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 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #ifndef _SYS_LCHAN_IMPL_H 28 #define _SYS_LCHAN_IMPL_H 29 30 #pragma ident "%Z%%M% %I% %E% SMI" 31 32 #ifdef __cplusplus 33 extern "C" { 34 #endif 35 36 #define LWPCHAN_CVPOOL 0 37 #define LWPCHAN_MPPOOL 1 38 39 #define LWPCHAN_INITIAL_BITS 2 /* initially: 4 hash buckets */ 40 #define LWPCHAN_MAX_BITS 16 /* finally: up to 64K hash buckets */ 41 42 /* 43 * An lwpchan entry translates a process-shared lwp sync object's 44 * virtual address into its logical address, an lwpchan, previously 45 * computed via as_getmemid(). 46 */ 47 typedef struct lwpchan_entry { 48 caddr_t lwpchan_addr; /* virtual address */ 49 uint16_t lwpchan_type; /* sync object type field */ 50 uint16_t lwpchan_pool; /* LWPCHAN_CVPOOL/LWPCHAN_MPPOOL */ 51 lwpchan_t lwpchan_lwpchan; /* unique logical address */ 52 struct lwpchan_entry *lwpchan_next; /* hash chain */ 53 } lwpchan_entry_t; 54 55 /* 56 * Hash bucket head. The mutex protects the consistency of the hash chain. 57 * Also, p->p_lcp cannot be changed while any one hash bucket lock is held. 58 * (The resizing thread must acquire all of the hash bucket locks.) 59 */ 60 typedef struct lwpchan_hashbucket { 61 kmutex_t lwpchan_lock; 62 lwpchan_entry_t *lwpchan_chain; 63 } lwpchan_hashbucket_t; 64 65 /* 66 * Each process maintains a cache of lwpchan translations for sync objects 67 * (lwp_mutex_t, lwp_cond_t, lwp_sema_t) that are shared between processes. 68 * The lwpchan cache is a hash table used to look up previously-computed 69 * lwpchan_t's by process virtual address. We keep this cache because we 70 * believe that as_getmemid() is slow and we only need to call it once, 71 * then remember the results. The hashing function is very simple, and 72 * assumes an even distribution of sync objects within the process's 73 * address space. When hash chains become too long, the cache is resized 74 * on the fly. The cache is freed when the process exits or execs. 75 */ 76 typedef struct lwpchan_data { 77 uint_t lwpchan_bits; /* number of bits */ 78 uint_t lwpchan_size; /* 1 << lwpchan_bits */ 79 uint_t lwpchan_mask; /* lwpchan_size - 1 */ 80 uint_t lwpchan_entries; /* number of entries in the cache */ 81 lwpchan_hashbucket_t *lwpchan_cache; 82 struct lwpchan_data *lwpchan_next_data; 83 } lwpchan_data_t; 84 85 /* 86 * exported functions 87 */ 88 void lwpchan_delete_mapping(proc_t *, caddr_t start, caddr_t end); 89 void lwpchan_destroy_cache(int); 90 91 #ifdef __cplusplus 92 } 93 #endif 94 95 #endif /* _SYS_LCHAN_IMPL_H */ 96