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 http://www.opensolaris.org/os/licensing. 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 2004 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include "streams_mmap.h" 30 #include "streams_common.h" 31 32 /* 33 * Single-byte character memory map-based streams implementation 34 */ 35 36 static int 37 stream_mmap_prime(stream_t *str) 38 { 39 char *nl; 40 41 if (stream_is_primed(str)) 42 return (PRIME_SUCCEEDED); 43 44 stream_set(str, STREAM_PRIMED); 45 46 if (str->s_buffer_size == 0) { 47 stream_set(str, STREAM_EOS_REACHED); 48 return (PRIME_FAILED_EMPTY_FILE); 49 } 50 51 str->s_current.l_data.sp = str->s_buffer; 52 str->s_type.SF.s_release_origin = str->s_buffer; 53 if ((nl = (char *)memchr(str->s_buffer, '\n', str->s_buffer_size)) == 54 NULL) { 55 warn(WMSG_NEWLINE_ADDED, str->s_filename); 56 str->s_current.l_data_length = str->s_buffer_size; 57 } else { 58 str->s_current.l_data_length = nl - (char *)str->s_buffer; 59 } 60 61 str->s_current.l_collate.sp = NULL; 62 str->s_current.l_collate_length = 0; 63 64 __S(stats_incr_fetches()); 65 return (PRIME_SUCCEEDED); 66 } 67 68 /* 69 * stream_mmap_fetch() sets the fields of str->s_current to delimit the next 70 * line of the field. 71 */ 72 static ssize_t 73 stream_mmap_fetch(stream_t *str) 74 { 75 ssize_t dist_to_buf_end; 76 char *next_nl; 77 78 ASSERT(stream_is_primed(str)); 79 ASSERT((str->s_status & STREAM_EOS_REACHED) == 0); 80 81 /* 82 * adding one for newline 83 */ 84 str->s_current.l_data.sp = str->s_current.l_data.sp + 85 str->s_current.l_data_length + 1; 86 87 dist_to_buf_end = str->s_buffer_size - (str->s_current.l_data.sp 88 - (char *)str->s_buffer); 89 ASSERT(dist_to_buf_end >= 0 && dist_to_buf_end <= str->s_buffer_size); 90 91 next_nl = memchr(str->s_current.l_data.sp, '\n', dist_to_buf_end); 92 93 if (next_nl) 94 str->s_current.l_data_length = next_nl 95 - str->s_current.l_data.sp; 96 else { 97 warn(WMSG_NEWLINE_ADDED, str->s_filename); 98 str->s_current.l_data_length = dist_to_buf_end; 99 } 100 101 /* 102 * adding one for newline 103 */ 104 if (str->s_current.l_data.sp + str->s_current.l_data_length + 1 >= 105 (char *)str->s_buffer + str->s_buffer_size) 106 stream_set(str, STREAM_EOS_REACHED); 107 108 str->s_current.l_collate_length = 0; 109 110 __S(stats_incr_fetches()); 111 return (NEXT_LINE_COMPLETE); 112 } 113 114 static int 115 stream_mmap_is_closable(stream_t *str) 116 { 117 if (str->s_status & STREAM_OPEN) 118 return (1); 119 return (0); 120 } 121 122 static int 123 stream_mmap_close(stream_t *str) 124 { 125 if (str->s_type.SF.s_fd > -1) { 126 (void) close(str->s_type.SF.s_fd); 127 stream_unset(str, STREAM_OPEN); 128 return (1); 129 } 130 131 return (0); 132 } 133 134 static int 135 stream_mmap_free(stream_t *str) 136 { 137 if (!(str->s_status & STREAM_OPEN) || 138 (str->s_consumer != NULL && 139 str->s_consumer->s_status & STREAM_NOT_FREEABLE)) 140 return (0); 141 142 if (str->s_buffer == NULL) 143 return (1); 144 145 if (munmap(str->s_buffer, str->s_buffer_size) < 0) 146 die(EMSG_MUNMAP, str->s_filename); 147 148 str->s_buffer = NULL; 149 str->s_buffer_size = 0; 150 151 stream_unset(str, STREAM_PRIMED); 152 153 return (1); 154 } 155 156 static int 157 stream_mmap_eos(stream_t *str) 158 { 159 int retval = 0; 160 161 if (str == NULL || str->s_status & STREAM_EOS_REACHED) 162 return (1); 163 164 /* 165 * If the file's size is known to be zero, then we are at EOS; the 166 * remaining checks are only sensible if we successfully primed this 167 * stream. The additional character is for the optional newline. 168 */ 169 if (str->s_filesize == 0 || 170 (stream_is_primed(str) && str->s_current.l_data.sp - 171 (char *)str->s_buffer + str->s_current.l_data_length + 1 >= 172 str->s_buffer_size)) { 173 retval = 1; 174 stream_set(str, STREAM_EOS_REACHED); 175 } 176 177 return (retval); 178 } 179 180 #define ALIGNED (~(ulong_t)(PAGESIZE - 1)) 181 182 /* 183 * In certain cases, we know that we will never need the data on a page again 184 * for the duration of the sort. (These cases are associated with merges 185 * involving temporary files.) We can thus release all pages previous to the 186 * page containing the current line, using the MADV_DONTNEED flag to 187 * madvise(3C). This additional memory management improves our chances of 188 * avoiding a paging situation, by evicting pages we know are of no use. 189 */ 190 static void 191 stream_mmap_release_line(stream_t *str) 192 { 193 caddr_t origin = str->s_type.SF.s_release_origin; 194 size_t release = 0; 195 196 while ((caddr_t)((ulong_t)str->s_current.l_data.sp & ALIGNED) - 197 (origin + release) >= DEFAULT_RELEASE_SIZE) 198 release += DEFAULT_RELEASE_SIZE; 199 200 if (release == 0) 201 return; 202 203 if (madvise(origin, release, MADV_DONTNEED) == -1) 204 warn(gettext("madvise failed")); 205 206 str->s_type.SF.s_release_origin += release; 207 } 208 209 const stream_ops_t stream_mmap_ops = { 210 stream_mmap_is_closable, 211 stream_mmap_close, 212 stream_mmap_eos, 213 stream_mmap_fetch, 214 NULL, 215 stream_mmap_free, 216 NULL, 217 stream_mmap_prime, 218 NULL, 219 stream_mmap_release_line, 220 NULL, 221 stream_stdio_unlink 222 }; 223