unbound/util/alloc.h

/*
 * util/alloc.h - memory allocation service. 
 *
 * Copyright (c) 2007, NLnet Labs. All rights reserved.
 *
 * This software is open source.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * Neither the name of the NLNET LABS nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * \file
 *
 * This file contains memory allocation functions.
 *
 * The reasons for this service are:
 *	o Avoid locking costs of getting global lock to call malloc().
 *	o The packed rrset type needs to be kept on special freelists,
 *	  so that they are reused for other packet rrset allocations.
 *
 */

#ifndef UTIL_ALLOC_H
#define UTIL_ALLOC_H

#include "util/locks.h"
struct ub_packed_rrset_key;
struct regional;

/** The special type, packed rrset. Not allowed to be used for other memory */
typedef struct ub_packed_rrset_key alloc_special_type;
/** clean the special type. Pass pointer. */
#define alloc_special_clean(x) (x)->id = 0;
/** access next pointer. (in available spot). Pass pointer. */
#define alloc_special_next(x) ((alloc_special_type*)((x)->entry.overflow_next))
/** set next pointer. (in available spot). Pass pointers. */
#define alloc_set_special_next(x, y) \
	((x)->entry.overflow_next) = (struct lruhash_entry*)(y);

/** how many blocks to cache locally. */
#define ALLOC_SPECIAL_MAX 10

/**
 * Structure that provides allocation. Use one per thread.
 * The one on top has a NULL super pointer.
 */
struct alloc_cache {
	/** lock, only used for the super. */
	lock_quick_type lock;
	/** global allocator above this one. NULL for none (malloc/free) */
	struct alloc_cache* super;
	/** singly linked lists of special type. These are free for use. */
	alloc_special_type* quar;
	/** number of items in quarantine. */
	size_t num_quar;
	/** thread number for id creation */
	int thread_num;
	/** next id number to pass out */
	uint64_t next_id;
	/** last id number possible */
	uint64_t last_id;
	/** what function to call to cleanup when last id is reached */
	void (*cleanup)(void*);
	/** user arg for cleanup */
	void* cleanup_arg;

	/** how many regional blocks to keep back max */
	size_t max_reg_blocks;
	/** how many regional blocks are kept now */
	size_t num_reg_blocks;
	/** linked list of regional blocks, using regional->next */
	struct regional* reg_list;
};

/**
 * Init alloc (zeroes the struct).
 * @param alloc: this parameter is allocated by the caller.
 * @param super: super to use (init that before with super_init).
 *    Pass this argument NULL to init the toplevel alloc structure.
 * @param thread_num: thread number for id creation of special type.
 */
void alloc_init(struct alloc_cache* alloc, struct alloc_cache* super,
	int thread_num);

/**
 * Free the alloc. Pushes all the cached items into the super structure.
 * Or deletes them if alloc->super is NULL.
 * Does not free the alloc struct itself (it was also allocated by caller).
 * @param alloc: is almost zeroed on exit (except some stats).
 */
void alloc_clear(struct alloc_cache* alloc);

/**
 * Free the special alloced items.  The rrset and message caches must be
 * empty, there must be no more references to rrset pointers into the
 * rrset cache.
 * @param alloc: the special allocs are freed.
 */
void alloc_clear_special(struct alloc_cache* alloc);

/**
 * Get a new special_type element.
 * @param alloc: where to alloc it.
 * @return: memory block. Will not return NULL (instead fatal_exit).
 *    The block is zeroed.
 */
alloc_special_type* alloc_special_obtain(struct alloc_cache* alloc);

/**
 * Return special_type back to pool.
 * The block is cleaned up (zeroed) which also invalidates the ID inside.
 * @param alloc: where to alloc it.
 * @param mem: block to free.
 */
void alloc_special_release(struct alloc_cache* alloc, alloc_special_type* mem);

/**
 * Set ID number of special type to a fresh new ID number.
 * In case of ID number overflow, the rrset cache has to be cleared.
 * @param alloc: the alloc cache
 * @return: fresh id is returned.
 */
uint64_t alloc_get_id(struct alloc_cache* alloc);

/**
 * Get memory size of alloc cache, alloc structure including special types.
 * @param alloc: on what alloc.
 * @return size in bytes.
 */
size_t alloc_get_mem(struct alloc_cache* alloc);

/**
 * Print debug information (statistics).
 * @param alloc: on what alloc.
 */
void alloc_stats(struct alloc_cache* alloc);

/**
 * Get a new regional for query states
 * @param alloc: where to alloc it.
 * @return regional for use or NULL on alloc failure.
 */
struct regional* alloc_reg_obtain(struct alloc_cache* alloc);

/**
 * Put regional for query states back into alloc cache.
 * @param alloc: where to alloc it.
 * @param r: regional to put back.
 */
void alloc_reg_release(struct alloc_cache* alloc, struct regional* r);

/**
 * Set cleanup on ID overflow callback function. This should remove all
 * RRset ID references from the program. Clear the caches.
 * @param alloc: the alloc
 * @param cleanup: the callback function, called as cleanup(arg).
 * @param arg: user argument to callback function.
 */
void alloc_set_id_cleanup(struct alloc_cache* alloc, void (*cleanup)(void*),
	void* arg);

#ifdef UNBOUND_ALLOC_LITE
#  include <sldns/ldns.h>
#  include <sldns/packet.h>
#  ifdef HAVE_OPENSSL_SSL_H
#    include <openssl/ssl.h>
#  endif
#  define malloc(s) unbound_stat_malloc_lite(s, __FILE__, __LINE__, __func__)
#  define calloc(n,s) unbound_stat_calloc_lite(n, s, __FILE__, __LINE__, __func__)
#  define free(p) unbound_stat_free_lite(p, __FILE__, __LINE__, __func__)
#  define realloc(p,s) unbound_stat_realloc_lite(p, s, __FILE__, __LINE__, __func__)
void *unbound_stat_malloc_lite(size_t size, const char* file, int line,
	const char* func);
void *unbound_stat_calloc_lite(size_t nmemb, size_t size, const char* file,
	int line, const char* func);
void unbound_stat_free_lite(void *ptr, const char* file, int line,
	const char* func);
void *unbound_stat_realloc_lite(void *ptr, size_t size, const char* file,
	int line, const char* func);
#  ifdef strdup
#    undef strdup
#  endif
#  define strdup(s) unbound_strdup_lite(s, __FILE__, __LINE__, __func__)
char* unbound_strdup_lite(const char* s, const char* file, int line, 
	const char* func);
char* unbound_lite_wrapstr(char* s);
#  define sldns_rr2str(rr) unbound_lite_wrapstr(sldns_rr2str(rr))
#  define sldns_rdf2str(rdf) unbound_lite_wrapstr(sldns_rdf2str(rdf))
#  define sldns_rr_type2str(t) unbound_lite_wrapstr(sldns_rr_type2str(t))
#  define sldns_rr_class2str(c) unbound_lite_wrapstr(sldns_rr_class2str(c))
#  define sldns_rr_list2str(r) unbound_lite_wrapstr(sldns_rr_list2str(r))
#  define sldns_pkt2str(p) unbound_lite_wrapstr(sldns_pkt2str(p))
#  define sldns_pkt_rcode2str(r) unbound_lite_wrapstr(sldns_pkt_rcode2str(r))
#  define sldns_pkt2wire(a, r, s) unbound_lite_pkt2wire(a, r, s)
sldns_status unbound_lite_pkt2wire(uint8_t **dest, const sldns_pkt *p, size_t *size);
#  define i2d_DSA_SIG(d, s) unbound_lite_i2d_DSA_SIG(d, s)
int unbound_lite_i2d_DSA_SIG(DSA_SIG* dsasig, unsigned char** sig);
#endif /* UNBOUND_ALLOC_LITE */

#endif /* UTIL_ALLOC_H */