1 /*- 2 * Copyright (c) 2015 The FreeBSD Foundation 3 * 4 * This software was developed by Konstantin Belousov 5 * under sponsorship from the FreeBSD Foundation. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/types.h> 33 #include <sys/mman.h> 34 #include <sys/queue.h> 35 #include "namespace.h" 36 #include <stdlib.h> 37 #include "un-namespace.h" 38 39 #include "thr_private.h" 40 41 struct psh { 42 LIST_ENTRY(psh) link; 43 void *key; 44 void *val; 45 }; 46 47 LIST_HEAD(pshared_hash_head, psh); 48 #define HASH_SIZE 128 49 static struct pshared_hash_head pshared_hash[HASH_SIZE]; 50 #define PSHARED_KEY_HASH(key) (((unsigned long)(key) >> 8) % HASH_SIZE) 51 /* XXXKIB: lock could be split to per-hash chain, if appears contested */ 52 static struct urwlock pshared_lock = DEFAULT_URWLOCK; 53 54 void 55 __thr_pshared_init(void) 56 { 57 int i; 58 59 _thr_urwlock_init(&pshared_lock); 60 for (i = 0; i < HASH_SIZE; i++) 61 LIST_INIT(&pshared_hash[i]); 62 } 63 64 static void 65 pshared_rlock(struct pthread *curthread) 66 { 67 68 curthread->locklevel++; 69 _thr_rwl_rdlock(&pshared_lock); 70 } 71 72 static void 73 pshared_wlock(struct pthread *curthread) 74 { 75 76 curthread->locklevel++; 77 _thr_rwl_wrlock(&pshared_lock); 78 } 79 80 static void 81 pshared_unlock(struct pthread *curthread) 82 { 83 84 _thr_rwl_unlock(&pshared_lock); 85 curthread->locklevel--; 86 _thr_ast(curthread); 87 } 88 89 static void 90 pshared_gc(struct pthread *curthread) 91 { 92 struct pshared_hash_head *hd; 93 struct psh *h, *h1; 94 int error, i; 95 96 pshared_wlock(curthread); 97 for (i = 0; i < HASH_SIZE; i++) { 98 hd = &pshared_hash[i]; 99 LIST_FOREACH_SAFE(h, hd, link, h1) { 100 error = _umtx_op(NULL, UMTX_OP_SHM, UMTX_SHM_ALIVE, 101 h->val, NULL); 102 if (error == 0) 103 continue; 104 LIST_REMOVE(h, link); 105 munmap(h->val, PAGE_SIZE); 106 free(h); 107 } 108 } 109 pshared_unlock(curthread); 110 } 111 112 static void * 113 pshared_lookup(void *key) 114 { 115 struct pshared_hash_head *hd; 116 struct psh *h; 117 118 hd = &pshared_hash[PSHARED_KEY_HASH(key)]; 119 LIST_FOREACH(h, hd, link) { 120 if (h->key == key) 121 return (h->val); 122 } 123 return (NULL); 124 } 125 126 static int 127 pshared_insert(void *key, void **val) 128 { 129 struct pshared_hash_head *hd; 130 struct psh *h; 131 132 hd = &pshared_hash[PSHARED_KEY_HASH(key)]; 133 LIST_FOREACH(h, hd, link) { 134 if (h->key == key) { 135 if (h->val != *val) { 136 munmap(*val, PAGE_SIZE); 137 *val = h->val; 138 } 139 return (1); 140 } 141 } 142 143 h = malloc(sizeof(*h)); 144 if (h == NULL) 145 return (0); 146 h->key = key; 147 h->val = *val; 148 LIST_INSERT_HEAD(hd, h, link); 149 return (1); 150 } 151 152 static void * 153 pshared_remove(void *key) 154 { 155 struct pshared_hash_head *hd; 156 struct psh *h; 157 void *val; 158 159 hd = &pshared_hash[PSHARED_KEY_HASH(key)]; 160 LIST_FOREACH(h, hd, link) { 161 if (h->key == key) { 162 LIST_REMOVE(h, link); 163 val = h->val; 164 free(h); 165 return (val); 166 } 167 } 168 return (NULL); 169 } 170 171 static void 172 pshared_clean(void *key, void *val) 173 { 174 175 if (val != NULL) 176 munmap(val, PAGE_SIZE); 177 _umtx_op(NULL, UMTX_OP_SHM, UMTX_SHM_DESTROY, key, NULL); 178 } 179 180 void * 181 __thr_pshared_offpage(void *key, int doalloc) 182 { 183 struct pthread *curthread; 184 void *res; 185 int fd, ins_done; 186 187 curthread = _get_curthread(); 188 pshared_rlock(curthread); 189 res = pshared_lookup(key); 190 pshared_unlock(curthread); 191 if (res != NULL) 192 return (res); 193 fd = _umtx_op(NULL, UMTX_OP_SHM, doalloc ? UMTX_SHM_CREAT : 194 UMTX_SHM_LOOKUP, key, NULL); 195 if (fd == -1) 196 return (NULL); 197 res = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); 198 close(fd); 199 if (res == MAP_FAILED) 200 return (NULL); 201 pshared_wlock(curthread); 202 ins_done = pshared_insert(key, &res); 203 pshared_unlock(curthread); 204 if (!ins_done) { 205 pshared_clean(key, res); 206 res = NULL; 207 } 208 return (res); 209 } 210 211 void 212 __thr_pshared_destroy(void *key) 213 { 214 struct pthread *curthread; 215 void *val; 216 217 curthread = _get_curthread(); 218 pshared_wlock(curthread); 219 val = pshared_remove(key); 220 pshared_unlock(curthread); 221 pshared_clean(key, val); 222 pshared_gc(curthread); 223 } 224