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authorTom Lane <tgl@sss.pgh.pa.us>2001-09-29 04:02:27 +0000
committerTom Lane <tgl@sss.pgh.pa.us>2001-09-29 04:02:27 +0000
commit499abb0c0f21cb861c5af1d49a06469f3cfcc1eb (patch)
tree0af6262d9b6d1159315e93e90e69047b959ea5f5 /src/backend/storage/buffer/buf_init.c
parent818fb55ac49b4b20e65d9899fc1784e54e86db58 (diff)
downloadpostgresql-499abb0c0f21cb861c5af1d49a06469f3cfcc1eb.tar.gz
postgresql-499abb0c0f21cb861c5af1d49a06469f3cfcc1eb.zip
Implement new 'lightweight lock manager' that's intermediate between
existing lock manager and spinlocks: it understands exclusive vs shared lock but has few other fancy features. Replace most uses of spinlocks with lightweight locks. All remaining uses of spinlocks have very short lock hold times (a few dozen instructions), so tweak spinlock backoff code to work efficiently given this assumption. All per my proposal on pghackers 26-Sep-01.
Diffstat (limited to 'src/backend/storage/buffer/buf_init.c')
-rw-r--r--src/backend/storage/buffer/buf_init.c24
1 files changed, 12 insertions, 12 deletions
diff --git a/src/backend/storage/buffer/buf_init.c b/src/backend/storage/buffer/buf_init.c
index 819fe7e206c..45a2e4aa160 100644
--- a/src/backend/storage/buffer/buf_init.c
+++ b/src/backend/storage/buffer/buf_init.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/buffer/buf_init.c,v 1.43 2001/07/06 21:04:25 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/buffer/buf_init.c,v 1.44 2001/09/29 04:02:22 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -28,10 +28,9 @@
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/lmgr.h"
-#include "storage/s_lock.h"
#include "storage/shmem.h"
#include "storage/smgr.h"
-#include "storage/spin.h"
+#include "storage/lwlock.h"
#include "utils/builtins.h"
#include "utils/hsearch.h"
#include "utils/memutils.h"
@@ -117,8 +116,6 @@ bool *BufferDirtiedByMe; /* T if buf has been dirtied in cur xact */
*
*/
-SPINLOCK BufMgrLock;
-
long int ReadBufferCount;
long int ReadLocalBufferCount;
long int BufferHitCount;
@@ -151,7 +148,7 @@ InitBufferPool(void)
* anyone else attached to the shmem at this point, we've got
* problems.
*/
- SpinAcquire(BufMgrLock);
+ LWLockAcquire(BufMgrLock, LW_EXCLUSIVE);
#ifdef BMTRACE
CurTraceBuf = (long *) ShmemInitStruct("Buffer trace",
@@ -186,8 +183,8 @@ InitBufferPool(void)
/*
* link the buffers into a circular, doubly-linked list to
- * initialize free list. Still don't know anything about
- * replacement strategy in this file.
+ * initialize free list, and initialize the buffer headers.
+ * Still don't know anything about replacement strategy in this file.
*/
for (i = 0; i < Data_Descriptors; block += BLCKSZ, buf++, i++)
{
@@ -197,12 +194,15 @@ InitBufferPool(void)
buf->freePrev = i - 1;
CLEAR_BUFFERTAG(&(buf->tag));
+ buf->buf_id = i;
+
buf->data = MAKE_OFFSET(block);
buf->flags = (BM_DELETED | BM_FREE | BM_VALID);
buf->refcount = 0;
- buf->buf_id = i;
- S_INIT_LOCK(&(buf->io_in_progress_lock));
- S_INIT_LOCK(&(buf->cntx_lock));
+ buf->io_in_progress_lock = LWLockAssign();
+ buf->cntx_lock = LWLockAssign();
+ buf->cntxDirty = false;
+ buf->wait_backend_id = 0;
}
/* close the circular queue */
@@ -214,7 +214,7 @@ InitBufferPool(void)
InitBufTable();
InitFreeList(!foundDescs);
- SpinRelease(BufMgrLock);
+ LWLockRelease(BufMgrLock);
}
/*