3 * Resource pool handling
5 * (c) 2000 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of the mLib utilities library.
12 * mLib is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU Library General Public License as
14 * published by the Free Software Foundation; either version 2 of the
15 * License, or (at your option) any later version.
17 * mLib 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 Library General Public License for more details.
22 * You should have received a copy of the GNU Library General Public
23 * License along with mLib; if not, write to the Free
24 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
28 /*----- Header files ------------------------------------------------------*/
34 #ifdef HAVE_VALGRIND_VALGRIND_H
35 # include <valgrind/valgrind.h>
36 # include <valgrind/memcheck.h>
47 /*----- Constants ---------------------------------------------------------*/
49 #define REDZONE_SIZE (2*ALIGNOF(union align))
51 /*----- Main code ---------------------------------------------------------*/
53 /* --- @doalloc@ --- *
55 * Arguments: @arena *a@ = pointer to arena to allocate memory from
56 * @pool_chunk **cc@ = pointer to chunk list
57 * @size_t sz@ = size of memory wanted
58 * @unsigned f@ = flags (@PF_...@)
60 * Returns: Pointer to the allocated block.
62 * Use: The basic allocator for resource pools. This is also used
63 * during pool creation, hence the slightly bizarre interface.
66 static void *doalloc(arena *a, pool_chunk **cc, size_t sz, unsigned f)
71 size_t redsz = VG( f&PF_VALGRIND ? REDZONE_SIZE : ) 0;
72 VG( size_t sz0 = sz; )
74 /* --- See if there's enough space --- *
76 * The chunks are sorted by available space, so if there's not enough space
77 * in the first chunk there isn't enough space anywhere.
80 ALIGN(sz); sz += redsz;
82 if (c && c->left >= sz) {
83 p = c->p; VG( if (f&PF_VALGRIND) VALGRIND_MEMPOOL_ALLOC(c, p, sz0); )
84 c->p += sz; c->left -= sz;
88 /* --- Failed to find anything --- *
90 * I must allocate a new block from the arena, then.
94 ssz = sizeof(pool_chunk);
96 csz = (ssz + redsz + sz + POOL_CHUNKSZ - 1); csz -= csz % POOL_CHUNKSZ;
98 p = (unsigned char *)c + ssz + redsz;
99 VG( if (f&PF_VALGRIND) {
100 VALGRIND_CREATE_MEMPOOL(c, REDZONE_SIZE, 0);
101 VALGRIND_MEMPOOL_ALLOC(c, p, sz0);
103 c->p = (unsigned char *)p + sz;
104 c->left = csz - ssz - redsz - sz;
107 /* --- Move this chunk in the list so that it's sorted --- */
109 while (*cc && (*cc)->left > c->left) cc = &(*cc)->next;
110 c->next = *cc; *cc = c;
117 /* --- @pool_alloc@ --- *
119 * Arguments: @pool *p@ = pool to allocate from
120 * @size_t sz@ = size of block wanted
122 * Returns: Pointer to the requested block.
124 * Use: Allocates memory from a resource pool. Memory is never freed
125 * from pools: it is released when the pool is destroyed.
128 void *pool_alloc(pool *p, size_t sz)
129 { return (doalloc(p->pa, &p->c, sz, p->f)); }
131 /* --- @pool_strdup@ --- *
133 * Arguments: @pool *p@ = pool to allocate from
134 * @const char *s@ = pointer to string
136 * Returns: A pointer to a copy of the string.
138 * Use: Allocates a copy of a string.
141 char *pool_strdup(pool *p, const char *s)
143 size_t sz = strlen(s) + 1;
144 char *pp = doalloc(p->pa, &p->c, sz, p->f);
150 /* --- Arena operations --- */
152 static void *palloc(arena *a, size_t sz)
156 return (doalloc(p->pa, &p->c, sz, p->f));
159 static void pfree(arena *a, void *p) { return; } /* Trivial */
161 static arena_ops pool_ops = { palloc, arena_fakerealloc, pfree, 0 };
163 /* --- @pool_create@ --- *
165 * Arguments: @arena *a@ = pointer to an arena to allocate memory from
167 * Returns: A newly created resource pool.
169 * Use: Creates a resource pool which is not a child of any other
173 pool *pool_create(arena *a)
179 VG( if (RUNNING_ON_VALGRIND) f |= PF_VALGRIND; )
180 p = doalloc(a, &c, sizeof(pool), f);
181 p->c = c; p->r = 0; p->pa = a; p->f = f;
182 p->a.ops = &pool_ops;
186 /* --- @pool_destroy@ --- *
188 * Arguments: @pool *p@ = pointer to pool to destroy
192 * Use: Destroys a pool, freeing all of the resources within it. If
193 * this is a pool created by @pool_create@, its memory will be
194 * deallocated; if it's a subpool or it was initialized by
195 * @pool_init@, it is emptied and can be used again.
198 void pool_destroy(pool *p)
200 pool_resource *r, *rr;
204 /* --- Dispose of all of the resources --- */
215 /* --- Free all of the memory --- *
217 * Since root pools are allocated in their own memory, this will free the
218 * root pool block. Subpools are allocated in their parent's memory, so
219 * the pool block itself will be left around.
222 a = p->pa; c = p->c; p->c = 0;
225 VG( if (p->f&PF_VALGRIND) VALGRIND_DESTROY_MEMPOOL(c); )
231 /* --- @pool_add@ --- *
233 * Arguments: @pool *p@ = pointer to pool to add the resource to
234 * @pool_resource *r@ = pointer to resource block
235 * @void (*dfn)(pool_resource *r)@ = destruction function
239 * Use: Adds a resource to a pool.
242 void pool_add(pool *p, pool_resource *r, void (*dfn)(pool_resource *r))
247 /* --- @pool_sub@ --- *
249 * Arguments: @pool *p@ = pointer to parent pool
251 * Returns: A new child pool of the parent.
253 * Use: Creates a subpool. The subpool can either be destroyed on
254 * its own, or will be automatically destroyed at the same time
258 typedef struct subpool {
263 static void subpool_destroy(pool_resource *r)
265 subpool *p = (subpool *)r;
269 pool *pool_sub(pool *p)
271 subpool *pp = pool_alloc(p, sizeof(subpool));
272 POOL_ADD(p, &pp->r, subpool_destroy);
273 pp->p.a.ops = &pool_ops;
280 /*----- That's all, folks -------------------------------------------------*/