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/******************************************************
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Mini-transaction buffer
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Created 11/26/1995 Heikki Tuuri
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*******************************************************/
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#include "page0types.h"
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/*******************************************************************
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Starts a mini-transaction and creates a mini-transaction handle
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and buffer in the memory buffer given by the caller. */
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/* out: mtr buffer which also acts as
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mtr_t* mtr) /* in: memory buffer for the mtr buffer */
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return(mtr_start(mtr));
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/*********************************************************************
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Releases the item in the slot given. */
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mtr_memo_slot_release(
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/*==================*/
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mtr_t* mtr, /* in: mtr */
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mtr_memo_slot_t* slot) /* in: memo slot */
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object = slot->object;
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if (UNIV_LIKELY(object != NULL)) {
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if (type <= MTR_MEMO_BUF_FIX) {
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buf_page_release((buf_block_t*)object, type, mtr);
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} else if (type == MTR_MEMO_S_LOCK) {
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rw_lock_s_unlock((rw_lock_t*)object);
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} else if (type == MTR_MEMO_X_LOCK) {
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rw_lock_x_unlock((rw_lock_t*)object);
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ut_ad(type == MTR_MEMO_MODIFY);
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ut_ad(mtr_memo_contains(mtr, object,
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MTR_MEMO_PAGE_X_FIX));
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rw_lock_x_unlock((rw_lock_t*)object);
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/**************************************************************
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Releases the mlocks and other objects stored in an mtr memo. They are released
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in the order opposite to which they were pushed to the memo. NOTE! It is
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essential that the x-rw-lock on a modified buffer page is not released before
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buf_page_note_modification is called for that page! Otherwise, some thread
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might race to modify it, and the flush list sort order on lsn would be
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mtr_t* mtr) /* in: mtr */
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mtr_memo_slot_t* slot;
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ut_ad(mtr->magic_n == MTR_MAGIC_N);
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ut_ad(mtr->state == MTR_COMMITTING); /* Currently only used in
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offset = dyn_array_get_data_size(memo);
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offset -= sizeof(mtr_memo_slot_t);
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slot = dyn_array_get_element(memo, offset);
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mtr_memo_slot_release(mtr, slot);
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/****************************************************************
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Writes the contents of a mini-transaction log, if any, to the database log. */
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mtr_log_reserve_and_write(
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/*======================*/
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mtr_t* mtr) /* in: mtr */
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first_data = dyn_block_get_data(mlog);
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if (mtr->n_log_recs > 1) {
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mlog_catenate_ulint(mtr, MLOG_MULTI_REC_END, MLOG_1BYTE);
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*first_data = (byte)((ulint)*first_data
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| MLOG_SINGLE_REC_FLAG);
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if (mlog->heap == NULL) {
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mtr->end_lsn = log_reserve_and_write_fast(
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first_data, dyn_block_get_used(mlog),
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&(mtr->start_lsn), &success);
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data_size = dyn_array_get_data_size(mlog);
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/* Open the database log for log_write_low */
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mtr->start_lsn = log_reserve_and_open(data_size);
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if (mtr->log_mode == MTR_LOG_ALL) {
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while (block != NULL) {
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log_write_low(dyn_block_get_data(block),
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dyn_block_get_used(block));
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block = dyn_array_get_next_block(mlog, block);
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ut_ad(mtr->log_mode == MTR_LOG_NONE);
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mtr->end_lsn = log_close();
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/*******************************************************************
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Commits a mini-transaction. */
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mtr_t* mtr) /* in: mini-transaction */
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ut_ad(mtr->magic_n == MTR_MAGIC_N);
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ut_ad(mtr->state == MTR_ACTIVE);
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mtr->state = MTR_COMMITTING;
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if (mtr->modifications) {
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mtr_log_reserve_and_write(mtr);
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/* We first update the modification info to buffer pages, and only
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after that release the log mutex: this guarantees that when the log
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mutex is free, all buffer pages contain an up-to-date info of their
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modifications. This fact is used in making a checkpoint when we look
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at the oldest modification of any page in the buffer pool. It is also
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required when we insert modified buffer pages in to the flush list
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which must be sorted on oldest_modification. */
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mtr_memo_pop_all(mtr);
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if (mtr->modifications) {
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mtr->state = MTR_COMMITTED;
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dyn_array_free(&(mtr->memo));
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dyn_array_free(&(mtr->log));
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/**************************************************************
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Releases the latches stored in an mtr memo down to a savepoint.
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NOTE! The mtr must not have made changes to buffer pages after the
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savepoint, as these can be handled only by mtr_commit. */
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mtr_rollback_to_savepoint(
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/*======================*/
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mtr_t* mtr, /* in: mtr */
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ulint savepoint) /* in: savepoint */
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mtr_memo_slot_t* slot;
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ut_ad(mtr->magic_n == MTR_MAGIC_N);
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ut_ad(mtr->state == MTR_ACTIVE);
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offset = dyn_array_get_data_size(memo);
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ut_ad(offset >= savepoint);
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while (offset > savepoint) {
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offset -= sizeof(mtr_memo_slot_t);
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slot = dyn_array_get_element(memo, offset);
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ut_ad(slot->type != MTR_MEMO_MODIFY);
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mtr_memo_slot_release(mtr, slot);
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/*******************************************************
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Releases an object in the memo stack. */
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mtr_t* mtr, /* in: mtr */
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void* object, /* in: object */
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ulint type) /* in: object type: MTR_MEMO_S_LOCK, ... */
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mtr_memo_slot_t* slot;
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ut_ad(mtr->magic_n == MTR_MAGIC_N);
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ut_ad(mtr->state == MTR_ACTIVE);
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offset = dyn_array_get_data_size(memo);
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offset -= sizeof(mtr_memo_slot_t);
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slot = dyn_array_get_element(memo, offset);
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if ((object == slot->object) && (type == slot->type)) {
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mtr_memo_slot_release(mtr, slot);
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/************************************************************
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Reads 1 - 4 bytes from a file page buffered in the buffer pool. */
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/* out: value read */
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byte* ptr, /* in: pointer from where to read */
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ulint type, /* in: MLOG_1BYTE, MLOG_2BYTES, MLOG_4BYTES */
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mtr_t* mtr __attribute__((unused)))
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/* in: mini-transaction handle */
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ut_ad(mtr->state == MTR_ACTIVE);
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ut_ad(mtr_memo_contains(mtr, buf_block_align(ptr),
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|| mtr_memo_contains(mtr, buf_block_align(ptr),
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MTR_MEMO_PAGE_X_FIX));
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if (type == MLOG_1BYTE) {
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return(mach_read_from_1(ptr));
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} else if (type == MLOG_2BYTES) {
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return(mach_read_from_2(ptr));
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ut_ad(type == MLOG_4BYTES);
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return(mach_read_from_4(ptr));
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/************************************************************
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Reads 8 bytes from a file page buffered in the buffer pool. */
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/* out: value read */
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byte* ptr, /* in: pointer from where to read */
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mtr_t* mtr __attribute__((unused)))
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/* in: mini-transaction handle */
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ut_ad(mtr->state == MTR_ACTIVE);
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ut_ad(mtr_memo_contains(mtr, buf_block_align(ptr),
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|| mtr_memo_contains(mtr, buf_block_align(ptr),
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MTR_MEMO_PAGE_X_FIX));
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return(mach_read_from_8(ptr));
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/*************************************************************
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Prints info of an mtr handle. */
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mtr_t* mtr) /* in: mtr */
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"Mini-transaction handle: memo size %lu bytes"
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" log size %lu bytes\n",
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(ulong) dyn_array_get_data_size(&(mtr->memo)),
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(ulong) dyn_array_get_data_size(&(mtr->log)));
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#endif /* UNIV_DEBUG */
added
removed
storage/innobase/mtr/mtr0mtr.c
