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Diffstat (limited to 'src/backend/access/transam/clog.c')
-rw-r--r--src/backend/access/transam/clog.c85
1 files changed, 41 insertions, 44 deletions
diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c
index a403838bd79..cd83da93ea6 100644
--- a/src/backend/access/transam/clog.c
+++ b/src/backend/access/transam/clog.c
@@ -13,7 +13,7 @@
* 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/clog.c,v 1.3 2001/08/26 16:55:59 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/transam/clog.c,v 1.4 2001/09/29 04:02:21 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -27,7 +27,7 @@
#include <unistd.h>
#include "access/clog.h"
-#include "storage/s_lock.h"
+#include "storage/lwlock.h"
#include "miscadmin.h"
@@ -74,8 +74,8 @@
* 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
+ * We use an overall LWLock to protect the shared data structures, plus
+ * per-buffer LWLocks 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.
*
@@ -105,10 +105,6 @@
* 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
@@ -121,7 +117,6 @@
* synchronization already.
*----------
*/
-#define NUM_CLOG_BUFFERS 8
typedef enum
{
@@ -153,14 +148,18 @@ typedef struct ClogCtlData
* 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;
/*
+ * ClogBufferLocks 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 LWLockId ClogBufferLocks[NUM_CLOG_BUFFERS]; /* Per-buffer I/O locks */
+
+/*
* 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.
@@ -211,7 +210,7 @@ TransactionIdSetStatus(TransactionId xid, XidStatus status)
Assert(status == TRANSACTION_STATUS_COMMITTED ||
status == TRANSACTION_STATUS_ABORTED);
- S_LOCK(&(ClogCtl->control_lck));
+ LWLockAcquire(CLogControlLock, LW_EXCLUSIVE);
slotno = ReadCLOGPage(pageno);
byteptr = ClogCtl->page_buffer[slotno] + byteno;
@@ -224,7 +223,7 @@ TransactionIdSetStatus(TransactionId xid, XidStatus status)
ClogCtl->page_status[slotno] = CLOG_PAGE_DIRTY;
- S_UNLOCK(&(ClogCtl->control_lck));
+ LWLockRelease(CLogControlLock);
}
/*
@@ -243,14 +242,14 @@ TransactionIdGetStatus(TransactionId xid)
char *byteptr;
XidStatus status;
- S_LOCK(&(ClogCtl->control_lck));
+ LWLockAcquire(CLogControlLock, LW_EXCLUSIVE);
slotno = ReadCLOGPage(pageno);
byteptr = ClogCtl->page_buffer[slotno] + byteno;
status = (*byteptr >> bshift) & CLOG_XACT_BITMASK;
- S_UNLOCK(&(ClogCtl->control_lck));
+ LWLockRelease(CLogControlLock);
return status;
}
@@ -283,15 +282,13 @@ CLOGShmemInit(void)
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]));
+ ClogBufferLocks[slotno] = LWLockAssign();
bufptr += CLOG_BLCKSZ;
}
@@ -312,7 +309,7 @@ BootStrapCLOG(void)
{
int slotno;
- S_LOCK(&(ClogCtl->control_lck));
+ LWLockAcquire(CLogControlLock, LW_EXCLUSIVE);
/* Create and zero the first page of the commit log */
slotno = ZeroCLOGPage(0, false);
@@ -321,7 +318,7 @@ BootStrapCLOG(void)
WriteCLOGPage(slotno);
Assert(ClogCtl->page_status[slotno] == CLOG_PAGE_CLEAN);
- S_UNLOCK(&(ClogCtl->control_lck));
+ LWLockRelease(CLogControlLock);
}
/*
@@ -411,8 +408,8 @@ ReadCLOGPage(int pageno)
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]));
+ LWLockRelease(CLogControlLock);
+ LWLockAcquire(ClogBufferLocks[slotno], LW_EXCLUSIVE);
/*
* Check to see if someone else already did the read, or took the
@@ -421,8 +418,8 @@ ReadCLOGPage(int pageno)
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));
+ LWLockRelease(ClogBufferLocks[slotno]);
+ LWLockAcquire(CLogControlLock, LW_EXCLUSIVE);
continue;
}
@@ -430,14 +427,14 @@ ReadCLOGPage(int pageno)
CLOGPhysicalReadPage(pageno, slotno);
/* Re-acquire shared control lock and update page state */
- S_LOCK(&(ClogCtl->control_lck));
+ LWLockAcquire(CLogControlLock, LW_EXCLUSIVE);
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]));
+ LWLockRelease(ClogBufferLocks[slotno]);
ClogRecentlyUsed(slotno);
return slotno;
@@ -468,8 +465,8 @@ WriteCLOGPage(int slotno)
pageno = ClogCtl->page_number[slotno];
/* Release shared lock, grab per-buffer lock instead */
- S_UNLOCK(&(ClogCtl->control_lck));
- S_LOCK(&(ClogCtl->buffer_lck[slotno]));
+ LWLockRelease(CLogControlLock);
+ LWLockAcquire(ClogBufferLocks[slotno], LW_EXCLUSIVE);
/*
* Check to see if someone else already did the write, or took the
@@ -482,8 +479,8 @@ WriteCLOGPage(int slotno)
(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));
+ LWLockRelease(ClogBufferLocks[slotno]);
+ LWLockAcquire(CLogControlLock, LW_EXCLUSIVE);
return;
}
@@ -504,7 +501,7 @@ WriteCLOGPage(int slotno)
CLOGPhysicalWritePage(pageno, slotno);
/* Re-acquire shared control lock and update page state */
- S_LOCK(&(ClogCtl->control_lck));
+ LWLockAcquire(CLogControlLock, LW_EXCLUSIVE);
Assert(ClogCtl->page_number[slotno] == pageno &&
(ClogCtl->page_status[slotno] == CLOG_PAGE_WRITE_IN_PROGRESS ||
@@ -514,7 +511,7 @@ WriteCLOGPage(int slotno)
if (ClogCtl->page_status[slotno] == CLOG_PAGE_WRITE_IN_PROGRESS)
ClogCtl->page_status[slotno] = CLOG_PAGE_CLEAN;
- S_UNLOCK(&(ClogCtl->buffer_lck[slotno]));
+ LWLockRelease(ClogBufferLocks[slotno]);
}
/*
@@ -714,7 +711,7 @@ ShutdownCLOG(void)
{
int slotno;
- S_LOCK(&(ClogCtl->control_lck));
+ LWLockAcquire(CLogControlLock, LW_EXCLUSIVE);
for (slotno = 0; slotno < NUM_CLOG_BUFFERS; slotno++)
{
@@ -723,7 +720,7 @@ ShutdownCLOG(void)
ClogCtl->page_status[slotno] == CLOG_PAGE_CLEAN);
}
- S_UNLOCK(&(ClogCtl->control_lck));
+ LWLockRelease(CLogControlLock);
}
/*
@@ -734,7 +731,7 @@ CheckPointCLOG(void)
{
int slotno;
- S_LOCK(&(ClogCtl->control_lck));
+ LWLockAcquire(CLogControlLock, LW_EXCLUSIVE);
for (slotno = 0; slotno < NUM_CLOG_BUFFERS; slotno++)
{
@@ -745,7 +742,7 @@ CheckPointCLOG(void)
*/
}
- S_UNLOCK(&(ClogCtl->control_lck));
+ LWLockRelease(CLogControlLock);
}
@@ -772,12 +769,12 @@ ExtendCLOG(TransactionId newestXact)
pageno = TransactionIdToPage(newestXact);
- S_LOCK(&(ClogCtl->control_lck));
+ LWLockAcquire(CLogControlLock, LW_EXCLUSIVE);
/* Zero the page and make an XLOG entry about it */
ZeroCLOGPage(pageno, true);
- S_UNLOCK(&(ClogCtl->control_lck));
+ LWLockRelease(CLogControlLock);
}
@@ -819,7 +816,7 @@ TruncateCLOG(TransactionId oldestXact)
* should have been flushed already during the checkpoint, we're
* just being extra careful here.)
*/
- S_LOCK(&(ClogCtl->control_lck));
+ LWLockAcquire(CLogControlLock, LW_EXCLUSIVE);
restart:;
/*
@@ -830,7 +827,7 @@ restart:;
*/
if (CLOGPagePrecedes(ClogCtl->latest_page_number, cutoffPage))
{
- S_UNLOCK(&(ClogCtl->control_lck));
+ LWLockRelease(CLogControlLock);
elog(LOG, "unable to truncate commit log: apparent wraparound");
return;
}
@@ -861,7 +858,7 @@ restart:;
goto restart;
}
- S_UNLOCK(&(ClogCtl->control_lck));
+ LWLockRelease(CLogControlLock);
/* Now we can remove the old CLOG segment(s) */
(void) ScanCLOGDirectory(cutoffPage, true);
@@ -974,13 +971,13 @@ clog_redo(XLogRecPtr lsn, XLogRecord *record)
memcpy(&pageno, XLogRecGetData(record), sizeof(int));
- S_LOCK(&(ClogCtl->control_lck));
+ LWLockAcquire(CLogControlLock, LW_EXCLUSIVE);
slotno = ZeroCLOGPage(pageno, false);
WriteCLOGPage(slotno);
Assert(ClogCtl->page_status[slotno] == CLOG_PAGE_CLEAN);
- S_UNLOCK(&(ClogCtl->control_lck));
+ LWLockRelease(CLogControlLock);
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-22 21:37:45 +0000