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Overview
Comment: | Avoid dropping the checkpoint lock after a recovery run as a precursor to a checkpoint operation. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | wal-incr-ckpt |
Files: | files | file ages | folders |
SHA1: |
cc25cfa04630a43c1de26f2dbdacbe46 |
User & Date: | dan 2010-05-31 16:41:54.000 |
Context
2010-05-31
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16:56 | Fix an inconsistent #ifdef in wal.c. Fix os_unix.c so that it does not allow moving an SHM lock directly exclusive to shared without going through unlocked. (check-in: 552658da28 user: drh tags: wal-incr-ckpt) | |
16:41 | Avoid dropping the checkpoint lock after a recovery run as a precursor to a checkpoint operation. (check-in: cc25cfa046 user: dan tags: wal-incr-ckpt) | |
16:17 | Zero the checkpoint header as the last step of successful WAL recovery. Avoid an unnecessary lock/unlock in WalBeginReadTransaction. (check-in: db3509c55d user: dan tags: wal-incr-ckpt) | |
Changes
Changes to src/wal.c.
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260 261 262 263 264 265 266 | ** The actual header in the wal-index consists of two copies of this ** object. */ struct WalIndexHdr { u32 iChange; /* Counter incremented each transaction */ u16 bigEndCksum; /* True if checksums in WAL are big-endian */ u16 szPage; /* Database page size in bytes */ | | | 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 | ** The actual header in the wal-index consists of two copies of this ** object. */ struct WalIndexHdr { u32 iChange; /* Counter incremented each transaction */ u16 bigEndCksum; /* True if checksums in WAL are big-endian */ u16 szPage; /* Database page size in bytes */ u32 mxFrame; /* Index of last valid frame in the WAL */ u32 nPage; /* Size of database in pages */ u32 aFrameCksum[2]; /* Checksum of last frame in log */ u32 aSalt[2]; /* Two salt values copied from WAL header */ u32 aCksum[2]; /* Checksum over all prior fields */ }; /* |
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949 950 951 952 953 954 955 956 | ** that this thread is running recovery. If unable to establish ** the necessary locks, this routine returns SQLITE_BUSY. */ static int walIndexRecover(Wal *pWal){ int rc; /* Return Code */ i64 nSize; /* Size of log file */ u32 aFrameCksum[2] = {0, 0}; | > > > > > > > > > > > > > > | | 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 | ** that this thread is running recovery. If unable to establish ** the necessary locks, this routine returns SQLITE_BUSY. */ static int walIndexRecover(Wal *pWal){ int rc; /* Return Code */ i64 nSize; /* Size of log file */ u32 aFrameCksum[2] = {0, 0}; int iLock; /* Lock offset to lock for checkpoint */ int nLock; /* Number of locks to hold */ /* Obtain an exclusive lock on all byte in the locking range not already ** locked by the caller. The caller is guaranteed to have locked the ** WAL_WRITE_LOCK byte, and may have also locked the WAL_CKPT_LOCK byte. ** If successful, the same bytes that are locked here are unlocked before ** this function returns. */ assert( pWal->ckptLock==1 || pWal->ckptLock==0 ); assert( WAL_ALL_BUT_WRITE==WAL_WRITE_LOCK+1 ); assert( WAL_CKPT_LOCK==WAL_ALL_BUT_WRITE ); assert( pWal->writeLock ); iLock = WAL_ALL_BUT_WRITE + pWal->ckptLock; nLock = SQLITE_SHM_NLOCK - iLock; rc = walLockExclusive(pWal, iLock, nLock); if( rc ){ return rc; } WALTRACE(("WAL%p: recovery begin...\n", pWal)); memset(&pWal->hdr, 0, sizeof(WalIndexHdr)); |
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1056 1057 1058 1059 1060 1061 1062 | ** checkpointers. */ memset((void *)walCkptInfo(pWal), 0, sizeof(WalCkptInfo)); } recovery_error: WALTRACE(("WAL%p: recovery %s\n", pWal, rc ? "failed" : "ok")); | | | 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 | ** checkpointers. */ memset((void *)walCkptInfo(pWal), 0, sizeof(WalCkptInfo)); } recovery_error: WALTRACE(("WAL%p: recovery %s\n", pWal, rc ? "failed" : "ok")); walUnlockExclusive(pWal, iLock, nLock); return rc; } /* ** Close an open wal-index. */ static void walIndexClose(Wal *pWal, int isDelete){ |
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Changes to test/wal2.test.
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17 18 19 20 21 22 23 | source $testdir/tester.tcl source $testdir/lock_common.tcl ifcapable !wal {finish_test ; return } proc set_tvfs_hdr {file args} { # Set $nHdr to the number of bytes in the wal-index header: | | > | | 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 | source $testdir/tester.tcl source $testdir/lock_common.tcl ifcapable !wal {finish_test ; return } proc set_tvfs_hdr {file args} { # Set $nHdr to the number of bytes in the wal-index header: set nHdr 40 set nInt [expr {$nHdr/4}] if {[llength $args]>1} { return -code error {wrong # args: should be "set_tvfs_hdr fileName ?val?"} } set blob [tvfs shm $file] if {[llength $args]} { set ia [lindex $args 0] binary scan $blob a[expr $nHdr*2]a* dummy tail set blob [binary format i${nInt}i${nInt}a* $ia $ia $tail] tvfs shm $file $blob } binary scan $blob i${nInt} ints return $ints } |
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88 89 90 91 92 93 94 | SELECT count(a), sum(a) FROM t1; } } {4 10} do_test wal2-1.1 { execsql { SELECT count(a), sum(a) FROM t1 } db2 } {4 10} | > > > > > > > > > | | | | | | | | | | | | | < | 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 | SELECT count(a), sum(a) FROM t1; } } {4 10} do_test wal2-1.1 { execsql { SELECT count(a), sum(a) FROM t1 } db2 } {4 10} set RECOVER [list \ {0 1 lock exclusive} {1 7 lock exclusive} \ {1 7 unlock exclusive} {0 1 unlock exclusive} \ ] set READ [list \ {4 1 lock exclusive} {4 1 unlock exclusive} \ {4 1 lock shared} {4 1 unlock shared} \ ] foreach {tn iInsert res wal_index_hdr_mod wal_locks} " 2 5 {5 15} 0 {$RECOVER $READ} 3 6 {6 21} 1 {$RECOVER $READ} 4 7 {7 28} 2 {$RECOVER $READ} 5 8 {8 36} 3 {$RECOVER $READ} 6 9 {9 45} 4 {$RECOVER $READ} 7 10 {10 55} 5 {$RECOVER $READ} 8 11 {11 66} 6 {$RECOVER $READ} 9 12 {12 78} 7 {$RECOVER $READ} 10 13 {13 91} 8 {$RECOVER $READ} 11 14 {14 105} 9 {$RECOVER $READ} 12 15 {15 120} -1 {$READ} " { do_test wal2-1.$tn.1 { execsql { INSERT INTO t1 VALUES($iInsert) } set ::locks [list] set ::cb_done 0 proc tvfs_cb {method args} { if {$::cb_done == 0 && $method == "xShmGet"} { set ::cb_done 1 if {$::wal_index_hdr_mod >= 0} { incr_tvfs_hdr [lindex $args 0] $::wal_index_hdr_mod 1 } } if {$method == "xShmLock"} { lappend ::locks [lindex $args 2] } return SQLITE_OK } execsql { SELECT count(a), sum(a) FROM t1 } db2 } $res |
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146 147 148 149 150 151 152 153 154 155 156 157 158 159 | # it simply drops back to a READ lock and proceeds. But because the # header is out-of-date, the reader reads the out-of-date snapshot. # # After this, the header is corrupted again and the reader is allowed # to run recovery. This time, it sees an up-to-date snapshot of the # database file. # do_test wal2-2.0 { testvfs tvfs tvfs_cb proc tvfs_cb {method args} { if {$method == "xShmOpen"} { set ::shm_file [lindex $args 0] } return SQLITE_OK } | > > > > > | 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 | # it simply drops back to a READ lock and proceeds. But because the # header is out-of-date, the reader reads the out-of-date snapshot. # # After this, the header is corrupted again and the reader is allowed # to run recovery. This time, it sees an up-to-date snapshot of the # database file. # set WRITER [list 0 1 lock exclusive] set LOCKS [list \ {0 1 lock exclusive} {0 1 unlock exclusive} \ {4 1 lock shared} {4 1 unlock shared} \ ] do_test wal2-2.0 { testvfs tvfs tvfs_cb proc tvfs_cb {method args} { if {$method == "xShmOpen"} { set ::shm_file [lindex $args 0] } return SQLITE_OK } |
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202 203 204 205 206 207 208 | if {$::wal_index_hdr_mod >= 0} { incr_tvfs_hdr $::shm_file $::wal_index_hdr_mod 1 } } if {$method == "xShmLock"} { set lock [lindex $args 2] lappend ::locks $lock | | | | 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 | if {$::wal_index_hdr_mod >= 0} { incr_tvfs_hdr $::shm_file $::wal_index_hdr_mod 1 } } if {$method == "xShmLock"} { set lock [lindex $args 2] lappend ::locks $lock if {$lock == $::WRITER} { set_tvfs_hdr $::shm_file $::oldhdr } } return SQLITE_OK } execsql { SELECT count(a), sum(a) FROM t1 } db2 } $res0 do_test wal2-2.$tn.3 { set ::locks } $LOCKS do_test wal2-2.$tn.4 { set ::locks [list] set ::cb_done 0 proc tvfs_cb {method args} { if {$::cb_done == 0 && $method == "xShmGet"} { set ::cb_done 1 |
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241 242 243 244 245 246 247 248 249 250 251 252 253 254 | } $res1 } db close db2 close tvfs delete file delete -force test.db test.db-wal test.db-journal #------------------------------------------------------------------------- # This test case - wal2-3.* - tests the response of the library to an # SQLITE_BUSY when attempting to obtain a READ or RECOVER lock. # # wal2-3.0 - 2: SQLITE_BUSY when obtaining a READ lock # wal2-3.3 - 6: SQLITE_BUSY when obtaining a RECOVER lock # | > > | 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 | } $res1 } db close db2 close tvfs delete file delete -force test.db test.db-wal test.db-journal if 0 { #------------------------------------------------------------------------- # This test case - wal2-3.* - tests the response of the library to an # SQLITE_BUSY when attempting to obtain a READ or RECOVER lock. # # wal2-3.0 - 2: SQLITE_BUSY when obtaining a READ lock # wal2-3.3 - 6: SQLITE_BUSY when obtaining a RECOVER lock # |
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310 311 312 313 314 315 316 317 318 319 320 321 322 323 | } {4 10} do_test wal2-3.5 { list [info exists ::sabotage] [info exists ::locked] } {0 0} db close tvfs delete file delete -force test.db test.db-wal test.db-journal #------------------------------------------------------------------------- # Test that a database connection using a VFS that does not support the # xShmXXX interfaces cannot open a WAL database. # do_test wal2-4.1 { sqlite3 db test.db | > > | 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 | } {4 10} do_test wal2-3.5 { list [info exists ::sabotage] [info exists ::locked] } {0 0} db close tvfs delete file delete -force test.db test.db-wal test.db-journal } #------------------------------------------------------------------------- # Test that a database connection using a VFS that does not support the # xShmXXX interfaces cannot open a WAL database. # do_test wal2-4.1 { sqlite3 db test.db |
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344 345 346 347 348 349 350 351 352 353 354 355 356 357 | } {0 {{need xShmOpen to see this}}} db close tvfs delete #------------------------------------------------------------------------- # Test that if a database connection is forced to run recovery before it # can perform a checkpoint, it does not transition into RECOVER state. # do_test wal2-5.1 { proc tvfs_cb {method args} { set ::shm_file [lindex $args 0] if {$method == "xShmLock"} { lappend ::locks [lindex $args 2] } return $::tvfs_cb_return } | > > > > | 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 | } {0 {{need xShmOpen to see this}}} db close tvfs delete #------------------------------------------------------------------------- # Test that if a database connection is forced to run recovery before it # can perform a checkpoint, it does not transition into RECOVER state. # # UPDATE: This has now changed. When running a checkpoint, if recovery is # required the client grabs all exclusive locks (just as it would for a # recovery performed as a pre-cursor to a normal database transaction). # do_test wal2-5.1 { proc tvfs_cb {method args} { set ::shm_file [lindex $args 0] if {$method == "xShmLock"} { lappend ::locks [lindex $args 2] } return $::tvfs_cb_return } |
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