ircd-hybrid-7.2/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 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 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));
}
1	/*
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	* \version $Id$
31	*
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
54	#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	#include "list.h"
67	#include "balloc.h"
68	#include "memory.h"
69	#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 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	static fde_t dpfd;
101	#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	int zero_fd = open("/dev/zero", O_RDWR);
113
114	if (zero_fd < 0)
115	outofmemory();
116	fd_open(&dpfd, zero_fd, 0, "Anonymous mmap()");
117	#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 void *
127	get_block(size_t size)
128	{
129	#ifdef HAVE_MMAP
130	void *ptr = NULL;
131
132	#ifndef MAP_ANON
133	ptr = mmap(NULL, size, PROT_READ \| PROT_WRITE, MAP_PRIVATE, dpfd.fd, 0);
134	#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	offset = (void *)((size_t)offset + bh->elemSize + sizeof(MemBlock));
189	}
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	assert(bh != NULL);
343
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	}
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