ircd-hybrid-7.3/src/balloc.c

/*
 *  ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd).
 *
 *  Copyright (C) 2002 by the past and present ircd coders, and others.
 *  Original credit lines follow:
 *
 *  File:   balloc.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., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 *  USA
 */

/*! \file balloc.c
 * \brief A block allocator
 * \version $Id$
 * 
 * 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.\n
 * 2. mmap() via the /dev/zero trick.\n
 * 3. malloc()\n
 *
 * 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 "stdinc.h"
#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 /* MAP_ANONYMOUS */
#endif

#include "list.h"
#include "balloc.h"
#include "memory.h"
#include "irc_string.h"
#include "client.h"
#include "send.h"
#include "numeric.h"
#include "fdlist.h"
#include "event.h"


static BlockHeap *heap_list = NULL;

static int BlockHeapGarbageCollect(BlockHeap *);
static void heap_garbage_collection(void *);

/*! \brief Returns memory for the block back to either the malloc heap
 *         in case of !HAVE_MMAP, or back to the OS otherwise.
 * \param ptr  Pointer to memory to be freed
 * \param size The size of the memory space
 */
static inline void
free_block(void *ptr, size_t size)
{
#ifdef HAVE_MMAP
  munmap(ptr, size);
#else
  free(ptr);
#endif
}

#ifdef HAVE_MMAP
#ifndef MAP_ANON /* But we cannot mmap() anonymous pages */
                 /* So we mmap() /dev/zero, which is just as good */
static fde_t dpfd;
#endif
#endif

/*! \brief Opens /dev/zero and saves the file handle for
 * future allocations.
 */
void
initBlockHeap(void)
{
#ifdef HAVE_MMAP
#ifndef MAP_ANON
  int zero_fd = open("/dev/zero", O_RDWR);

  if (zero_fd < 0)
    outofmemory();
  fd_open(&dpfd, zero_fd, 0, "Anonymous mmap()");
#endif
  eventAdd("heap_garbage_collection", &heap_garbage_collection, NULL, 119);
#endif
}

/*!
 * \param size Size of block to allocate
 * \return Address pointer to allocated data space
 */
static inline void *
get_block(size_t size)
{
#ifdef HAVE_MMAP
  void *ptr = NULL;

#ifndef MAP_ANON
  ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, dpfd.fd, 0);
#else
  ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
#endif
  return ptr == MAP_FAILED ? NULL : ptr;
#else
  return malloc(size);
#endif
}

static void
heap_garbage_collection(void *arg)
{
  BlockHeap *bh;

  for (bh = heap_list; bh != NULL; bh = bh->next)
    BlockHeapGarbageCollect(bh);
}

/*! \brief Allocates a new block for addition to a blockheap
 * \param bh Pointer to parent blockheap
 * \return 0 if successful, 1 if not
 */
static int
newblock(BlockHeap *bh)
{
  MemBlock *newblk = NULL;
  Block *b = NULL;
  int i = 0;
  void *offset = NULL;

  /* Setup the initial data structure. */
  if ((b = calloc(1, sizeof(Block))) == NULL)
    return 1;

  b->freeElems = bh->elemsPerBlock;
  b->next = bh->base;
  b->alloc_size = bh->elemsPerBlock * (bh->elemSize + sizeof(MemBlock));
  b->elems = get_block(b->alloc_size);

  if (b->elems == NULL)
    return 1;

  offset = b->elems;

  /* Setup our blocks now */
  for (; i < bh->elemsPerBlock; ++i)
  {
    void *data;

    newblk = offset;
    newblk->block = b;
    data = (void *)((size_t)offset + sizeof(MemBlock));

    dlinkAdd(data, &newblk->self, &b->free_list);
    offset = (void *)((size_t)offset + bh->elemSize + sizeof(MemBlock));
  }

  ++bh->blocksAllocated;
  bh->freeElems += bh->elemsPerBlock;
  bh->base = b;

  return 0;
}

/*! \brief Creates a new blockheap
 *
 * 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.
 *
 * \param name          Name of the blockheap
 * \param elemsize      Size of the basic element to be stored
 * \param elemsperblock 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.
 * \return Pointer to new BlockHeap, or NULL if unsuccessful
 */
BlockHeap *
BlockHeapCreate(const char *const name, size_t elemsize, int elemsperblock)
{
  BlockHeap *bh = NULL;
  assert(elemsize > 0 && elemsperblock > 0);

  /* Catch idiotic requests up front */
  if ((elemsize <= 0) || (elemsperblock <= 0))
    outofmemory();    /* die.. out of memory */

  /* Allocate our new BlockHeap */
  if ((bh = calloc(1, sizeof(BlockHeap))) == NULL)
    outofmemory();    /* die.. out of memory */

  if ((elemsize % sizeof(void *)) != 0)
  {
    /* Pad to even pointer boundary */
    elemsize += sizeof(void *);
    elemsize &= ~(sizeof(void *) - 1);
  }

  bh->name = name;
  bh->elemSize = elemsize;
  bh->elemsPerBlock = elemsperblock;

  /* Be sure our malloc was successful */
  if (newblock(bh))
  {
    if (bh != NULL)
      free(bh);

     outofmemory();    /* die.. out of memory */
  }

  bh->next = heap_list;
  heap_list = bh;

  return bh;
}

/*! \brief Returns a pointer to a struct within our BlockHeap that's free for
 *         the taking.
 * \param bh Pointer to the Blockheap
 * \return Address pointer to allocated data space, or NULL if unsuccessful
 */
void *
BlockHeapAlloc(BlockHeap *bh)
{
  Block *walker = NULL;
  dlink_node *new_node = NULL;

  assert(bh != NULL);

  if (bh->freeElems == 0)
  {   
    /* Allocate new block and assign */
    /* newblock returns 1 if unsuccessful, 0 if not */
    if (newblock(bh))
    {
      /* That didn't work..try to garbage collect */
      BlockHeapGarbageCollect(bh);  

      if (newblock(bh))
        outofmemory(); /* Well that didn't work either...bail */
    }
  }
      
  for (walker = bh->base; walker != NULL; walker = walker->next)
  {
    if (walker->freeElems > 0)
    {
      --bh->freeElems;
      --walker->freeElems;
      new_node = walker->free_list.head;

      dlinkDelete(new_node, &walker->free_list);
      assert(new_node->data != NULL);

      memset(new_node->data, 0, bh->elemSize);
      return new_node->data;
    }
  }

  assert(0 == 1);
  outofmemory();
  return NULL;
}

/*! \brief Returns an element to the free pool, does not free()
 * \param bh  Pointer to BlockHeap containing element
 * \param ptr Pointer to element to be "freed"
 * \return 0 if successful, 1 if element not contained within BlockHeap
 */
int
BlockHeapFree(BlockHeap *bh, void *ptr)
{
  Block *block = NULL;
  struct MemBlock *memblock = NULL;
    
  assert(bh != NULL);
  assert(ptr != NULL);

  memblock = (void *)((size_t)ptr - sizeof(MemBlock));
  assert(memblock->block != NULL);

  if (memblock->block == NULL)
    outofmemory();

  block = memblock->block;
  ++bh->freeElems;
  ++block->freeElems;
  mem_frob(ptr, bh->elemSize);

  dlinkAdd(ptr, &memblock->self, &block->free_list);
  return 0;
}

/*! \brief Performs garbage collection on the block heap.
 *
 * Performs garbage collection on the block heap.  Any blocks that are
 * completely unallocated are removed from the heap.  Garbage collection
 * will \b never remove the root node of the heap.
 *
 * \param bh Pointer to the BlockHeap to be cleaned up
 * \return 0 if successful, 1 if bh == NULL
 */
static int
BlockHeapGarbageCollect(BlockHeap *bh)
{
  Block *walker = NULL, *last = NULL;

  assert(bh != NULL);

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

  walker = bh->base;

  while (walker != NULL)
  {
    if (walker->freeElems == bh->elemsPerBlock)
    {
      free_block(walker->elems, walker->alloc_size);

      if (last != NULL)
      {
        last->next = walker->next;

        if (walker != NULL)
          free(walker);
        walker = last->next;
      }
      else
      {
        bh->base = walker->next;

        if (walker != NULL)
          free(walker);
        walker = bh->base;
      }

      --bh->blocksAllocated;
      bh->freeElems -= bh->elemsPerBlock;
    }
    else
    {
      last = walker;
      walker = walker->next;
    }
  }

  return 0;
}

/*! \brief Completely free()s a BlockHeap.  Use for cleanup.
 * \param bh Pointer to the BlockHeap to be destroyed
 * \return 0 if successful, 1 if bh == NULL
 */
int
BlockHeapDestroy(BlockHeap *bh)
{
  Block *walker = NULL, *next = NULL;

  if (bh == NULL)
    return 1;

  for (walker = bh->base; walker != NULL; walker = next)
  {
    next = walker->next;
    free_block(walker->elems, walker->alloc_size);

    if (walker != NULL)
      free(walker);
  }

  if (heap_list == bh)
    heap_list = bh->next;
  else {
    BlockHeap *prev;

    for (prev = heap_list; prev->next != bh; prev = prev->next)
      /* nothing */ ;
    prev->next = bh->next;
  }

  free(bh);
  return 0;
}

/*! \brief Returns the number of bytes being used
 * \param bh Pointer to a BlockHeap
 * \return Number of bytes being used
 */
static size_t
block_heap_get_used_mem(const BlockHeap *const bh)
{
  return(((bh->blocksAllocated *
           bh->elemsPerBlock)-bh->freeElems) *
          (bh->elemSize + sizeof(MemBlock)));
}

/*! \brief Returns the number of bytes being free for further allocations
 * \param bh Pointer to a BlockHeap
 * \return Number of bytes being free for further allocations
 */
static size_t
block_heap_get_free_mem(const BlockHeap *const bh)
{
  return(bh->freeElems * (bh->elemSize + sizeof(MemBlock)));
}

/*! \brief Returns the total number of bytes of memory belonging to a heap
 * \param bh Pointer to a BlockHeap
 * \return Total number of bytes of memory belonging to a heap
 */
static size_t
block_heap_get_size_mem(const BlockHeap *const bh)
{
  return(((bh->blocksAllocated *
           bh->elemsPerBlock)) *
          (bh->elemSize + sizeof(MemBlock)));
}

/*! \brief Returns the number of elements being used.
 * \param bh Pointer to a BlockHeap
 * \return Number of elements being free for further allocations
 */
static unsigned int
block_heap_get_used_elm(const BlockHeap *const bh)
{
  return((bh->blocksAllocated *
          bh->elemsPerBlock)-bh->freeElems);
}

/*! \brief Returns the number of elements being free for further allocations.
 * \param bh Pointer to a BlockHeap
 * \return Number of elements being free for further allocations
 */
static unsigned int
block_heap_get_free_elm(const BlockHeap *const bh)
{
  return(bh->freeElems);
}

/*! \brief Returns the number of total elements belonging to a heap.
 *         Includes \b free and \b used elements.
 * \param bh Pointer to a BlockHeap
 * \return Number of total elements belonging to a heap
 */
static unsigned int
block_heap_get_size_elm(const BlockHeap *const bh)
{
  return(bh->blocksAllocated * bh->elemsPerBlock);
}

void
block_heap_report_stats(struct Client *client_p)
{
  const BlockHeap *bh = NULL;

  for (bh = heap_list; bh != NULL; bh = bh->next)
    sendto_one(client_p, ":%s %d %s z :%s mempool: used %u/%u free %u/%u (size %u/%u)",
               me.name, RPL_STATSDEBUG, client_p->name, bh->name,
               block_heap_get_used_elm(bh),
               block_heap_get_used_mem(bh),
               block_heap_get_free_elm(bh),
               block_heap_get_free_mem(bh),
               block_heap_get_size_elm(bh),
               block_heap_get_size_mem(bh));
}
Revision:	1011
Committed:	Fri Sep 18 10:14:09 2009 UTC (15 years, 11 months ago) by michael
Content type:	text/x-csrc
Original Path:	*ircd-hybrid-7.2/src/balloc.c*
File size:	12977 byte(s)
Log Message:	- move list manipulation routines from tools.c to list.c - mem_frob() goes to memory.c - sort out redundant/unneeded header includes
#	User	Rev	Content
1	adx	30	/*
2			* ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd).
3			*
4			* Copyright (C) 2002 by the past and present ircd coders, and others.
5			* Original credit lines follow:
6			*
7			* File: balloc.c
8			* Owner: Wohali (Joan Touzet)
9			*
10			* Modified 2001/11/29 for mmap() support by Aaron Sethman <androsyn@ratbox.org>
11			*
12			* This program is free software; you can redistribute it and/or modify
13			* it under the terms of the GNU General Public License as published by
14			* the Free Software Foundation; either version 2 of the License, or
15			* (at your option) any later version.
16			*
17			* This program is distributed in the hope that it will be useful,
18			* but WITHOUT ANY WARRANTY; without even the implied warranty of
19			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20			* GNU General Public License for more details.
21			*
22			* You should have received a copy of the GNU General Public License
23			* along with this program; if not, write to the Free Software
24			* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
25			* USA
26			*/
27
28			/*! \file balloc.c
29			* \brief A block allocator
30	knight	31	* \version $Id$
31	adx	30	*
32			* About the block allocator
33			*
34			* Basically we have three ways of getting memory off of the operating
35			* system. Below are this list of methods and the order of preference.
36			*
37			* 1. mmap() anonymous pages with the MMAP_ANON flag.\n
38			* 2. mmap() via the /dev/zero trick.\n
39			* 3. malloc()\n
40			*
41			* The advantages of 1 and 2 are this. We can munmap() the pages which will
42			* return the pages back to the operating system, thus reducing the size
43			* of the process as the memory is unused. malloc() on many systems just keeps
44			* a heap of memory to itself, which never gets given back to the OS, except on
45			* exit. This of course is bad, if say we have an event that causes us to allocate
46			* say, 200MB of memory, while our normal memory consumption would be 15MB. In the
47			* malloc() case, the amount of memory allocated to our process never goes down, as
48			* malloc() has it locked up in its heap. With the mmap() method, we can munmap()
49			* the block and return it back to the OS, thus causing our memory consumption to go
50			* down after we no longer need it.
51			*/
52
53	stu	908
54	adx	30	#include "stdinc.h"
55			#ifdef HAVE_MMAP /* We've got mmap() that is good */
56			#include <sys/mman.h>
57
58			/* HP-UX sucks */
59			#ifdef MAP_ANONYMOUS
60			#ifndef MAP_ANON
61			#define MAP_ANON MAP_ANONYMOUS
62			#endif
63			#endif /* MAP_ANONYMOUS */
64			#endif
65
66	michael	1011	#include "list.h"
67	adx	30	#include "balloc.h"
68	michael	1011	#include "memory.h"
69	adx	30	#include "irc_string.h"
70			#include "client.h"
71			#include "send.h"
72			#include "numeric.h"
73			#include "fdlist.h"
74			#include "event.h"
75
76
77			static BlockHeap *heap_list = NULL;
78
79			static int BlockHeapGarbageCollect(BlockHeap *);
80			static void heap_garbage_collection(void *);
81
82			/*! \brief Returns memory for the block back to either the malloc heap
83			* in case of !HAVE_MMAP, or back to the OS otherwise.
84			* \param ptr Pointer to memory to be freed
85			* \param size The size of the memory space
86			*/
87			static inline void
88			free_block(void *ptr, size_t size)
89			{
90			#ifdef HAVE_MMAP
91			munmap(ptr, size);
92			#else
93			free(ptr);
94			#endif
95			}
96
97			#ifdef HAVE_MMAP
98			#ifndef MAP_ANON /* But we cannot mmap() anonymous pages */
99			/* So we mmap() /dev/zero, which is just as good */
100	michael	368	static fde_t dpfd;
101	adx	30	#endif
102			#endif
103
104			/*! \brief Opens /dev/zero and saves the file handle for
105			* future allocations.
106			*/
107			void
108			initBlockHeap(void)
109			{
110			#ifdef HAVE_MMAP
111			#ifndef MAP_ANON
112	michael	368	int zero_fd = open("/dev/zero", O_RDWR);
113	adx	30
114			if (zero_fd < 0)
115			outofmemory();
116	michael	368	fd_open(&dpfd, zero_fd, 0, "Anonymous mmap()");
117	adx	30	#endif
118			eventAdd("heap_garbage_collection", &heap_garbage_collection, NULL, 119);
119			#endif
120			}
121
122			/*!
123			* \param size Size of block to allocate
124			* \return Address pointer to allocated data space
125			*/
126			static inline void *
127			get_block(size_t size)
128			{
129			#ifdef HAVE_MMAP
130			void *ptr = NULL;
131
132			#ifndef MAP_ANON
133	michael	368	ptr = mmap(NULL, size, PROT_READ \| PROT_WRITE, MAP_PRIVATE, dpfd.fd, 0);
134	adx	30	#else
135			ptr = mmap(NULL, size, PROT_READ \| PROT_WRITE, MAP_PRIVATE \| MAP_ANON, -1, 0);
136			#endif
137			return ptr == MAP_FAILED ? NULL : ptr;
138			#else
139			return malloc(size);
140			#endif
141			}
142
143			static void
144			heap_garbage_collection(void *arg)
145			{
146			BlockHeap *bh;
147
148			for (bh = heap_list; bh != NULL; bh = bh->next)
149			BlockHeapGarbageCollect(bh);
150			}
151
152			/*! \brief Allocates a new block for addition to a blockheap
153			* \param bh Pointer to parent blockheap
154			* \return 0 if successful, 1 if not
155			*/
156			static int
157			newblock(BlockHeap *bh)
158			{
159			MemBlock *newblk = NULL;
160			Block *b = NULL;
161			int i = 0;
162			void *offset = NULL;
163
164			/* Setup the initial data structure. */
165			if ((b = calloc(1, sizeof(Block))) == NULL)
166			return 1;
167
168			b->freeElems = bh->elemsPerBlock;
169			b->next = bh->base;
170			b->alloc_size = bh->elemsPerBlock * (bh->elemSize + sizeof(MemBlock));
171			b->elems = get_block(b->alloc_size);
172
173			if (b->elems == NULL)
174			return 1;
175
176			offset = b->elems;
177
178			/* Setup our blocks now */
179			for (; i < bh->elemsPerBlock; ++i)
180			{
181			void *data;
182
183			newblk = offset;
184			newblk->block = b;
185			data = (void *)((size_t)offset + sizeof(MemBlock));
186
187			dlinkAdd(data, &newblk->self, &b->free_list);
188	michael	585	offset = (void *)((size_t)offset + bh->elemSize + sizeof(MemBlock));
189	adx	30	}
190
191			++bh->blocksAllocated;
192			bh->freeElems += bh->elemsPerBlock;
193			bh->base = b;
194
195			return 0;
196			}
197
198			/*! \brief Creates a new blockheap
199			*
200			* Creates a new blockheap from which smaller blocks can be allocated.
201			* Intended to be used instead of multiple calls to malloc() when
202			* performance is an issue.
203			*
204			* \param name Name of the blockheap
205			* \param elemsize Size of the basic element to be stored
206			* \param elemsperblock Number of elements to be stored in a single block of
207			* memory. When the blockheap runs out of free memory,
208			* it will allocate elemsize * elemsperblock more.
209			* \return Pointer to new BlockHeap, or NULL if unsuccessful
210			*/
211			BlockHeap *
212			BlockHeapCreate(const char *const name, size_t elemsize, int elemsperblock)
213			{
214			BlockHeap *bh = NULL;
215			assert(elemsize > 0 && elemsperblock > 0);
216
217			/* Catch idiotic requests up front */
218			if ((elemsize <= 0) \|\| (elemsperblock <= 0))
219			outofmemory(); /* die.. out of memory */
220
221			/* Allocate our new BlockHeap */
222			if ((bh = calloc(1, sizeof(BlockHeap))) == NULL)
223			outofmemory(); /* die.. out of memory */
224
225			if ((elemsize % sizeof(void *)) != 0)
226			{
227			/* Pad to even pointer boundary */
228			elemsize += sizeof(void *);
229			elemsize &= ~(sizeof(void *) - 1);
230			}
231
232			bh->name = name;
233			bh->elemSize = elemsize;
234			bh->elemsPerBlock = elemsperblock;
235
236			/* Be sure our malloc was successful */
237			if (newblock(bh))
238			{
239			if (bh != NULL)
240			free(bh);
241
242			outofmemory(); /* die.. out of memory */
243			}
244
245			bh->next = heap_list;
246			heap_list = bh;
247
248			return bh;
249			}
250
251			/*! \brief Returns a pointer to a struct within our BlockHeap that's free for
252			* the taking.
253			* \param bh Pointer to the Blockheap
254			* \return Address pointer to allocated data space, or NULL if unsuccessful
255			*/
256			void *
257			BlockHeapAlloc(BlockHeap *bh)
258			{
259			Block *walker = NULL;
260			dlink_node *new_node = NULL;
261
262			assert(bh != NULL);
263
264			if (bh->freeElems == 0)
265			{
266			/* Allocate new block and assign */
267			/* newblock returns 1 if unsuccessful, 0 if not */
268			if (newblock(bh))
269			{
270			/* That didn't work..try to garbage collect */
271			BlockHeapGarbageCollect(bh);
272
273			if (newblock(bh))
274			outofmemory(); /* Well that didn't work either...bail */
275			}
276			}
277
278			for (walker = bh->base; walker != NULL; walker = walker->next)
279			{
280			if (walker->freeElems > 0)
281			{
282			--bh->freeElems;
283			--walker->freeElems;
284			new_node = walker->free_list.head;
285
286			dlinkDelete(new_node, &walker->free_list);
287			assert(new_node->data != NULL);
288
289			memset(new_node->data, 0, bh->elemSize);
290			return new_node->data;
291			}
292			}
293
294			assert(0 == 1);
295			outofmemory();
296			return NULL;
297			}
298
299			/*! \brief Returns an element to the free pool, does not free()
300			* \param bh Pointer to BlockHeap containing element
301			* \param ptr Pointer to element to be "freed"
302			* \return 0 if successful, 1 if element not contained within BlockHeap
303			*/
304			int
305			BlockHeapFree(BlockHeap bh, void ptr)
306			{
307			Block *block = NULL;
308			struct MemBlock *memblock = NULL;
309
310			assert(bh != NULL);
311			assert(ptr != NULL);
312
313			memblock = (void *)((size_t)ptr - sizeof(MemBlock));
314			assert(memblock->block != NULL);
315
316			if (memblock->block == NULL)
317			outofmemory();
318
319			block = memblock->block;
320			++bh->freeElems;
321			++block->freeElems;
322			mem_frob(ptr, bh->elemSize);
323
324			dlinkAdd(ptr, &memblock->self, &block->free_list);
325			return 0;
326			}
327
328			/*! \brief Performs garbage collection on the block heap.
329			*
330			* Performs garbage collection on the block heap. Any blocks that are
331			* completely unallocated are removed from the heap. Garbage collection
332			* will \b never remove the root node of the heap.
333			*
334			* \param bh Pointer to the BlockHeap to be cleaned up
335			* \return 0 if successful, 1 if bh == NULL
336			*/
337			static int
338			BlockHeapGarbageCollect(BlockHeap *bh)
339			{
340			Block walker = NULL, last = NULL;
341
342	michael	670	assert(bh != NULL);
343	adx	30
344			if (bh->freeElems < bh->elemsPerBlock \|\| bh->blocksAllocated == 1)
345			{
346			/* There couldn't possibly be an entire free block. Return. */
347			return 0;
348			}
349
350			walker = bh->base;
351
352			while (walker != NULL)
353			{
354			if (walker->freeElems == bh->elemsPerBlock)
355			{
356			free_block(walker->elems, walker->alloc_size);
357
358			if (last != NULL)
359			{
360			last->next = walker->next;
361
362			if (walker != NULL)
363			free(walker);
364			walker = last->next;
365			}
366			else
367			{
368			bh->base = walker->next;
369
370			if (walker != NULL)
371			free(walker);
372			walker = bh->base;
373			}
374
375			--bh->blocksAllocated;
376			bh->freeElems -= bh->elemsPerBlock;
377			}
378			else
379			{
380			last = walker;
381			walker = walker->next;
382			}
383			}
384
385			return 0;
386			}
387
388			/*! \brief Completely free()s a BlockHeap. Use for cleanup.
389			* \param bh Pointer to the BlockHeap to be destroyed
390			* \return 0 if successful, 1 if bh == NULL
391			*/
392			int
393			BlockHeapDestroy(BlockHeap *bh)
394			{
395			Block walker = NULL, next = NULL;
396
397			if (bh == NULL)
398			return 1;
399
400			for (walker = bh->base; walker != NULL; walker = next)
401			{
402			next = walker->next;
403			free_block(walker->elems, walker->alloc_size);
404
405			if (walker != NULL)
406			free(walker);
407			}
408
409			if (heap_list == bh)
410			heap_list = bh->next;
411			else {
412			BlockHeap *prev;
413
414			for (prev = heap_list; prev->next != bh; prev = prev->next)
415			/* nothing */ ;
416			prev->next = bh->next;
417			}
418
419			free(bh);
420			return 0;
421			}
422
423			/*! \brief Returns the number of bytes being used
424			* \param bh Pointer to a BlockHeap
425			* \return Number of bytes being used
426			*/
427			static size_t
428			block_heap_get_used_mem(const BlockHeap *const bh)
429			{
430			return(((bh->blocksAllocated *
431			bh->elemsPerBlock)-bh->freeElems) *
432			(bh->elemSize + sizeof(MemBlock)));
433			}
434
435			/*! \brief Returns the number of bytes being free for further allocations
436			* \param bh Pointer to a BlockHeap
437			* \return Number of bytes being free for further allocations
438			*/
439			static size_t
440			block_heap_get_free_mem(const BlockHeap *const bh)
441			{
442			return(bh->freeElems * (bh->elemSize + sizeof(MemBlock)));
443			}
444
445			/*! \brief Returns the total number of bytes of memory belonging to a heap
446			* \param bh Pointer to a BlockHeap
447			* \return Total number of bytes of memory belonging to a heap
448			*/
449			static size_t
450			block_heap_get_size_mem(const BlockHeap *const bh)
451			{
452			return(((bh->blocksAllocated *
453			bh->elemsPerBlock)) *
454			(bh->elemSize + sizeof(MemBlock)));
455			}
456
457			/*! \brief Returns the number of elements being used.
458			* \param bh Pointer to a BlockHeap
459			* \return Number of elements being free for further allocations
460			*/
461			static unsigned int
462			block_heap_get_used_elm(const BlockHeap *const bh)
463			{
464			return((bh->blocksAllocated *
465			bh->elemsPerBlock)-bh->freeElems);
466			}
467
468			/*! \brief Returns the number of elements being free for further allocations.
469			* \param bh Pointer to a BlockHeap
470			* \return Number of elements being free for further allocations
471			*/
472			static unsigned int
473			block_heap_get_free_elm(const BlockHeap *const bh)
474			{
475			return(bh->freeElems);
476			}
477
478			/*! \brief Returns the number of total elements belonging to a heap.
479			* Includes \b free and \b used elements.
480			* \param bh Pointer to a BlockHeap
481			* \return Number of total elements belonging to a heap
482			*/
483			static unsigned int
484			block_heap_get_size_elm(const BlockHeap *const bh)
485			{
486			return(bh->blocksAllocated * bh->elemsPerBlock);
487			}
488
489			void
490			block_heap_report_stats(struct Client *client_p)
491			{
492			const BlockHeap *bh = NULL;
493
494			for (bh = heap_list; bh != NULL; bh = bh->next)
495			sendto_one(client_p, ":%s %d %s z :%s mempool: used %u/%u free %u/%u (size %u/%u)",
496			me.name, RPL_STATSDEBUG, client_p->name, bh->name,
497			block_heap_get_used_elm(bh),
498			block_heap_get_used_mem(bh),
499			block_heap_get_free_elm(bh),
500			block_heap_get_free_mem(bh),
501			block_heap_get_size_elm(bh),
502			block_heap_get_size_mem(bh));
503			}