Replace implementation of pg_log as a relation accessed through the

buffer manager with 'pg_clog', a specialized access method modeled
on pg_xlog.  This simplifies startup (don't need to play games to
open pg_log; among other things, OverrideTransactionSystem goes away),
should improve performance a little, and opens the door to recycling
commit log space by removing no-longer-needed segments of the commit
log.  Actual recycling is not there yet, but I felt I should commit
this part separately since it'd still be useful if we chose not to
do transaction ID wraparound.
This commit is contained in:
Tom Lane 2001-08-25 18:52:43 +00:00
parent 4699d81dc9
commit 2589735da0
39 changed files with 1248 additions and 1128 deletions

View File

@ -1,4 +1,4 @@
<!-- $Header: /cvsroot/pgsql/doc/src/sgml/backup.sgml,v 2.11 2001/08/16 04:30:41 ishii Exp $ -->
<!-- $Header: /cvsroot/pgsql/doc/src/sgml/backup.sgml,v 2.12 2001/08/25 18:52:41 tgl Exp $ -->
<chapter id="backup">
<title>Backup and Restore</title>
@ -339,11 +339,11 @@ tar -cf backup.tar /usr/local/pgsql/data
individual tables or databases from their respective files or
directories. This will <emphasis>not</> work because the
information contained in these files contains only half the
truth. The other half is in the file
<filename>pg_log</filename>, which contains the commit status of
truth. The other half is in the commit log files
<filename>pg_clog/*</filename>, which contain the commit status of
all transactions. A table file is only usable with this
information. Of course it is also impossible to restore only a
table and the associated <filename>pg_log</filename> file
table and the associated <filename>pg_clog</filename> data
because that will render all other tables in the database
cluster useless.
</para>

View File

@ -1,4 +1,4 @@
<!-- $Header: /cvsroot/pgsql/doc/src/sgml/wal.sgml,v 1.7 2001/05/17 21:50:16 petere Exp $ -->
<!-- $Header: /cvsroot/pgsql/doc/src/sgml/wal.sgml,v 1.8 2001/08/25 18:52:41 tgl Exp $ -->
<chapter id="wal">
<title>Write-Ahead Logging (<acronym>WAL</acronym>)</title>
@ -83,12 +83,12 @@
In this first release of <acronym>WAL</acronym>, UNDO operation is
not implemented, because of lack of time. This means that changes
made by aborted transactions will still occupy disk space and that
we still need a permanent <filename>pg_log</filename> file to hold
we still need a permanent <filename>pg_clog</filename> file to hold
the status of transactions, since we are not able to re-use
transaction identifiers. Once UNDO is implemented,
<filename>pg_log</filename> will no longer be required to be
<filename>pg_clog</filename> will no longer be required to be
permanent; it will be possible to remove
<filename>pg_log</filename> at shutdown, split it into segments
<filename>pg_clog</filename> at shutdown, split it into segments
and remove old segments.
</para>

View File

@ -4,7 +4,7 @@
# Makefile for access/transam
#
# IDENTIFICATION
# $Header: /cvsroot/pgsql/src/backend/access/transam/Makefile,v 1.14 2001/08/24 14:07:48 petere Exp $
# $Header: /cvsroot/pgsql/src/backend/access/transam/Makefile,v 1.15 2001/08/25 18:52:41 tgl Exp $
#
#-------------------------------------------------------------------------
@ -12,7 +12,7 @@ subdir = src/backend/access/transam
top_builddir = ../../../..
include $(top_builddir)/src/Makefile.global
OBJS = transam.o transsup.o varsup.o xact.o xid.o xlog.o xlogutils.o rmgr.o
OBJS = clog.o transam.o varsup.o xact.o xid.o xlog.o xlogutils.o rmgr.o
all: SUBSYS.o

View File

@ -0,0 +1,987 @@
/*-------------------------------------------------------------------------
*
* clog.c
* PostgreSQL transaction-commit-log manager
*
* This module replaces the old "pg_log" access code, which treated pg_log
* essentially like a relation, in that it went through the regular buffer
* manager. The problem with that was that there wasn't any good way to
* recycle storage space for transactions so old that they'll never be
* looked up again. Now we use specialized access code so that the commit
* log can be broken into relatively small, independent segments.
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Header: /cvsroot/pgsql/src/backend/access/transam/clog.c,v 1.1 2001/08/25 18:52:41 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <fcntl.h>
#include <dirent.h>
#include <errno.h>
#include <unistd.h>
#include "access/clog.h"
#include "storage/s_lock.h"
#include "miscadmin.h"
/*
* Defines for CLOG page and segment sizes. A page is the same BLCKSZ
* as is used everywhere else in Postgres. The CLOG segment size can be
* chosen somewhat arbitrarily; we make it 1 million transactions by default,
* or 256Kb.
*
* Note: because TransactionIds are 32 bits and wrap around at 0xFFFFFFFF,
* CLOG page numbering also wraps around at 0xFFFFFFFF/CLOG_XACTS_PER_PAGE,
* and CLOG segment numbering at 0xFFFFFFFF/CLOG_XACTS_PER_SEGMENT. We need
* take no explicit notice of that fact in this module, except when comparing
* segment and page numbers in TruncateCLOG (see CLOGPagePrecedes).
*/
#define CLOG_BLCKSZ BLCKSZ
/* We need two bits per xact, so four xacts fit in a byte */
#define CLOG_BITS_PER_XACT 2
#define CLOG_XACTS_PER_BYTE 4
#define CLOG_XACTS_PER_PAGE (CLOG_BLCKSZ * CLOG_XACTS_PER_BYTE)
#define CLOG_XACT_BITMASK ((1 << CLOG_BITS_PER_XACT) - 1)
#define CLOG_XACTS_PER_SEGMENT 0x100000
#define CLOG_PAGES_PER_SEGMENT (CLOG_XACTS_PER_SEGMENT / CLOG_XACTS_PER_PAGE)
#define TransactionIdToPage(xid) ((xid) / (TransactionId) CLOG_XACTS_PER_PAGE)
#define TransactionIdToPgIndex(xid) ((xid) % (TransactionId) CLOG_XACTS_PER_PAGE)
#define TransactionIdToByte(xid) (TransactionIdToPgIndex(xid) / CLOG_XACTS_PER_BYTE)
#define TransactionIdToBIndex(xid) ((xid) % (TransactionId) CLOG_XACTS_PER_BYTE)
/*----------
* Shared-memory data structures for CLOG control
*
* We use a simple least-recently-used scheme to manage a pool of page
* buffers for the CLOG. Under ordinary circumstances we expect that write
* traffic will occur mostly to the latest CLOG page (and to the just-prior
* page, soon after a page transition). Read traffic will probably touch
* a larger span of pages, but in any case a fairly small number of page
* buffers should be sufficient. So, we just search the buffers using plain
* linear search; there's no need for a hashtable or anything fancy.
* The management algorithm is straight LRU except that we will never swap
* out the latest page (since we know it's going to be hit again eventually).
*
* We use an overall spinlock to protect the shared data structures, plus
* per-buffer spinlocks that synchronize I/O for each buffer. A process
* that is reading in or writing out a page buffer does not hold the control
* lock, only the per-buffer lock for the buffer it is working on.
*
* To change the page number or state of a buffer, one must normally hold
* the control lock. (The sole exception to this rule is that a writer
* process changes the state from DIRTY to WRITE_IN_PROGRESS while holding
* only the per-buffer lock.) If the buffer's state is neither EMPTY nor
* CLEAN, then there may be processes doing (or waiting to do) I/O on the
* buffer, so the page number may not be changed, and the only allowed state
* transition is to change WRITE_IN_PROGRESS to DIRTY after dirtying the page.
* To do any other state transition involving a buffer with potential I/O
* processes, one must hold both the per-buffer lock and the control lock.
* (Note the control lock must be acquired second; do not wait on a buffer
* lock while holding the control lock.) A process wishing to read a page
* marks the buffer state as READ_IN_PROGRESS, then drops the control lock,
* acquires the per-buffer lock, and rechecks the state before proceeding.
* This recheck takes care of the possibility that someone else already did
* the read, while the early marking prevents someone else from trying to
* read the same page into a different buffer.
*
* Note we are assuming that read and write of the state value is atomic,
* since I/O processes may examine and change the state while not holding
* the control lock.
*
* As with the regular buffer manager, it is possible for another process
* to re-dirty a page that is currently being written out. This is handled
* by setting the page's state from WRITE_IN_PROGRESS to DIRTY. The writing
* process must notice this and not mark the page CLEAN when it's done.
*
* XXX it's probably okay to use a spinlock for the control lock, since
* that lock is only held for very short operations. It'd be nice to use
* some other form of lock for the per-buffer I/O locks, however.
*
* XLOG interactions: this module generates an XLOG record whenever a new
* CLOG page is initialized to zeroes. Other writes of CLOG come from
* recording of transaction commit or abort in xact.c, which generates its
* own XLOG records for these events and will re-perform the status update
* on redo; so we need make no additional XLOG entry here. Also, the XLOG
* is guaranteed flushed through the XLOG commit record before we are called
* to log a commit, so the WAL rule "write xlog before data" is satisfied
* automatically for commits, and we don't really care for aborts. Therefore,
* we don't need to mark XLOG pages with LSN information; we have enough
* synchronization already.
*----------
*/
#define NUM_CLOG_BUFFERS 8
typedef enum
{
CLOG_PAGE_EMPTY, /* CLOG buffer is not in use */
CLOG_PAGE_READ_IN_PROGRESS, /* CLOG page is being read in */
CLOG_PAGE_CLEAN, /* CLOG page is valid and not dirty */
CLOG_PAGE_DIRTY, /* CLOG page is valid but needs write */
CLOG_PAGE_WRITE_IN_PROGRESS /* CLOG page is being written out in */
} ClogPageStatus;
/*
* Shared-memory state for CLOG.
*/
typedef struct ClogCtlData
{
/*
* Info for each buffer slot. Page number is undefined when status is
* EMPTY. lru_count is essentially the number of operations since last
* use of this page; the page with highest lru_count is the best candidate
* to replace.
*/
char *page_buffer[NUM_CLOG_BUFFERS];
ClogPageStatus page_status[NUM_CLOG_BUFFERS];
int page_number[NUM_CLOG_BUFFERS];
unsigned int page_lru_count[NUM_CLOG_BUFFERS];
/*
* latest_page_number is the page number of the current end of the
* CLOG; this is not critical data, since we use it only to avoid
* swapping out the latest page.
*/
int latest_page_number;
slock_t control_lck; /* Lock for ClogCtlData itself */
slock_t buffer_lck[NUM_CLOG_BUFFERS]; /* Per-buffer I/O locks */
} ClogCtlData;
static ClogCtlData *ClogCtl = NULL;
/*
* ClogDir is set during CLOGShmemInit and does not change thereafter.
* The value is automatically inherited by backends via fork, and
* doesn't need to be in shared memory.
*/
static char ClogDir[MAXPGPATH];
#define ClogFileName(path, seg) \
snprintf(path, MAXPGPATH, "%s/%04X", ClogDir, seg)
/*
* Macro to mark a buffer slot "most recently used".
*/
#define ClogRecentlyUsed(slotno) \
do { \
int iilru; \
for (iilru = 0; iilru < NUM_CLOG_BUFFERS; iilru++) \
ClogCtl->page_lru_count[iilru]++; \
ClogCtl->page_lru_count[slotno] = 0; \
} while (0)
static int ZeroCLOGPage(int pageno, bool writeXlog);
static int ReadCLOGPage(int pageno);
static void WriteCLOGPage(int slotno);
static void CLOGPhysicalReadPage(int pageno, int slotno);
static void CLOGPhysicalWritePage(int pageno, int slotno);
static int SelectLRUCLOGPage(int pageno);
static bool ScanCLOGDirectory(int cutoffPage, bool doDeletions);
static bool CLOGPagePrecedes(int page1, int page2);
static void WriteZeroPageXlogRec(int pageno);
/*
* Record the final state of a transaction in the commit log.
*
* NB: this is a low-level routine and is NOT the preferred entry point
* for most uses; TransactionLogUpdate() in transam.c is the intended caller.
*/
void
TransactionIdSetStatus(TransactionId xid, XidStatus status)
{
int pageno = TransactionIdToPage(xid);
int byteno = TransactionIdToByte(xid);
int bshift = TransactionIdToBIndex(xid) * CLOG_BITS_PER_XACT;
int slotno;
char *byteptr;
Assert(status == TRANSACTION_STATUS_COMMITTED ||
status == TRANSACTION_STATUS_ABORTED);
S_LOCK(&(ClogCtl->control_lck));
slotno = ReadCLOGPage(pageno);
byteptr = ClogCtl->page_buffer[slotno] + byteno;
/* Current state should be 0 or target state */
Assert(((*byteptr >> bshift) & CLOG_XACT_BITMASK) == 0 ||
((*byteptr >> bshift) & CLOG_XACT_BITMASK) == status);
*byteptr |= (status << bshift);
ClogCtl->page_status[slotno] = CLOG_PAGE_DIRTY;
S_UNLOCK(&(ClogCtl->control_lck));
}
/*
* Interrogate the state of a transaction in the commit log.
*
* NB: this is a low-level routine and is NOT the preferred entry point
* for most uses; TransactionLogTest() in transam.c is the intended caller.
*/
XidStatus
TransactionIdGetStatus(TransactionId xid)
{
int pageno = TransactionIdToPage(xid);
int byteno = TransactionIdToByte(xid);
int bshift = TransactionIdToBIndex(xid) * CLOG_BITS_PER_XACT;
int slotno;
char *byteptr;
XidStatus status;
S_LOCK(&(ClogCtl->control_lck));
slotno = ReadCLOGPage(pageno);
byteptr = ClogCtl->page_buffer[slotno] + byteno;
status = (*byteptr >> bshift) & CLOG_XACT_BITMASK;
S_UNLOCK(&(ClogCtl->control_lck));
return status;
}
/*
* Initialization of shared memory for CLOG
*/
int
CLOGShmemSize(void)
{
return MAXALIGN(sizeof(ClogCtlData) + CLOG_BLCKSZ * NUM_CLOG_BUFFERS);
}
void
CLOGShmemInit(void)
{
bool found;
char *bufptr;
int slotno;
/* this must agree with space requested by CLOGShmemSize() */
ClogCtl = (ClogCtlData *)
ShmemInitStruct("CLOG Ctl",
MAXALIGN(sizeof(ClogCtlData) +
CLOG_BLCKSZ * NUM_CLOG_BUFFERS),
&found);
Assert(!found);
memset(ClogCtl, 0, sizeof(ClogCtlData));
S_INIT_LOCK(&(ClogCtl->control_lck));
bufptr = ((char *) ClogCtl) + sizeof(ClogCtlData);
for (slotno = 0; slotno < NUM_CLOG_BUFFERS; slotno++)
{
ClogCtl->page_buffer[slotno] = bufptr;
ClogCtl->page_status[slotno] = CLOG_PAGE_EMPTY;
S_INIT_LOCK(&(ClogCtl->buffer_lck[slotno]));
bufptr += CLOG_BLCKSZ;
}
/* ClogCtl->latest_page_number will be set later */
/* Init CLOG directory path */
snprintf(ClogDir, MAXPGPATH, "%s/pg_clog", DataDir);
}
/*
* This func must be called ONCE on system install. It creates
* the initial CLOG segment. (The CLOG directory is assumed to
* have been created by the initdb shell script, and CLOGShmemInit
* must have been called already.)
*/
void
BootStrapCLOG(void)
{
int slotno;
S_LOCK(&(ClogCtl->control_lck));
/* Create and zero the first page of the commit log */
slotno = ZeroCLOGPage(0, false);
/* Make sure it's written out */
WriteCLOGPage(slotno);
Assert(ClogCtl->page_status[slotno] == CLOG_PAGE_CLEAN);
S_UNLOCK(&(ClogCtl->control_lck));
}
/*
* Initialize (or reinitialize) a page of CLOG to zeroes.
* If writeXlog is TRUE, also emit an XLOG record saying we did this.
*
* The page is not actually written, just set up in shared memory.
* The slot number of the new page is returned.
*
* Control lock must be held at entry, and will be held at exit.
*/
static int
ZeroCLOGPage(int pageno, bool writeXlog)
{
int slotno;
/* Find a suitable buffer slot for the page */
slotno = SelectLRUCLOGPage(pageno);
Assert(ClogCtl->page_status[slotno] == CLOG_PAGE_EMPTY ||
ClogCtl->page_status[slotno] == CLOG_PAGE_CLEAN ||
ClogCtl->page_number[slotno] == pageno);
/* Mark the slot as containing this page */
ClogCtl->page_number[slotno] = pageno;
ClogCtl->page_status[slotno] = CLOG_PAGE_DIRTY;
ClogRecentlyUsed(slotno);
/* Set the buffer to zeroes */
MemSet(ClogCtl->page_buffer[slotno], 0, CLOG_BLCKSZ);
/* Assume this page is now the latest active page */
ClogCtl->latest_page_number = pageno;
if (writeXlog)
WriteZeroPageXlogRec(pageno);
return slotno;
}
/*
* Find a CLOG page in a shared buffer, reading it in if necessary.
* The page number must correspond to an already-initialized page.
*
* Return value is the shared-buffer slot number now holding the page.
* The buffer's LRU access info is updated.
*
* Control lock must be held at entry, and will be held at exit.
*/
static int
ReadCLOGPage(int pageno)
{
/* Outer loop handles restart if we lose the buffer to someone else */
for (;;)
{
int slotno;
/* See if page already is in memory; if not, pick victim slot */
slotno = SelectLRUCLOGPage(pageno);
/* Did we find the page in memory? */
if (ClogCtl->page_number[slotno] == pageno &&
ClogCtl->page_status[slotno] != CLOG_PAGE_EMPTY)
{
/* If page is still being read in, we cannot use it yet */
if (ClogCtl->page_status[slotno] != CLOG_PAGE_READ_IN_PROGRESS)
{
/* otherwise, it's ready to use */
ClogRecentlyUsed(slotno);
return slotno;
}
}
else
{
/* We found no match; assert we selected a freeable slot */
Assert(ClogCtl->page_status[slotno] == CLOG_PAGE_EMPTY ||
ClogCtl->page_status[slotno] == CLOG_PAGE_CLEAN);
}
/* Mark the slot read-busy (no-op if it already was) */
ClogCtl->page_number[slotno] = pageno;
ClogCtl->page_status[slotno] = CLOG_PAGE_READ_IN_PROGRESS;
/*
* Temporarily mark page as recently-used to discourage
* SelectLRUCLOGPage from selecting it again for someone else.
*/
ClogCtl->page_lru_count[slotno] = 0;
/* Release shared lock, grab per-buffer lock instead */
S_UNLOCK(&(ClogCtl->control_lck));
S_LOCK(&(ClogCtl->buffer_lck[slotno]));
/*
* Check to see if someone else already did the read, or took the
* buffer away from us. If so, restart from the top.
*/
if (ClogCtl->page_number[slotno] != pageno ||
ClogCtl->page_status[slotno] != CLOG_PAGE_READ_IN_PROGRESS)
{
S_UNLOCK(&(ClogCtl->buffer_lck[slotno]));
S_LOCK(&(ClogCtl->control_lck));
continue;
}
/* Okay, do the read */
CLOGPhysicalReadPage(pageno, slotno);
/* Re-acquire shared control lock and update page state */
S_LOCK(&(ClogCtl->control_lck));
Assert(ClogCtl->page_number[slotno] == pageno &&
ClogCtl->page_status[slotno] == CLOG_PAGE_READ_IN_PROGRESS);
ClogCtl->page_status[slotno] = CLOG_PAGE_CLEAN;
S_UNLOCK(&(ClogCtl->buffer_lck[slotno]));
ClogRecentlyUsed(slotno);
return slotno;
}
}
/*
* Write a CLOG page from a shared buffer, if necessary.
* Does nothing if the specified slot is not dirty.
*
* NOTE: only one write attempt is made here. Hence, it is possible that
* the page is still dirty at exit (if someone else re-dirtied it during
* the write). However, we *do* attempt a fresh write even if the page
* is already being written; this is for checkpoints.
*
* Control lock must be held at entry, and will be held at exit.
*/
static void
WriteCLOGPage(int slotno)
{
int pageno;
/* Do nothing if page does not need writing */
if (ClogCtl->page_status[slotno] != CLOG_PAGE_DIRTY &&
ClogCtl->page_status[slotno] != CLOG_PAGE_WRITE_IN_PROGRESS)
return;
pageno = ClogCtl->page_number[slotno];
/* Release shared lock, grab per-buffer lock instead */
S_UNLOCK(&(ClogCtl->control_lck));
S_LOCK(&(ClogCtl->buffer_lck[slotno]));
/*
* Check to see if someone else already did the write, or took the
* buffer away from us. If so, do nothing. NOTE: we really should
* never see WRITE_IN_PROGRESS here, since that state should only
* occur while the writer is holding the buffer lock. But accept it
* so that we have a recovery path if a writer aborts.
*/
if (ClogCtl->page_number[slotno] != pageno ||
(ClogCtl->page_status[slotno] != CLOG_PAGE_DIRTY &&
ClogCtl->page_status[slotno] != CLOG_PAGE_WRITE_IN_PROGRESS))
{
S_UNLOCK(&(ClogCtl->buffer_lck[slotno]));
S_LOCK(&(ClogCtl->control_lck));
return;
}
/*
* Mark the slot write-busy. After this point, a transaction status
* update on this page will mark it dirty again. NB: we are assuming
* that read/write of the page status field is atomic, since we change
* the state while not holding control lock. However, we cannot set
* this state any sooner, or we'd possibly fool a previous writer
* into thinking he's successfully dumped the page when he hasn't.
* (Scenario: other writer starts, page is redirtied, we come along and
* set WRITE_IN_PROGRESS again, other writer completes and sets CLEAN
* because redirty info has been lost, then we think it's clean too.)
*/
ClogCtl->page_status[slotno] = CLOG_PAGE_WRITE_IN_PROGRESS;
/* Okay, do the write */
CLOGPhysicalWritePage(pageno, slotno);
/* Re-acquire shared control lock and update page state */
S_LOCK(&(ClogCtl->control_lck));
Assert(ClogCtl->page_number[slotno] == pageno &&
(ClogCtl->page_status[slotno] == CLOG_PAGE_WRITE_IN_PROGRESS ||
ClogCtl->page_status[slotno] == CLOG_PAGE_DIRTY));
/* Cannot set CLEAN if someone re-dirtied page since write started */
if (ClogCtl->page_status[slotno] == CLOG_PAGE_WRITE_IN_PROGRESS)
ClogCtl->page_status[slotno] = CLOG_PAGE_CLEAN;
S_UNLOCK(&(ClogCtl->buffer_lck[slotno]));
}
/*
* Physical read of a (previously existing) page into a buffer slot
*
* For now, assume it's not worth keeping a file pointer open across
* read/write operations. We could cache one virtual file pointer ...
*/
static void
CLOGPhysicalReadPage(int pageno, int slotno)
{
int segno = pageno / CLOG_PAGES_PER_SEGMENT;
int rpageno = pageno % CLOG_PAGES_PER_SEGMENT;
int offset = rpageno * CLOG_BLCKSZ;
char path[MAXPGPATH];
int fd;
ClogFileName(path, segno);
/*
* In a crash-and-restart situation, it's possible for us to receive
* commands to set the commit status of transactions whose bits are
* in already-truncated segments of the commit log (see notes in
* CLOGPhysicalWritePage). Hence, if we are InRecovery, allow the
* case where the file doesn't exist, and return zeroes instead.
*/
fd = BasicOpenFile(path, O_RDWR | PG_BINARY, S_IRUSR | S_IWUSR);
if (fd < 0)
{
if (errno != ENOENT || !InRecovery)
elog(STOP, "open of %s failed: %m", path);
elog(DEBUG, "clog file %s doesn't exist, reading as zeroes", path);
MemSet(ClogCtl->page_buffer[slotno], 0, CLOG_BLCKSZ);
return;
}
if (lseek(fd, (off_t) offset, SEEK_SET) < 0)
elog(STOP, "lseek of clog file %u, offset %u failed: %m",
segno, offset);
errno = 0;
if (read(fd, ClogCtl->page_buffer[slotno], CLOG_BLCKSZ) != CLOG_BLCKSZ)
elog(STOP, "read of clog file %u, offset %u failed: %m",
segno, offset);
close(fd);
}
/*
* Physical write of a page from a buffer slot
*
* For now, assume it's not worth keeping a file pointer open across
* read/write operations. We could cache one virtual file pointer ...
*/
static void
CLOGPhysicalWritePage(int pageno, int slotno)
{
int segno = pageno / CLOG_PAGES_PER_SEGMENT;
int rpageno = pageno % CLOG_PAGES_PER_SEGMENT;
int offset = rpageno * CLOG_BLCKSZ;
char path[MAXPGPATH];
int fd;
ClogFileName(path, segno);
/*
* If the file doesn't already exist, we should create it. It is possible
* for this to need to happen when writing a page that's not first in
* its segment; we assume the OS can cope with that. (Note: it might seem
* that it'd be okay to create files only when ZeroCLOGPage is called for
* the first page of a segment. However, if after a crash and restart
* the REDO logic elects to replay the log from a checkpoint before the
* latest one, then it's possible that we will get commands to set
* transaction status of transactions that have already been truncated
* from the commit log. Easiest way to deal with that is to accept
* references to nonexistent files here and in CLOGPhysicalReadPage.)
*/
fd = BasicOpenFile(path, O_RDWR | PG_BINARY, S_IRUSR | S_IWUSR);
if (fd < 0)
{
if (errno != ENOENT)
elog(STOP, "open of %s failed: %m", path);
fd = BasicOpenFile(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
S_IRUSR | S_IWUSR);
if (fd < 0)
elog(STOP, "creation of file %s failed: %m", path);
}
if (lseek(fd, (off_t) offset, SEEK_SET) < 0)
elog(STOP, "lseek of clog file %u, offset %u failed: %m",
segno, offset);
errno = 0;
if (write(fd, ClogCtl->page_buffer[slotno], CLOG_BLCKSZ) != CLOG_BLCKSZ)
{
/* if write didn't set errno, assume problem is no disk space */
if (errno == 0)
errno = ENOSPC;
elog(STOP, "write of clog file %u, offset %u failed: %m",
segno, offset);
}
close(fd);
}
/*
* Select the slot to re-use when we need a free slot.
*
* The target page number is passed because we need to consider the
* possibility that some other process reads in the target page while
* we are doing I/O to free a slot. Hence, check or recheck to see if
* any slot already holds the target page, and return that slot if so.
* Thus, the returned slot is *either* a slot already holding the pageno
* (could be any state except EMPTY), *or* a freeable slot (state EMPTY
* or CLEAN).
*
* Control lock must be held at entry, and will be held at exit.
*/
static int
SelectLRUCLOGPage(int pageno)
{
/* Outer loop handles restart after I/O */
for (;;)
{
int slotno;
int bestslot = 0;
unsigned int bestcount = 0;
/* See if page already has a buffer assigned */
for (slotno = 0; slotno < NUM_CLOG_BUFFERS; slotno++)
{
if (ClogCtl->page_number[slotno] == pageno &&
ClogCtl->page_status[slotno] != CLOG_PAGE_EMPTY)
return slotno;
}
/*
* If we find any EMPTY slot, just select that one.
* Else locate the least-recently-used slot that isn't the
* latest CLOG page.
*/
for (slotno = 0; slotno < NUM_CLOG_BUFFERS; slotno++)
{
if (ClogCtl->page_status[slotno] == CLOG_PAGE_EMPTY)
return slotno;
if (ClogCtl->page_lru_count[slotno] > bestcount &&
ClogCtl->page_number[slotno] != ClogCtl->latest_page_number)
{
bestslot = slotno;
bestcount = ClogCtl->page_lru_count[slotno];
}
}
/*
* If the selected page is clean, we're set.
*/
if (ClogCtl->page_status[bestslot] == CLOG_PAGE_CLEAN)
return bestslot;
/*
* We need to do I/O. Normal case is that we have to write it out,
* but it's possible in the worst case to have selected a read-busy
* page. In that case we use ReadCLOGPage to wait for the read to
* complete.
*/
if (ClogCtl->page_status[bestslot] == CLOG_PAGE_READ_IN_PROGRESS)
(void) ReadCLOGPage(ClogCtl->page_number[bestslot]);
else
WriteCLOGPage(bestslot);
/*
* Now loop back and try again. This is the easiest way of dealing
* with corner cases such as the victim page being re-dirtied while
* we wrote it.
*/
}
}
/*
* This must be called ONCE during postmaster or standalone-backend startup,
* after StartupXLOG has initialized ShmemVariableCache->nextXid.
*/
void
StartupCLOG(void)
{
/*
* Initialize our idea of the latest page number.
*/
ClogCtl->latest_page_number = TransactionIdToPage(ShmemVariableCache->nextXid);
}
/*
* This must be called ONCE during postmaster or standalone-backend shutdown
*/
void
ShutdownCLOG(void)
{
int slotno;
S_LOCK(&(ClogCtl->control_lck));
for (slotno = 0; slotno < NUM_CLOG_BUFFERS; slotno++)
{
WriteCLOGPage(slotno);
Assert(ClogCtl->page_status[slotno] == CLOG_PAGE_EMPTY ||
ClogCtl->page_status[slotno] == CLOG_PAGE_CLEAN);
}
S_UNLOCK(&(ClogCtl->control_lck));
}
/*
* Perform a checkpoint --- either during shutdown, or on-the-fly
*/
void
CheckPointCLOG(void)
{
int slotno;
S_LOCK(&(ClogCtl->control_lck));
for (slotno = 0; slotno < NUM_CLOG_BUFFERS; slotno++)
{
WriteCLOGPage(slotno);
/*
* We cannot assert that the slot is clean now, since another
* process might have re-dirtied it already. That's okay.
*/
}
S_UNLOCK(&(ClogCtl->control_lck));
}
/*
* Make sure that CLOG has room for a newly-allocated XID.
*
* NB: this is called while holding XidGenLock. We want it to be very fast
* most of the time; even when it's not so fast, no actual I/O need happen
* unless we're forced to write out a dirty clog or xlog page to make room
* in shared memory.
*/
void
ExtendCLOG(TransactionId newestXact)
{
int pageno;
/* No work except at first XID of a page */
if (TransactionIdToPgIndex(newestXact) != 0)
return;
pageno = TransactionIdToPage(newestXact);
S_LOCK(&(ClogCtl->control_lck));
/* Zero the page and make an XLOG entry about it */
ZeroCLOGPage(pageno, true);
S_UNLOCK(&(ClogCtl->control_lck));
}
/*
* Remove all CLOG segments before the one holding the passed transaction ID
*
* When this is called, we know that the database logically contains no
* reference to transaction IDs older than oldestXact. However, we must
* not truncate the CLOG until we have performed a checkpoint, to ensure
* that no such references remain on disk either; else a crash just after
* the truncation might leave us with a problem. Since CLOG segments hold
* a large number of transactions, the opportunity to actually remove a
* segment is fairly rare, and so it seems best not to do the checkpoint
* unless we have confirmed that there is a removable segment. Therefore
* we issue the checkpoint command here, not in higher-level code as might
* seem cleaner.
*/
void
TruncateCLOG(TransactionId oldestXact)
{
int cutoffPage;
int slotno;
/*
* The cutoff point is the start of the segment containing oldestXact.
*/
oldestXact -= oldestXact % CLOG_XACTS_PER_SEGMENT;
cutoffPage = TransactionIdToPage(oldestXact);
if (!ScanCLOGDirectory(cutoffPage, false))
return; /* nothing to remove */
/* Perform a CHECKPOINT */
CreateCheckPoint(false);
/*
* Scan CLOG shared memory and remove any pages preceding the cutoff
* page, to ensure we won't rewrite them later. (Any dirty pages
* should have been flushed already during the checkpoint, we're
* just being extra careful here.)
*/
S_LOCK(&(ClogCtl->control_lck));
restart:;
for (slotno = 0; slotno < NUM_CLOG_BUFFERS; slotno++)
{
if (ClogCtl->page_status[slotno] == CLOG_PAGE_EMPTY)
continue;
if (!CLOGPagePrecedes(ClogCtl->page_number[slotno], cutoffPage))
continue;
/*
* If page is CLEAN, just change state to EMPTY (expected case).
*/
if (ClogCtl->page_status[slotno] == CLOG_PAGE_CLEAN)
{
ClogCtl->page_status[slotno] = CLOG_PAGE_EMPTY;
continue;
}
/*
* Hmm, we have (or may have) I/O operations acting on the page,
* so we've got to wait for them to finish and then start again.
* This is the same logic as in SelectLRUCLOGPage.
*/
if (ClogCtl->page_status[slotno] == CLOG_PAGE_READ_IN_PROGRESS)
(void) ReadCLOGPage(ClogCtl->page_number[slotno]);
else
WriteCLOGPage(slotno);
goto restart;
}
S_UNLOCK(&(ClogCtl->control_lck));
/* Now we can remove the old CLOG segment(s) */
(void) ScanCLOGDirectory(cutoffPage, true);
}
/*
* TruncateCLOG subroutine: scan CLOG directory for removable segments.
* Actually remove them iff doDeletions is true. Return TRUE iff any
* removable segments were found. Note: no locking is needed.
*/
static bool
ScanCLOGDirectory(int cutoffPage, bool doDeletions)
{
bool found = false;
DIR *cldir;
struct dirent *clde;
int segno;
int segpage;
char path[MAXPGPATH];
cldir = opendir(ClogDir);
if (cldir == NULL)
elog(STOP, "could not open transaction-commit log directory (%s): %m",
ClogDir);
errno = 0;
while ((clde = readdir(cldir)) != NULL)
{
if (strlen(clde->d_name) == 4 &&
strspn(clde->d_name, "0123456789ABCDEF") == 4)
{
segno = (int) strtol(clde->d_name, NULL, 16);
segpage = segno * CLOG_PAGES_PER_SEGMENT;
if (CLOGPagePrecedes(segpage, cutoffPage))
{
found = true;
if (doDeletions)
{
snprintf(path, MAXPGPATH, "%s/%s", ClogDir, clde->d_name);
unlink(path);
}
}
}
errno = 0;
}
if (errno)
elog(STOP, "could not read transaction-commit log directory (%s): %m",
ClogDir);
closedir(cldir);
return found;
}
/*
* Decide which of two CLOG page numbers is "older" for truncation purposes.
*
* We need to use comparison of TransactionIds here in order to do the right
* thing with wraparound XID arithmetic. However, if we are asked about
* page number zero, we don't want to hand InvalidTransactionId to
* TransactionIdPrecedes: it'll get weird about permanent xact IDs. So,
* offset both xids by FirstNormalTransactionId to avoid that.
*/
static bool
CLOGPagePrecedes(int page1, int page2)
{
TransactionId xid1;
TransactionId xid2;
xid1 = (TransactionId) page1 * CLOG_XACTS_PER_PAGE;
xid1 += FirstNormalTransactionId;
xid2 = (TransactionId) page2 * CLOG_XACTS_PER_PAGE;
xid2 += FirstNormalTransactionId;
return TransactionIdPrecedes(xid1, xid2);
}
/*
* Write a ZEROPAGE xlog record
*
* Note: xlog record is marked as outside transaction control, since we
* want it to be redone whether the invoking transaction commits or not.
* (Besides which, this is normally done just before entering a transaction.)
*/
static void
WriteZeroPageXlogRec(int pageno)
{
XLogRecData rdata;
rdata.buffer = InvalidBuffer;
rdata.data = (char *) (&pageno);
rdata.len = sizeof(int);
rdata.next = NULL;
(void) XLogInsert(RM_CLOG_ID, CLOG_ZEROPAGE | XLOG_NO_TRAN, &rdata);
}
/*
* CLOG resource manager's routines
*/
void
clog_redo(XLogRecPtr lsn, XLogRecord *record)
{
uint8 info = record->xl_info & ~XLR_INFO_MASK;
if (info == CLOG_ZEROPAGE)
{
int pageno;
int slotno;
memcpy(&pageno, XLogRecGetData(record), sizeof(int));
S_LOCK(&(ClogCtl->control_lck));
slotno = ZeroCLOGPage(pageno, false);
WriteCLOGPage(slotno);
Assert(ClogCtl->page_status[slotno] == CLOG_PAGE_CLEAN);
S_UNLOCK(&(ClogCtl->control_lck));
}
}
void
clog_undo(XLogRecPtr lsn, XLogRecord *record)
{
}
void
clog_desc(char *buf, uint8 xl_info, char *rec)
{
uint8 info = xl_info & ~XLR_INFO_MASK;
if (info == CLOG_ZEROPAGE)
{
int pageno;
memcpy(&pageno, rec, sizeof(int));
sprintf(buf + strlen(buf), "zeropage: %d", pageno);
}
else
strcat(buf, "UNKNOWN");
}

View File

@ -1,4 +1,13 @@
/*
* rmgr.c
*
* Resource managers definition
*
* $Header: /cvsroot/pgsql/src/backend/access/transam/rmgr.c,v 1.9 2001/08/25 18:52:41 tgl Exp $
*/
#include "postgres.h"
#include "access/clog.h"
#include "access/gist.h"
#include "access/hash.h"
#include "access/heapam.h"
@ -9,11 +18,12 @@
#include "storage/smgr.h"
#include "commands/sequence.h"
RmgrData RmgrTable[] = {
{"XLOG", xlog_redo, xlog_undo, xlog_desc},
{"Transaction", xact_redo, xact_undo, xact_desc},
{"Storage", smgr_redo, smgr_undo, smgr_desc},
{"Reserved 3", NULL, NULL, NULL},
{"CLOG", clog_redo, clog_undo, clog_desc},
{"Reserved 4", NULL, NULL, NULL},
{"Reserved 5", NULL, NULL, NULL},
{"Reserved 6", NULL, NULL, NULL},

View File

@ -1,14 +1,14 @@
/*-------------------------------------------------------------------------
*
* transam.c
* postgres transaction log/time interface routines
* postgres transaction log interface routines
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/transam/transam.c,v 1.46 2001/08/23 23:06:37 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/access/transam/transam.c,v 1.47 2001/08/25 18:52:41 tgl Exp $
*
* NOTES
* This file contains the high level access-method interface to the
@ -19,27 +19,14 @@
#include "postgres.h"
#include "access/heapam.h"
#include "access/clog.h"
#include "access/transam.h"
#include "catalog/catname.h"
#include "miscadmin.h"
static int RecoveryCheckingEnabled(void);
static void TransRecover(Relation logRelation);
static bool TransactionLogTest(TransactionId transactionId, XidStatus status);
static void TransactionLogUpdate(TransactionId transactionId,
XidStatus status);
/* ----------------
* global variables holding pointers to relations used
* by the transaction system. These are initialized by
* InitializeTransactionLog().
* ----------------
*/
Relation LogRelation = (Relation) NULL;
/* ----------------
* Single-item cache for results of TransactionLogTest.
* ----------------
@ -47,48 +34,12 @@ Relation LogRelation = (Relation) NULL;
static TransactionId cachedTestXid = InvalidTransactionId;
static XidStatus cachedTestXidStatus;
/* ----------------
* transaction recovery state variables
*
* When the transaction system is initialized, we may
* need to do recovery checking. This decision is decided
* by the postmaster or the user by supplying the backend
* with a special flag. In general, we want to do recovery
* checking whenever we are running without a postmaster
* or when the number of backends running under the postmaster
* goes from zero to one. -cim 3/21/90
* ----------------
*/
static int RecoveryCheckingEnableState = 0;
/* ----------------
* recovery checking accessors
* ----------------
*/
static int
RecoveryCheckingEnabled(void)
{
return RecoveryCheckingEnableState;
}
#ifdef NOT_USED
static void
SetRecoveryCheckingEnabled(bool state)
{
RecoveryCheckingEnableState = (state == true);
}
#endif
/* ----------------------------------------------------------------
* postgres log access method interface
*
* TransactionLogTest
* TransactionLogUpdate
* ========
* these functions do work for the interface
* functions - they search/retrieve and append/update
* information in the log and time relations.
* ----------------------------------------------------------------
*/
@ -102,59 +53,42 @@ static bool /* true/false: does transaction id have
TransactionLogTest(TransactionId transactionId, /* transaction id to test */
XidStatus status) /* transaction status */
{
BlockNumber blockNumber;
XidStatus xidstatus; /* recorded status of xid */
bool fail = false; /* success/failure */
/*
* during initialization consider all transactions as having been
* committed
*/
if (!RelationIsValid(LogRelation))
return (bool) (status == XID_COMMIT);
/*
* before going to the buffer manager, check our single item cache to
* Before going to the commit log manager, check our single item cache to
* see if we didn't just check the transaction status a moment ago.
*/
if (TransactionIdEquals(transactionId, cachedTestXid))
return (bool)
(status == cachedTestXidStatus);
return (status == cachedTestXidStatus);
/*
* compute the item pointer corresponding to the page containing our
* transaction id. We save the item in our cache to speed up things
* if we happen to ask for the same xid's status more than once.
* Also, check to see if the transaction ID is a permanent one.
*/
TransComputeBlockNumber(LogRelation, transactionId, &blockNumber);
xidstatus = TransBlockNumberGetXidStatus(LogRelation,
blockNumber,
transactionId,
&fail);
if (!fail)
if (! TransactionIdIsNormal(transactionId))
{
/*
* DO NOT cache status for transactions in unknown state !!!
*/
if (xidstatus == XID_COMMIT || xidstatus == XID_ABORT)
{
TransactionIdStore(transactionId, &cachedTestXid);
cachedTestXidStatus = xidstatus;
}
return (bool) (status == xidstatus);
if (TransactionIdEquals(transactionId, BootstrapTransactionId))
return (status == TRANSACTION_STATUS_COMMITTED);
if (TransactionIdEquals(transactionId, FrozenTransactionId))
return (status == TRANSACTION_STATUS_COMMITTED);
return (status == TRANSACTION_STATUS_ABORTED);
}
/*
* here the block didn't contain the information we wanted
* Get the status.
*/
elog(ERROR, "TransactionLogTest: failed to get xidstatus");
xidstatus = TransactionIdGetStatus(transactionId);
/*
* so lint is happy...
*/
return false;
/*
* DO NOT cache status for unfinished transactions!
*/
if (xidstatus != TRANSACTION_STATUS_IN_PROGRESS)
{
TransactionIdStore(transactionId, &cachedTestXid);
cachedTestXidStatus = xidstatus;
}
return (status == xidstatus);
}
/* --------------------------------
@ -165,24 +99,10 @@ static void
TransactionLogUpdate(TransactionId transactionId, /* trans id to update */
XidStatus status) /* new trans status */
{
BlockNumber blockNumber;
bool fail = false; /* success/failure */
/*
* during initialization we don't record any updates.
* update the commit log
*/
if (!RelationIsValid(LogRelation))
return;
/*
* update the log relation
*/
TransComputeBlockNumber(LogRelation, transactionId, &blockNumber);
TransBlockNumberSetXidStatus(LogRelation,
blockNumber,
transactionId,
status,
&fail);
TransactionIdSetStatus(transactionId, status);
/*
* update (invalidate) our single item TransactionLogTest cache.
@ -191,85 +111,21 @@ TransactionLogUpdate(TransactionId transactionId, /* trans id to update */
cachedTestXidStatus = status;
}
/* ----------------------------------------------------------------
* transaction recovery code
* ----------------------------------------------------------------
*/
/* --------------------------------
* TransRecover
* AmiTransactionOverride
*
* preform transaction recovery checking.
*
* Note: this should only be preformed if no other backends
* are running. This is known by the postmaster and
* conveyed by the postmaster passing a "do recovery checking"
* flag to the backend.
*
* here we get the last recorded transaction from the log,
* get the "last" and "next" transactions from the variable relation
* and then preform some integrity tests:
*
* 1) No transaction may exist higher then the "next" available
* transaction recorded in the variable relation. If this is the
* case then it means either the log or the variable relation
* has become corrupted.
*
* 2) The last committed transaction may not be higher then the
* next available transaction for the same reason.
*
* 3) The last recorded transaction may not be lower then the
* last committed transaction. (the reverse is ok - it means
* that some transactions have aborted since the last commit)
*
* Here is what the proper situation looks like. The line
* represents the data stored in the log. 'c' indicates the
* transaction was recorded as committed, 'a' indicates an
* abortted transaction and '.' represents information not
* recorded. These may correspond to in progress transactions.
*
* c c a c . . a . . . . . . . . . .
* | |
* last next
*
* Since "next" is only incremented by GetNewTransactionId() which
* is called when transactions are started. Hence if there
* are commits or aborts after "next", then it means we committed
* or aborted BEFORE we started the transaction. This is the
* rational behind constraint (1).
*
* Likewise, "last" should never greater then "next" for essentially
* the same reason - it would imply we committed before we started.
* This is the reasoning for (2).
*
* (3) implies we may never have a situation such as:
*
* c c a c . . a c . . . . . . . . .
* | |
* last next
*
* where there is a 'c' greater then "last".
*
* Recovery checking is more difficult in the case where
* several backends are executing concurrently because the
* transactions may be executing in the other backends.
* So, we only do recovery stuff when the backend is explicitly
* passed a flag on the command line.
* This function is used to manipulate the bootstrap flag.
* --------------------------------
*/
static void
TransRecover(Relation logRelation)
void
AmiTransactionOverride(bool flag)
{
AMI_OVERRIDE = flag;
}
/* ----------------------------------------------------------------
* Interface functions
*
* InitializeTransactionLog
* ========
* this function (called near cinit) initializes
* the transaction log, time and variable relations.
*
* TransactionId DidCommit
* TransactionId DidAbort
* TransactionId IsInProgress
@ -279,104 +135,13 @@ TransRecover(Relation logRelation)
*
* TransactionId Commit
* TransactionId Abort
* TransactionId SetInProgress
* ========
* these functions set the transaction status
* of the specified xid. TransactionIdCommit() also
* records the current time in the time relation
* and updates the variable relation counter.
* of the specified xid.
*
* ----------------------------------------------------------------
*/
/*
* InitializeTransactionLog
* Initializes transaction logging.
*/
void
InitializeTransactionLog(void)
{
Relation logRelation;
MemoryContext oldContext;
/*
* don't do anything during bootstrapping
*/
if (AMI_OVERRIDE)
return;
/*
* disable the transaction system so the access methods don't
* interfere during initialization.
*/
OverrideTransactionSystem(true);
/*
* make sure allocations occur within the top memory context so that
* our log management structures are protected from garbage collection
* at the end of every transaction.
*/
oldContext = MemoryContextSwitchTo(TopMemoryContext);
/*
* first open the log and time relations (these are created by amiint
* so they are guaranteed to exist)
*/
logRelation = heap_openr(LogRelationName, NoLock);
/*
* XXX TransactionLogUpdate requires that LogRelation is valid so we
* temporarily set it so we can initialize things properly. This could
* be done cleaner.
*/
LogRelation = logRelation;
/*
* if we have a virgin database, we initialize the log relation by
* committing the BootstrapTransactionId and we initialize the
* variable relation by setting the next available transaction id to
* FirstNormalTransactionId. OID initialization happens as a side
* effect of bootstrapping in varsup.c.
*/
SpinAcquire(OidGenLockId);
if (!TransactionIdDidCommit(BootstrapTransactionId))
{
TransactionLogUpdate(BootstrapTransactionId, XID_COMMIT);
Assert(!IsUnderPostmaster &&
TransactionIdEquals(ShmemVariableCache->nextXid,
FirstNormalTransactionId));
ShmemVariableCache->nextXid = FirstNormalTransactionId;
}
else if (RecoveryCheckingEnabled())
{
/*
* if we have a pre-initialized database and if the perform
* recovery checking flag was passed then we do our database
* integrity checking.
*/
TransRecover(logRelation);
}
LogRelation = (Relation) NULL;
SpinRelease(OidGenLockId);
/*
* now re-enable the transaction system
*/
OverrideTransactionSystem(false);
/*
* instantiate the global variables
*/
LogRelation = logRelation;
/*
* restore the memory context to the previous context before we return
* from initialization.
*/
MemoryContextSwitchTo(oldContext);
}
/* --------------------------------
* TransactionId DidCommit
* TransactionId DidAbort
@ -397,16 +162,15 @@ TransactionIdDidCommit(TransactionId transactionId)
if (AMI_OVERRIDE)
return true;
return TransactionLogTest(transactionId, XID_COMMIT);
return TransactionLogTest(transactionId, TRANSACTION_STATUS_COMMITTED);
}
/*
* TransactionIdDidAborted
* TransactionIdDidAbort
* True iff transaction associated with the identifier did abort.
*
* Note:
* Assumes transaction identifier is valid.
* XXX Is this unneeded?
*/
bool /* true if given transaction aborted */
TransactionIdDidAbort(TransactionId transactionId)
@ -414,7 +178,7 @@ TransactionIdDidAbort(TransactionId transactionId)
if (AMI_OVERRIDE)
return false;
return TransactionLogTest(transactionId, XID_ABORT);
return TransactionLogTest(transactionId, TRANSACTION_STATUS_ABORTED);
}
/*
@ -422,22 +186,22 @@ TransactionIdDidAbort(TransactionId transactionId)
* PROC structures of all running backend. - vadim 11/26/96
*
* Old comments:
* true if given transaction neither committed nor aborted
* true if given transaction has neither committed nor aborted
*/
#ifdef NOT_USED
bool
TransactionIdIsInProgress(TransactionId transactionId)
{
if (AMI_OVERRIDE)
return false;
return TransactionLogTest(transactionId, XID_INPROGRESS);
return TransactionLogTest(transactionId, TRANSACTION_STATUS_IN_PROGRESS);
}
*/
#endif /* NOT_USED */
/* --------------------------------
* TransactionId Commit
* TransactionId Abort
* TransactionId SetInProgress
* --------------------------------
*/
@ -454,7 +218,7 @@ TransactionIdCommit(TransactionId transactionId)
if (AMI_OVERRIDE)
return;
TransactionLogUpdate(transactionId, XID_COMMIT);
TransactionLogUpdate(transactionId, TRANSACTION_STATUS_COMMITTED);
}
/*
@ -470,5 +234,5 @@ TransactionIdAbort(TransactionId transactionId)
if (AMI_OVERRIDE)
return;
TransactionLogUpdate(transactionId, XID_ABORT);
TransactionLogUpdate(transactionId, TRANSACTION_STATUS_ABORTED);
}

View File

@ -1,466 +0,0 @@
/*-------------------------------------------------------------------------
*
* transsup.c
* postgres transaction access method support code
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/transam/Attic/transsup.c,v 1.31 2001/07/12 04:11:13 tgl Exp $
*
* NOTES
* This file contains support functions for the high
* level access method interface routines found in transam.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/xact.h"
#include "utils/bit.h"
/* ----------------
* transaction system version id
*
* this is stored on the first page of the log, time and variable
* relations on the first 4 bytes. This is so that if we improve
* the format of the transaction log after postgres version 2, then
* people won't have to rebuild their databases.
*
* TRANS_SYSTEM_VERSION 100 means major version 1 minor version 0.
* Two databases with the same major version should be compatible,
* even if their minor versions differ.
*
* XXX This isn't actually being used!
* ----------------
*/
#define TRANS_SYSTEM_VERSION 200
/* ----------------
* LogRelationContents structure
*
* This structure describes the storage of the data in the
* first 128 bytes of the log relation. This storage is never
* used for transaction status because transaction id's begin
* their numbering at 512.
*
* The first 4 bytes of this relation store the version
* number of the transaction system.
*
* XXX This isn't actually being used!
* ----------------
*/
typedef struct LogRelationContentsData
{
XLogRecPtr LSN; /* temp hack: LSN is member of any block */
/* so should be described in bufmgr */
int TransSystemVersion;
} LogRelationContentsData;
typedef LogRelationContentsData *LogRelationContents;
/* ----------------
* BitIndexOf computes the index of the Nth xid on a given block
* ----------------
*/
#define BitIndexOf(N) ((N) * 2)
/* ----------------
* transaction page definitions
* ----------------
*/
#define TP_DataSize (BLCKSZ - sizeof(XLogRecPtr))
#define TP_NumXidStatusPerBlock (TP_DataSize * 4)
static XidStatus TransBlockGetXidStatus(Block tblock,
TransactionId transactionId);
static void TransBlockSetXidStatus(Block tblock,
TransactionId transactionId, XidStatus xstatus);
/* ----------------------------------------------------------------
* general support routines
* ----------------------------------------------------------------
*/
/* --------------------------------
* AmiTransactionOverride
*
* This function is used to manipulate the bootstrap flag.
* --------------------------------
*/
void
AmiTransactionOverride(bool flag)
{
AMI_OVERRIDE = flag;
}
/* --------------------------------
* TransComputeBlockNumber
* --------------------------------
*/
void
TransComputeBlockNumber(Relation relation, /* relation to test */
TransactionId transactionId, /* transaction id to
* test */
BlockNumber *blockNumberOutP)
{
uint32 itemsPerBlock = 0;
/*
* we calculate the block number of our transaction by dividing the
* transaction id by the number of transaction things per block.
*/
if (relation == LogRelation)
itemsPerBlock = TP_NumXidStatusPerBlock;
else
elog(ERROR, "TransComputeBlockNumber: unknown relation");
/* ----------------
* warning! if the transaction id's get too large
* then a BlockNumber may not be large enough to hold the results
* of our division.
*
* XXX this will all vanish soon when we implement an improved
* transaction id schema -cim 3/23/90
*
* This has vanished now that xid's are 4 bytes (no longer 5).
* -mer 5/24/92
* ----------------
*/
(*blockNumberOutP) = transactionId / itemsPerBlock;
}
/* ----------------------------------------------------------------
* trans block support routines
* ----------------------------------------------------------------
*/
/* --------------------------------
* TransBlockGetLastTransactionIdStatus
*
* This returns the status and transaction id of the last
* transaction information recorded on the given TransBlock.
* --------------------------------
*/
#ifdef NOT_USED
static XidStatus
TransBlockGetLastTransactionIdStatus(Block tblock,
TransactionId baseXid,
TransactionId *returnXidP)
{
Index index;
Index maxIndex;
bits8 bit1;
bits8 bit2;
BitIndex offset;
XidStatus xstatus;
/*
* sanity check
*/
Assert((tblock != NULL));
/*
* search downward from the top of the block data, looking for the
* first Non-in progress transaction status. Since we are scanning
* backward, this will be last recorded transaction status on the
* block.
*/
maxIndex = TP_NumXidStatusPerBlock;
for (index = maxIndex; index > 0; index--)
{
offset = BitIndexOf(index - 1);
bit1 = ((bits8) BitArrayBitIsSet((BitArray) tblock, offset++)) << 1;
bit2 = (bits8) BitArrayBitIsSet((BitArray) tblock, offset);
xstatus = (bit1 | bit2);
/*
* here we have the status of some transaction, so test if the
* status is recorded as "in progress". If so, then we save the
* transaction id in the place specified by the caller.
*/
if (xstatus != XID_INPROGRESS)
{
if (returnXidP != NULL)
TransactionIdStore(baseXid + (index - 1), returnXidP);
break;
}
}
/*
* if we get here and index is 0 it means we couldn't find a
* non-inprogress transaction on the block. For now we just return
* this info to the user. They can check if the return status is "in
* progress" to know this condition has arisen.
*/
if (index == 0)
{
if (returnXidP != NULL)
TransactionIdStore(baseXid, returnXidP);
}
/*
* return the status to the user
*/
return xstatus;
}
#endif
/* --------------------------------
* TransBlockGetXidStatus
*
* This returns the status of the desired transaction
* --------------------------------
*/
static XidStatus
TransBlockGetXidStatus(Block tblock,
TransactionId transactionId)
{
Index index;
bits8 bit1;
bits8 bit2;
BitIndex offset;
tblock = (Block) ((char *) tblock + sizeof(XLogRecPtr));
/* ----------------
* calculate the index into the transaction data where
* our transaction status is located
*
* XXX this will be replaced soon when we move to the
* new transaction id scheme -cim 3/23/90
*
* The old system has now been replaced. -mer 5/24/92
* ----------------
*/
index = transactionId % TP_NumXidStatusPerBlock;
/*
* get the data at the specified index
*/
offset = BitIndexOf(index);
bit1 = ((bits8) BitArrayBitIsSet((BitArray) tblock, offset++)) << 1;
bit2 = (bits8) BitArrayBitIsSet((BitArray) tblock, offset);
/*
* return the transaction status to the caller
*/
return (XidStatus) (bit1 | bit2);
}
/* --------------------------------
* TransBlockSetXidStatus
*
* This sets the status of the desired transaction
* --------------------------------
*/
static void
TransBlockSetXidStatus(Block tblock,
TransactionId transactionId,
XidStatus xstatus)
{
Index index;
BitIndex offset;
tblock = (Block) ((char *) tblock + sizeof(XLogRecPtr));
/* ----------------
* calculate the index into the transaction data where
* we sould store our transaction status.
*
* XXX this will be replaced soon when we move to the
* new transaction id scheme -cim 3/23/90
*
* The new scheme is here -mer 5/24/92
* ----------------
*/
index = transactionId % TP_NumXidStatusPerBlock;
offset = BitIndexOf(index);
/*
* store the transaction value at the specified offset
*/
switch (xstatus)
{
case XID_COMMIT: /* set 10 */
BitArraySetBit((BitArray) tblock, offset);
BitArrayClearBit((BitArray) tblock, offset + 1);
break;
case XID_ABORT: /* set 01 */
BitArrayClearBit((BitArray) tblock, offset);
BitArraySetBit((BitArray) tblock, offset + 1);
break;
case XID_INPROGRESS: /* set 00 */
BitArrayClearBit((BitArray) tblock, offset);
BitArrayClearBit((BitArray) tblock, offset + 1);
break;
default:
elog(NOTICE,
"TransBlockSetXidStatus: invalid status: %d (ignored)",
xstatus);
break;
}
}
/* ----------------------------------------------------------------
* transam i/o support routines
* ----------------------------------------------------------------
*/
/* --------------------------------
* TransBlockNumberGetXidStatus
* --------------------------------
*/
XidStatus
TransBlockNumberGetXidStatus(Relation relation,
BlockNumber blockNumber,
TransactionId xid,
bool *failP)
{
Buffer buffer; /* buffer associated with block */
Block block; /* block containing xstatus */
XidStatus xstatus; /* recorded status of xid */
bool localfail; /* bool used if failP = NULL */
/*
* get the page containing the transaction information
*/
buffer = ReadBuffer(relation, blockNumber);
LockBuffer(buffer, BUFFER_LOCK_SHARE);
block = BufferGetBlock(buffer);
/*
* get the status from the block. note, for now we always return
* false in failP.
*/
if (failP == NULL)
failP = &localfail;
(*failP) = false;
xstatus = TransBlockGetXidStatus(block, xid);
/*
* release the buffer and return the status
*/
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
ReleaseBuffer(buffer);
return xstatus;
}
/* --------------------------------
* TransBlockNumberSetXidStatus
* --------------------------------
*/
void
TransBlockNumberSetXidStatus(Relation relation,
BlockNumber blockNumber,
TransactionId xid,
XidStatus xstatus,
bool *failP)
{
Buffer buffer; /* buffer associated with block */
Block block; /* block containing xstatus */
bool localfail; /* bool used if failP = NULL */
/*
* get the block containing the transaction status
*/
buffer = ReadBuffer(relation, blockNumber);
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
block = BufferGetBlock(buffer);
/*
* attempt to update the status of the transaction on the block. if we
* are successful, write the block. otherwise release the buffer.
* note, for now we always return false in failP.
*/
if (failP == NULL)
failP = &localfail;
(*failP) = false;
TransBlockSetXidStatus(block, xid, xstatus);
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
if ((*failP) == false)
WriteBuffer(buffer);
else
ReleaseBuffer(buffer);
}
/* --------------------------------
* TransGetLastRecordedTransaction
* --------------------------------
*/
#ifdef NOT_USED
void
TransGetLastRecordedTransaction(Relation relation,
TransactionId xid, /* return: transaction
* id */
bool *failP)
{
BlockNumber blockNumber; /* block number */
Buffer buffer; /* buffer associated with block */
Block block; /* block containing xid status */
BlockNumber n; /* number of blocks in the relation */
TransactionId baseXid;
(*failP) = false;
/*
* SOMEDAY gain exclusive access to the log relation
*
* That someday is today 5 Aug. 1991 -mer It looks to me like we only
* need to set a read lock here, despite the above comment about
* exclusive access. The block is never actually written into, we
* only check status bits.
*/
RelationSetLockForRead(relation);
/*
* we assume the last block of the log contains the last recorded
* transaction. If the relation is empty we return failure to the
* user.
*/
n = RelationGetNumberOfBlocks(relation);
if (n == 0)
{
(*failP) = true;
return;
}
/*
* get the block containing the transaction information
*/
blockNumber = n - 1;
buffer = ReadBuffer(relation, blockNumber);
block = BufferGetBlock(buffer);
/*
* get the last xid on the block
*/
baseXid = blockNumber * TP_NumXidStatusPerBlock;
/* XXX ???? xid won't get returned! - AY '94 */
TransBlockGetLastTransactionIdStatus(block, baseXid, &xid);
ReleaseBuffer(buffer);
/*
* SOMEDAY release our lock on the log relation
*/
RelationUnsetLockForRead(relation);
}
#endif

View File

@ -6,15 +6,15 @@
* Copyright (c) 2000, PostgreSQL Global Development Group
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/transam/varsup.c,v 1.44 2001/08/23 23:06:37 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/access/transam/varsup.c,v 1.45 2001/08/25 18:52:41 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/clog.h"
#include "access/transam.h"
#include "access/xlog.h"
#include "storage/proc.h"
@ -32,25 +32,34 @@ VariableCache ShmemVariableCache = NULL;
/*
* Allocate the next XID for my new transaction.
*/
void
GetNewTransactionId(TransactionId *xid)
TransactionId
GetNewTransactionId(void)
{
TransactionId xid;
/*
* During bootstrap initialization, we return the special bootstrap
* transaction id.
*/
if (AMI_OVERRIDE)
{
*xid = BootstrapTransactionId;
return;
}
return BootstrapTransactionId;
SpinAcquire(XidGenLockId);
*xid = ShmemVariableCache->nextXid;
xid = ShmemVariableCache->nextXid;
TransactionIdAdvance(ShmemVariableCache->nextXid);
/*
* If we have just allocated the first XID of a new page of the
* commit log, zero out that commit-log page before returning.
* We must do this while holding XidGenLock, else another xact could
* acquire and commit a later XID before we zero the page. Fortunately,
* a page of the commit log holds 32K or more transactions, so we don't
* have to do this very often.
*/
ExtendCLOG(xid);
/*
* Must set MyProc->xid before releasing XidGenLock. This ensures that
* when GetSnapshotData calls ReadNewTransactionId, all active XIDs
@ -72,30 +81,33 @@ GetNewTransactionId(TransactionId *xid)
* removed while holding the lock.)
*/
if (MyProc != (PROC *) NULL)
MyProc->xid = *xid;
MyProc->xid = xid;
SpinRelease(XidGenLockId);
return xid;
}
/*
* Read nextXid but don't allocate it.
*/
void
ReadNewTransactionId(TransactionId *xid)
TransactionId
ReadNewTransactionId(void)
{
TransactionId xid;
/*
* During bootstrap initialization, we return the special bootstrap
* transaction id.
*/
if (AMI_OVERRIDE)
{
*xid = BootstrapTransactionId;
return;
}
return BootstrapTransactionId;
SpinAcquire(XidGenLockId);
*xid = ShmemVariableCache->nextXid;
xid = ShmemVariableCache->nextXid;
SpinRelease(XidGenLockId);
return xid;
}
/* ----------------------------------------------------------------

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.108 2001/07/16 22:43:33 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.109 2001/08/25 18:52:41 tgl Exp $
*
* NOTES
* Transaction aborts can now occur two ways:
@ -228,22 +228,6 @@ int CommitSiblings = 5; /* number of concurrent xacts needed to
static void (*_RollbackFunc) (void *) = NULL;
static void *_RollbackData = NULL;
/* ----------------
* info returned when the system is disabled
*
* Apparently a lot of this code is inherited from other prototype systems.
*
* For DisabledStartTime, use a symbolic value to make the relationships clearer.
* The old value of 1073741823 corresponds to a date in y2004, which is coming closer
* every day. It appears that if we return a value guaranteed larger than
* any real time associated with a transaction then comparisons in other
* modules will still be correct. Let's use BIG_ABSTIME for this. tgl 2/14/97
* ----------------
*/
static CommandId DisabledCommandId = (CommandId) -1;
static AbsoluteTime DisabledStartTime = (AbsoluteTime) BIG_ABSTIME;
/* ----------------
* catalog creation transaction bootstrapping flag.
* This should be eliminated and added to the transaction
@ -309,8 +293,6 @@ IsTransactionState(void)
return true;
case TRANS_ABORT:
return true;
case TRANS_DISABLED:
return false;
}
/*
@ -339,44 +321,9 @@ IsAbortedTransactionBlockState(void)
return false;
}
/* --------------------------------
* OverrideTransactionSystem
*
* This is used to temporarily disable the transaction
* processing system in order to do initialization of
* the transaction system data structures and relations
* themselves.
* --------------------------------
*/
static int SavedTransactionState;
void
OverrideTransactionSystem(bool flag)
{
TransactionState s = CurrentTransactionState;
if (flag == true)
{
if (s->state == TRANS_DISABLED)
return;
SavedTransactionState = s->state;
s->state = TRANS_DISABLED;
}
else
{
if (s->state != TRANS_DISABLED)
return;
s->state = SavedTransactionState;
}
}
/* --------------------------------
* GetCurrentTransactionId
*
* This returns the id of the current transaction, or
* the id of the "disabled" transaction.
* --------------------------------
*/
TransactionId
@ -384,16 +331,6 @@ GetCurrentTransactionId(void)
{
TransactionState s = CurrentTransactionState;
/*
* if the transaction system is disabled, we return the special
* "disabled" transaction id.
*/
if (s->state == TRANS_DISABLED)
return DisabledTransactionId;
/*
* otherwise return the current transaction id.
*/
return s->transactionIdData;
}
@ -407,13 +344,6 @@ GetCurrentCommandId(void)
{
TransactionState s = CurrentTransactionState;
/*
* if the transaction system is disabled, we return the special
* "disabled" command id.
*/
if (s->state == TRANS_DISABLED)
return DisabledCommandId;
return s->commandId;
}
@ -422,13 +352,6 @@ GetScanCommandId(void)
{
TransactionState s = CurrentTransactionState;
/*
* if the transaction system is disabled, we return the special
* "disabled" command id.
*/
if (s->state == TRANS_DISABLED)
return DisabledCommandId;
return s->scanCommandId;
}
@ -442,13 +365,6 @@ GetCurrentTransactionStartTime(void)
{
TransactionState s = CurrentTransactionState;
/*
* if the transaction system is disabled, we return the special
* "disabled" starting time.
*/
if (s->state == TRANS_DISABLED)
return DisabledStartTime;
return s->startTime;
}
@ -523,16 +439,6 @@ SetScanCommandId(CommandId savedId)
CurrentTransactionStateData.scanCommandId = savedId;
}
/* ----------------------------------------------------------------
* initialization stuff
* ----------------------------------------------------------------
*/
void
InitializeTransactionSystem(void)
{
InitializeTransactionLog();
}
/* ----------------------------------------------------------------
* StartTransaction stuff
* ----------------------------------------------------------------
@ -617,15 +523,19 @@ AtStart_Memory(void)
* --------------------------------
*/
void
RecordTransactionCommit()
RecordTransactionCommit(void)
{
TransactionId xid;
bool leak;
xid = GetCurrentTransactionId();
leak = BufferPoolCheckLeak();
xid = GetCurrentTransactionId();
/*
* We needn't write anything in xlog or clog if the transaction was
* read-only, which we check by testing if it made any xlog entries.
*/
if (MyLastRecPtr.xrecoff != 0)
{
XLogRecData rdata;
@ -673,6 +583,7 @@ RecordTransactionCommit()
/* Break the chain of back-links in the XLOG records I output */
MyLastRecPtr.xrecoff = 0;
/* Mark the transaction committed in clog */
TransactionIdCommit(xid);
END_CRIT_SECTION();
@ -765,7 +676,10 @@ RecordTransactionAbort(void)
TransactionId xid = GetCurrentTransactionId();
/*
* Double check here is to catch case that we aborted partway through
* We needn't write anything in xlog or clog if the transaction was
* read-only, which we check by testing if it made any xlog entries.
*
* Extra check here is to catch case that we aborted partway through
* RecordTransactionCommit ...
*/
if (MyLastRecPtr.xrecoff != 0 && !TransactionIdDidCommit(xid))
@ -782,8 +696,17 @@ RecordTransactionAbort(void)
START_CRIT_SECTION();
/*
* SHOULD SAVE ARRAY OF RELFILENODE-s TO DROP
*/
recptr = XLogInsert(RM_XACT_ID, XLOG_XACT_ABORT, &rdata);
/*
* There's no need for XLogFlush here, since the default assumption
* would be that we aborted, anyway.
*/
/* Mark the transaction aborted in clog */
TransactionIdAbort(xid);
END_CRIT_SECTION();
@ -913,7 +836,7 @@ StartTransaction(void)
* fix to a communications problem, and we keep having to deal with it
* here. We should fix the comm channel code. mao 080891
*/
if (s->state == TRANS_DISABLED || s->state == TRANS_INPROGRESS)
if (s->state == TRANS_INPROGRESS)
return;
/*
@ -927,7 +850,7 @@ StartTransaction(void)
/*
* generate a new transaction id
*/
GetNewTransactionId(&(s->transactionIdData));
s->transactionIdData = GetNewTransactionId();
XactLockTableInsert(s->transactionIdData);
@ -984,11 +907,8 @@ CommitTransaction(void)
/*
* check the current transaction state
*/
if (s->state == TRANS_DISABLED)
return;
if (s->state != TRANS_INPROGRESS)
elog(NOTICE, "CommitTransaction and not in in-progress state ");
elog(NOTICE, "CommitTransaction and not in in-progress state");
/*
* Tell the trigger manager that this transaction is about to be
@ -1109,12 +1029,6 @@ AbortTransaction(void)
/*
* check the current transaction state
*/
if (s->state == TRANS_DISABLED)
{
RESUME_INTERRUPTS();
return;
}
if (s->state != TRANS_INPROGRESS)
elog(NOTICE, "AbortTransaction and not in in-progress state");
@ -1138,7 +1052,7 @@ AbortTransaction(void)
CloseSequences();
AtEOXact_portals();
/* Advertise the fact that we aborted in pg_log. */
/* Advertise the fact that we aborted in pg_clog. */
RecordTransactionAbort();
/*
@ -1191,9 +1105,6 @@ CleanupTransaction(void)
{
TransactionState s = CurrentTransactionState;
if (s->state == TRANS_DISABLED)
return;
/*
* State should still be TRANS_ABORT from AbortTransaction().
*/
@ -1464,9 +1375,6 @@ BeginTransactionBlock(void)
/*
* check the current transaction state
*/
if (s->state == TRANS_DISABLED)
return;
if (s->blockState != TBLOCK_DEFAULT)
elog(NOTICE, "BEGIN: already a transaction in progress");
@ -1498,9 +1406,6 @@ EndTransactionBlock(void)
/*
* check the current transaction state
*/
if (s->state == TRANS_DISABLED)
return;
if (s->blockState == TBLOCK_INPROGRESS)
{
@ -1552,9 +1457,6 @@ AbortTransactionBlock(void)
/*
* check the current transaction state
*/
if (s->state == TRANS_DISABLED)
return;
if (s->blockState == TBLOCK_INPROGRESS)
{
@ -1591,12 +1493,6 @@ UserAbortTransactionBlock(void)
{
TransactionState s = CurrentTransactionState;
/*
* check the current transaction state
*/
if (s->state == TRANS_DISABLED)
return;
/*
* if the transaction has already been automatically aborted with an
* error, and the user subsequently types 'abort', allow it. (the
@ -1665,7 +1561,6 @@ AbortOutOfAnyTransaction(void)
CleanupTransaction();
break;
case TRANS_DEFAULT:
case TRANS_DISABLED:
/* Not in a transaction, do nothing */
break;
}
@ -1700,7 +1595,10 @@ xact_redo(XLogRecPtr lsn, XLogRecord *record)
/* SHOULD REMOVE FILES OF ALL DROPPED RELATIONS */
}
else if (info == XLOG_XACT_ABORT)
{
TransactionIdAbort(record->xl_xid);
/* SHOULD REMOVE FILES OF ALL FAILED-TO-BE-CREATED RELATIONS */
}
else
elog(STOP, "xact_redo: unknown op code %u", info);
}

View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Header: /cvsroot/pgsql/src/backend/access/transam/xlog.c,v 1.74 2001/08/23 23:06:37 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/access/transam/xlog.c,v 1.75 2001/08/25 18:52:41 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -26,8 +26,11 @@
#include <locale.h>
#endif
#include "access/clog.h"
#include "access/transam.h"
#include "access/xact.h"
#include "access/xlog.h"
#include "access/xlogutils.h"
#include "catalog/catversion.h"
#include "catalog/pg_control.h"
#include "storage/sinval.h"
@ -35,8 +38,6 @@
#include "storage/spin.h"
#include "storage/s_lock.h"
#include "storage/bufpage.h"
#include "access/xlog.h"
#include "access/xlogutils.h"
#include "utils/builtins.h"
#include "utils/relcache.h"
#include "utils/selfuncs.h"
@ -1580,7 +1581,7 @@ MoveOfflineLogs(uint32 log, uint32 seg, XLogRecPtr endptr)
strspn(xlde->d_name, "0123456789ABCDEF") == 16 &&
strcmp(xlde->d_name, lastoff) <= 0)
{
sprintf(path, "%s/%s", XLogDir, xlde->d_name);
snprintf(path, MAXPGPATH, "%s/%s", XLogDir, xlde->d_name);
if (XLOG_archive_dir[0])
{
elog(LOG, "archiving transaction log file %s",
@ -2409,6 +2410,9 @@ BootStrapXLOG(void)
/* some additional ControlFile fields are set in WriteControlFile() */
WriteControlFile();
/* Bootstrap the commit log, too */
BootStrapCLOG();
}
static char *
@ -2543,7 +2547,6 @@ StartupXLOG(void)
ControlFile->time = time(NULL);
UpdateControlFile();
XLogOpenLogRelation(); /* open pg_log */
XLogInitRelationCache();
/* Is REDO required ? */
@ -2724,6 +2727,9 @@ StartupXLOG(void)
ThisStartUpID++;
XLogCtl->ThisStartUpID = ThisStartUpID;
/* Start up the commit log, too */
StartupCLOG();
elog(LOG, "database system is ready");
CritSectionCount--;
@ -2845,6 +2851,7 @@ ShutdownXLOG(void)
CritSectionCount++;
CreateDummyCaches();
CreateCheckPoint(true);
ShutdownCLOG();
CritSectionCount--;
elog(LOG, "database system is shut down");
@ -2981,6 +2988,9 @@ CreateCheckPoint(bool shutdown)
*/
FlushBufferPool();
/* And commit-log buffers, too */
CheckPointCLOG();
/*
* Now insert the checkpoint record into XLOG.
*/

View File

@ -6,24 +6,21 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Header: /cvsroot/pgsql/src/backend/access/transam/xlogutils.c,v 1.17 2001/08/23 23:06:37 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/access/transam/xlogutils.c,v 1.18 2001/08/25 18:52:41 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/xlog.h"
#include "access/transam.h"
#include "access/xact.h"
#include "storage/bufpage.h"
#include "storage/bufmgr.h"
#include "storage/smgr.h"
#include "access/htup.h"
#include "access/xlogutils.h"
#include "catalog/pg_database.h"
#include "lib/hasht.h"
#include "storage/bufpage.h"
#include "storage/smgr.h"
#include "utils/relcache.h"
/*
* ---------------------------------------------------------------
*
@ -152,33 +149,6 @@ XLogIsValidTuple(RelFileNode hnode, ItemPointer iptr)
return (true);
}
/*
* Open pg_log in recovery
*/
extern Relation LogRelation; /* pg_log relation */
void
XLogOpenLogRelation(void)
{
Relation logRelation;
Assert(!LogRelation);
logRelation = (Relation) malloc(sizeof(RelationData));
memset(logRelation, 0, sizeof(RelationData));
logRelation->rd_rel = (Form_pg_class) malloc(sizeof(FormData_pg_class));
memset(logRelation->rd_rel, 0, sizeof(FormData_pg_class));
sprintf(RelationGetPhysicalRelationName(logRelation), "pg_log");
logRelation->rd_node.tblNode = InvalidOid;
logRelation->rd_node.relNode = RelOid_pg_log;
logRelation->rd_targblock = InvalidBlockNumber;
logRelation->rd_fd = -1;
logRelation->rd_fd = smgropen(DEFAULT_SMGR, logRelation, false);
if (logRelation->rd_fd < 0)
elog(STOP, "XLogOpenLogRelation: failed to open pg_log");
LogRelation = logRelation;
}
/*
* ---------------------------------------------------------------
*

View File

@ -2,7 +2,7 @@
#
# Makefile for catalog
#
# $Header: /cvsroot/pgsql/src/backend/catalog/Makefile,v 1.36 2001/08/24 14:07:48 petere Exp $
# $Header: /cvsroot/pgsql/src/backend/catalog/Makefile,v 1.37 2001/08/25 18:52:41 tgl Exp $
#
#-------------------------------------------------------------------------
@ -31,7 +31,7 @@ POSTGRES_BKI_SRCS := $(addprefix $(top_srcdir)/src/include/catalog/,\
pg_operator.h pg_opclass.h pg_am.h pg_amop.h pg_amproc.h \
pg_language.h pg_largeobject.h pg_aggregate.h pg_statistic.h \
pg_rewrite.h pg_trigger.h pg_listener.h pg_description.h \
pg_database.h pg_shadow.h pg_group.h pg_log.h indexing.h \
pg_database.h pg_shadow.h pg_group.h indexing.h \
)
pg_includes := $(sort -I$(top_srcdir)/src/include -I$(top_builddir)/src/include)

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.174 2001/08/10 18:57:33 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.175 2001/08/25 18:52:41 tgl Exp $
*
*
* INTERFACE ROUTINES
@ -252,11 +252,6 @@ heap_create(char *relname,
tblNode = InvalidOid;
relid = RelOid_pg_database;
}
else if (strcmp(LogRelationName, relname) == 0)
{
tblNode = InvalidOid;
relid = RelOid_pg_log;
}
else
{
relid = newoid();

View File

@ -11,7 +11,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.247 2001/08/21 16:36:03 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.248 2001/08/25 18:52:41 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@ -51,7 +51,6 @@
#include <ctype.h>
#include "access/htup.h"
#include "catalog/catname.h"
#include "catalog/pg_type.h"
#include "nodes/params.h"
#include "nodes/parsenodes.h"
@ -5423,11 +5422,7 @@ relation_name: SpecialRuleRelation
}
| ColId
{
/* disallow refs to variable system tables */
if (strcmp(LogRelationName, $1) == 0)
elog(ERROR,"%s cannot be accessed by users",$1);
else
$$ = $1;
$$ = $1;
}
;

View File

@ -1,4 +1,4 @@
$Header: /cvsroot/pgsql/src/backend/storage/buffer/README,v 1.1 2001/07/06 21:04:25 tgl Exp $
$Header: /cvsroot/pgsql/src/backend/storage/buffer/README,v 1.2 2001/08/25 18:52:42 tgl Exp $
Notes about shared buffer access rules
--------------------------------------
@ -66,7 +66,7 @@ at about the same time would OR the same bits into the field, so there
is little or no risk of conflicting update; what's more, if there did
manage to be a conflict it would merely mean that one bit-update would
be lost and need to be done again later. These four bits are only hints
(they cache the results of transaction status lookups in pg_log), so no
(they cache the results of transaction status lookups in pg_clog), so no
great harm is done if they get reset to zero by conflicting updates.
5. To physically remove a tuple or compact free space on a page, one

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/storage/ipc/ipci.c,v 1.41 2001/06/27 23:31:39 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/ipc/ipci.c,v 1.42 2001/08/25 18:52:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -17,6 +17,7 @@
#include <sys/types.h>
#include "miscadmin.h"
#include "access/clog.h"
#include "access/xlog.h"
#include "storage/bufmgr.h"
#include "storage/freespace.h"
@ -51,6 +52,7 @@ CreateSharedMemoryAndSemaphores(bool makePrivate, int maxBackends)
size = BufferShmemSize();
size += LockShmemSize(maxBackends);
size += XLOGShmemSize();
size += CLOGShmemSize();
size += SLockShmemSize();
size += SInvalShmemSize(maxBackends);
size += FreeSpaceShmemSize();
@ -80,9 +82,10 @@ CreateSharedMemoryAndSemaphores(bool makePrivate, int maxBackends)
InitShmemAllocation(seghdr);
/*
* Set up xlog and buffers
* Set up xlog, clog, and buffers
*/
XLOGShmemInit();
CLOGShmemInit();
InitBufferPool();
/*

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/storage/ipc/sinval.c,v 1.38 2001/08/23 23:06:37 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/ipc/sinval.c,v 1.39 2001/08/25 18:52:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -327,7 +327,7 @@ GetSnapshotData(bool serializable)
*--------------------
*/
ReadNewTransactionId(&(snapshot->xmax));
snapshot->xmax = ReadNewTransactionId();
for (index = 0; index < segP->lastBackend; index++)
{

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lmgr.c,v 1.49 2001/07/09 22:18:33 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lmgr.c,v 1.50 2001/08/25 18:52:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -373,7 +373,7 @@ XactLockTableWait(TransactionId xid)
/*
* Transaction was committed/aborted/crashed - we have to update
* pg_log if transaction is still marked as running.
* pg_clog if transaction is still marked as running.
*/
if (!TransactionIdDidCommit(xid) && !TransactionIdDidAbort(xid))
TransactionIdAbort(xid);

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.142 2001/08/10 18:57:37 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.143 2001/08/25 18:52:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -43,7 +43,6 @@
#include "catalog/indexing.h"
#include "catalog/pg_attrdef.h"
#include "catalog/pg_index.h"
#include "catalog/pg_log.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_relcheck.h"
#include "catalog/pg_rewrite.h"
@ -67,7 +66,6 @@ static FormData_pg_attribute Desc_pg_class[Natts_pg_class] = {Schema_pg_class};
static FormData_pg_attribute Desc_pg_attribute[Natts_pg_attribute] = {Schema_pg_attribute};
static FormData_pg_attribute Desc_pg_proc[Natts_pg_proc] = {Schema_pg_proc};
static FormData_pg_attribute Desc_pg_type[Natts_pg_type] = {Schema_pg_type};
static FormData_pg_attribute Desc_pg_log[Natts_pg_log] = {Schema_pg_log};
/*
* Hash tables that index the relation cache
@ -2120,7 +2118,6 @@ RelationCacheInitialize(void)
formrdesc(AttributeRelationName, Natts_pg_attribute, Desc_pg_attribute);
formrdesc(ProcedureRelationName, Natts_pg_proc, Desc_pg_proc);
formrdesc(TypeRelationName, Natts_pg_type, Desc_pg_type);
formrdesc(LogRelationName, Natts_pg_log, Desc_pg_log);
/*
* init_irels() used to be called here. It is changed to be called in
@ -2167,10 +2164,6 @@ RelationCacheInitializePhase2(void)
fixrdesc(AttributeRelationName);
fixrdesc(ProcedureRelationName);
fixrdesc(TypeRelationName);
/*
* We don't bother to update the entries for pg_log.
*/
}
}

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/init/globals.c,v 1.58 2001/06/12 05:55:50 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/init/globals.c,v 1.59 2001/08/25 18:52:42 tgl Exp $
*
* NOTES
* Globals used all over the place should be declared here and not
@ -102,7 +102,6 @@ char *SharedSystemRelationNames[] = {
GroupRelationName,
GroupNameIndex,
GroupSysidIndex,
LogRelationName,
ShadowRelationName,
ShadowNameIndex,
ShadowSysidIndex,

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/init/postinit.c,v 1.87 2001/06/16 22:58:16 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/init/postinit.c,v 1.88 2001/08/25 18:52:42 tgl Exp $
*
*
*-------------------------------------------------------------------------
@ -285,26 +285,15 @@ InitPostgres(const char *dbname, const char *username)
elog(FATAL, "InitPostgres: bad backend id %d", MyBackendId);
/*
* Initialize the transaction system and the relation descriptor
* cache. Note we have to make certain the lock manager is off while
* we do this.
* Initialize the transaction system override state.
*/
AmiTransactionOverride(IsBootstrapProcessingMode());
LockDisable(true);
AmiTransactionOverride(bootstrap);
/*
* Part of the initialization processing done here sets a read lock on
* pg_log. Since locking is disabled the set doesn't have intended
* effect of locking out writers, but this is ok, since we only lock
* it to examine AMI transaction status, and this is never written
* after initdb is done. -mer 15 June 1992
* Initialize the relation descriptor cache.
* The pre-allocated reldescs are created here.
*/
RelationCacheInitialize(); /* pre-allocated reldescs created here */
InitializeTransactionSystem(); /* pg_log,etc init/crash recovery
* here */
LockDisable(false);
RelationCacheInitialize();
/*
* Initialize the access methods. Does not touch files (?) - thomas

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/misc/Attic/database.c,v 1.47 2001/05/30 20:52:34 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/misc/Attic/database.c,v 1.48 2001/08/25 18:52:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -193,7 +193,7 @@ GetRawDatabaseInfo(const char *name, Oid *db_id, char *path)
* happens right here. We cannot really determine if the
* tuple is valid without checking transaction commit status,
* and the only way to do that at init time is to paw over
* pg_log by hand, too. Instead of checking, we assume that
* pg_clog by hand, too. Instead of checking, we assume that
* the inserting transaction committed, and that any deleting
* transaction did also, unless shown otherwise by on-row
* commit status bits.

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/time/tqual.c,v 1.40 2001/08/23 23:06:38 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/time/tqual.c,v 1.41 2001/08/25 18:52:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -611,12 +611,12 @@ HeapTupleSatisfiesVacuum(HeapTupleHeader tuple, TransactionId XmaxRecent)
* If the inserting transaction aborted, then the tuple was never visible
* to any other transaction, so we can delete it immediately.
*
* NOTE: must check TransactionIdIsInProgress (which looks in shared mem)
* NOTE: must check TransactionIdIsInProgress (which looks in PROC array)
* before TransactionIdDidCommit/TransactionIdDidAbort (which look in
* pg_log). Otherwise we have a race condition where we might decide
* pg_clog). Otherwise we have a race condition where we might decide
* that a just-committed transaction crashed, because none of the tests
* succeed. xact.c is careful to record commit/abort in pg_log before
* it unsets MyProc->xid in shared memory.
* succeed. xact.c is careful to record commit/abort in pg_clog before
* it unsets MyProc->xid in PROC array.
*/
if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
{

View File

@ -27,7 +27,7 @@
# Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
# Portions Copyright (c) 1994, Regents of the University of California
#
# $Header: /cvsroot/pgsql/src/bin/initdb/Attic/initdb.sh,v 1.133 2001/08/25 00:31:17 petere Exp $
# $Header: /cvsroot/pgsql/src/bin/initdb/Attic/initdb.sh,v 1.134 2001/08/25 18:52:42 tgl Exp $
#
#-------------------------------------------------------------------------
@ -440,6 +440,12 @@ else
mkdir "$PGDATA"/pg_xlog || exit_nicely
echo "ok"
fi
if [ ! -d "$PGDATA"/pg_clog ]
then
$ECHO_N "creating directory $PGDATA/pg_clog... "$ECHO_C
mkdir "$PGDATA"/pg_clog || exit_nicely
echo "ok"
fi
fi

View File

@ -3,7 +3,7 @@
# pg_upgrade: update a database without needing a full dump/reload cycle.
# CAUTION: read the manual page before trying to use this!
# $Header: /cvsroot/pgsql/src/bin/pg_dump/Attic/pg_upgrade,v 1.16 2000/12/18 16:30:07 momjian Exp $
# $Header: /cvsroot/pgsql/src/bin/pg_dump/Attic/pg_upgrade,v 1.17 2001/08/25 18:52:42 tgl Exp $
#
# NOTE: we must be sure to update the version-checking code a few dozen lines
# below for each new PostgreSQL release.
@ -127,9 +127,9 @@ fi
echo "Input script $INPUT complete, fixing row commit statuses..."
# Now vacuum each result database to mark all system-table rows as committed,
# because when pg_log is replaced with the saved version, the transaction
# because when pg_clog is replaced with the saved version, the transaction
# statuses will no longer match the data. VACUUM will force the on-row
# status flags to the right value so that pg_log will not matter anymore.
# status flags to the right value so that pg_clog will not matter anymore.
# Note: we used to try to do this as part of the previous step, but that
# risks permissions problems if VACUUM is run as the wrong user.
# Note: the initial VACUUM does template1, then we do everything else.
@ -171,7 +171,7 @@ do
fi
done
mv -f $OLDDIR/pg_log data
mv -f $OLDDIR/pg_clog data
mv -f $OLDDIR/pg_variable data
echo "You must stop/start the postmaster before doing anything else."

47
src/include/access/clog.h Normal file
View File

@ -0,0 +1,47 @@
/*
* clog.h
*
* PostgreSQL transaction-commit-log manager
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: clog.h,v 1.1 2001/08/25 18:52:42 tgl Exp $
*/
#ifndef CLOG_H
#define CLOG_H
#include "access/xlog.h"
/*
* Possible transaction statuses --- note that all-zeroes is the initial
* state.
*/
typedef int XidStatus;
#define TRANSACTION_STATUS_IN_PROGRESS 0x00
#define TRANSACTION_STATUS_COMMITTED 0x01
#define TRANSACTION_STATUS_ABORTED 0x02
/* 0x03 is available without changing commit log space allocation */
extern void TransactionIdSetStatus(TransactionId xid, XidStatus status);
extern XidStatus TransactionIdGetStatus(TransactionId xid);
extern int CLOGShmemSize(void);
extern void CLOGShmemInit(void);
extern void BootStrapCLOG(void);
extern void StartupCLOG(void);
extern void ShutdownCLOG(void);
extern void CheckPointCLOG(void);
extern void ExtendCLOG(TransactionId newestXact);
extern void TruncateCLOG(TransactionId oldestXact);
/* XLOG stuff */
#define CLOG_ZEROPAGE 0x00
extern void clog_redo(XLogRecPtr lsn, XLogRecord *record);
extern void clog_undo(XLogRecPtr lsn, XLogRecord *record);
extern void clog_desc(char *buf, uint8 xl_info, char *rec);
#endif /* CLOG_H */

View File

@ -1,9 +1,9 @@
/*
*
* rmgr.h
*
* Resource managers definition
*
* $Id: rmgr.h,v 1.6 2001/08/25 18:52:42 tgl Exp $
*/
#ifndef RMGR_H
#define RMGR_H
@ -16,6 +16,7 @@ typedef uint8 RmgrId;
#define RM_XLOG_ID 0
#define RM_XACT_ID 1
#define RM_SMGR_ID 2
#define RM_CLOG_ID 3
#define RM_HEAP_ID 10
#define RM_BTREE_ID 11
#define RM_HASH_ID 12

View File

@ -7,33 +7,30 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: transam.h,v 1.38 2001/08/23 23:06:38 tgl Exp $
* $Id: transam.h,v 1.39 2001/08/25 18:52:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef TRANSAM_H
#define TRANSAM_H
#include "storage/bufmgr.h"
#include "storage/spin.h"
/* ----------------
* Special transaction ID values
*
* We do not use any transaction IDs less than 512 --- this leaves the first
* 128 bytes of pg_log available for special purposes such as version number
* storage. (Currently, we do not actually use them for anything.)
*
* BootstrapTransactionId is the XID for "bootstrap" operations. It should
* BootstrapTransactionId is the XID for "bootstrap" operations, and
* FrozenTransactionId is used for very old tuples. Both should
* always be considered valid.
*
* FirstNormalTransactionId is the first "normal" transaction id.
* ----------------
*/
#define InvalidTransactionId ((TransactionId) 0)
#define DisabledTransactionId ((TransactionId) 1)
#define BootstrapTransactionId ((TransactionId) 512)
#define FirstNormalTransactionId ((TransactionId) 514)
#define BootstrapTransactionId ((TransactionId) 1)
#define FrozenTransactionId ((TransactionId) 2)
#define FirstNormalTransactionId ((TransactionId) 3)
/* ----------------
* transaction ID manipulation macros
@ -56,19 +53,6 @@
(dest) = FirstNormalTransactionId; \
} while(0)
/* ----------------
* transaction status values
*
* someday we will use "11" = 3 = XID_COMMIT_CHILD to mean the
* commiting of child xactions.
* ----------------
*/
#define XID_INPROGRESS 0 /* transaction in progress */
#define XID_ABORT 1 /* transaction aborted */
#define XID_COMMIT 2 /* transaction commited */
#define XID_COMMIT_CHILD 3 /* child xact commited */
typedef unsigned char XidStatus; /* (2 bits) */
/* ----------
* Object ID (OID) zero is InvalidOid.
@ -116,25 +100,15 @@ typedef VariableCacheData *VariableCache;
/*
* prototypes for functions in transam/transam.c
*/
extern void InitializeTransactionLog(void);
extern void AmiTransactionOverride(bool flag);
extern bool TransactionIdDidCommit(TransactionId transactionId);
extern bool TransactionIdDidAbort(TransactionId transactionId);
extern void TransactionIdCommit(TransactionId transactionId);
extern void TransactionIdAbort(TransactionId transactionId);
/* in transam/transsup.c */
extern void AmiTransactionOverride(bool flag);
extern void TransComputeBlockNumber(Relation relation,
TransactionId transactionId, BlockNumber *blockNumberOutP);
extern XidStatus TransBlockNumberGetXidStatus(Relation relation,
BlockNumber blockNumber, TransactionId xid, bool *failP);
extern void TransBlockNumberSetXidStatus(Relation relation,
BlockNumber blockNumber, TransactionId xid, XidStatus xstatus,
bool *failP);
/* in transam/varsup.c */
extern void GetNewTransactionId(TransactionId *xid);
extern void ReadNewTransactionId(TransactionId *xid);
extern TransactionId GetNewTransactionId(void);
extern TransactionId ReadNewTransactionId(void);
extern Oid GetNewObjectId(void);
extern void CheckMaxObjectId(Oid assigned_oid);
@ -143,9 +117,6 @@ extern void CheckMaxObjectId(Oid assigned_oid);
* ----------------
*/
/* in transam.c */
extern Relation LogRelation;
/* in xact.c */
extern bool AMI_OVERRIDE;

View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: xact.h,v 1.34 2001/07/12 04:11:13 tgl Exp $
* $Id: xact.h,v 1.35 2001/08/25 18:52:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -54,7 +54,6 @@ typedef TransactionStateData *TransactionState;
#define TRANS_INPROGRESS 2
#define TRANS_COMMIT 3
#define TRANS_ABORT 4
#define TRANS_DISABLED 5
/* ----------------
* transaction block states
@ -100,7 +99,6 @@ extern int TransactionFlushEnabled(void);
extern void SetTransactionFlushEnabled(bool state);
extern bool IsAbortedTransactionBlockState(void);
extern void OverrideTransactionSystem(bool flag);
extern TransactionId GetCurrentTransactionId(void);
extern CommandId GetCurrentCommandId(void);
extern CommandId GetScanCommandId(void);
@ -110,7 +108,6 @@ extern bool TransactionIdIsCurrentTransactionId(TransactionId xid);
extern bool CommandIdIsCurrentCommandId(CommandId cid);
extern bool CommandIdGEScanCommandId(CommandId cid);
extern void CommandCounterIncrement(void);
extern void InitializeTransactionSystem(void);
extern void StartTransactionCommand(void);
extern void CommitTransactionCommand(void);
extern void AbortCurrentTransaction(void);

View File

@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: xlog.h,v 1.24 2001/07/19 02:12:35 tgl Exp $
* $Id: xlog.h,v 1.25 2001/08/25 18:52:42 tgl Exp $
*/
#ifndef XLOG_H
#define XLOG_H
@ -14,6 +14,7 @@
#include "access/rmgr.h"
#include "access/transam.h"
#include "access/xlogdefs.h"
#include "storage/bufmgr.h"
#include "utils/pg_crc.h"

View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: xlogdefs.h,v 1.3 2001/03/22 04:00:32 momjian Exp $
* $Id: xlogdefs.h,v 1.4 2001/08/25 18:52:42 tgl Exp $
*/
#ifndef XLOG_DEFS_H
#define XLOG_DEFS_H
@ -52,7 +52,7 @@ typedef struct XLogRecPtr
/*
* StartUpID (SUI) - system startups counter. It's to allow removing
* pg_log after shutdown, in future.
* pg_clog after shutdown, in future.
*/
typedef uint32 StartUpID;

View File

@ -6,20 +6,20 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: xlogutils.h,v 1.7 2001/03/22 04:00:32 momjian Exp $
* $Id: xlogutils.h,v 1.8 2001/08/25 18:52:42 tgl Exp $
*/
#ifndef XLOG_UTILS_H
#define XLOG_UTILS_H
#include "access/rmgr.h"
#include "storage/buf.h"
#include "storage/itemptr.h"
#include "utils/rel.h"
extern int XLogIsOwnerOfTuple(RelFileNode hnode, ItemPointer iptr,
TransactionId xid, CommandId cid);
extern bool XLogIsValidTuple(RelFileNode hnode, ItemPointer iptr);
extern void XLogOpenLogRelation(void);
extern void XLogInitRelationCache(void);
extern void XLogCloseRelationCache(void);

View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: catname.h,v 1.19 2001/05/14 20:30:21 momjian Exp $
* $Id: catname.h,v 1.20 2001/08/25 18:52:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -29,7 +29,6 @@
#define LanguageRelationName "pg_language"
#define LargeObjectRelationName "pg_largeobject"
#define ListenerRelationName "pg_listener"
#define LogRelationName "pg_log"
#define OperatorClassRelationName "pg_opclass"
#define OperatorRelationName "pg_operator"
#define ProcedureRelationName "pg_proc"

View File

@ -37,7 +37,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: catversion.h,v 1.91 2001/08/21 16:36:05 tgl Exp $
* $Id: catversion.h,v 1.92 2001/08/25 18:52:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -53,6 +53,6 @@
*/
/* yyyymmddN */
#define CATALOG_VERSION_NO 200108211
#define CATALOG_VERSION_NO 200108241
#endif

View File

@ -8,7 +8,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: pg_attribute.h,v 1.74 2001/08/10 18:57:40 tgl Exp $
* $Id: pg_attribute.h,v 1.75 2001/08/25 18:52:42 tgl Exp $
*
* NOTES
* the genbki.sh script reads this file and generates .bki
@ -474,25 +474,13 @@ DATA(insert ( 1259 cmax 29 0 4 -6 0 -1 -1 t p f i f f));
DATA(insert ( 1259 tableoid 26 0 4 -7 0 -1 -1 t p f i f f));
/* ----------------
* pg_log - this relation is modified by special purpose access
* method code. The following is garbage but is needed
* so that the reldesc code works properly.
* pg_xactlock - this is not a real relation, but is a placeholder
* to allow a relation OID to be used for transaction
* waits. We need a pg_xactlock entry in pg_class only to
* ensure that that OID can never be allocated to a real
* table; and this entry is just to link to that one.
* ----------------
*/
#define Schema_pg_log \
{ 1269, {"logfoo"}, 26, 0, 4, 1, 0, -1, -1, true, 'p', false, 'i', false, false }
DATA(insert ( 1269 logfoo 26 0 4 1 0 -1 -1 t p f i f f));
/* ----------------
* pg_xactlock - this relation is modified by special purpose access
* method code. The following is garbage but is needed
* so that the reldesc code works properly.
* ----------------
*/
#define Schema_pg_xactlock \
{ 376, {"xactlockfoo"}, 26, 0, 4, 1, 0, -1, -1, true, 'p', false, 'i', false, false }
DATA(insert ( 376 xactlockfoo 26 0 4 1 0 -1 -1 t p f i f f));
#endif /* PG_ATTRIBUTE_H */

View File

@ -8,7 +8,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: pg_class.h,v 1.52 2001/08/10 18:57:40 tgl Exp $
* $Id: pg_class.h,v 1.53 2001/08/25 18:52:43 tgl Exp $
*
* NOTES
* the genbki.sh script reads this file and generates .bki
@ -144,8 +144,6 @@ DATA(insert OID = 1261 ( pg_group 87 PGUID 0 1261 0 0 0 0 f t r 3 0 0 0 0 0 f
DESCR("");
DATA(insert OID = 1262 ( pg_database 88 PGUID 0 1262 0 0 0 0 f t r 7 0 0 0 0 0 t f f f _null_ ));
DESCR("");
DATA(insert OID = 1269 ( pg_log 99 PGUID 0 1269 0 0 0 0 f t s 1 0 0 0 0 0 f f f f _null_ ));
DESCR("");
DATA(insert OID = 376 ( pg_xactlock 0 PGUID 0 0 0 0 0 0 f t s 1 0 0 0 0 0 f f f f _null_ ));
DESCR("");
@ -156,7 +154,6 @@ DESCR("");
#define RelOid_pg_shadow 1260
#define RelOid_pg_group 1261
#define RelOid_pg_database 1262
#define RelOid_pg_log 1269
/* Xact lock pseudo-table */
#define XactLockTableId 376

View File

@ -1,41 +0,0 @@
/*-------------------------------------------------------------------------
*
* pg_log.h
* the system log relation "pg_log" is not a "heap" relation.
* it is automatically created by the transam/ code and the
* information here is all bogus and is just here to make the
* relcache code happy.
*
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: pg_log.h,v 1.9 2001/08/10 18:57:40 tgl Exp $
*
* NOTES
* The structures and macros used by the transam/ code
* to access pg_log should some day go here -cim 6/18/90
*
*-------------------------------------------------------------------------
*/
#ifndef PG_LOG_H
#define PG_LOG_H
/* ----------------
* postgres.h contains the system type definintions and the
* CATALOG(), BOOTSTRAP and DATA() sugar words so this file
* can be read by both genbki.sh and the C compiler.
* ----------------
*/
CATALOG(pg_log) BOOTSTRAP BKI_WITHOUT_OIDS
{
Oid logfoo;
} FormData_pg_log;
typedef FormData_pg_log *Form_pg_log;
#define Natts_pg_log 1
#define Anum_pg_log_logfoo 1
#endif /* PG_LOG_H */

View File

@ -8,7 +8,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: pg_type.h,v 1.109 2001/06/12 05:55:50 tgl Exp $
* $Id: pg_type.h,v 1.110 2001/08/25 18:52:43 tgl Exp $
*
* NOTES
* the genbki.sh script reads this file and generates .bki
@ -239,7 +239,6 @@ DATA(insert OID = 83 ( pg_class PGUID 4 4 t c t \054 1259 0 int4in int4out int4
DATA(insert OID = 86 ( pg_shadow PGUID 4 4 t c t \054 1260 0 int4in int4out int4in int4out i p _null_));
DATA(insert OID = 87 ( pg_group PGUID 4 4 t c t \054 1261 0 int4in int4out int4in int4out i p _null_));
DATA(insert OID = 88 ( pg_database PGUID 4 4 t c t \054 1262 0 int4in int4out int4in int4out i p _null_));
DATA(insert OID = 99 ( pg_log PGUID 4 4 t c t \054 1269 0 int4in int4out int4in int4out i p _null_));
/* OIDS 100 - 199 */

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@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: bufpage.h,v 1.42 2001/05/14 22:06:41 momjian Exp $
* $Id: bufpage.h,v 1.43 2001/08/25 18:52:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -54,10 +54,6 @@
* obviously, a page is not formatted before it is initialized with by
* a call to PageInit.
*
* The contents of the special pg_log tables are raw disk blocks with
* special formats. these are the only "access methods" that need not
* write disk pages.
*
* NOTES:
*
* linp1..N form an ItemId array. ItemPointers point into this array