/****************************************************** 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" extern ulint buf_dbg_counter; /* This is used to insert validation operations in execution in the debug version */ /************************************************************************ 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 */ { if (buf_pool->freed_page_clock >= block->freed_page_clock + 1 + (buf_pool->curr_size / 1024)) { return(TRUE); } return(FALSE); } /************************************************************************* 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 maximum size of buffer buf_pool in bytes. */ UNIV_INLINE ulint buf_pool_get_max_size(void) /*=======================*/ /* out: size in bytes */ { return((buf_pool->max_size) * UNIV_PAGE_SIZE); } /*********************************************************************** Accessor function for block array. */ UNIV_INLINE buf_block_t* buf_pool_get_nth_block( /*===================*/ /* out: pointer to block */ buf_pool_t* buf_pool,/* in: buf_pool */ ulint i) /* in: index of the block */ { ut_ad(buf_pool); ut_ad(i < buf_pool->max_size); return(i + buf_pool->blocks); } /*********************************************************************** Checks if a pointer points to the block array of the buffer pool (blocks, not the frames). */ UNIV_INLINE ibool buf_pool_is_block( /*==============*/ /* out: TRUE if pointer to block */ void* ptr) /* in: pointer to memory */ { if ((buf_pool->blocks <= (buf_block_t*)ptr) && ((buf_block_t*)ptr < buf_pool->blocks + buf_pool->max_size)) { return(TRUE); } return(FALSE); } /************************************************************************ 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 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 >= buf_pool->blocks); ut_ad(block < buf_pool->blocks + buf_pool->max_size); 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 */ buf_block_t* block) /* in: pointer to the control block */ { ut_ad(block); ut_ad(block >= buf_pool->blocks); ut_ad(block < buf_pool->blocks + buf_pool->max_size); ut_ad(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 */ buf_block_t* block) /* in: pointer to the control block */ { ut_ad(block); ut_ad(block >= buf_pool->blocks); ut_ad(block < buf_pool->blocks + buf_pool->max_size); ut_ad(block->state == BUF_BLOCK_FILE_PAGE); ut_ad(block->buf_fix_count > 0); return(block->offset); } /*********************************************************************** 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; buf_frame_t* frame_zero; ut_ad(ptr); frame_zero = buf_pool->frame_zero; ut_ad((ulint)ptr >= (ulint)frame_zero); block = buf_pool_get_nth_block(buf_pool, ((ulint)(ptr - frame_zero)) >> UNIV_PAGE_SIZE_SHIFT); if (block < buf_pool->blocks || block >= buf_pool->blocks + buf_pool->max_size) { fprintf(stderr, "InnoDB: Error: trying to access a stray pointer %p\n" "InnoDB: buf pool start is at %p, number of pages %lu\n", ptr, frame_zero, buf_pool->max_size); ut_error; } return(block); } /*********************************************************************** Gets the block to whose frame the pointer is pointing to. Does not require a file page to be bufferfixed. */ UNIV_INLINE buf_block_t* buf_block_align_low( /*================*/ /* out: pointer to block */ byte* ptr) /* in: pointer to a frame */ { buf_block_t* block; buf_frame_t* frame_zero; ut_ad(ptr); frame_zero = buf_pool->frame_zero; ut_ad((ulint)ptr >= (ulint)frame_zero); block = buf_pool_get_nth_block(buf_pool, ((ulint)(ptr - frame_zero)) >> UNIV_PAGE_SIZE_SHIFT); if (block < buf_pool->blocks || block >= buf_pool->blocks + buf_pool->max_size) { fprintf(stderr, "InnoDB: Error: trying to access a stray pointer %p\n" "InnoDB: buf pool start is at %p, number of pages %lu\n", ptr, frame_zero, buf_pool->max_size); ut_error; } return(block); } /*********************************************************************** Gets the frame the pointer is pointing to. */ UNIV_INLINE buf_frame_t* buf_frame_align( /*============*/ /* out: pointer to block */ byte* ptr) /* in: pointer to a frame */ { buf_frame_t* frame; ut_ad(ptr); frame = ut_align_down(ptr, UNIV_PAGE_SIZE); if (((ulint)frame < (ulint)(buf_pool->frame_zero)) || ((ulint)frame > (ulint)(buf_pool_get_nth_block(buf_pool, buf_pool->max_size - 1)->frame))) { fprintf(stderr, "InnoDB: Error: trying to access a stray pointer %p\n" "InnoDB: buf pool start is at %p, number of pages %lu\n", ptr, buf_pool->frame_zero, buf_pool->max_size); ut_error; } return(frame); } /************************************************************************** Gets the page number of a pointer pointing within a buffer frame containing a file page. */ UNIV_INLINE ulint buf_frame_get_page_no( /*==================*/ /* out: page number */ byte* ptr) /* in: pointer to within a buffer frame */ { return(buf_block_get_page_no(buf_block_align(ptr))); } /************************************************************************** Gets the space id of a pointer pointing within a buffer frame containing a file page. */ UNIV_INLINE ulint buf_frame_get_space_id( /*===================*/ /* out: space id */ byte* ptr) /* in: pointer to within a buffer frame */ { return(buf_block_get_space(buf_block_align(ptr))); } /************************************************************************** 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( /*=================*/ byte* ptr, /* in: pointer to a buffer frame */ ulint* space, /* out: space id */ fil_addr_t* addr) /* out: page offset and byte offset */ { buf_block_t* block; block = buf_block_align(ptr); *space = buf_block_get_space(block); addr->page = buf_block_get_page_no(block); addr->boffset = ptr - buf_frame_align(ptr); } /************************************************************************** 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_frame_get_lock_hash_val( /*========================*/ /* out: lock hash value */ byte* ptr) /* in: pointer to within a buffer frame */ { buf_block_t* block; block = buf_block_align(ptr); return(block->lock_hash_val); } /************************************************************************** Gets the mutex number protecting the page record lock hash chain in the lock table. */ UNIV_INLINE mutex_t* buf_frame_get_mutex( /*================*/ /* out: mutex */ byte* ptr) /* in: pointer to within a buffer frame */ { buf_block_t* block; block = buf_block_align(ptr); return(&block->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 */ 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_frame_get_newest_modification( /*==============================*/ /* out: newest modification to the page */ buf_frame_t* frame) /* in: pointer to a frame */ { buf_block_t* block; dulint lsn; ut_ad(frame); block = buf_block_align(frame); mutex_enter(&(buf_pool->mutex)); if (block->state == 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 dulint buf_frame_modify_clock_inc( /*=======================*/ /* out: new value */ buf_frame_t* frame) /* in: pointer to a frame */ { buf_block_t* block; ut_ad(frame); block = buf_block_align_low(frame); #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); return(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_frame_get_modify_clock( /*=======================*/ /* out: value */ buf_frame_t* frame) /* in: pointer to a frame */ { buf_block_t* block; ut_ad(frame); block = buf_block_align(frame); #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 */ char* file, /* in: file name */ ulint line) /* in: line */ { ibool ret; ret = rw_lock_s_lock_func_nowait(&(block->debug_latch), file, line); ut_ad(ret == TRUE); ut_ad(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)); 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_frame_t* buf_page_get_release_on_io( /*=======================*/ /* out: pointer to the frame, 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_frame_t* guess, /* in: guessed frame 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_frame_t* frame; frame = buf_page_get_gen(space, offset, rw_latch, guess, BUF_GET_IF_IN_POOL, IB__FILE__, __LINE__, mtr); if (frame != NULL) { return(frame); } /* 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_ad(block->state == BUF_BLOCK_FILE_PAGE); ut_ad(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. If UNIV_SYNC_DEBUG is not defined, compiles to an empty function. */ UNIV_INLINE void buf_page_dbg_add_level( /*===================*/ buf_frame_t* frame __attribute__((unused)), /* in: buffer page where we have acquired latch */ ulint level __attribute__((unused))) /* in: latching order level */ { sync_thread_add_level(&(buf_block_align(frame)->lock), level); } #endif /* UNIV_SYNC_DEBUG */