libratbox/src/balloc.c

/*
 *  ircd-ratbox: A slightly useful ircd.
 *  balloc.c: A block allocator.
 *
 * Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center
 * Copyright (C) 1996-2002 Hybrid Development Team
 * Copyright (C) 2002-2006 ircd-ratbox development team
 *
 *  Below are the orignal headers from the old blalloc.c
 *
 *  File:   blalloc.c
 *  Owner:  Wohali (Joan Touzet)
 *
 *  Modified 2001/11/29 for mmap() support by Aaron Sethman <androsyn@ratbox.org>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
 *  USA
 *
 */

/*
 * About the block allocator
 *
 * Basically we have three ways of getting memory off of the operating
 * system. Below are this list of methods and the order of preference.
 *
 * 1. mmap() anonymous pages with the MMAP_ANON flag.
 * 2. mmap() via the /dev/zero trick.
 * 3. HeapCreate/HeapAlloc (on win32)
 * 4. malloc()
 *
 * The advantages of 1 and 2 are this.  We can munmap() the pages which will
 * return the pages back to the operating system, thus reducing the size
 * of the process as the memory is unused.  malloc() on many systems just keeps
 * a heap of memory to itself, which never gets given back to the OS, except on
 * exit.  This of course is bad, if say we have an event that causes us to allocate
 * say, 200MB of memory, while our normal memory consumption would be 15MB.  In the
 * malloc() case, the amount of memory allocated to our process never goes down, as
 * malloc() has it locked up in its heap.  With the mmap() method, we can munmap()
 * the block and return it back to the OS, thus causing our memory consumption to go
 * down after we no longer need it.
 *
 *
 *
 */
#include <libratbox_config.h>
#include <ratbox_lib.h>

#ifndef NOBALLOC
#ifdef HAVE_MMAP		/* We've got mmap() that is good */
#include <sys/mman.h>
/* HP-UX sucks */
#ifdef MAP_ANONYMOUS
#ifndef MAP_ANON
#define MAP_ANON MAP_ANONYMOUS
#endif
#endif
#endif
#endif

static uintptr_t offset_pad;

/* status information for an allocated block in heap */
struct rb_heap_block
{
	size_t alloc_size;
	rb_dlink_node node;
	unsigned long free_count;
	void *elems;		/* Points to allocated memory */
};
typedef struct rb_heap_block rb_heap_block;

/* information for the root node of the heap */
struct rb_bh
{
	rb_dlink_node hlist;
	size_t elemSize;	/* Size of each element to be stored */
	unsigned long elemsPerBlock;	/* Number of elements per block */
	rb_dlink_list block_list;
	rb_dlink_list free_list;
	char *desc;
};

#ifndef NOBALLOC
static int newblock(rb_bh *bh);
static void rb_bh_gc_event(void *unused);
#endif /* !NOBALLOC */
static rb_dlink_list *heap_lists;

#if defined(WIN32)
static HANDLE block_heap;
#endif

#define rb_bh_fail(x) _rb_bh_fail(x, __FILE__, __LINE__)

static void
_rb_bh_fail(const char *reason, const char *file, int line)
{
	rb_lib_log("rb_heap_blockheap failure: %s (%s:%d)", reason, file, line);
	abort();
}

#ifndef NOBALLOC
/*
 * static inline void free_block(void *ptr, size_t size)
 *
 * Inputs: The block and its size
 * Output: None
 * Side Effects: Returns memory for the block back to the OS
 */
static inline void
free_block(void *ptr, size_t size)
{
#ifdef HAVE_MMAP
	munmap(ptr, size);
#else
#ifdef _WIN32
	HeapFree(block_heap, 0, ptr);
#else
	free(ptr);
#endif
#endif
}
#endif /* !NOBALLOC */

/*
 * void rb_init_bh(void)
 *
 * Inputs: None
 * Outputs: None
 * Side Effects: Initializes the block heap
 */

void
rb_init_bh(void)
{
	heap_lists = rb_malloc(sizeof(rb_dlink_list));
	offset_pad = sizeof(void *);
	/* XXX if you get SIGBUS when trying to use a long long..here is where you need to
	 * fix your shit
	 */
#ifdef __sparc__
	if((offset_pad % __alignof__(long long)) != 0)
	{
		offset_pad += __alignof__(long long);
		offset_pad &= ~(__alignof__(long long) - 1);
	}
#endif

#ifndef NOBALLOC
#ifdef _WIN32
	block_heap = HeapCreate(HEAP_NO_SERIALIZE, 0, 0);
#endif
	rb_event_addish("rb_bh_gc_event", rb_bh_gc_event, NULL, 300);
#endif /* !NOBALLOC */
}

#ifndef NOBALLOC
/*
 * static inline void *get_block(size_t size)
 *
 * Input: Size of block to allocate
 * Output: Pointer to new block
 * Side Effects: None
 */
static inline void *
get_block(size_t size)
{
	void *ptr;
#ifdef HAVE_MMAP
#ifdef MAP_ANON
	ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
#else
	int zero_fd;
	zero_fd = open("/dev/zero", O_RDWR);
	if(zero_fd < 0)
		rb_bh_fail("Failed opening /dev/zero");
	ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, zero_fd, 0);
	close(zero_fd);
#endif /* MAP_ANON */
	if(ptr == MAP_FAILED)
		ptr = NULL;
#else
#ifdef _WIN32
	ptr = HeapAlloc(block_heap, 0, size);
#else
	ptr = malloc(size);
#endif
#endif
	return (ptr);
}


static void
rb_bh_gc_event(void *unused)
{
	rb_dlink_node *ptr;
	RB_DLINK_FOREACH(ptr, heap_lists->head)
	{
		rb_bh_gc(ptr->data);
	}
}

/* ************************************************************************ */
/* FUNCTION DOCUMENTATION:                                                  */
/*    newblock                                                              */
/* Description:                                                             */
/*    Allocates a new block for addition to a blockheap                     */
/* Parameters:                                                              */
/*    bh (IN): Pointer to parent blockheap.                                 */
/* Returns:                                                                 */
/*    0 if successful, 1 if not                                             */
/* ************************************************************************ */

static int
newblock(rb_bh *bh)
{
	rb_heap_block *b;
	unsigned long i;
	uintptr_t offset;
	rb_dlink_node *node;
	/* Setup the initial data structure. */
	b = rb_malloc(sizeof(rb_heap_block));

	b->alloc_size = bh->elemsPerBlock * bh->elemSize;

	b->elems = get_block(b->alloc_size);
	if(rb_unlikely(b->elems == NULL))
	{
		return (1);
	}
	offset = (uintptr_t)b->elems;
	/* Setup our blocks now */
	for(i = 0; i < bh->elemsPerBlock; i++, offset += bh->elemSize)
	{
		*((void **)offset) = b;
		node = (void *)(offset + offset_pad);
		rb_dlinkAdd((void *)offset, node, &bh->free_list);
	}
	rb_dlinkAdd(b, &b->node, &bh->block_list);
	b->free_count = bh->elemsPerBlock;
	return (0);
}
#endif /* !NOBALLOC */

/* ************************************************************************ */
/* FUNCTION DOCUMENTATION:                                                  */
/*    rb_bh_create                                                       */
/* Description:                                                             */
/*   Creates a new blockheap from which smaller blocks can be allocated.    */
/*   Intended to be used instead of multiple calls to malloc() when         */
/*   performance is an issue.                                               */
/* Parameters:                                                              */
/*   elemsize (IN):  Size of the basic element to be stored                 */
/*   elemsperblock (IN):  Number of elements to be stored in a single block */
/*         of memory.  When the blockheap runs out of free memory, it will  */
/*         allocate elemsize * elemsperblock more.                          */
/* Returns:                                                                 */
/*   Pointer to new rb_bh, or NULL if unsuccessful                      */
/* ************************************************************************ */
rb_bh *
rb_bh_create(size_t elemsize, int elemsperblock, const char *desc)
{
	rb_bh *bh;
	lrb_assert(elemsize > 0 && elemsperblock > 0);
	lrb_assert(elemsize >= sizeof(rb_dlink_node));

	/* Catch idiotic requests up front */
	if((elemsize == 0) || (elemsperblock <= 0))
	{
		rb_bh_fail("Attempting to rb_bh_create idiotic sizes");
	}

	if(elemsize < sizeof(rb_dlink_node))
		rb_bh_fail("Attempt to rb_bh_create smaller than sizeof(rb_dlink_node)");

	/* Allocate our new rb_bh */
	bh = rb_malloc(sizeof(rb_bh));
#ifndef NOBALLOC
	elemsize += offset_pad;
	if((elemsize % sizeof(void *)) != 0)
	{
		/* Pad to even pointer boundary */
		elemsize += sizeof(void *);
		elemsize &= ~(sizeof(void *) - 1);
	}
#endif

	bh->elemSize = elemsize;
	bh->elemsPerBlock = elemsperblock;
	if(desc != NULL)
		bh->desc = rb_strdup(desc);

#ifndef NOBALLOC
	/* Be sure our malloc was successful */
	if(newblock(bh))
	{
		if(bh != NULL)
			free(bh);
		rb_lib_log("newblock() failed");
		rb_outofmemory();	/* die.. out of memory */
	}
#endif /* !NOBALLOC */

	if(bh == NULL)
	{
		rb_bh_fail("bh == NULL when it shouldn't be");
	}
	rb_dlinkAdd(bh, &bh->hlist, heap_lists);
	return (bh);
}

/* ************************************************************************ */
/* FUNCTION DOCUMENTATION:                                                  */
/*    rb_bh_alloc                                                        */
/* Description:                                                             */
/*    Returns a pointer to a struct within our rb_bh that's free for    */
/*    the taking.                                                           */
/* Parameters:                                                              */
/*    bh (IN):  Pointer to the Blockheap.                                   */
/* Returns:                                                                 */
/*    Pointer to a structure (void *), or NULL if unsuccessful.             */
/* ************************************************************************ */

void *
rb_bh_alloc(rb_bh *bh)
{
#ifndef NOBALLOC
	rb_dlink_node *new_node;
	rb_heap_block **block;
	void *ptr;
#endif
	lrb_assert(bh != NULL);
	if(rb_unlikely(bh == NULL))
	{
		rb_bh_fail("Cannot allocate if bh == NULL");
	}

#ifdef NOBALLOC
	return (rb_malloc(bh->elemSize));
#else
	if(bh->free_list.head == NULL)
	{
		/* Allocate new block and assign */
		/* newblock returns 1 if unsuccessful, 0 if not */

		if(rb_unlikely(newblock(bh)))
		{
			rb_lib_log("newblock() failed");
			rb_outofmemory();	/* Well that didn't work either...bail */
		}
		if(bh->free_list.head == NULL)
		{
			rb_lib_log("out of memory after newblock()...");
			rb_outofmemory();
		}
	}

	new_node = bh->free_list.head;
	block = (rb_heap_block **) new_node->data;
	ptr = (void *)((uintptr_t)new_node->data + (uintptr_t)offset_pad);
	rb_dlinkDelete(new_node, &bh->free_list);
	(*block)->free_count--;
	memset(ptr, 0, bh->elemSize - offset_pad);
	return (ptr);
#endif
}


/* ************************************************************************ */
/* FUNCTION DOCUMENTATION:                                                  */
/*    rb_bh_free                                                          */
/* Description:                                                             */
/*    Returns an element to the free pool, does not free()                  */
/* Parameters:                                                              */
/*    bh (IN): Pointer to rb_bh containing element                        */
/*    ptr (in):  Pointer to element to be "freed"                           */
/* Returns:                                                                 */
/*    0 if successful, 1 if element not contained within rb_bh.           */
/* ************************************************************************ */
int
rb_bh_free(rb_bh *bh, void *ptr)
{
#ifndef NOBALLOC
	rb_heap_block *block;
	void *data;
#endif
	lrb_assert(bh != NULL);
	lrb_assert(ptr != NULL);

	if(rb_unlikely(bh == NULL))
	{
		rb_lib_log("balloc.c:rb_bhFree() bh == NULL");
		return (1);
	}

	if(rb_unlikely(ptr == NULL))
	{
		rb_lib_log("balloc.rb_bhFree() ptr == NULL");
		return (1);
	}

#ifdef NOBALLOC
	rb_free(ptr);
#else
	data = (void *)((uintptr_t)ptr - (uintptr_t)offset_pad);
	block = *(rb_heap_block **) data;
	/* XXX */
	if(rb_unlikely
	   (!((uintptr_t)ptr >= (uintptr_t)block->elems
	      && (uintptr_t)ptr < (uintptr_t)block->elems + (uintptr_t)block->alloc_size)))
	{
		rb_bh_fail("rb_bh_free() bogus pointer");
	}
	block->free_count++;

	rb_dlinkAdd(data, (rb_dlink_node *)ptr, &bh->free_list);
#endif /* !NOBALLOC */
	return (0);
}


/* ************************************************************************ */
/* FUNCTION DOCUMENTATION:                                                  */
/*    rb_bhDestroy                                                      */
/* Description:                                                             */
/*    Completely free()s a rb_bh.  Use for cleanup.                     */
/* Parameters:                                                              */
/*    bh (IN):  Pointer to the rb_bh to be destroyed.                   */
/* Returns:                                                                 */
/*   0 if successful, 1 if bh == NULL                                       */
/* ************************************************************************ */
int
rb_bh_destroy(rb_bh *bh)
{
#ifndef NOBALLOC
	rb_dlink_node *ptr, *next;
	rb_heap_block *b;
#endif
	if(bh == NULL)
		return (1);

#ifndef NOBALLOC
	RB_DLINK_FOREACH_SAFE(ptr, next, bh->block_list.head)
	{
		b = ptr->data;
		free_block(b->elems, b->alloc_size);
		rb_free(b);
	}
#endif /* !NOBALLOC */

	rb_dlinkDelete(&bh->hlist, heap_lists);
	rb_free(bh->desc);
	rb_free(bh);

	return (0);
}

void
rb_bh_usage(rb_bh *bh, size_t *bused, size_t *bfree, size_t *bmemusage, const char **desc)
{
#ifndef NOBALLOC
	size_t used, freem, memusage;

	if(bh == NULL)
	{
		return;
	}

	freem = rb_dlink_list_length(&bh->free_list);
	used = (rb_dlink_list_length(&bh->block_list) * bh->elemsPerBlock) - freem;
	memusage = used * bh->elemSize;
	if(bused != NULL)
		*bused = used;
	if(bfree != NULL)
		*bfree = freem;
	if(bmemusage != NULL)
		*bmemusage = memusage;
	if(desc != NULL)
		*desc = bh->desc;
#else
	if(bused != NULL)
		*bused = 0;
	if(bfree != NULL)
		*bfree = 0;
	if(bmemusage != NULL)
		*bmemusage = 0;
	if(desc != NULL)
		*desc = "no blockheap";
#endif
}

void
rb_bh_usage_all(rb_bh_usage_cb *cb, void *data)
{
	rb_dlink_node *ptr;
	rb_bh *bh;
	size_t used, freem, memusage, heapalloc;
	static const char *unnamed = "(unnamed_heap)";
	const char *desc = unnamed;

	if(cb == NULL)
		return;

	RB_DLINK_FOREACH(ptr, heap_lists->head)
	{
		bh = (rb_bh *)ptr->data;
		freem = rb_dlink_list_length(&bh->free_list);
		used = (rb_dlink_list_length(&bh->block_list) * bh->elemsPerBlock) - freem;
		memusage = used * bh->elemSize;
		heapalloc = (freem + used) * bh->elemSize;
		if(bh->desc != NULL)
			desc = bh->desc;
		cb(used, freem, memusage, heapalloc, desc, data);
	}
	return;
}

void
rb_bh_total_usage(size_t *total_alloc, size_t *total_used)
{
	rb_dlink_node *ptr;
	size_t total_memory = 0, used_memory = 0, used, freem;
	rb_bh *bh;

	RB_DLINK_FOREACH(ptr, heap_lists->head)
	{
		bh = (rb_bh *)ptr->data;
		freem = rb_dlink_list_length(&bh->free_list);
		used = (rb_dlink_list_length(&bh->block_list) * bh->elemsPerBlock) - freem;
		used_memory += used * bh->elemSize;
		total_memory += (freem + used) * bh->elemSize;
	}

	if(total_alloc != NULL)
		*total_alloc = total_memory;
	if(total_used != NULL)
		*total_used = used_memory;
}

#ifndef NOBALLOC
int
rb_bh_gc(rb_bh *bh)
{
	rb_heap_block *b;
	rb_dlink_node *ptr, *next;
	unsigned long i;
	uintptr_t offset;

	if(bh == NULL)
	{
		/* somebody is smoking some craq..(probably lee, but don't tell him that) */
		return (1);
	}

	if((rb_dlink_list_length(&bh->free_list) < bh->elemsPerBlock)
	   || rb_dlink_list_length(&bh->block_list) == 1)
	{
		/* There couldn't possibly be an entire free block.  Return. */
		return (0);
	}

	RB_DLINK_FOREACH_SAFE(ptr, next, bh->block_list.head)
	{
		b = ptr->data;
		if(rb_dlink_list_length(&bh->block_list) == 1)
			return (0);

		if(b->free_count == bh->elemsPerBlock)
		{
			/* i'm seriously going to hell for this.. */

			offset = (uintptr_t)b->elems;
			for(i = 0; i < bh->elemsPerBlock; i++, offset += (uintptr_t)bh->elemSize)
			{
				rb_dlinkDelete((rb_dlink_node *)(offset + offset_pad),
					       &bh->free_list);
			}
			rb_dlinkDelete(&b->node, &bh->block_list);
			free_block(b->elems, b->alloc_size);
			rb_free(b);
		}

	}
	return (0);
}
#endif /* !NOBALLOC */
Commit	Line	Data
	1	/*
	2	* ircd-ratbox: A slightly useful ircd.
	3	* balloc.c: A block allocator.
	4	*
	5	* Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center
	6	* Copyright (C) 1996-2002 Hybrid Development Team
	7	* Copyright (C) 2002-2006 ircd-ratbox development team
	8	*
	9	* Below are the orignal headers from the old blalloc.c
	10	*
	11	* File: blalloc.c
	12	* Owner: Wohali (Joan Touzet)
	13	*
	14	* Modified 2001/11/29 for mmap() support by Aaron Sethman <androsyn@ratbox.org>
	15	*
	16	* This program is free software; you can redistribute it and/or modify
	17	* it under the terms of the GNU General Public License as published by
	18	* the Free Software Foundation; either version 2 of the License, or
	19	* (at your option) any later version.
	20	*
	21	* This program is distributed in the hope that it will be useful,
	22	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	23	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	24	* GNU General Public License for more details.
	25	*
	26	* You should have received a copy of the GNU General Public License
	27	* along with this program; if not, write to the Free Software
	28	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
	29	* USA
	30	*
	31	*/
	32
	33	/*
	34	* About the block allocator
	35	*
	36	* Basically we have three ways of getting memory off of the operating
	37	* system. Below are this list of methods and the order of preference.
	38	*
	39	* 1. mmap() anonymous pages with the MMAP_ANON flag.
	40	* 2. mmap() via the /dev/zero trick.
	41	* 3. HeapCreate/HeapAlloc (on win32)
	42	* 4. malloc()
	43	*
	44	* The advantages of 1 and 2 are this. We can munmap() the pages which will
	45	* return the pages back to the operating system, thus reducing the size
	46	* of the process as the memory is unused. malloc() on many systems just keeps
	47	* a heap of memory to itself, which never gets given back to the OS, except on
	48	* exit. This of course is bad, if say we have an event that causes us to allocate
	49	* say, 200MB of memory, while our normal memory consumption would be 15MB. In the
	50	* malloc() case, the amount of memory allocated to our process never goes down, as
	51	* malloc() has it locked up in its heap. With the mmap() method, we can munmap()
	52	* the block and return it back to the OS, thus causing our memory consumption to go
	53	* down after we no longer need it.
	54	*
	55	*
	56	*
	57	*/
	58	#include <libratbox_config.h>
	59	#include <ratbox_lib.h>
	60
	61	#ifndef NOBALLOC
	62	#ifdef HAVE_MMAP /* We've got mmap() that is good */
	63	#include <sys/mman.h>
	64	/* HP-UX sucks */
	65	#ifdef MAP_ANONYMOUS
	66	#ifndef MAP_ANON
	67	#define MAP_ANON MAP_ANONYMOUS
	68	#endif
	69	#endif
	70	#endif
	71	#endif
	72
	73	static uintptr_t offset_pad;
	74
	75	/* status information for an allocated block in heap */
	76	struct rb_heap_block
	77	{
	78	size_t alloc_size;
	79	rb_dlink_node node;
	80	unsigned long free_count;
	81	void elems; / Points to allocated memory */
	82	};
	83	typedef struct rb_heap_block rb_heap_block;
	84
	85	/* information for the root node of the heap */
	86	struct rb_bh
	87	{
	88	rb_dlink_node hlist;
	89	size_t elemSize; /* Size of each element to be stored */
	90	unsigned long elemsPerBlock; /* Number of elements per block */
	91	rb_dlink_list block_list;
	92	rb_dlink_list free_list;
	93	char *desc;
	94	};
	95
	96	#ifndef NOBALLOC
	97	static int newblock(rb_bh *bh);
	98	static void rb_bh_gc_event(void *unused);
	99	#endif /* !NOBALLOC */
	100	static rb_dlink_list *heap_lists;
	101
	102	#if defined(WIN32)
	103	static HANDLE block_heap;
	104	#endif
	105
	106	#define rb_bh_fail(x) _rb_bh_fail(x, __FILE__, __LINE__)
	107
	108	static void
	109	_rb_bh_fail(const char reason, const char file, int line)
	110	{
	111	rb_lib_log("rb_heap_blockheap failure: %s (%s:%d)", reason, file, line);
	112	abort();
	113	}
	114
	115	#ifndef NOBALLOC
	116	/*
	117	* static inline void free_block(void *ptr, size_t size)
	118	*
	119	* Inputs: The block and its size
	120	* Output: None
	121	* Side Effects: Returns memory for the block back to the OS
	122	*/
	123	static inline void
	124	free_block(void *ptr, size_t size)
	125	{
	126	#ifdef HAVE_MMAP
	127	munmap(ptr, size);
	128	#else
	129	#ifdef _WIN32
	130	HeapFree(block_heap, 0, ptr);
	131	#else
	132	free(ptr);
	133	#endif
	134	#endif
	135	}
	136	#endif /* !NOBALLOC */
	137
	138	/*
	139	* void rb_init_bh(void)
	140	*
	141	* Inputs: None
	142	* Outputs: None
	143	* Side Effects: Initializes the block heap
	144	*/
	145
	146	void
	147	rb_init_bh(void)
	148	{
	149	heap_lists = rb_malloc(sizeof(rb_dlink_list));
	150	offset_pad = sizeof(void *);
	151	/* XXX if you get SIGBUS when trying to use a long long..here is where you need to
	152	* fix your shit
	153	*/
	154	#ifdef __sparc__
	155	if((offset_pad % __alignof__(long long)) != 0)
	156	{
	157	offset_pad += __alignof__(long long);
	158	offset_pad &= ~(__alignof__(long long) - 1);
	159	}
	160	#endif
	161
	162	#ifndef NOBALLOC
	163	#ifdef _WIN32
	164	block_heap = HeapCreate(HEAP_NO_SERIALIZE, 0, 0);
	165	#endif
	166	rb_event_addish("rb_bh_gc_event", rb_bh_gc_event, NULL, 300);
	167	#endif /* !NOBALLOC */
	168	}
	169
	170	#ifndef NOBALLOC
	171	/*
	172	* static inline void *get_block(size_t size)
	173	*
	174	* Input: Size of block to allocate
	175	* Output: Pointer to new block
	176	* Side Effects: None
	177	*/
	178	static inline void *
	179	get_block(size_t size)
	180	{
	181	void *ptr;
	182	#ifdef HAVE_MMAP
	183	#ifdef MAP_ANON
	184	ptr = mmap(NULL, size, PROT_READ \| PROT_WRITE, MAP_PRIVATE \| MAP_ANON, -1, 0);
	185	#else
	186	int zero_fd;
	187	zero_fd = open("/dev/zero", O_RDWR);
	188	if(zero_fd < 0)
	189	rb_bh_fail("Failed opening /dev/zero");
	190	ptr = mmap(NULL, size, PROT_READ \| PROT_WRITE, MAP_PRIVATE, zero_fd, 0);
	191	close(zero_fd);
	192	#endif /* MAP_ANON */
	193	if(ptr == MAP_FAILED)
	194	ptr = NULL;
	195	#else
	196	#ifdef _WIN32
	197	ptr = HeapAlloc(block_heap, 0, size);
	198	#else
	199	ptr = malloc(size);
	200	#endif
	201	#endif
	202	return (ptr);
	203	}
	204
	205
	206	static void
	207	rb_bh_gc_event(void *unused)
	208	{
	209	rb_dlink_node *ptr;
	210	RB_DLINK_FOREACH(ptr, heap_lists->head)
	211	{
	212	rb_bh_gc(ptr->data);
	213	}
	214	}
	215
	216	/* ************************************************************************ */
	217	/* FUNCTION DOCUMENTATION: */
	218	/* newblock */
	219	/* Description: */
	220	/* Allocates a new block for addition to a blockheap */
	221	/* Parameters: */
	222	/* bh (IN): Pointer to parent blockheap. */
	223	/* Returns: */
	224	/* 0 if successful, 1 if not */
	225	/* ************************************************************************ */
	226
	227	static int
	228	newblock(rb_bh *bh)
	229	{
	230	rb_heap_block *b;
	231	unsigned long i;
	232	uintptr_t offset;
	233	rb_dlink_node *node;
	234	/* Setup the initial data structure. */
	235	b = rb_malloc(sizeof(rb_heap_block));
	236
	237	b->alloc_size = bh->elemsPerBlock * bh->elemSize;
	238
	239	b->elems = get_block(b->alloc_size);
	240	if(rb_unlikely(b->elems == NULL))
	241	{
	242	return (1);
	243	}
	244	offset = (uintptr_t)b->elems;
	245	/* Setup our blocks now */
	246	for(i = 0; i < bh->elemsPerBlock; i++, offset += bh->elemSize)
	247	{
	248	((void *)offset) = b;
	249	node = (void *)(offset + offset_pad);
	250	rb_dlinkAdd((void *)offset, node, &bh->free_list);
	251	}
	252	rb_dlinkAdd(b, &b->node, &bh->block_list);
	253	b->free_count = bh->elemsPerBlock;
	254	return (0);
	255	}
	256	#endif /* !NOBALLOC */
	257
	258	/* ************************************************************************ */
	259	/* FUNCTION DOCUMENTATION: */
	260	/* rb_bh_create */
	261	/* Description: */
	262	/* Creates a new blockheap from which smaller blocks can be allocated. */
	263	/* Intended to be used instead of multiple calls to malloc() when */
	264	/* performance is an issue. */
	265	/* Parameters: */
	266	/* elemsize (IN): Size of the basic element to be stored */
	267	/* elemsperblock (IN): Number of elements to be stored in a single block */
	268	/* of memory. When the blockheap runs out of free memory, it will */
	269	/* allocate elemsize * elemsperblock more. */
	270	/* Returns: */
	271	/* Pointer to new rb_bh, or NULL if unsuccessful */
	272	/* ************************************************************************ */
	273	rb_bh *
	274	rb_bh_create(size_t elemsize, int elemsperblock, const char *desc)
	275	{
	276	rb_bh *bh;
	277	lrb_assert(elemsize > 0 && elemsperblock > 0);
	278	lrb_assert(elemsize >= sizeof(rb_dlink_node));
	279
	280	/* Catch idiotic requests up front */
	281	if((elemsize == 0) \|\| (elemsperblock <= 0))
	282	{
	283	rb_bh_fail("Attempting to rb_bh_create idiotic sizes");
	284	}
	285
	286	if(elemsize < sizeof(rb_dlink_node))
	287	rb_bh_fail("Attempt to rb_bh_create smaller than sizeof(rb_dlink_node)");
	288
	289	/* Allocate our new rb_bh */
	290	bh = rb_malloc(sizeof(rb_bh));
	291	#ifndef NOBALLOC
	292	elemsize += offset_pad;
	293	if((elemsize % sizeof(void *)) != 0)
	294	{
	295	/* Pad to even pointer boundary */
	296	elemsize += sizeof(void *);
	297	elemsize &= ~(sizeof(void *) - 1);
	298	}
	299	#endif
	300
	301	bh->elemSize = elemsize;
	302	bh->elemsPerBlock = elemsperblock;
	303	if(desc != NULL)
	304	bh->desc = rb_strdup(desc);
	305
	306	#ifndef NOBALLOC
	307	/* Be sure our malloc was successful */
	308	if(newblock(bh))
	309	{
	310	if(bh != NULL)
	311	free(bh);
	312	rb_lib_log("newblock() failed");
	313	rb_outofmemory(); /* die.. out of memory */
	314	}
	315	#endif /* !NOBALLOC */
	316
	317	if(bh == NULL)
	318	{
	319	rb_bh_fail("bh == NULL when it shouldn't be");
	320	}
	321	rb_dlinkAdd(bh, &bh->hlist, heap_lists);
	322	return (bh);
	323	}
	324
	325	/* ************************************************************************ */
	326	/* FUNCTION DOCUMENTATION: */
	327	/* rb_bh_alloc */
	328	/* Description: */
	329	/* Returns a pointer to a struct within our rb_bh that's free for */
	330	/* the taking. */
	331	/* Parameters: */
	332	/* bh (IN): Pointer to the Blockheap. */
	333	/* Returns: */
	334	/* Pointer to a structure (void ), or NULL if unsuccessful. /
	335	/* ************************************************************************ */
	336
	337	void *
	338	rb_bh_alloc(rb_bh *bh)
	339	{
	340	#ifndef NOBALLOC
	341	rb_dlink_node *new_node;
	342	rb_heap_block **block;
	343	void *ptr;
	344	#endif
	345	lrb_assert(bh != NULL);
	346	if(rb_unlikely(bh == NULL))
	347	{
	348	rb_bh_fail("Cannot allocate if bh == NULL");
	349	}
	350
	351	#ifdef NOBALLOC
	352	return (rb_malloc(bh->elemSize));
	353	#else
	354	if(bh->free_list.head == NULL)
	355	{
	356	/* Allocate new block and assign */
	357	/* newblock returns 1 if unsuccessful, 0 if not */
	358
	359	if(rb_unlikely(newblock(bh)))
	360	{
	361	rb_lib_log("newblock() failed");
	362	rb_outofmemory(); /* Well that didn't work either...bail */
	363	}
	364	if(bh->free_list.head == NULL)
	365	{
	366	rb_lib_log("out of memory after newblock()...");
	367	rb_outofmemory();
	368	}
	369	}
	370
	371	new_node = bh->free_list.head;
	372	block = (rb_heap_block **) new_node->data;
	373	ptr = (void *)((uintptr_t)new_node->data + (uintptr_t)offset_pad);
	374	rb_dlinkDelete(new_node, &bh->free_list);
	375	(*block)->free_count--;
	376	memset(ptr, 0, bh->elemSize - offset_pad);
	377	return (ptr);
	378	#endif
	379	}
	380
	381
	382	/* ************************************************************************ */
	383	/* FUNCTION DOCUMENTATION: */
	384	/* rb_bh_free */
	385	/* Description: */
	386	/* Returns an element to the free pool, does not free() */
	387	/* Parameters: */
	388	/* bh (IN): Pointer to rb_bh containing element */
	389	/* ptr (in): Pointer to element to be "freed" */
	390	/* Returns: */
	391	/* 0 if successful, 1 if element not contained within rb_bh. */
	392	/* ************************************************************************ */
	393	int
	394	rb_bh_free(rb_bh bh, void ptr)
	395	{
	396	#ifndef NOBALLOC
	397	rb_heap_block *block;
	398	void *data;
	399	#endif
	400	lrb_assert(bh != NULL);
	401	lrb_assert(ptr != NULL);
	402
	403	if(rb_unlikely(bh == NULL))
	404	{
	405	rb_lib_log("balloc.c:rb_bhFree() bh == NULL");
	406	return (1);
	407	}
	408
	409	if(rb_unlikely(ptr == NULL))
	410	{
	411	rb_lib_log("balloc.rb_bhFree() ptr == NULL");
	412	return (1);
	413	}
	414
	415	#ifdef NOBALLOC
	416	rb_free(ptr);
	417	#else
	418	data = (void *)((uintptr_t)ptr - (uintptr_t)offset_pad);
	419	block = (rb_heap_block *) data;
	420	/* XXX */
	421	if(rb_unlikely
	422	(!((uintptr_t)ptr >= (uintptr_t)block->elems
	423	&& (uintptr_t)ptr < (uintptr_t)block->elems + (uintptr_t)block->alloc_size)))
	424	{
	425	rb_bh_fail("rb_bh_free() bogus pointer");
	426	}
	427	block->free_count++;
	428
	429	rb_dlinkAdd(data, (rb_dlink_node *)ptr, &bh->free_list);
	430	#endif /* !NOBALLOC */
	431	return (0);
	432	}
	433
	434
	435	/* ************************************************************************ */
	436	/* FUNCTION DOCUMENTATION: */
	437	/* rb_bhDestroy */
	438	/* Description: */
	439	/* Completely free()s a rb_bh. Use for cleanup. */
	440	/* Parameters: */
	441	/* bh (IN): Pointer to the rb_bh to be destroyed. */
	442	/* Returns: */
	443	/* 0 if successful, 1 if bh == NULL */
	444	/* ************************************************************************ */
	445	int
	446	rb_bh_destroy(rb_bh *bh)
	447	{
	448	#ifndef NOBALLOC
	449	rb_dlink_node ptr, next;
	450	rb_heap_block *b;
	451	#endif
	452	if(bh == NULL)
	453	return (1);
	454
	455	#ifndef NOBALLOC
	456	RB_DLINK_FOREACH_SAFE(ptr, next, bh->block_list.head)
	457	{
	458	b = ptr->data;
	459	free_block(b->elems, b->alloc_size);
	460	rb_free(b);
	461	}
	462	#endif /* !NOBALLOC */
	463
	464	rb_dlinkDelete(&bh->hlist, heap_lists);
	465	rb_free(bh->desc);
	466	rb_free(bh);
	467
	468	return (0);
	469	}
	470
	471	void
	472	rb_bh_usage(rb_bh bh, size_t bused, size_t bfree, size_t bmemusage, const char **desc)
	473	{
	474	#ifndef NOBALLOC
	475	size_t used, freem, memusage;
	476
	477	if(bh == NULL)
	478	{
	479	return;
	480	}
	481
	482	freem = rb_dlink_list_length(&bh->free_list);
	483	used = (rb_dlink_list_length(&bh->block_list) * bh->elemsPerBlock) - freem;
	484	memusage = used * bh->elemSize;
	485	if(bused != NULL)
	486	*bused = used;
	487	if(bfree != NULL)
	488	*bfree = freem;
	489	if(bmemusage != NULL)
	490	*bmemusage = memusage;
	491	if(desc != NULL)
	492	*desc = bh->desc;
	493	#else
	494	if(bused != NULL)
	495	*bused = 0;
	496	if(bfree != NULL)
	497	*bfree = 0;
	498	if(bmemusage != NULL)
	499	*bmemusage = 0;
	500	if(desc != NULL)
	501	*desc = "no blockheap";
	502	#endif
	503	}
	504
	505	void
	506	rb_bh_usage_all(rb_bh_usage_cb cb, void data)
	507	{
	508	rb_dlink_node *ptr;
	509	rb_bh *bh;
	510	size_t used, freem, memusage, heapalloc;
	511	static const char *unnamed = "(unnamed_heap)";
	512	const char *desc = unnamed;
	513
	514	if(cb == NULL)
	515	return;
	516
	517	RB_DLINK_FOREACH(ptr, heap_lists->head)
	518	{
	519	bh = (rb_bh *)ptr->data;
	520	freem = rb_dlink_list_length(&bh->free_list);
	521	used = (rb_dlink_list_length(&bh->block_list) * bh->elemsPerBlock) - freem;
	522	memusage = used * bh->elemSize;
	523	heapalloc = (freem + used) * bh->elemSize;
	524	if(bh->desc != NULL)
	525	desc = bh->desc;
	526	cb(used, freem, memusage, heapalloc, desc, data);
	527	}
	528	return;
	529	}
	530
	531	void
	532	rb_bh_total_usage(size_t total_alloc, size_t total_used)
	533	{
	534	rb_dlink_node *ptr;
	535	size_t total_memory = 0, used_memory = 0, used, freem;
	536	rb_bh *bh;
	537
	538	RB_DLINK_FOREACH(ptr, heap_lists->head)
	539	{
	540	bh = (rb_bh *)ptr->data;
	541	freem = rb_dlink_list_length(&bh->free_list);
	542	used = (rb_dlink_list_length(&bh->block_list) * bh->elemsPerBlock) - freem;
	543	used_memory += used * bh->elemSize;
	544	total_memory += (freem + used) * bh->elemSize;
	545	}
	546
	547	if(total_alloc != NULL)
	548	*total_alloc = total_memory;
	549	if(total_used != NULL)
	550	*total_used = used_memory;
	551	}
	552
	553	#ifndef NOBALLOC
	554	int
	555	rb_bh_gc(rb_bh *bh)
	556	{
	557	rb_heap_block *b;
	558	rb_dlink_node ptr, next;
	559	unsigned long i;
	560	uintptr_t offset;
	561
	562	if(bh == NULL)
	563	{
	564	/* somebody is smoking some craq..(probably lee, but don't tell him that) */
	565	return (1);
	566	}
	567
	568	if((rb_dlink_list_length(&bh->free_list) < bh->elemsPerBlock)
	569	\|\| rb_dlink_list_length(&bh->block_list) == 1)
	570	{
	571	/* There couldn't possibly be an entire free block. Return. */
	572	return (0);
	573	}
	574
	575	RB_DLINK_FOREACH_SAFE(ptr, next, bh->block_list.head)
	576	{
	577	b = ptr->data;
	578	if(rb_dlink_list_length(&bh->block_list) == 1)
	579	return (0);
	580
	581	if(b->free_count == bh->elemsPerBlock)
	582	{
	583	/* i'm seriously going to hell for this.. */
	584
	585	offset = (uintptr_t)b->elems;
	586	for(i = 0; i < bh->elemsPerBlock; i++, offset += (uintptr_t)bh->elemSize)
	587	{
	588	rb_dlinkDelete((rb_dlink_node *)(offset + offset_pad),
	589	&bh->free_list);
	590	}
	591	rb_dlinkDelete(&b->node, &bh->block_list);
	592	free_block(b->elems, b->alloc_size);
	593	rb_free(b);
	594	}
	595
	596	}
	597	return (0);
	598	}
	599	#endif /* !NOBALLOC */