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firebird-mirror/src/jrd/cch.h

287 lines
9.2 KiB
C++

/*
* PROGRAM: JRD access method
* MODULE: cch.h
* DESCRIPTION: Cache manager definitions
*
* The contents of this file are subject to the Interbase Public
* License Version 1.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy
* of the License at http://www.Inprise.com/IPL.html
*
* Software distributed under the License is distributed on an
* "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
* or implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code was created by Inprise Corporation
* and its predecessors. Portions created by Inprise Corporation are
* Copyright (C) Inprise Corporation.
*
* All Rights Reserved.
* Contributor(s): ______________________________________.
*/
#ifndef JRD_CCH_H
#define JRD_CCH_H
#include "../include/fb_blk.h"
#include "../jrd/os/pio.h"
#ifdef SUPERSERVER_V2
#include "../jrd/sbm.h"
#include "../jrd/pag.h"
#endif
//#define CCH_DEBUG
#ifdef CCH_DEBUG
DEFINE_TRACE_ROUTINE(cch_trace);
#define CCH_TRACE(args) cch_trace args
#define CCH_TRACE_AST(message) gds__trace(message)
#else
#define CCH_TRACE(args) /* nothing */
#define CCH_TRACEE_AST(message) /* nothing */
#endif
struct exp_index_buf;
namespace Ods {
struct pag;
}
namespace Jrd {
class Lock;
class Precedence;
class thread_db;
struct que;
class BufferDesc;
//class BlockingThread;
class Database;
/* Page buffer cache size constraints. */
const ULONG MIN_PAGE_BUFFERS = 50;
const ULONG MAX_PAGE_BUFFERS = 131072;
#define DIRTY_LIST
//#define DIRTY_TREE
#ifdef DIRTY_TREE
/* AVL-balanced tree node */
struct BalancedTreeNode {
BufferDesc* bdb_node;
SSHORT comp;
};
#endif // DIRTY_TREE
/* BufferControl -- Buffer control block -- one per system */
struct bcb_repeat
{
BufferDesc* bcb_bdb; /* Buffer descriptor block */
que bcb_page_mod; /* Que of buffers with page mod n */
};
class BufferControl : public pool_alloc_rpt<bcb_repeat, type_bcb>
{
public:
BufferControl(MemoryPool& p) : bcb_memory(p) { }
UCharStack bcb_memory; /* Large block partitioned into buffers */
que bcb_in_use; /* Que of buffers in use */
que bcb_empty; /* Que of empty buffers */
#ifdef DIRTY_TREE
BufferDesc* bcb_btree; /* root of dirty page btree */
#endif
#ifdef DIRTY_LIST
que bcb_dirty; // que of dirty buffers
SLONG bcb_dirty_count; // count of pages in dirty page btree
#endif
Precedence* bcb_free; /* Free precedence blocks */
que bcb_free_lwt; /* Free latch wait blocks */
SSHORT bcb_flags; /* see below */
SSHORT bcb_free_minimum; /* Threshold to activate cache writer */
ULONG bcb_count; /* Number of buffers allocated */
ULONG bcb_checkpoint; /* Count of buffers to checkpoint */
#ifdef SUPERSERVER_V2
PageBitmap* bcb_prefetch; /* Bitmap of pages to prefetch */
#endif
bcb_repeat bcb_rpt[1];
};
const int BCB_keep_pages = 1; /* set during btc_flush(), pages not removed from dirty binary tree */
const int BCB_cache_writer = 2; /* cache writer thread has been started */
//const int BCB_checkpoint_db = 4; // WAL has requested a database checkpoint
const int BCB_writer_start = 4; // cache writer thread is starting now
const int BCB_writer_active = 8; /* no need to post writer event count */
#ifdef SUPERSERVER_V2
const int BCB_cache_reader = 16; /* cache reader thread has been started */
const int BCB_reader_active = 32; /* cache reader not blocked on event */
#endif
const int BCB_free_pending = 64; /* request cache writer to free pages */
/* BufferDesc -- Buffer descriptor block */
const int BDB_max_shared = 20; /* maximum number of shared latch owners per BufferDesc */
class BufferDesc : public pool_alloc<type_bdb>
{
public:
BufferDesc() : bdb_page(0, 0) {};
Database* bdb_dbb; /* Database block (for ASTs) */
Lock* bdb_lock; /* Lock block for buffer */
que bdb_que; /* Buffer que */
que bdb_in_use; /* queue of buffers in use */
#ifdef DIRTY_LIST
que bdb_dirty; // dirty pages LRU queue
#endif
Ods::pag* bdb_buffer; /* Actual buffer */
exp_index_buf* bdb_expanded_buffer; /* expanded index buffer */
//BlockingThread* bdb_blocked; // Blocked attachments block
PageNumber bdb_page; /* Database page number in buffer */
SLONG bdb_incarnation;
ULONG bdb_transactions; /* vector of dirty flags to reduce commit overhead */
SLONG bdb_mark_transaction; /* hi-water mark transaction to defer header page I/O */
#ifdef DIRTY_TREE
BufferDesc* bdb_left; /* dirty page binary tree link */
BufferDesc* bdb_right; /* dirty page binary tree link */
BufferDesc* bdb_parent; /* dirty page binary tree link */
SSHORT bdb_balance; /* AVL-tree balance (-1, 0, 1) */
#endif
que bdb_lower; /* lower precedence que */
que bdb_higher; /* higher precedence que */
que bdb_waiters; /* latch wait que */
thread_db* bdb_exclusive; /* thread holding exclusive latch */
thread_db* bdb_io; /* thread holding io latch */
UATOM bdb_ast_flags; /* flags manipulated at AST level */
USHORT bdb_flags;
SSHORT bdb_use_count; /* Number of active users */
SSHORT bdb_scan_count; /* concurrent sequential scans */
ULONG bdb_difference_page; // Number of page in difference file, NBAK
SLONG bdb_backup_lock_owner; // Logical owner of database_lock for buffer
thread_db* bdb_shared[BDB_max_shared]; /* threads holding shared latches */
};
/* bdb_flags */
// to clear BDB_dirty use clear_page_dirty_flag()
const int BDB_dirty = 1; /* page has been updated but not written yet */
const int BDB_garbage_collect = 2; /* left by scan for garbage collector */
const int BDB_writer = 4; /* someone is updating the page */
const int BDB_marked = 8; /* page has been updated */
const int BDB_must_write = 16; /* forces a write as soon as the page is released */
const int BDB_faked = 32; /* page was just allocated */
//const int BDB_journal = 64; // Journal buffer
const int BDB_system_dirty = 128; /* system transaction has marked dirty */
const int BDB_io_error = 256; /* page i/o error */
const int BDB_read_pending = 512; /* read is pending */
const int BDB_free_pending = 1024; /* buffer being freed for reuse */
const int BDB_not_valid = 2048; /* i/o error invalidated buffer */
const int BDB_db_dirty = 4096; /* page must be written to database */
const int BDB_checkpoint = 8192; /* page must be written by next checkpoint */
const int BDB_prefetch = 16384; /* page has been prefetched but not yet referenced */
const int BDB_no_blocking_ast = 32768; /* No blocking AST registered with page lock */
/* bdb_ast_flags */
const int BDB_blocking = 1; /* a blocking ast was sent while page locked */
/* PRE -- Precedence block */
class Precedence : public pool_alloc<type_pre>
{
public:
BufferDesc* pre_hi;
BufferDesc* pre_low;
que pre_lower;
que pre_higher;
SSHORT pre_flags;
};
const int PRE_cleared = 1;
/* Compatibility matrix for latch types.
An exclusive latch is needed to modify a page. Before
marking a page an 'io-prevention' latch is needed: a mark latch.
To look at a buffer, a shared latch is needed. To write a page,
an io latch is needed.
Exclusive and shared latches interact. Io and mark latches
interact.
An mark latch is implemented as an io latch.
Latches are granted in the order in which they are
queued with one notable exception -- if buffer write
is in-progress then shared latches are granted ahead
of any pending exclusive latches.
shared io exclusive mark
-------------------------------------------------
shared 1 - 0 -
io - 0 - 0
exclusive 0 - 0 -
mark - 0 - 0 */
/* LATCH types */
enum LATCH
{
LATCH_none,
LATCH_shared,
LATCH_io,
LATCH_exclusive,
LATCH_mark
};
/* LWT -- Latch wait block */
class LatchWait : public pool_alloc<type_lwt>
{
public:
thread_db* lwt_tdbb;
LATCH lwt_latch; /* latch type requested */
que lwt_waiters; /* latch queue */
struct event_t lwt_event; /* grant event to wait on */
USHORT lwt_flags;
};
const int LWT_pending = 1; /* latch request is pending */
#include "../jrd/os/pio.h"
/* Constants used by prefetch mechanism */
const int PREFETCH_MAX_TRANSFER = 16384; /* maximum block I/O transfer (bytes) */
const int PREFETCH_MAX_PAGES = (2 * PREFETCH_MAX_TRANSFER / MIN_PAGE_SIZE); /* maximum pages allowed per prefetch request */
/* Prefetch block */
#ifdef SUPERSERVER_V2
class Prefetch : public pool_alloc<type_prf>
{
public:
thread_db* prf_tdbb; /* thread database context */
SLONG prf_start_page; /* starting page of multipage prefetch */
USHORT prf_max_prefetch; /* maximum no. of pages to prefetch */
USHORT prf_page_count; /* actual no. of pages being prefetched */
phys_io_blk prf_piob; /* physical I/O status block */
SCHAR* prf_aligned_buffer; /* buffer address aligned for raw (OS cache bypass) I/O */
SCHAR* prf_io_buffer; /* I/O buffer address */
UCHAR prf_flags;
BufferDesc* prf_bdbs[PREFETCH_MAX_TRANSFER / MIN_PAGE_SIZE];
SCHAR prf_unaligned_buffer[PREFETCH_MAX_TRANSFER + MIN_PAGE_SIZE];
};
const int PRF_active = 1; /* prefetch block currently in use */
#endif
} //namespace Jrd
#endif // JRD_CCH_H