/****************************************************** The database buffer buf_pool (c) 1995 Innobase Oy Created 11/5/1995 Heikki Tuuri *******************************************************/ #include "buf0flu.h" #include "buf0lru.h" #include "buf0rea.h" #include "mtr0mtr.h" /************************************************************************ Recommends a move of a block to the start of the LRU list if there is danger of dropping from the buffer pool. NOTE: does not reserve the buffer pool mutex. */ UNIV_INLINE ibool buf_block_peek_if_too_old( /*======================*/ /* out: TRUE if should be made younger */ buf_block_t* block) /* in: block to make younger */ { return(buf_pool->freed_page_clock >= block->freed_page_clock + 1 + (buf_pool->curr_size / 1024)); } /************************************************************************* Gets the current size of buffer buf_pool in bytes. */ UNIV_INLINE ulint buf_pool_get_curr_size(void) /*========================*/ /* out: size in bytes */ { return(buf_pool->curr_size * UNIV_PAGE_SIZE); } /************************************************************************ Gets the smallest oldest_modification lsn for any page in the pool. Returns ut_dulint_zero if all modified pages have been flushed to disk. */ UNIV_INLINE dulint buf_pool_get_oldest_modification(void) /*==================================*/ /* out: oldest modification in pool, ut_dulint_zero if none */ { buf_block_t* block; dulint lsn; mutex_enter(&(buf_pool->mutex)); block = UT_LIST_GET_LAST(buf_pool->flush_list); if (block == NULL) { lsn = ut_dulint_zero; } else { lsn = block->oldest_modification; } mutex_exit(&(buf_pool->mutex)); return(lsn); } /*********************************************************************** Increments the buf_pool clock by one and returns its new value. Remember that in the 32 bit version the clock wraps around at 4 billion! */ UNIV_INLINE ulint buf_pool_clock_tic(void) /*====================*/ /* out: new clock value */ { #ifdef UNIV_SYNC_DEBUG ut_ad(mutex_own(&(buf_pool->mutex))); #endif /* UNIV_SYNC_DEBUG */ buf_pool->ulint_clock++; return(buf_pool->ulint_clock); } /************************************************************************* Gets the state of a block. */ UNIV_INLINE enum buf_block_state buf_block_get_state( /*================*/ /* out: state */ const buf_block_t* block) /* in: pointer to the control block */ { enum buf_block_state state = block->state; #ifdef UNIV_DEBUG switch (state) { case BUF_BLOCK_NOT_USED: case BUF_BLOCK_READY_FOR_USE: case BUF_BLOCK_FILE_PAGE: case BUF_BLOCK_MEMORY: case BUF_BLOCK_REMOVE_HASH: break; default: ut_error; } #endif /* UNIV_DEBUG */ return(state); } /************************************************************************* Gets a pointer to the memory frame of a block. */ UNIV_INLINE buf_frame_t* buf_block_get_frame( /*================*/ /* out: pointer to the frame */ buf_block_t* block) /* in: pointer to the control block */ { ut_ad(block); ut_ad(block->state != BUF_BLOCK_NOT_USED); ut_ad((block->state != BUF_BLOCK_FILE_PAGE) || (block->buf_fix_count > 0)); return(block->frame); } /************************************************************************* Gets the space id of a block. */ UNIV_INLINE ulint buf_block_get_space( /*================*/ /* out: space id */ const buf_block_t* block) /* in: pointer to the control block */ { ut_ad(block); ut_a(block->state == BUF_BLOCK_FILE_PAGE); ut_ad(block->buf_fix_count > 0); return(block->space); } /************************************************************************* Gets the page number of a block. */ UNIV_INLINE ulint buf_block_get_page_no( /*==================*/ /* out: page number */ const buf_block_t* block) /* in: pointer to the control block */ { ut_ad(block); ut_a(block->state == BUF_BLOCK_FILE_PAGE); ut_ad(block->buf_fix_count > 0); return(block->offset); } /************************************************************************* Gets the compressed page size of a block. */ UNIV_INLINE ulint buf_block_get_zip_size( /*===================*/ /* out: compressed page size, or 0 */ const buf_block_t* block) /* in: pointer to the control block */ { return(block->page_zip.size); } /************************************************************************* Gets the compressed page descriptor corresponding to an uncompressed page if applicable. */ UNIV_INLINE page_zip_des_t* buf_block_get_page_zip( /*===================*/ /* out: compressed page descriptor, or NULL */ buf_block_t* block) /* in: pointer to the control block */ { if (UNIV_LIKELY_NULL(block->page_zip.data)) { return(&block->page_zip); } return(NULL); } #if defined UNIV_DEBUG || defined UNIV_ZIP_DEBUG /*********************************************************************** Gets the block to whose frame the pointer is pointing to. */ UNIV_INLINE buf_block_t* buf_block_align( /*============*/ /* out: pointer to block */ byte* ptr) /* in: pointer to a frame */ { buf_block_t* block; ulint space_id, page_no; ptr = ut_align_down(ptr, UNIV_PAGE_SIZE); page_no = mach_read_from_4(ptr + FIL_PAGE_OFFSET); space_id = mach_read_from_4(ptr + FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID); block = buf_page_hash_get(space_id, page_no); ut_ad(block); ut_ad(block->frame == ptr); return(block); } /************************************************************************* Gets the compressed page descriptor corresponding to an uncompressed page if applicable. */ UNIV_INLINE page_zip_des_t* buf_frame_get_page_zip( /*===================*/ /* out: compressed page descriptor, or NULL */ byte* ptr) /* in: pointer to the page */ { page_zip_des_t* page_zip; mutex_enter(&buf_pool->mutex); page_zip = buf_block_get_page_zip(buf_block_align(ptr)); mutex_exit(&buf_pool->mutex); return(page_zip); } #endif /* UNIV_DEBUG || UNIV_ZIP_DEBUG */ /************************************************************************** Gets the space id, page offset, and byte offset within page of a pointer pointing to a buffer frame containing a file page. */ UNIV_INLINE void buf_ptr_get_fsp_addr( /*=================*/ const void* ptr, /* in: pointer to a buffer frame */ ulint* space, /* out: space id */ fil_addr_t* addr) /* out: page offset and byte offset */ { const page_t* page = ut_align_down((void*) ptr, UNIV_PAGE_SIZE); *space = mach_read_from_4(page + FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID); addr->page = mach_read_from_4(page + FIL_PAGE_OFFSET); addr->boffset = ut_align_offset(ptr, UNIV_PAGE_SIZE); } /************************************************************************** Gets the hash value of the page the pointer is pointing to. This can be used in searches in the lock hash table. */ UNIV_INLINE ulint buf_block_get_lock_hash_val( /*========================*/ /* out: lock hash value */ const buf_block_t* block) /* in: block */ { return(block->lock_hash_val); } /************************************************************************ Allocates a buffer block. */ UNIV_INLINE buf_block_t* buf_block_alloc( /*============*/ /* out, own: the allocated block */ ulint zip_size) /* in: compressed page size in bytes, or 0 if uncompressed tablespace */ { buf_block_t* block; block = buf_LRU_get_free_block(zip_size); return(block); } /************************************************************************ Frees a buffer block which does not contain a file page. */ UNIV_INLINE void buf_block_free( /*===========*/ buf_block_t* block) /* in, own: block to be freed */ { mutex_enter(&(buf_pool->mutex)); mutex_enter(&block->mutex); ut_a(buf_block_get_state(block) != BUF_BLOCK_FILE_PAGE); buf_LRU_block_free_non_file_page(block); mutex_exit(&block->mutex); mutex_exit(&(buf_pool->mutex)); } /************************************************************************* Copies contents of a buffer frame to a given buffer. */ UNIV_INLINE byte* buf_frame_copy( /*===========*/ /* out: buf */ byte* buf, /* in: buffer to copy to */ const buf_frame_t* frame) /* in: buffer frame */ { ut_ad(buf && frame); ut_memcpy(buf, frame, UNIV_PAGE_SIZE); return(buf); } /************************************************************************ Calculates a folded value of a file page address to use in the page hash table. */ UNIV_INLINE ulint buf_page_address_fold( /*==================*/ /* out: the folded value */ ulint space, /* in: space id */ ulint offset) /* in: offset of the page within space */ { return((space << 20) + space + offset); } /************************************************************************ This function is used to get info if there is an io operation going on on a buffer page. */ UNIV_INLINE ibool buf_page_io_query( /*==============*/ /* out: TRUE if io going on */ buf_block_t* block) /* in: buf_pool block, must be bufferfixed */ { mutex_enter(&(buf_pool->mutex)); ut_ad(block->state == BUF_BLOCK_FILE_PAGE); ut_ad(block->buf_fix_count > 0); if (block->io_fix != 0) { mutex_exit(&(buf_pool->mutex)); return(TRUE); } mutex_exit(&(buf_pool->mutex)); return(FALSE); } /************************************************************************ Gets the youngest modification log sequence number for a frame. Returns zero if not a file page or no modification occurred yet. */ UNIV_INLINE dulint buf_block_get_newest_modification( /*==============================*/ /* out: newest modification to the page */ buf_block_t* block) /* in: block containing the page frame */ { dulint lsn; mutex_enter(&(buf_pool->mutex)); if (buf_block_get_state(block) == BUF_BLOCK_FILE_PAGE) { lsn = block->newest_modification; } else { lsn = ut_dulint_zero; } mutex_exit(&(buf_pool->mutex)); return(lsn); } /************************************************************************ Increments the modify clock of a frame by 1. The caller must (1) own the buf_pool mutex and block bufferfix count has to be zero, (2) or own an x-lock on the block. */ UNIV_INLINE void buf_block_modify_clock_inc( /*=======================*/ buf_block_t* block) /* in: block */ { #ifdef UNIV_SYNC_DEBUG ut_ad((mutex_own(&(buf_pool->mutex)) && (block->buf_fix_count == 0)) || rw_lock_own(&(block->lock), RW_LOCK_EXCLUSIVE)); #endif /* UNIV_SYNC_DEBUG */ UT_DULINT_INC(block->modify_clock); } /************************************************************************ Returns the value of the modify clock. The caller must have an s-lock or x-lock on the block. */ UNIV_INLINE dulint buf_block_get_modify_clock( /*=======================*/ /* out: value */ buf_block_t* block) /* in: block */ { #ifdef UNIV_SYNC_DEBUG ut_ad(rw_lock_own(&(block->lock), RW_LOCK_SHARED) || rw_lock_own(&(block->lock), RW_LOCK_EXCLUSIVE)); #endif /* UNIV_SYNC_DEBUG */ return(block->modify_clock); } #ifdef UNIV_SYNC_DEBUG /*********************************************************************** Increments the bufferfix count. */ UNIV_INLINE void buf_block_buf_fix_inc_debug( /*========================*/ buf_block_t* block, /* in: block to bufferfix */ const char* file, /* in: file name */ ulint line) /* in: line */ { ibool ret; ret = rw_lock_s_lock_func_nowait(&(block->debug_latch), file, line); ut_a(ret); ut_a(mutex_own(&block->mutex)); block->buf_fix_count++; } #else /* UNIV_SYNC_DEBUG */ /*********************************************************************** Increments the bufferfix count. */ UNIV_INLINE void buf_block_buf_fix_inc( /*==================*/ buf_block_t* block) /* in: block to bufferfix */ { block->buf_fix_count++; } #endif /* UNIV_SYNC_DEBUG */ /********************************************************************** Returns the control block of a file page, NULL if not found. */ UNIV_INLINE buf_block_t* buf_page_hash_get( /*==============*/ /* out: block, NULL if not found */ ulint space, /* in: space id */ ulint offset) /* in: offset of the page within space */ { buf_block_t* block; ulint fold; ut_ad(buf_pool); #ifdef UNIV_SYNC_DEBUG ut_ad(mutex_own(&(buf_pool->mutex))); #endif /* UNIV_SYNC_DEBUG */ /* Look for the page in the hash table */ fold = buf_page_address_fold(space, offset); HASH_SEARCH(hash, buf_pool->page_hash, fold, block, (block->space == space) && (block->offset == offset)); ut_a(!block || buf_block_get_state(block) == BUF_BLOCK_FILE_PAGE); return(block); } /************************************************************************ Tries to get the page, but if file io is required, releases all latches in mtr down to the given savepoint. If io is required, this function retrieves the page to buffer buf_pool, but does not bufferfix it or latch it. */ UNIV_INLINE buf_block_t* buf_page_get_release_on_io( /*=======================*/ /* out: pointer to the block, or NULL if not in buffer buf_pool */ ulint space, /* in: space id */ ulint offset, /* in: offset of the page within space in units of a page */ buf_block_t* guess, /* in: guessed block or NULL */ ulint rw_latch, /* in: RW_X_LATCH, RW_S_LATCH, or RW_NO_LATCH */ ulint savepoint, /* in: mtr savepoint */ mtr_t* mtr) /* in: mtr */ { buf_block_t* block; block = buf_page_get_gen(space, offset, rw_latch, guess, BUF_GET_IF_IN_POOL, __FILE__, __LINE__, mtr); if (block != NULL) { return(block); } /* The page was not in the buffer buf_pool: release the latches down to the savepoint */ mtr_rollback_to_savepoint(mtr, savepoint); buf_page_get(space, offset, RW_S_LATCH, mtr); /* When we get here, the page is in buffer, but we release the latches again down to the savepoint, before returning */ mtr_rollback_to_savepoint(mtr, savepoint); return(NULL); } /************************************************************************ Decrements the bufferfix count of a buffer control block and releases a latch, if specified. */ UNIV_INLINE void buf_page_release( /*=============*/ buf_block_t* block, /* in: buffer block */ ulint rw_latch, /* in: RW_S_LATCH, RW_X_LATCH, RW_NO_LATCH */ mtr_t* mtr) /* in: mtr */ { ut_ad(block); ut_a(buf_block_get_state(block) == BUF_BLOCK_FILE_PAGE); ut_a(block->buf_fix_count > 0); if (rw_latch == RW_X_LATCH && mtr->modifications) { mutex_enter(&buf_pool->mutex); buf_flush_note_modification(block, mtr); mutex_exit(&buf_pool->mutex); } mutex_enter(&block->mutex); #ifdef UNIV_SYNC_DEBUG rw_lock_s_unlock(&(block->debug_latch)); #endif block->buf_fix_count--; mutex_exit(&block->mutex); if (rw_latch == RW_S_LATCH) { rw_lock_s_unlock(&(block->lock)); } else if (rw_latch == RW_X_LATCH) { rw_lock_x_unlock(&(block->lock)); } } #ifdef UNIV_SYNC_DEBUG /************************************************************************* Adds latch level info for the rw-lock protecting the buffer frame. This should be called in the debug version after a successful latching of a page if we know the latching order level of the acquired latch. */ UNIV_INLINE void buf_block_dbg_add_level( /*====================*/ buf_block_t* block, /* in: buffer page where we have acquired latch */ ulint level) /* in: latching order level */ { sync_thread_add_level(&block->lock, level); } #endif /* UNIV_SYNC_DEBUG */