xref: /freebsd/sys/contrib/openzfs/lib/libspl/include/umem.h (revision d4eeb02986980bf33dd56c41ceb9fc5f180c0d47)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or https://opensource.org/licenses/CDDL-1.0.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #ifndef _LIBSPL_UMEM_H
28 #define	_LIBSPL_UMEM_H
29 
30 /*
31  * XXX: We should use the real portable umem library if it is detected
32  * at configure time.  However, if the library is not available, we can
33  * use a trivial malloc based implementation.  This obviously impacts
34  * performance, but unless you are using a full userspace build of zpool for
35  * something other than ztest, you are likely not going to notice or care.
36  *
37  * https://labs.omniti.com/trac/portableumem
38  */
39 #include <sys/debug.h>
40 
41 #include <stdlib.h>
42 #include <stdio.h>
43 #include <string.h>
44 
45 #ifdef  __cplusplus
46 extern "C" {
47 #endif
48 
49 typedef void vmem_t;
50 
51 /*
52  * Flags for umem_alloc/umem_free
53  */
54 #define	UMEM_DEFAULT		0x0000  /* normal -- may fail */
55 #define	UMEM_NOFAIL		0x0100  /* Never fails */
56 
57 /*
58  * Flags for umem_cache_create()
59  */
60 #define	UMC_NODEBUG		0x00020000
61 
62 #define	UMEM_CACHE_NAMELEN	31
63 
64 typedef int umem_nofail_callback_t(void);
65 typedef int umem_constructor_t(void *, void *, int);
66 typedef void umem_destructor_t(void *, void *);
67 typedef void umem_reclaim_t(void *);
68 
69 typedef struct umem_cache {
70 	char			cache_name[UMEM_CACHE_NAMELEN + 1];
71 	size_t			cache_bufsize;
72 	size_t			cache_align;
73 	umem_constructor_t	*cache_constructor;
74 	umem_destructor_t	*cache_destructor;
75 	umem_reclaim_t		*cache_reclaim;
76 	void			*cache_private;
77 	void			*cache_arena;
78 	int			cache_cflags;
79 } umem_cache_t;
80 
81 /* Prototypes for functions to provide defaults for umem envvars */
82 const char *_umem_debug_init(void);
83 const char *_umem_options_init(void);
84 const char *_umem_logging_init(void);
85 
86 static inline void *
87 umem_alloc(size_t size, int flags)
88 {
89 	void *ptr = NULL;
90 
91 	do {
92 		ptr = malloc(size);
93 	} while (ptr == NULL && (flags & UMEM_NOFAIL));
94 
95 	return (ptr);
96 }
97 
98 static inline void *
99 umem_alloc_aligned(size_t size, size_t align, int flags)
100 {
101 	void *ptr = NULL;
102 	int rc = EINVAL;
103 
104 	do {
105 		rc = posix_memalign(&ptr, align, size);
106 	} while (rc == ENOMEM && (flags & UMEM_NOFAIL));
107 
108 	if (rc == EINVAL) {
109 		fprintf(stderr, "%s: invalid memory alignment (%zd)\n",
110 		    __func__, align);
111 		if (flags & UMEM_NOFAIL)
112 			abort();
113 		return (NULL);
114 	}
115 
116 	return (ptr);
117 }
118 
119 static inline void *
120 umem_zalloc(size_t size, int flags)
121 {
122 	void *ptr = NULL;
123 
124 	ptr = umem_alloc(size, flags);
125 	if (ptr)
126 		memset(ptr, 0, size);
127 
128 	return (ptr);
129 }
130 
131 static inline void
132 umem_free(const void *ptr, size_t size __maybe_unused)
133 {
134 	free((void *)ptr);
135 }
136 
137 static inline void
138 umem_nofail_callback(umem_nofail_callback_t *cb __maybe_unused)
139 {}
140 
141 static inline umem_cache_t *
142 umem_cache_create(
143     const char *name, size_t bufsize, size_t align,
144     umem_constructor_t *constructor,
145     umem_destructor_t *destructor,
146     umem_reclaim_t *reclaim,
147     void *priv, void *vmp, int cflags)
148 {
149 	umem_cache_t *cp;
150 
151 	cp = (umem_cache_t *)umem_alloc(sizeof (umem_cache_t), UMEM_DEFAULT);
152 	if (cp) {
153 		strlcpy(cp->cache_name, name, UMEM_CACHE_NAMELEN);
154 		cp->cache_bufsize = bufsize;
155 		cp->cache_align = align;
156 		cp->cache_constructor = constructor;
157 		cp->cache_destructor = destructor;
158 		cp->cache_reclaim = reclaim;
159 		cp->cache_private = priv;
160 		cp->cache_arena = vmp;
161 		cp->cache_cflags = cflags;
162 	}
163 
164 	return (cp);
165 }
166 
167 static inline void
168 umem_cache_destroy(umem_cache_t *cp)
169 {
170 	umem_free(cp, sizeof (umem_cache_t));
171 }
172 
173 static inline void *
174 umem_cache_alloc(umem_cache_t *cp, int flags)
175 {
176 	void *ptr = NULL;
177 
178 	if (cp->cache_align != 0)
179 		ptr = umem_alloc_aligned(
180 		    cp->cache_bufsize, cp->cache_align, flags);
181 	else
182 		ptr = umem_alloc(cp->cache_bufsize, flags);
183 
184 	if (ptr && cp->cache_constructor)
185 		cp->cache_constructor(ptr, cp->cache_private, UMEM_DEFAULT);
186 
187 	return (ptr);
188 }
189 
190 static inline void
191 umem_cache_free(umem_cache_t *cp, void *ptr)
192 {
193 	if (cp->cache_destructor)
194 		cp->cache_destructor(ptr, cp->cache_private);
195 
196 	umem_free(ptr, cp->cache_bufsize);
197 }
198 
199 static inline void
200 umem_cache_reap_now(umem_cache_t *cp __maybe_unused)
201 {
202 }
203 
204 #ifdef  __cplusplus
205 }
206 #endif
207 
208 #endif
209