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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-13 12:24:36 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-13 12:24:36 +0000 |
commit | 06eaf7232e9a920468c0f8d74dcf2fe8b555501c (patch) | |
tree | e2c7b5777f728320e5b5542b6213fd3591ba51e2 /storage/maria/ma_checkpoint.h | |
parent | Initial commit. (diff) | |
download | mariadb-06eaf7232e9a920468c0f8d74dcf2fe8b555501c.tar.xz mariadb-06eaf7232e9a920468c0f8d74dcf2fe8b555501c.zip |
Adding upstream version 1:10.11.6.upstream/1%10.11.6
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'storage/maria/ma_checkpoint.h')
-rw-r--r-- | storage/maria/ma_checkpoint.h | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/storage/maria/ma_checkpoint.h b/storage/maria/ma_checkpoint.h new file mode 100644 index 00000000..c719c3cf --- /dev/null +++ b/storage/maria/ma_checkpoint.h @@ -0,0 +1,92 @@ +/* Copyright (C) 2006,2007 MySQL AB + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */ + +/* + WL#3071 Maria checkpoint + First version written by Guilhem Bichot on 2006-04-27. + Does not compile yet. +*/ + +/* This is the interface of this module. */ + +typedef enum enum_ma_checkpoint_level { + CHECKPOINT_NONE= 0, + /* just write dirty_pages, transactions table and sync files */ + CHECKPOINT_INDIRECT, + /* also flush all dirty pages which were already dirty at prev checkpoint */ + CHECKPOINT_MEDIUM, + /* also flush all dirty pages */ + CHECKPOINT_FULL +} CHECKPOINT_LEVEL; + +C_MODE_START +int ma_checkpoint_init(ulong interval); +void ma_checkpoint_end(void); +int ma_checkpoint_execute(CHECKPOINT_LEVEL level, my_bool no_wait); +C_MODE_END + +/** + @brief reads some LSNs with special trickery + + If a 64-bit variable transitions between both halves being zero to both + halves being non-zero, and back, this function can be used to do a read of + it (without mutex, without atomic load) which always produces a correct + (though maybe slightly old) value (even on 32-bit CPUs). The value is at + least as new as the latest mutex unlock done by the calling thread. + The assumption is that the system sets both 4-byte halves either at the + same time, or one after the other (in any order), but NOT some bytes of the + first half then some bytes of the second half then the rest of bytes of the + first half. With this assumption, the function can detect when it is + seeing an inconsistent value. + + @param LSN pointer to the LSN variable to read + + @return LSN part (most significant byte always 0) +*/ +#if ( SIZEOF_CHARP >= 8 ) +/* 64-bit CPU, 64-bit reads are atomic */ +#define lsn_read_non_atomic LSN_WITH_FLAGS_TO_LSN +#else +static inline LSN lsn_read_non_atomic_32(const volatile LSN *x) +{ + /* + 32-bit CPU, 64-bit reads may give a mixed of old half and new half (old + low bits and new high bits, or the contrary). + */ + for (;;) /* loop until no atomicity problems */ + { + /* + Remove most significant byte in case this is a LSN_WITH_FLAGS object. + Those flags in TRN::first_undo_lsn break the condition on transitions so + they must be removed below. + */ + LSN y= LSN_WITH_FLAGS_TO_LSN(*x); + if (likely((y == LSN_IMPOSSIBLE) || LSN_VALID(y))) + return y; + } +} +#define lsn_read_non_atomic(x) lsn_read_non_atomic_32(&x) +#endif + +/** + prints a message from a task not connected to any user (checkpoint + and recovery for example). + + @param level 0 if error, ME_WARNING if warning, + ME_NOTE if info + @param sentence text to write +*/ +#define ma_message_no_user(level, sentence) \ + my_printf_error(HA_ERR_GENERIC, "Aria engine: %s", MYF(level), sentence) |