
}
/*
* curr is now pointing at the last block in the
* array.
*/
((memcluster_element *)curr)->next = NULL;
basic_blocks = new;
}
total_size = mem_target;
new = basic_blocks;
basic_blocks = basic_blocks->next;
#else
if (new_size > mem_target_half)
total_size = mem_target_fudge;
else
total_size = mem_target;
new = malloc(total_size);
if (new == NULL) {
errno = ENOMEM;
return (NULL);
}
#endif
frags = total_size / new_size;
stats[new_size].blocks++;
stats[new_size].freefrags += frags;
/* Set up a linked-list of blocks of size "new_size". */
curr = new;
next = curr + new_size;
for (i = 0; i < (frags - 1); i++) {
#if defined (DEBUGGING_MEMCLUSTER)
memset(curr, 0xa5, new_size);
#endif
((memcluster_element *)curr)->next = next;
curr = next;
next += new_size;
}
/* curr is now pointing at the last block in the array. */
#if defined (DEBUGGING_MEMCLUSTER)
memset(curr, 0xa5, new_size);
#endif
((memcluster_element *)curr)->next = freelists[new_size];
freelists[new_size] = new;
}
/* The free list uses the "rounded-up" size "new_size". */
#if defined (DEBUGGING_MEMCLUSTER)
e = freelists[new_size];
ret = (char *)e + sizeof *e;
/*
* Check to see if this buffer has been written to while on free list.
*/
check(ret, 0xa5, new_size - sizeof *e);
/*
* Mark memory we are returning.
*/
memset(ret, 0xe5, size);
#else
ret = freelists[new_size];
#endif
freelists[new_size] = freelists[new_size]->next;
#if defined(DEBUGGING_MEMCLUSTER)
e->next = NULL;
e->size = size;
e->fencepost = FRONT_FENCEPOST;
#ifdef MEMCLUSTER_RECORD
e->file = file;
e->line = line;
e->next = activelists[size];
activelists[size] = e;
#endif
p = (char *)e + sizeof *e + size;
memcpy(p, &fp, sizeof fp);
#endif
/*
* The stats[] uses the _actual_ "size" requested by the
* caller, with the caveat (in the code above) that "size" >= the
* max. size (max_size) ends up getting recorded as a call to
* max_size.
*/
stats[size].gets++;
stats[size].totalgets++;
stats[new_size].freefrags--;
#if defined(DEBUGGING_MEMCLUSTER)
return ((char *)e + sizeof *e);
#else
return (ret);
#endif
}
/*
* This is a call from an external caller,
* so we want to count this as a user "put".
*/
void
__memput(void *mem, size_t size) {
__memput_record(mem, size, NULL, 0);
}
void
__memput_record(void *mem, size_t size, const char *file, int line) {
size_t new_size = quantize(size);
#if defined (DEBUGGING_MEMCLUSTER)
memcluster_element *e;
#ifdef MEMCLUSTER_RECORD
memcluster_element *prev, *el;
#endif
int fp;
char *p;
#endif
REQUIRE(freelists != NULL);
if (size == 0) {
errno = EINVAL;
return;
}
#if defined (DEBUGGING_MEMCLUSTER)
e = (memcluster_element *) ((char *)mem - sizeof *e);
INSIST(e->fencepost == FRONT_FENCEPOST);
INSIST(e->size == size);
p = (char *)e + sizeof *e + size;
memcpy(&fp, p, sizeof fp);
INSIST(fp == BACK_FENCEPOST);
INSIST(((int)mem % 4) == 0);
#ifdef MEMCLUSTER_RECORD
prev = NULL;
if (size == max_size || new_size >= max_size)
el = activelists[max_size];
else
el = activelists[size];
while (el != NULL && el != e) {
prev = el;
el = el->next;
}
INSIST(el != NULL); /* double free */
if (prev == NULL) {
if (size == max_size || new_size >= max_size)
activelists[max_size] = el->next;
else
activelists[size] = el->next;
} else
prev->next = el->next;
#endif
#endif
if (size == max_size || new_size >= max_size) {
/* memput() called on something beyond our upper limit */
#if defined(DEBUGGING_MEMCLUSTER)
free(e);
#else
free(mem);
#endif
INSIST(stats[max_size].gets != 0);
stats[max_size].gets--;
return;
}
/* The free list uses the "rounded-up" size "new_size": */
#if defined(DEBUGGING_MEMCLUSTER)
memset(mem, 0xa5, new_size - sizeof *e); /* catch write after free */
e->size = 0; /* catch double memput() */
#ifdef MEMCLUSTER_RECORD
e->file = file;
e->line = line;
#endif
e->next = freelists[new_size];
freelists[new_size] = (void *)e;
#else
((memcluster_element *)mem)->next = freelists[new_size];
freelists[new_size] = (memcluster_element *)mem;
#endif
/*
* The stats[] uses the _actual_ "size" requested by the
* caller, with the caveat (in the code above) that "size" >= the
* max. size (max_size) ends up getting recorded as a call to
* max_size.
*/
INSIST(stats[size].gets != 0);
stats[size].gets--;
stats[new_size].freefrags++;
}
void *
__memget_debug(size_t size, const char *file, int line) {
void *ptr;
ptr = __memget_record(size, file, line);
fprintf(stderr, "%s:%d: memget(%lu) -> %p\n", file, line,
(u_long)size, ptr);
return (ptr);
}
void
__memput_debug(void *ptr, size_t size, const char *file, int line) {
fprintf(stderr, "%s:%d: memput(%p, %lu)\n", file, line, ptr,
(u_long)size);
__memput_record(ptr, size, file, line);
}
/*
* Print the stats[] on the stream "out" with suitable formatting.
*/
void
memstats(FILE *out) {
size_t i;
#ifdef MEMCLUSTER_RECORD
memcluster_element *e;
#endif
if (freelists == NULL)
return;
for (i = 1; i <= max_size; i++) {
const struct stats *s = &stats[i];
if (s->totalgets == 0 && s->gets == 0)
continue;
fprintf(out, "%s%5d: %11lu gets, %11lu rem",
(i == max_size) ? ">=" : " ",
i, s->totalgets, s->gets);
if (s->blocks != 0)
fprintf(out, " (%lu bl, %lu ff)",
s->blocks, s->freefrags);
fputc('\n', out);
}
#ifdef MEMCLUSTER_RECORD
fprintf(out, "Active Memory:\n");
for (i = 1; i <= max_size; i++) {
if ((e = activelists[i]) != NULL)
while (e != NULL) {
fprintf(out, "%s:%d %#p:%d\n",
e->file != NULL ? e->file :
"<UNKNOWN>", e->line,
(char *)e + sizeof *e, e->size);
e = e->next;
}
}
#endif
}
/* Private. */
/*
* Round up size to a multiple of sizeof(void *). This guarantees that a
* block is at least sizeof void *, and that we won't violate alignment
* restrictions, both of which are needed to make lists of blocks.
*/
static size_t
quantize(size_t size) {
int remainder;
/*
* If there is no remainder for the integer division of
*
* (rightsize/P_SIZE)
*
* then we already have a good size; if not, then we need
* to round up the result in order to get a size big
* enough to satisfy the request _and_ aligned on P_SIZE boundaries.
*/
remainder = size % P_SIZE;
if (remainder != 0)
size += P_SIZE - remainder;
#if defined(DEBUGGING_MEMCLUSTER)
return (size + SMALL_SIZE_LIMIT + sizeof (int));
#else
return (size);
#endif
}
#if defined(DEBUGGING_MEMCLUSTER)
static void
check(unsigned char *a, int value, size_t len) {
int i;
for (i = 0; i < len; i++)
INSIST(a[i] == value);
}
#endif
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