/* $NetBSD: memcluster.c,v 1.1.1.2 2012/09/09 16:08:02 christos Exp $ */ /* * Copyright (c) 2005 by Internet Systems Consortium, Inc. ("ISC") * 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 ISC DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC 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 */ #define MEMCLUSTER_ATEND #if !defined(LINT) && !defined(CODECENTER) static const char rcsid[] = "Id: memcluster.c,v 1.11 2006/08/30 23:34:38 marka 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 size_t 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; }; #ifdef DO_PTHREADS #include <pthread.h> static pthread_mutex_t memlock = PTHREAD_MUTEX_INITIALIZER; #define MEMLOCK (void)pthread_mutex_lock(&memlock) #define MEMUNLOCK (void)pthread_mutex_unlock(&memlock) #else /* * Catch bad lock usage in non threaded build. */ static unsigned int memlock = 0; #define MEMLOCK do { INSIST(memlock == 0); memlock = 1; } while (0) #define MEMUNLOCK do { INSIST(memlock == 1); memlock = 0; } while (0) #endif /* DO_PTHEADS */ /* Private data. */ static size_t max_size; static size_t mem_target; #ifndef MEMCLUSTER_BIG_MALLOC static size_t mem_target_half; static size_t mem_target_fudge; #endif 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 == 0U) max_size = DEF_MAX_SIZE; else max_size = init_max_size; if (target_size == 0U) mem_target = DEF_MEM_TARGET; else mem_target = target_size; #ifndef MEMCLUSTER_BIG_MALLOC mem_target_half = mem_target / 2; mem_target_fudge = mem_target + mem_target / 4; #endif 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; MEMLOCK; #if !defined(MEMCLUSTER_RECORD) UNUSED(file); UNUSED(line); #endif if (freelists == NULL) { if (meminit(0, 0) == -1) { MEMUNLOCK; return (NULL); } } if (size == 0U) { MEMUNLOCK; 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) { MEMUNLOCK; 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 MEMUNLOCK; e->fencepost = FRONT_FENCEPOST; p = (char *)e + sizeof *e + size; memcpy(p, &fp, sizeof fp); return ((char *)e + sizeof *e); #else MEMUNLOCK; 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) { MEMUNLOCK; 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) { MEMUNLOCK; 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--; MEMUNLOCK; #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; memcluster_element *el; #ifdef MEMCLUSTER_RECORD memcluster_element *prev; #endif fence_t fp; char *p; #endif MEMLOCK; #if !defined (MEMCLUSTER_RECORD) UNUSED(file); UNUSED(line); #endif REQUIRE(freelists != NULL); if (size == 0U) { MEMUNLOCK; 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(((u_long)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 != 0U); stats[max_size].gets--; MEMUNLOCK; 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 #ifdef MEMCLUSTER_ATEND e->next = NULL; el = freelists[new_size]; while (el != NULL && el->next != NULL) el = el->next; if (el) el->next = e; else freelists[new_size] = e; #else e->next = freelists[new_size]; freelists[new_size] = (void *)e; #endif #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 != 0U); stats[size].gets--; stats[new_size].freefrags++; MEMUNLOCK; } 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 MEMLOCK; if (freelists == NULL) { MEMUNLOCK; return; } for (i = 1; i <= max_size; i++) { const struct stats *s = &stats[i]; if (s->totalgets == 0U && s->gets == 0U) continue; fprintf(out, "%s%5lu: %11lu gets, %11lu rem", (i == max_size) ? ">=" : " ", (unsigned long)i, s->totalgets, s->gets); if (s->blocks != 0U) 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:%lu\n", e->file != NULL ? e->file : "<UNKNOWN>", e->line, (char *)e + sizeof *e, (u_long)e->size); e = e->next; } } #endif MEMUNLOCK; } int memactive(void) { size_t i; if (stats == NULL) return (0); for (i = 1; i <= max_size; i++) if (stats[i].gets != 0U) return (1); return (0); } /* 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) { size_t i; for (i = 0; i < len; i++) INSIST(a[i] == value); } #endif /*! \file */