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 (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 * 26 * iexpr.c -- instanced expression cache module 27 * 28 * this module provides a cache of fully instantized expressions. 29 */ 30 31 #pragma ident "%Z%%M% %I% %E% SMI" 32 33 #include <stdio.h> 34 #include <string.h> 35 #include "alloc.h" 36 #include "out.h" 37 #include "lut.h" 38 #include "tree.h" 39 #include "ptree.h" 40 #include "itree.h" 41 #include "ipath.h" 42 #include "iexpr.h" 43 #include "stats.h" 44 #include "eval.h" 45 #include "config.h" 46 47 #define IEXPRSZ 1024 /* hash table size */ 48 49 static struct stats *Niexpr; 50 51 /* the cache is a hash table of these structs */ 52 static struct iexpr { 53 struct node *np; 54 struct iexpr *next; /* next entry in hash bucket */ 55 int count; 56 } *Cache[IEXPRSZ]; 57 58 /* 59 * iexpr_init -- initialize the iexpr module 60 */ 61 void 62 iexpr_init(void) 63 { 64 Niexpr = stats_new_counter("iexpr.niexpr", "iexpr cache entries", 1); 65 } 66 67 /* 68 * iexpr_hash -- produce a simple hash from an instanced expression tree 69 */ 70 static unsigned 71 iexpr_hash(struct node *np) 72 { 73 if (np == NULL) 74 return (1); 75 76 switch (np->t) { 77 case T_GLOBID: 78 return ((int)np->u.globid.s); 79 80 case T_ASSIGN: 81 case T_CONDIF: 82 case T_CONDELSE: 83 case T_NE: 84 case T_EQ: 85 case T_LT: 86 case T_LE: 87 case T_GT: 88 case T_GE: 89 case T_BITAND: 90 case T_BITOR: 91 case T_BITXOR: 92 case T_BITNOT: 93 case T_LSHIFT: 94 case T_RSHIFT: 95 case T_LIST: 96 case T_AND: 97 case T_OR: 98 case T_NOT: 99 case T_ADD: 100 case T_SUB: 101 case T_MUL: 102 case T_DIV: 103 case T_MOD: 104 return ((int)np->t * 105 (iexpr_hash(np->u.expr.left) + 106 iexpr_hash(np->u.expr.right))); 107 108 case T_NAME: 109 return ((int)np->u.name.s); 110 111 case T_EVENT: 112 return (iexpr_hash(np->u.event.ename) + 113 iexpr_hash(np->u.event.epname)); 114 115 case T_FUNC: 116 return ((int)np->u.func.s + 117 iexpr_hash(np->u.func.arglist)); 118 119 case T_QUOTE: 120 return ((int)np->u.quote.s); 121 122 case T_NUM: 123 return ((int)np->u.ull); 124 125 default: 126 outfl(O_DIE, np->file, np->line, 127 "iexpr_hash: unexpected node type: %s", 128 ptree_nodetype2str(np->t)); 129 } 130 /*NOTREACHED*/ 131 return (1); 132 } 133 134 /* 135 * iexpr_cmp -- compare two instanced expression trees 136 */ 137 static int 138 iexpr_cmp(struct node *np1, struct node *np2) 139 { 140 int diff; 141 142 if (np1 == np2) 143 return (0); 144 145 if (np1 == NULL) 146 return (1); 147 148 if (np2 == NULL) 149 return (-1); 150 151 if (np1->t != np2->t) 152 return (np2->t - np1->t); 153 154 /* types match, need to see additional info matches */ 155 switch (np1->t) { 156 case T_GLOBID: 157 return (np2->u.globid.s - np1->u.globid.s); 158 159 case T_ASSIGN: 160 case T_CONDIF: 161 case T_CONDELSE: 162 case T_NE: 163 case T_EQ: 164 case T_LT: 165 case T_LE: 166 case T_GT: 167 case T_GE: 168 case T_BITAND: 169 case T_BITOR: 170 case T_BITXOR: 171 case T_BITNOT: 172 case T_LSHIFT: 173 case T_RSHIFT: 174 case T_LIST: 175 case T_AND: 176 case T_OR: 177 case T_NOT: 178 case T_ADD: 179 case T_SUB: 180 case T_MUL: 181 case T_DIV: 182 case T_MOD: 183 diff = iexpr_cmp(np1->u.expr.left, np2->u.expr.left); 184 if (diff != 0) 185 return (diff); 186 return (iexpr_cmp(np1->u.expr.right, np2->u.expr.right)); 187 188 case T_NAME: 189 if (np2->u.name.s != np1->u.name.s) 190 return (np2->u.name.s - np1->u.name.s); 191 diff = iexpr_cmp(np1->u.name.child, np2->u.name.child); 192 if (diff != 0) 193 return (diff); 194 return (iexpr_cmp(np1->u.name.next, np2->u.name.next)); 195 196 case T_EVENT: 197 diff = iexpr_cmp(np1->u.event.ename, np2->u.event.ename); 198 if (diff != 0) 199 return (diff); 200 return (iexpr_cmp(np1->u.event.epname, np2->u.event.epname)); 201 202 case T_FUNC: 203 if (np1->u.func.s != np2->u.func.s) 204 return (np2->u.func.s - np1->u.func.s); 205 return (iexpr_cmp(np1->u.func.arglist, np2->u.func.arglist)); 206 207 case T_QUOTE: 208 return (np2->u.quote.s - np1->u.quote.s); 209 210 case T_NUM: 211 if (np2->u.ull > np1->u.ull) 212 return (1); 213 else if (np1->u.ull > np2->u.ull) 214 return (-1); 215 else 216 return (0); 217 218 default: 219 outfl(O_DIE, np1->file, np1->line, 220 "iexpr_cmp: unexpected node type: %s", 221 ptree_nodetype2str(np1->t)); 222 } 223 /*NOTREACHED*/ 224 return (0); 225 } 226 227 /* 228 * iexpr -- find instanced expr in cache, or add it if necessary 229 */ 230 struct node * 231 iexpr(struct node *np) 232 { 233 unsigned idx = iexpr_hash(np) % IEXPRSZ; 234 struct iexpr *bucketp = Cache[idx]; 235 struct iexpr *cp; 236 237 /* search cache */ 238 for (cp = bucketp; cp != NULL; cp = cp->next) 239 if (iexpr_cmp(cp->np, np) == 0) { 240 /* found it */ 241 tree_free(np); 242 cp->count++; 243 return (cp->np); 244 } 245 246 /* allocate new cache entry */ 247 cp = MALLOC(sizeof (*cp)); 248 cp->np = np; 249 cp->next = bucketp; 250 cp->count = 1; 251 Cache[idx] = cp; 252 253 stats_counter_bump(Niexpr); 254 255 return (np); 256 } 257 258 void 259 iexpr_free(struct node *np) 260 { 261 unsigned idx = iexpr_hash(np) % IEXPRSZ; 262 struct iexpr *cp; 263 struct iexpr *prevcp = NULL; 264 265 /* search cache */ 266 for (cp = Cache[idx]; cp != NULL; cp = cp->next) { 267 if (iexpr_cmp(cp->np, np) == 0) { 268 /* found it */ 269 cp->count--; 270 if (cp->count == 0) { 271 tree_free(cp->np); 272 if (prevcp == NULL) 273 Cache[idx] = cp->next; 274 else 275 prevcp->next = cp->next; 276 FREE(cp); 277 } 278 return; 279 } 280 prevcp = cp; 281 } 282 } 283 284 /* 285 * iexpr_cached -- return true if np is in the iexpr cache 286 */ 287 int 288 iexpr_cached(struct node *np) 289 { 290 struct iexpr *cp = Cache[iexpr_hash(np) % IEXPRSZ]; 291 292 /* search cache */ 293 for (; cp != NULL; cp = cp->next) 294 if (iexpr_cmp(cp->np, np) == 0) { 295 /* found it */ 296 return (1); 297 } 298 299 return (0); 300 } 301 302 /* 303 * iexpr_fini -- free the iexpr cache 304 */ 305 void 306 iexpr_fini(void) 307 { 308 int i; 309 310 for (i = 0; i < IEXPRSZ; i++) { 311 struct iexpr *cp; 312 struct iexpr *ncp; 313 314 for (cp = Cache[i]; cp != NULL; cp = ncp) { 315 tree_free(cp->np); 316 ncp = cp->next; 317 FREE(cp); 318 } 319 Cache[i] = NULL; 320 } 321 } 322