(My mailer has been fixed.)
At Mon, 11 Apr 2022 21:45:59 +0200, Markus Wanner
<markus.wan...@enterprisedb.com> wrote in
> On Mon, 2022-04-11 at 15:21 -0400, Robert Haas wrote:
> > ... before v13, the commit in question actually
> > changed the size of PGXACT, which is really quite bad -- it needs to
> > be 12 bytes for performance reasons. And there's no spare bytes
> > available, so I think we should follow one of the suggestions that he
> > had over in that email thread, and put delayChkptEnd in PGPROC even
> > though delayChkpt is in PGXACT.
>
> This makes sense to me. Kudos to Kyotaro for considering this.
>
> At first read, this sounded like a trade-off between compatibility and
> performance for PG 12 and older. But I realize leaving delayChkpt in
> PGXACT and adding just delayChkptEnd to PGPROC is compatible and leaves
> PGXACT at a size of 12 bytes. So this sounds like a good approach to
> me.
Thanks!
So, I created the patches for back-patching from 10 to 14. (With
fixed a silly bug of the v1-pg14 that HaveVirtualXIDsDelayingChkpt and
HaveVirtualXIDsDelayingChkptEnd are inverted..)
They revert delayChkpt-related changes made by the patch and add
delayChkptEnd stuff. I compared among every pair of the patches for
neighbouring versions, to make sure not making the same change in
different way and they have the same set of hunks.
This version takes the way sharing the common static function
(*ChkptGuts) between the functions *Chkpt() and *ChkptEnd().
regards.
--
Kyotaro Horiguchi
NTT Open Source Software Center
>From 471ca4aa38a92f837ed4e4aeda40648c3b0b0a9b Mon Sep 17 00:00:00 2001
From: Kyotaro Horiguchi <horikyota....@gmail.com>
Date: Wed, 6 Apr 2022 15:47:50 +0900
Subject: [PATCH v2] Fix ABI/API break
Commit bbace5697d caused ABI break by changing the type and width of
PGPROC.delayChkpt and API break by changing the signature of some
public functions. Restore the member and function signature to
previous state and add delayChkptEnd to an existing gap in PGPROC
struct.
Backpatch to 10, all supported branches.
---
src/backend/access/transam/multixact.c | 6 +--
src/backend/access/transam/twophase.c | 13 +++---
src/backend/access/transam/xact.c | 5 +--
src/backend/access/transam/xlog.c | 10 ++---
src/backend/access/transam/xloginsert.c | 2 +-
src/backend/catalog/storage.c | 6 +--
src/backend/storage/buffer/bufmgr.c | 6 +--
src/backend/storage/ipc/procarray.c | 60 +++++++++++++++++++------
src/backend/storage/lmgr/proc.c | 6 ++-
src/include/storage/proc.h | 42 +++--------------
src/include/storage/procarray.h | 8 ++--
11 files changed, 82 insertions(+), 82 deletions(-)
diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c
index 50d8bab9e2..b643564f16 100644
--- a/src/backend/access/transam/multixact.c
+++ b/src/backend/access/transam/multixact.c
@@ -3075,8 +3075,8 @@ TruncateMultiXact(MultiXactId newOldestMulti, Oid newOldestMultiDB)
* crash/basebackup, even though the state of the data directory would
* require it.
*/
- Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0);
- MyProc->delayChkpt |= DELAY_CHKPT_START;
+ Assert(!MyProc->delayChkpt);
+ MyProc->delayChkpt = true;
/* WAL log truncation */
WriteMTruncateXlogRec(newOldestMultiDB,
@@ -3102,7 +3102,7 @@ TruncateMultiXact(MultiXactId newOldestMulti, Oid newOldestMultiDB)
/* Then offsets */
PerformOffsetsTruncation(oldestMulti, newOldestMulti);
- MyProc->delayChkpt &= ~DELAY_CHKPT_START;
+ MyProc->delayChkpt = false;
END_CRIT_SECTION();
LWLockRelease(MultiXactTruncationLock);
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index dea3f485f7..911d93fbf4 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -474,7 +474,8 @@ MarkAsPreparingGuts(GlobalTransaction gxact, TransactionId xid, const char *gid,
}
proc->xid = xid;
Assert(proc->xmin == InvalidTransactionId);
- proc->delayChkpt = 0;
+ proc->delayChkpt = false;
+ proc->delayChkptEnd = false;
proc->statusFlags = 0;
proc->pid = 0;
proc->databaseId = databaseid;
@@ -1165,8 +1166,7 @@ EndPrepare(GlobalTransaction gxact)
START_CRIT_SECTION();
- Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0);
- MyProc->delayChkpt |= DELAY_CHKPT_START;
+ MyProc->delayChkpt = true;
XLogBeginInsert();
for (record = records.head; record != NULL; record = record->next)
@@ -1209,7 +1209,7 @@ EndPrepare(GlobalTransaction gxact)
* checkpoint starting after this will certainly see the gxact as a
* candidate for fsyncing.
*/
- MyProc->delayChkpt &= ~DELAY_CHKPT_START;
+ MyProc->delayChkpt = false;
/*
* Remember that we have this GlobalTransaction entry locked for us. If
@@ -2276,8 +2276,7 @@ RecordTransactionCommitPrepared(TransactionId xid,
START_CRIT_SECTION();
/* See notes in RecordTransactionCommit */
- Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0);
- MyProc->delayChkpt |= DELAY_CHKPT_START;
+ MyProc->delayChkpt = true;
/*
* Emit the XLOG commit record. Note that we mark 2PC commits as
@@ -2325,7 +2324,7 @@ RecordTransactionCommitPrepared(TransactionId xid,
TransactionIdCommitTree(xid, nchildren, children);
/* Checkpoint can proceed now */
- MyProc->delayChkpt &= ~DELAY_CHKPT_START;
+ MyProc->delayChkpt = false;
END_CRIT_SECTION();
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index c5e7261921..514044f3db 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -1335,9 +1335,8 @@ RecordTransactionCommit(void)
* This makes checkpoint's determination of which xacts are delayChkpt
* a bit fuzzy, but it doesn't matter.
*/
- Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0);
START_CRIT_SECTION();
- MyProc->delayChkpt |= DELAY_CHKPT_START;
+ MyProc->delayChkpt = true;
SetCurrentTransactionStopTimestamp();
@@ -1438,7 +1437,7 @@ RecordTransactionCommit(void)
*/
if (markXidCommitted)
{
- MyProc->delayChkpt &= ~DELAY_CHKPT_START;
+ MyProc->delayChkpt = false;
END_CRIT_SECTION();
}
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index d889d69387..8edf0fa646 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -9228,27 +9228,25 @@ CreateCheckPoint(int flags)
* and we will correctly flush the update below. So we cannot miss any
* xacts we need to wait for.
*/
- vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_START);
+ vxids = GetVirtualXIDsDelayingChkpt(&nvxids);
if (nvxids > 0)
{
do
{
pg_usleep(10000L); /* wait for 10 msec */
- } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
- DELAY_CHKPT_START));
+ } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids));
}
pfree(vxids);
CheckPointGuts(checkPoint.redo, flags);
- vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_COMPLETE);
+ vxids = GetVirtualXIDsDelayingChkptEnd(&nvxids);
if (nvxids > 0)
{
do
{
pg_usleep(10000L); /* wait for 10 msec */
- } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
- DELAY_CHKPT_COMPLETE));
+ } while (HaveVirtualXIDsDelayingChkptEnd(vxids, nvxids));
}
pfree(vxids);
diff --git a/src/backend/access/transam/xloginsert.c b/src/backend/access/transam/xloginsert.c
index 1af4a90c41..b153fad594 100644
--- a/src/backend/access/transam/xloginsert.c
+++ b/src/backend/access/transam/xloginsert.c
@@ -925,7 +925,7 @@ XLogSaveBufferForHint(Buffer buffer, bool buffer_std)
/*
* Ensure no checkpoint can change our view of RedoRecPtr.
*/
- Assert((MyProc->delayChkpt & DELAY_CHKPT_START) != 0);
+ Assert(MyProc->delayChkpt);
/*
* Update RedoRecPtr so that we can make the right decision
diff --git a/src/backend/catalog/storage.c b/src/backend/catalog/storage.c
index fa5682dce8..b7fc491a68 100644
--- a/src/backend/catalog/storage.c
+++ b/src/backend/catalog/storage.c
@@ -338,8 +338,8 @@ RelationTruncate(Relation rel, BlockNumber nblocks)
* the blocks to not exist on disk at all, but not for them to have the
* wrong contents.
*/
- Assert((MyProc->delayChkpt & DELAY_CHKPT_COMPLETE) == 0);
- MyProc->delayChkpt |= DELAY_CHKPT_COMPLETE;
+ Assert(!MyProc->delayChkptEnd);
+ MyProc->delayChkptEnd = true;
/*
* We WAL-log the truncation before actually truncating, which means
@@ -387,7 +387,7 @@ RelationTruncate(Relation rel, BlockNumber nblocks)
smgrtruncate(rel->rd_smgr, forks, nforks, blocks);
/* We've done all the critical work, so checkpoints are OK now. */
- MyProc->delayChkpt &= ~DELAY_CHKPT_COMPLETE;
+ MyProc->delayChkptEnd = false;
/*
* Update upper-level FSM pages to account for the truncation. This is
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index a55545a187..ffc6056c60 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -3946,9 +3946,7 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
* essential that CreateCheckpoint waits for virtual transactions
* rather than full transactionids.
*/
- Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0);
- MyProc->delayChkpt |= DELAY_CHKPT_START;
- delayChkpt = true;
+ MyProc->delayChkpt = delayChkpt = true;
lsn = XLogSaveBufferForHint(buffer, buffer_std);
}
@@ -3981,7 +3979,7 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
UnlockBufHdr(bufHdr, buf_state);
if (delayChkpt)
- MyProc->delayChkpt &= ~DELAY_CHKPT_START;
+ MyProc->delayChkpt = false;
if (dirtied)
{
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index ae71d7538b..f250dbcce5 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -355,6 +355,10 @@ static void MaintainLatestCompletedXidRecovery(TransactionId latestXid);
static inline FullTransactionId FullXidRelativeTo(FullTransactionId rel,
TransactionId xid);
static void GlobalVisUpdateApply(ComputeXidHorizonsResult *horizons);
+static VirtualTransactionId *GetVirtualXIDsDelayingChkptGuts(int *nvxids,
+ bool start);
+static bool HaveVirtualXIDsDelayingChkptGuts(VirtualTransactionId *vxids,
+ int nvxids, bool start);
/*
* Report shared-memory space needed by CreateSharedProcArray.
@@ -690,8 +694,9 @@ ProcArrayEndTransaction(PGPROC *proc, TransactionId latestXid)
proc->lxid = InvalidLocalTransactionId;
proc->xmin = InvalidTransactionId;
- /* be sure this is cleared in abort */
- proc->delayChkpt = 0;
+ /* be sure these are cleared in abort */
+ proc->delayChkpt = false;
+ proc->delayChkptEnd = false;
proc->recoveryConflictPending = false;
@@ -732,8 +737,9 @@ ProcArrayEndTransactionInternal(PGPROC *proc, TransactionId latestXid)
proc->lxid = InvalidLocalTransactionId;
proc->xmin = InvalidTransactionId;
- /* be sure this is cleared in abort */
- proc->delayChkpt = 0;
+ /* be sure these are cleared in abort */
+ proc->delayChkpt = false;
+ proc->delayChkptEnd = false;
proc->recoveryConflictPending = false;
@@ -921,6 +927,7 @@ ProcArrayClearTransaction(PGPROC *proc)
Assert(!(proc->statusFlags & PROC_VACUUM_STATE_MASK));
Assert(!proc->delayChkpt);
+ Assert(!proc->delayChkptEnd);
/*
* Need to increment completion count even though transaction hasn't
@@ -3049,8 +3056,9 @@ GetOldestSafeDecodingTransactionId(bool catalogOnly)
* delaying checkpoint because they have critical actions in progress.
*
* Constructs an array of VXIDs of transactions that are currently in commit
- * critical sections, as shown by having specified delayChkpt bits set in their
- * PGPROC.
+ * critical sections, as shown by having the corresponding flag set in
+ * their PGPROC. GetVirtualXIDsDelayingChkpt checks delayChkpt, and
+ * GetVirtualXIDsDelayingChkptEnd checks delayChkptEnd.
*
* Returns a palloc'd array that should be freed by the caller.
* *nvxids is the number of valid entries.
@@ -3064,15 +3072,25 @@ GetOldestSafeDecodingTransactionId(bool catalogOnly)
* for clearing of delayChkpt to propagate is unimportant for correctness.
*/
VirtualTransactionId *
-GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
+GetVirtualXIDsDelayingChkpt(int *nvxids)
+{
+ return GetVirtualXIDsDelayingChkptGuts(nvxids, true);
+}
+
+VirtualTransactionId *
+GetVirtualXIDsDelayingChkptEnd(int *nvxids)
+{
+ return GetVirtualXIDsDelayingChkptGuts(nvxids, false);
+}
+
+static VirtualTransactionId *
+GetVirtualXIDsDelayingChkptGuts(int *nvxids, bool start)
{
VirtualTransactionId *vxids;
ProcArrayStruct *arrayP = procArray;
int count = 0;
int index;
- Assert(type != 0);
-
/* allocate what's certainly enough result space */
vxids = (VirtualTransactionId *)
palloc(sizeof(VirtualTransactionId) * arrayP->maxProcs);
@@ -3084,7 +3102,7 @@ GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
int pgprocno = arrayP->pgprocnos[index];
PGPROC *proc = &allProcs[pgprocno];
- if ((proc->delayChkpt & type) != 0)
+ if (start ? proc->delayChkpt : proc->delayChkptEnd)
{
VirtualTransactionId vxid;
@@ -3106,18 +3124,32 @@ GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
* This is used with the results of GetVirtualXIDsDelayingChkpt to see if any
* of the specified VXIDs are still in critical sections of code.
*
+ * HaveVirtualXIDsDelayingChkptEnd corresponds to
+ * GetVirtualXIDsDelayingChkptEnd above.
+ *
* Note: this is O(N^2) in the number of vxacts that are/were delaying, but
* those numbers should be small enough for it not to be a problem.
*/
bool
-HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids, int type)
+HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids)
+{
+ return HaveVirtualXIDsDelayingChkptGuts(vxids, nvxids, true);
+}
+
+bool
+HaveVirtualXIDsDelayingChkptEnd(VirtualTransactionId *vxids, int nvxids)
+{
+ return HaveVirtualXIDsDelayingChkptGuts(vxids, nvxids, false);
+}
+
+static bool
+HaveVirtualXIDsDelayingChkptGuts(VirtualTransactionId *vxids, int nvxids,
+ bool start)
{
bool result = false;
ProcArrayStruct *arrayP = procArray;
int index;
- Assert(type != 0);
-
LWLockAcquire(ProcArrayLock, LW_SHARED);
for (index = 0; index < arrayP->numProcs; index++)
@@ -3128,7 +3160,7 @@ HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids, int type)
GET_VXID_FROM_PGPROC(vxid, *proc);
- if ((proc->delayChkpt & type) != 0 &&
+ if ((start ? proc->delayChkpt : proc->delayChkptEnd) &&
VirtualTransactionIdIsValid(vxid))
{
int i;
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index c50a419a54..4d2db6dff2 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -394,7 +394,8 @@ InitProcess(void)
MyProc->roleId = InvalidOid;
MyProc->tempNamespaceId = InvalidOid;
MyProc->isBackgroundWorker = IsBackgroundWorker;
- MyProc->delayChkpt = 0;
+ MyProc->delayChkpt = false;
+ MyProc->delayChkptEnd = false;
MyProc->statusFlags = 0;
/* NB -- autovac launcher intentionally does not set IS_AUTOVACUUM */
if (IsAutoVacuumWorkerProcess())
@@ -579,7 +580,8 @@ InitAuxiliaryProcess(void)
MyProc->roleId = InvalidOid;
MyProc->tempNamespaceId = InvalidOid;
MyProc->isBackgroundWorker = IsBackgroundWorker;
- MyProc->delayChkpt = 0;
+ MyProc->delayChkpt = false;
+ MyProc->delayChkptEnd = false;
MyProc->statusFlags = 0;
MyProc->lwWaiting = false;
MyProc->lwWaitMode = 0;
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index b78012ec2b..5000818ca4 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -86,41 +86,6 @@ struct XidCache
*/
#define INVALID_PGPROCNO PG_INT32_MAX
-/*
- * Flags for PGPROC.delayChkpt
- *
- * These flags can be used to delay the start or completion of a checkpoint
- * for short periods. A flag is in effect if the corresponding bit is set in
- * the PGPROC of any backend.
- *
- * For our purposes here, a checkpoint has three phases: (1) determine the
- * location to which the redo pointer will be moved, (2) write all the
- * data durably to disk, and (3) WAL-log the checkpoint.
- *
- * Setting DELAY_CHKPT_START prevents the system from moving from phase 1
- * to phase 2. This is useful when we are performing a WAL-logged modification
- * of data that will be flushed to disk in phase 2. By setting this flag
- * before writing WAL and clearing it after we've both written WAL and
- * performed the corresponding modification, we ensure that if the WAL record
- * is inserted prior to the new redo point, the corresponding data changes will
- * also be flushed to disk before the checkpoint can complete. (In the
- * extremely common case where the data being modified is in shared buffers
- * and we acquire an exclusive content lock on the relevant buffers before
- * writing WAL, this mechanism is not needed, because phase 2 will block
- * until we release the content lock and then flush the modified data to
- * disk.)
- *
- * Setting DELAY_CHKPT_COMPLETE prevents the system from moving from phase 2
- * to phase 3. This is useful if we are performing a WAL-logged operation that
- * might invalidate buffers, such as relation truncation. In this case, we need
- * to ensure that any buffers which were invalidated and thus not flushed by
- * the checkpoint are actaully destroyed on disk. Replay can cope with a file
- * or block that doesn't exist, but not with a block that has the wrong
- * contents.
- */
-#define DELAY_CHKPT_START (1<<0)
-#define DELAY_CHKPT_COMPLETE (1<<1)
-
typedef enum
{
PROC_WAIT_STATUS_OK,
@@ -226,11 +191,16 @@ struct PGPROC
pg_atomic_uint64 waitStart; /* time at which wait for lock acquisition
* started */
- int delayChkpt; /* for DELAY_CHKPT_* flags */
+ bool delayChkpt; /* true if this proc delays checkpoint start */
uint8 statusFlags; /* this backend's status flags, see PROC_*
* above. mirrored in
* ProcGlobal->statusFlags[pgxactoff] */
+ /*
+ * delayChkptEnd is placed here to prevent ABI breakage by moving other
+ * struct members around.
+ */
+ bool delayChkptEnd; /* true if this proc delays checkpoint end */
/*
* Info to allow us to wait for synchronous replication, if needed.
diff --git a/src/include/storage/procarray.h b/src/include/storage/procarray.h
index 93de230a32..30fd7438a9 100644
--- a/src/include/storage/procarray.h
+++ b/src/include/storage/procarray.h
@@ -59,9 +59,11 @@ extern TransactionId GetOldestActiveTransactionId(void);
extern TransactionId GetOldestSafeDecodingTransactionId(bool catalogOnly);
extern void GetReplicationHorizons(TransactionId *slot_xmin, TransactionId *catalog_xmin);
-extern VirtualTransactionId *GetVirtualXIDsDelayingChkpt(int *nvxids, int type);
-extern bool HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids,
- int nvxids, int type);
+extern VirtualTransactionId *GetVirtualXIDsDelayingChkpt(int *nvxids);
+extern bool HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids);
+extern VirtualTransactionId *GetVirtualXIDsDelayingChkptEnd(int *nvxids);
+extern bool HaveVirtualXIDsDelayingChkptEnd(VirtualTransactionId *vxids,
+ int nvxids);
extern PGPROC *BackendPidGetProc(int pid);
extern PGPROC *BackendPidGetProcWithLock(int pid);
--
2.27.0
>From 670fe40df53b44056845045b757d0d04f2fe28de Mon Sep 17 00:00:00 2001
From: Kyotaro Horiguchi <horikyota....@gmail.com>
Date: Tue, 12 Apr 2022 18:00:07 +0900
Subject: [PATCH v2] Fix ABI/API break
Commit 1ce14b6b2f caused ABI break by changing the type and width of
PGPROC.delayChkpt and API break by changing the signature of some
public functions. Restore the member and function signature to
previous state and add delayChkptEnd to an existing gap in PGPROC
struct.
Backpatch to 10, all supported branches.
---
src/backend/access/transam/multixact.c | 6 +--
src/backend/access/transam/twophase.c | 13 +++---
src/backend/access/transam/xact.c | 5 +--
src/backend/access/transam/xlog.c | 10 ++---
src/backend/access/transam/xloginsert.c | 2 +-
src/backend/catalog/storage.c | 6 +--
src/backend/storage/buffer/bufmgr.c | 6 +--
src/backend/storage/ipc/procarray.c | 59 +++++++++++++++++++------
src/backend/storage/lmgr/proc.c | 6 ++-
src/include/storage/proc.h | 43 +++---------------
src/include/storage/procarray.h | 9 ++--
11 files changed, 82 insertions(+), 83 deletions(-)
diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c
index 3e6443fd41..7990b5e5dd 100644
--- a/src/backend/access/transam/multixact.c
+++ b/src/backend/access/transam/multixact.c
@@ -3071,8 +3071,8 @@ TruncateMultiXact(MultiXactId newOldestMulti, Oid newOldestMultiDB)
* crash/basebackup, even though the state of the data directory would
* require it.
*/
- Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0);
- MyProc->delayChkpt |= DELAY_CHKPT_START;
+ Assert(!MyProc->delayChkpt);
+ MyProc->delayChkpt = true;
/* WAL log truncation */
WriteMTruncateXlogRec(newOldestMultiDB,
@@ -3098,7 +3098,7 @@ TruncateMultiXact(MultiXactId newOldestMulti, Oid newOldestMultiDB)
/* Then offsets */
PerformOffsetsTruncation(oldestMulti, newOldestMulti);
- MyProc->delayChkpt &= ~DELAY_CHKPT_START;
+ MyProc->delayChkpt = false;
END_CRIT_SECTION();
LWLockRelease(MultiXactTruncationLock);
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 716c17c98f..4c58c7579a 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -476,7 +476,8 @@ MarkAsPreparingGuts(GlobalTransaction gxact, TransactionId xid, const char *gid,
}
pgxact->xid = xid;
pgxact->xmin = InvalidTransactionId;
- proc->delayChkpt = 0;
+ proc->delayChkpt = false;
+ proc->delayChkptEnd = false;
pgxact->vacuumFlags = 0;
proc->pid = 0;
proc->databaseId = databaseid;
@@ -1170,8 +1171,7 @@ EndPrepare(GlobalTransaction gxact)
START_CRIT_SECTION();
- Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0);
- MyProc->delayChkpt |= DELAY_CHKPT_START;
+ MyProc->delayChkpt = true;
XLogBeginInsert();
for (record = records.head; record != NULL; record = record->next)
@@ -1214,7 +1214,7 @@ EndPrepare(GlobalTransaction gxact)
* checkpoint starting after this will certainly see the gxact as a
* candidate for fsyncing.
*/
- MyProc->delayChkpt &= ~DELAY_CHKPT_START;
+ MyProc->delayChkpt = false;
/*
* Remember that we have this GlobalTransaction entry locked for us. If
@@ -2287,8 +2287,7 @@ RecordTransactionCommitPrepared(TransactionId xid,
START_CRIT_SECTION();
/* See notes in RecordTransactionCommit */
- Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0);
- MyProc->delayChkpt |= DELAY_CHKPT_START;
+ MyProc->delayChkpt = true;
/*
* Emit the XLOG commit record. Note that we mark 2PC commits as
@@ -2336,7 +2335,7 @@ RecordTransactionCommitPrepared(TransactionId xid,
TransactionIdCommitTree(xid, nchildren, children);
/* Checkpoint can proceed now */
- MyProc->delayChkpt &= ~DELAY_CHKPT_START;
+ MyProc->delayChkpt = false;
END_CRIT_SECTION();
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index da6ce5a09e..fb6220e491 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -1308,9 +1308,8 @@ RecordTransactionCommit(void)
* This makes checkpoint's determination of which xacts are delayChkpt
* a bit fuzzy, but it doesn't matter.
*/
- Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0);
START_CRIT_SECTION();
- MyProc->delayChkpt |= DELAY_CHKPT_START;
+ MyProc->delayChkpt = true;
SetCurrentTransactionStopTimestamp();
@@ -1411,7 +1410,7 @@ RecordTransactionCommit(void)
*/
if (markXidCommitted)
{
- MyProc->delayChkpt &= ~DELAY_CHKPT_START;
+ MyProc->delayChkpt = false;
END_CRIT_SECTION();
}
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 5ac45e612e..ffc1b8e995 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -9028,27 +9028,25 @@ CreateCheckPoint(int flags)
* and we will correctly flush the update below. So we cannot miss any
* xacts we need to wait for.
*/
- vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_START);
+ vxids = GetVirtualXIDsDelayingChkpt(&nvxids);
if (nvxids > 0)
{
do
{
pg_usleep(10000L); /* wait for 10 msec */
- } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
- DELAY_CHKPT_START));
+ } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids));
}
pfree(vxids);
CheckPointGuts(checkPoint.redo, flags);
- vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_COMPLETE);
+ vxids = GetVirtualXIDsDelayingChkptEnd(&nvxids);
if (nvxids > 0)
{
do
{
pg_usleep(10000L); /* wait for 10 msec */
- } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
- DELAY_CHKPT_COMPLETE));
+ } while (HaveVirtualXIDsDelayingChkptEnd(vxids, nvxids));
}
pfree(vxids);
diff --git a/src/backend/access/transam/xloginsert.c b/src/backend/access/transam/xloginsert.c
index 5cff486d9e..b21679f09e 100644
--- a/src/backend/access/transam/xloginsert.c
+++ b/src/backend/access/transam/xloginsert.c
@@ -904,7 +904,7 @@ XLogSaveBufferForHint(Buffer buffer, bool buffer_std)
/*
* Ensure no checkpoint can change our view of RedoRecPtr.
*/
- Assert((MyProc->delayChkpt & DELAY_CHKPT_START) != 0);
+ Assert(MyProc->delayChkpt);
/*
* Update RedoRecPtr so that we can make the right decision
diff --git a/src/backend/catalog/storage.c b/src/backend/catalog/storage.c
index 0eb14cc885..d7c74105a4 100644
--- a/src/backend/catalog/storage.c
+++ b/src/backend/catalog/storage.c
@@ -338,8 +338,8 @@ RelationTruncate(Relation rel, BlockNumber nblocks)
* the blocks to not exist on disk at all, but not for them to have the
* wrong contents.
*/
- Assert((MyProc->delayChkpt & DELAY_CHKPT_COMPLETE) == 0);
- MyProc->delayChkpt |= DELAY_CHKPT_COMPLETE;
+ Assert(!MyProc->delayChkptEnd);
+ MyProc->delayChkptEnd = true;
/*
* We WAL-log the truncation before actually truncating, which means
@@ -387,7 +387,7 @@ RelationTruncate(Relation rel, BlockNumber nblocks)
smgrtruncate(rel->rd_smgr, forks, nforks, blocks);
/* We've done all the critical work, so checkpoints are OK now. */
- MyProc->delayChkpt &= ~DELAY_CHKPT_COMPLETE;
+ MyProc->delayChkptEnd = false;
/*
* Update upper-level FSM pages to account for the truncation. This is
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 033ef46811..597afedef7 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -3647,9 +3647,7 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
* essential that CreateCheckpoint waits for virtual transactions
* rather than full transactionids.
*/
- Assert((MyProc->delayChkpt & DELAY_CHKPT_START) == 0);
- MyProc->delayChkpt |= DELAY_CHKPT_START;
- delayChkpt = true;
+ MyProc->delayChkpt = delayChkpt = true;
lsn = XLogSaveBufferForHint(buffer, buffer_std);
}
@@ -3682,7 +3680,7 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
UnlockBufHdr(bufHdr, buf_state);
if (delayChkpt)
- MyProc->delayChkpt &= ~DELAY_CHKPT_START;
+ MyProc->delayChkpt = false;
if (dirtied)
{
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index 725680f34f..88853d25c6 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -175,6 +175,10 @@ static void KnownAssignedXidsReset(void);
static inline void ProcArrayEndTransactionInternal(PGPROC *proc,
PGXACT *pgxact, TransactionId latestXid);
static void ProcArrayGroupClearXid(PGPROC *proc, TransactionId latestXid);
+static VirtualTransactionId *GetVirtualXIDsDelayingChkptGuts(int *nvxids,
+ bool start);
+static bool HaveVirtualXIDsDelayingChkptGuts(VirtualTransactionId *vxids,
+ int nvxids, bool start);
/*
* Report shared-memory space needed by CreateSharedProcArray.
@@ -435,8 +439,9 @@ ProcArrayEndTransaction(PGPROC *proc, TransactionId latestXid)
/* must be cleared with xid/xmin: */
pgxact->vacuumFlags &= ~PROC_VACUUM_STATE_MASK;
- /* be sure this is cleared in abort */
- proc->delayChkpt = 0;
+ /* be sure these are cleared in abort */
+ proc->delayChkpt = false;
+ proc->delayChkptEnd = false;
proc->recoveryConflictPending = false;
@@ -460,8 +465,9 @@ ProcArrayEndTransactionInternal(PGPROC *proc, PGXACT *pgxact,
/* must be cleared with xid/xmin: */
pgxact->vacuumFlags &= ~PROC_VACUUM_STATE_MASK;
- /* be sure this is cleared in abort */
- proc->delayChkpt = 0;
+ /* be sure these are cleared in abort */
+ proc->delayChkpt = false;
+ proc->delayChkptEnd = false;
proc->recoveryConflictPending = false;
@@ -2278,8 +2284,9 @@ GetOldestSafeDecodingTransactionId(bool catalogOnly)
* delaying checkpoint because they have critical actions in progress.
*
* Constructs an array of VXIDs of transactions that are currently in commit
- * critical sections, as shown by having specified delayChkpt bits set in their
- * PGPROC.
+ * critical sections, as shown by having the corresponding flag set in
+ * their PGPROC. GetVirtualXIDsDelayingChkpt checks delayChkpt, and
+ * GetVirtualXIDsDelayingChkptEnd checks delayChkptEnd.
*
* Returns a palloc'd array that should be freed by the caller.
* *nvxids is the number of valid entries.
@@ -2293,15 +2300,25 @@ GetOldestSafeDecodingTransactionId(bool catalogOnly)
* for clearing of delayChkpt to propagate is unimportant for correctness.
*/
VirtualTransactionId *
-GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
+GetVirtualXIDsDelayingChkpt(int *nvxids)
+{
+ return GetVirtualXIDsDelayingChkptGuts(nvxids, true);
+}
+
+VirtualTransactionId *
+GetVirtualXIDsDelayingChkptEnd(int *nvxids)
+{
+ return GetVirtualXIDsDelayingChkptGuts(nvxids, false);
+}
+
+static VirtualTransactionId *
+GetVirtualXIDsDelayingChkptGuts(int *nvxids, bool start)
{
VirtualTransactionId *vxids;
ProcArrayStruct *arrayP = procArray;
int count = 0;
int index;
- Assert(type != 0);
-
/* allocate what's certainly enough result space */
vxids = (VirtualTransactionId *)
palloc(sizeof(VirtualTransactionId) * arrayP->maxProcs);
@@ -2313,7 +2330,7 @@ GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
int pgprocno = arrayP->pgprocnos[index];
PGPROC *proc = &allProcs[pgprocno];
- if ((proc->delayChkpt & type) != 0)
+ if (start ? proc->delayChkpt : proc->delayChkptEnd)
{
VirtualTransactionId vxid;
@@ -2335,18 +2352,32 @@ GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
* This is used with the results of GetVirtualXIDsDelayingChkpt to see if any
* of the specified VXIDs are still in critical sections of code.
*
+ * HaveVirtualXIDsDelayingChkptEnd corresponds to
+ * GetVirtualXIDsDelayingChkptEnd above.
+ *
* Note: this is O(N^2) in the number of vxacts that are/were delaying, but
* those numbers should be small enough for it not to be a problem.
*/
bool
-HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids, int type)
+HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids)
+{
+ return HaveVirtualXIDsDelayingChkptGuts(vxids, nvxids, true);
+}
+
+bool
+HaveVirtualXIDsDelayingChkptEnd(VirtualTransactionId *vxids, int nvxids)
+{
+ return HaveVirtualXIDsDelayingChkptGuts(vxids, nvxids, false);
+}
+
+static bool
+HaveVirtualXIDsDelayingChkptGuts(VirtualTransactionId *vxids, int nvxids,
+ bool start)
{
bool result = false;
ProcArrayStruct *arrayP = procArray;
int index;
- Assert(type != 0);
-
LWLockAcquire(ProcArrayLock, LW_SHARED);
for (index = 0; index < arrayP->numProcs; index++)
@@ -2357,7 +2388,7 @@ HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids, int type)
GET_VXID_FROM_PGPROC(vxid, *proc);
- if ((proc->delayChkpt & type) != 0 &&
+ if ((start ? proc->delayChkpt : proc->delayChkptEnd) &&
VirtualTransactionIdIsValid(vxid))
{
int i;
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index f3a6c598bf..3d8b0c7098 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -396,7 +396,8 @@ InitProcess(void)
MyProc->roleId = InvalidOid;
MyProc->tempNamespaceId = InvalidOid;
MyProc->isBackgroundWorker = IsBackgroundWorker;
- MyProc->delayChkpt = 0;
+ MyProc->delayChkpt = false;
+ MyProc->delayChkptEnd = false;
MyPgXact->vacuumFlags = 0;
/* NB -- autovac launcher intentionally does not set IS_AUTOVACUUM */
if (IsAutoVacuumWorkerProcess())
@@ -578,7 +579,8 @@ InitAuxiliaryProcess(void)
MyProc->roleId = InvalidOid;
MyProc->tempNamespaceId = InvalidOid;
MyProc->isBackgroundWorker = IsBackgroundWorker;
- MyProc->delayChkpt = 0;
+ MyProc->delayChkpt = false;
+ MyProc->delayChkptEnd = false;
MyPgXact->vacuumFlags = 0;
MyProc->lwWaiting = false;
MyProc->lwWaitMode = 0;
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index 5798b91186..878a6b12e8 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -83,41 +83,6 @@ struct XidCache
*/
#define INVALID_PGPROCNO PG_INT32_MAX
-/*
- * Flags for PGPROC.delayChkpt
- *
- * These flags can be used to delay the start or completion of a checkpoint
- * for short periods. A flag is in effect if the corresponding bit is set in
- * the PGPROC of any backend.
- *
- * For our purposes here, a checkpoint has three phases: (1) determine the
- * location to which the redo pointer will be moved, (2) write all the
- * data durably to disk, and (3) WAL-log the checkpoint.
- *
- * Setting DELAY_CHKPT_START prevents the system from moving from phase 1
- * to phase 2. This is useful when we are performing a WAL-logged modification
- * of data that will be flushed to disk in phase 2. By setting this flag
- * before writing WAL and clearing it after we've both written WAL and
- * performed the corresponding modification, we ensure that if the WAL record
- * is inserted prior to the new redo point, the corresponding data changes will
- * also be flushed to disk before the checkpoint can complete. (In the
- * extremely common case where the data being modified is in shared buffers
- * and we acquire an exclusive content lock on the relevant buffers before
- * writing WAL, this mechanism is not needed, because phase 2 will block
- * until we release the content lock and then flush the modified data to
- * disk.)
- *
- * Setting DELAY_CHKPT_COMPLETE prevents the system from moving from phase 2
- * to phase 3. This is useful if we are performing a WAL-logged operation that
- * might invalidate buffers, such as relation truncation. In this case, we need
- * to ensure that any buffers which were invalidated and thus not flushed by
- * the checkpoint are actaully destroyed on disk. Replay can cope with a file
- * or block that doesn't exist, but not with a block that has the wrong
- * contents.
- */
-#define DELAY_CHKPT_START (1<<0)
-#define DELAY_CHKPT_COMPLETE (1<<1)
-
/*
* Each backend has a PGPROC struct in shared memory. There is also a list of
* currently-unused PGPROC structs that will be reallocated to new backends.
@@ -184,7 +149,13 @@ struct PGPROC
LOCKMASK heldLocks; /* bitmask for lock types already held on this
* lock object by this backend */
- int delayChkpt; /* for DELAY_CHKPT_* flags */
+ bool delayChkpt; /* true if this proc delays checkpoint start */
+
+ /*
+ * delayChkptEnd is placed here to prevent ABI breakage by moving other
+ * struct members around.
+ */
+ bool delayChkptEnd; /* true if this proc delays checkpoint end */
/*
* Info to allow us to wait for synchronous replication, if needed.
diff --git a/src/include/storage/procarray.h b/src/include/storage/procarray.h
index 4dee2dab10..e6b5fe6153 100644
--- a/src/include/storage/procarray.h
+++ b/src/include/storage/procarray.h
@@ -91,10 +91,11 @@ extern bool TransactionIdIsActive(TransactionId xid);
extern TransactionId GetOldestXmin(Relation rel, int flags);
extern TransactionId GetOldestActiveTransactionId(void);
extern TransactionId GetOldestSafeDecodingTransactionId(bool catalogOnly);
-
-extern VirtualTransactionId *GetVirtualXIDsDelayingChkpt(int *nvxids, int type);
-extern bool HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids,
- int nvxids, int type);
+extern VirtualTransactionId *GetVirtualXIDsDelayingChkpt(int *nvxids);
+extern bool HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids);
+extern VirtualTransactionId *GetVirtualXIDsDelayingChkptEnd(int *nvxids);
+extern bool HaveVirtualXIDsDelayingChkptEnd(VirtualTransactionId *vxids,
+ int nvxids);
extern PGPROC *BackendPidGetProc(int pid);
extern PGPROC *BackendPidGetProcWithLock(int pid);
--
2.27.0
>From 5f25ca8356ebcb2f31eef434f25322ac92a26778 Mon Sep 17 00:00:00 2001
From: Kyotaro Horiguchi <horikyota....@gmail.com>
Date: Tue, 12 Apr 2022 17:50:36 +0900
Subject: [PATCH v2] Fix ABI/API break
Commit 3821d66a7b caused ABI break by changing the type and width of
PGXACT.delayChkpt and API break by changing the signature of some
public functions. Restore the member and function signature to
previous state, and add delayChkptEnd to an existing gap in PGPROC
struct instead of PGXACT since there's no room for the new variable in
PGXACT.
Backpatch to 10, all supported branches.
---
src/backend/access/transam/multixact.c | 6 +--
src/backend/access/transam/twophase.c | 13 +++---
src/backend/access/transam/xact.c | 5 +-
src/backend/access/transam/xlog.c | 10 ++--
src/backend/access/transam/xloginsert.c | 2 +-
src/backend/catalog/storage.c | 6 +--
src/backend/storage/buffer/bufmgr.c | 6 +--
src/backend/storage/ipc/procarray.c | 61 +++++++++++++++++++------
src/backend/storage/lmgr/proc.c | 6 ++-
src/include/storage/proc.h | 46 ++++---------------
src/include/storage/procarray.h | 8 ++--
11 files changed, 87 insertions(+), 82 deletions(-)
diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c
index 757346cbbb..09748905a8 100644
--- a/src/backend/access/transam/multixact.c
+++ b/src/backend/access/transam/multixact.c
@@ -3069,8 +3069,8 @@ TruncateMultiXact(MultiXactId newOldestMulti, Oid newOldestMultiDB)
* crash/basebackup, even though the state of the data directory would
* require it.
*/
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) == 0);
- MyPgXact->delayChkpt |= DELAY_CHKPT_START;
+ Assert(!MyPgXact->delayChkpt);
+ MyPgXact->delayChkpt = true;
/* WAL log truncation */
WriteMTruncateXlogRec(newOldestMultiDB,
@@ -3096,7 +3096,7 @@ TruncateMultiXact(MultiXactId newOldestMulti, Oid newOldestMultiDB)
/* Then offsets */
PerformOffsetsTruncation(oldestMulti, newOldestMulti);
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = false;
END_CRIT_SECTION();
LWLockRelease(MultiXactTruncationLock);
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 602ca41054..44f7349920 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -477,7 +477,8 @@ MarkAsPreparingGuts(GlobalTransaction gxact, TransactionId xid, const char *gid,
}
pgxact->xid = xid;
pgxact->xmin = InvalidTransactionId;
- pgxact->delayChkpt = 0;
+ pgxact->delayChkpt = false;
+ proc->delayChkptEnd = false;
pgxact->vacuumFlags = 0;
proc->pid = 0;
proc->databaseId = databaseid;
@@ -1187,8 +1188,7 @@ EndPrepare(GlobalTransaction gxact)
START_CRIT_SECTION();
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) == 0);
- MyPgXact->delayChkpt |= DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = true;
XLogBeginInsert();
for (record = records.head; record != NULL; record = record->next)
@@ -1231,7 +1231,7 @@ EndPrepare(GlobalTransaction gxact)
* checkpoint starting after this will certainly see the gxact as a
* candidate for fsyncing.
*/
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = false;
/*
* Remember that we have this GlobalTransaction entry locked for us. If
@@ -2338,8 +2338,7 @@ RecordTransactionCommitPrepared(TransactionId xid,
START_CRIT_SECTION();
/* See notes in RecordTransactionCommit */
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) == 0);
- MyPgXact->delayChkpt |= DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = true;
/*
* Emit the XLOG commit record. Note that we mark 2PC commits as
@@ -2387,7 +2386,7 @@ RecordTransactionCommitPrepared(TransactionId xid,
TransactionIdCommitTree(xid, nchildren, children);
/* Checkpoint can proceed now */
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = false;
END_CRIT_SECTION();
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 9d23298b2b..9c6b87c6ec 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -1306,9 +1306,8 @@ RecordTransactionCommit(void)
* This makes checkpoint's determination of which xacts are delayChkpt
* a bit fuzzy, but it doesn't matter.
*/
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) == 0);
START_CRIT_SECTION();
- MyPgXact->delayChkpt |= DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = true;
SetCurrentTransactionStopTimestamp();
@@ -1409,7 +1408,7 @@ RecordTransactionCommit(void)
*/
if (markXidCommitted)
{
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = false;
END_CRIT_SECTION();
}
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 7141e5dca8..889606517c 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -8920,27 +8920,25 @@ CreateCheckPoint(int flags)
* and we will correctly flush the update below. So we cannot miss any
* xacts we need to wait for.
*/
- vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_START);
+ vxids = GetVirtualXIDsDelayingChkpt(&nvxids);
if (nvxids > 0)
{
do
{
pg_usleep(10000L); /* wait for 10 msec */
- } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
- DELAY_CHKPT_START));
+ } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids));
}
pfree(vxids);
CheckPointGuts(checkPoint.redo, flags);
- vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_COMPLETE);
+ vxids = GetVirtualXIDsDelayingChkptEnd(&nvxids);
if (nvxids > 0)
{
do
{
pg_usleep(10000L); /* wait for 10 msec */
- } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
- DELAY_CHKPT_COMPLETE));
+ } while (HaveVirtualXIDsDelayingChkptEnd(vxids, nvxids));
}
pfree(vxids);
diff --git a/src/backend/access/transam/xloginsert.c b/src/backend/access/transam/xloginsert.c
index b51b0edd67..24a6f3148b 100644
--- a/src/backend/access/transam/xloginsert.c
+++ b/src/backend/access/transam/xloginsert.c
@@ -899,7 +899,7 @@ XLogSaveBufferForHint(Buffer buffer, bool buffer_std)
/*
* Ensure no checkpoint can change our view of RedoRecPtr.
*/
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) != 0);
+ Assert(MyPgXact->delayChkpt);
/*
* Update RedoRecPtr so that we can make the right decision
diff --git a/src/backend/catalog/storage.c b/src/backend/catalog/storage.c
index 5a6324fec4..5c76e7a39b 100644
--- a/src/backend/catalog/storage.c
+++ b/src/backend/catalog/storage.c
@@ -266,8 +266,8 @@ RelationTruncate(Relation rel, BlockNumber nblocks)
* the blocks to not exist on disk at all, but not for them to have the
* wrong contents.
*/
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_COMPLETE) == 0);
- MyPgXact->delayChkpt |= DELAY_CHKPT_COMPLETE;
+ Assert(!MyProc->delayChkptEnd);
+ MyProc->delayChkptEnd = true;
/*
* We WAL-log the truncation before actually truncating, which means
@@ -315,7 +315,7 @@ RelationTruncate(Relation rel, BlockNumber nblocks)
smgrtruncate(rel->rd_smgr, MAIN_FORKNUM, nblocks);
/* We've done all the critical work, so checkpoints are OK now. */
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_COMPLETE;
+ MyProc->delayChkptEnd = false;
}
/*
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 7d11b0963f..01c09fd532 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -3514,9 +3514,7 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
* essential that CreateCheckpoint waits for virtual transactions
* rather than full transactionids.
*/
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) == 0);
- MyPgXact->delayChkpt |= DELAY_CHKPT_START;
- delayChkpt = true;
+ MyPgXact->delayChkpt = delayChkpt = true;
lsn = XLogSaveBufferForHint(buffer, buffer_std);
}
@@ -3549,7 +3547,7 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
UnlockBufHdr(bufHdr, buf_state);
if (delayChkpt)
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = false;
if (dirtied)
{
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index 39093253fe..43456e36ae 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -172,6 +172,10 @@ static void KnownAssignedXidsReset(void);
static inline void ProcArrayEndTransactionInternal(PGPROC *proc,
PGXACT *pgxact, TransactionId latestXid);
static void ProcArrayGroupClearXid(PGPROC *proc, TransactionId latestXid);
+static VirtualTransactionId *GetVirtualXIDsDelayingChkptGuts(int *nvxids,
+ bool start);
+static bool HaveVirtualXIDsDelayingChkptGuts(VirtualTransactionId *vxids,
+ int nvxids, bool start);
/*
* Report shared-memory space needed by CreateSharedProcArray.
@@ -435,8 +439,9 @@ ProcArrayEndTransaction(PGPROC *proc, TransactionId latestXid)
/* must be cleared with xid/xmin: */
pgxact->vacuumFlags &= ~PROC_VACUUM_STATE_MASK;
- /* be sure this is cleared in abort */
- pgxact->delayChkpt = 0;
+ /* be sure these are cleared in abort */
+ pgxact->delayChkpt = false;
+ proc->delayChkptEnd = false;
proc->recoveryConflictPending = false;
@@ -460,8 +465,9 @@ ProcArrayEndTransactionInternal(PGPROC *proc, PGXACT *pgxact,
/* must be cleared with xid/xmin: */
pgxact->vacuumFlags &= ~PROC_VACUUM_STATE_MASK;
- /* be sure this is cleared in abort */
- pgxact->delayChkpt = 0;
+ /* be sure these are cleared in abort */
+ pgxact->delayChkpt = false;
+ proc->delayChkptEnd = false;
proc->recoveryConflictPending = false;
@@ -621,6 +627,7 @@ ProcArrayClearTransaction(PGPROC *proc)
/* redundant, but just in case */
pgxact->vacuumFlags &= ~PROC_VACUUM_STATE_MASK;
pgxact->delayChkpt = false;
+ proc->delayChkptEnd = false;
/* Clear the subtransaction-XID cache too */
pgxact->nxids = 0;
@@ -2267,8 +2274,10 @@ GetOldestSafeDecodingTransactionId(bool catalogOnly)
* delaying checkpoint because they have critical actions in progress.
*
* Constructs an array of VXIDs of transactions that are currently in commit
- * critical sections, as shown by having specified delayChkpt bits set in their
- * PGXACT.
+ * critical sections, as shown by having the corresponding flag set in their
+ * PGPROC or PGXACT. GetVirtualXIDsDelayingChkpt checks PGXACT.delayChkpt, and
+ * GetVirtualXIDsDelayingChkptEnd checks PGPROC.delayChkptEnd. See PGPROC for
+ * the reason for the placement.
*
* Returns a palloc'd array that should be freed by the caller.
* *nvxids is the number of valid entries.
@@ -2282,15 +2291,25 @@ GetOldestSafeDecodingTransactionId(bool catalogOnly)
* for clearing of delayChkpt to propagate is unimportant for correctness.
*/
VirtualTransactionId *
-GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
+GetVirtualXIDsDelayingChkpt(int *nvxids)
+{
+ return GetVirtualXIDsDelayingChkptGuts(nvxids, true);
+}
+
+VirtualTransactionId *
+GetVirtualXIDsDelayingChkptEnd(int *nvxids)
+{
+ return GetVirtualXIDsDelayingChkptGuts(nvxids, false);
+}
+
+static VirtualTransactionId *
+GetVirtualXIDsDelayingChkptGuts(int *nvxids, bool start)
{
VirtualTransactionId *vxids;
ProcArrayStruct *arrayP = procArray;
int count = 0;
int index;
- Assert(type != 0);
-
/* allocate what's certainly enough result space */
vxids = (VirtualTransactionId *)
palloc(sizeof(VirtualTransactionId) * arrayP->maxProcs);
@@ -2303,7 +2322,7 @@ GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
PGPROC *proc = &allProcs[pgprocno];
PGXACT *pgxact = &allPgXact[pgprocno];
- if ((pgxact->delayChkpt & type) != 0)
+ if (start ? pgxact->delayChkpt : proc->delayChkptEnd)
{
VirtualTransactionId vxid;
@@ -2325,18 +2344,32 @@ GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
* This is used with the results of GetVirtualXIDsDelayingChkpt to see if any
* of the specified VXIDs are still in critical sections of code.
*
+ * HaveVirtualXIDsDelayingChkptEnd corresponds to
+ * GetVirtualXIDsDelayingChkptEnd above.
+ *
* Note: this is O(N^2) in the number of vxacts that are/were delaying, but
* those numbers should be small enough for it not to be a problem.
*/
bool
-HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids, int type)
+HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids)
+{
+ return HaveVirtualXIDsDelayingChkptGuts(vxids, nvxids, true);
+}
+
+bool
+HaveVirtualXIDsDelayingChkptEnd(VirtualTransactionId *vxids, int nvxids)
+{
+ return HaveVirtualXIDsDelayingChkptGuts(vxids, nvxids, false);
+}
+
+static bool
+HaveVirtualXIDsDelayingChkptGuts(VirtualTransactionId *vxids, int nvxids,
+ bool start)
{
bool result = false;
ProcArrayStruct *arrayP = procArray;
int index;
- Assert(type != 0);
-
LWLockAcquire(ProcArrayLock, LW_SHARED);
for (index = 0; index < arrayP->numProcs; index++)
@@ -2348,7 +2381,7 @@ HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids, int type)
GET_VXID_FROM_PGPROC(vxid, *proc);
- if ((pgxact->delayChkpt & type) != 0 &&
+ if ((start ? pgxact->delayChkpt : proc->delayChkptEnd) &&
VirtualTransactionIdIsValid(vxid))
{
int i;
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 59291e01f4..cfb33199d5 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -397,7 +397,8 @@ InitProcess(void)
MyProc->roleId = InvalidOid;
MyProc->tempNamespaceId = InvalidOid;
MyProc->isBackgroundWorker = IsBackgroundWorker;
- MyPgXact->delayChkpt = 0;
+ MyPgXact->delayChkpt = false;
+ MyProc->delayChkptEnd = false;
MyPgXact->vacuumFlags = 0;
/* NB -- autovac launcher intentionally does not set IS_AUTOVACUUM */
if (IsAutoVacuumWorkerProcess())
@@ -579,7 +580,8 @@ InitAuxiliaryProcess(void)
MyProc->roleId = InvalidOid;
MyProc->tempNamespaceId = InvalidOid;
MyProc->isBackgroundWorker = IsBackgroundWorker;
- MyPgXact->delayChkpt = 0;
+ MyPgXact->delayChkpt = false;
+ MyProc->delayChkptEnd = false;
MyPgXact->vacuumFlags = 0;
MyProc->lwWaiting = false;
MyProc->lwWaitMode = 0;
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index 2a16fd23d4..de9326baa2 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -76,41 +76,6 @@ struct XidCache
*/
#define INVALID_PGPROCNO PG_INT32_MAX
-/*
- * Flags for PGPROC.delayChkpt
- *
- * These flags can be used to delay the start or completion of a checkpoint
- * for short periods. A flag is in effect if the corresponding bit is set in
- * the PGPROC of any backend.
- *
- * For our purposes here, a checkpoint has three phases: (1) determine the
- * location to which the redo pointer will be moved, (2) write all the
- * data durably to disk, and (3) WAL-log the checkpoint.
- *
- * Setting DELAY_CHKPT_START prevents the system from moving from phase 1
- * to phase 2. This is useful when we are performing a WAL-logged modification
- * of data that will be flushed to disk in phase 2. By setting this flag
- * before writing WAL and clearing it after we've both written WAL and
- * performed the corresponding modification, we ensure that if the WAL record
- * is inserted prior to the new redo point, the corresponding data changes will
- * also be flushed to disk before the checkpoint can complete. (In the
- * extremely common case where the data being modified is in shared buffers
- * and we acquire an exclusive content lock on the relevant buffers before
- * writing WAL, this mechanism is not needed, because phase 2 will block
- * until we release the content lock and then flush the modified data to
- * disk.)
- *
- * Setting DELAY_CHKPT_COMPLETE prevents the system from moving from phase 2
- * to phase 3. This is useful if we are performing a WAL-logged operation that
- * might invalidate buffers, such as relation truncation. In this case, we need
- * to ensure that any buffers which were invalidated and thus not flushed by
- * the checkpoint are actaully destroyed on disk. Replay can cope with a file
- * or block that doesn't exist, but not with a block that has the wrong
- * contents.
- */
-#define DELAY_CHKPT_START (1<<0)
-#define DELAY_CHKPT_COMPLETE (1<<1)
-
/*
* Each backend has a PGPROC struct in shared memory. There is also a list of
* currently-unused PGPROC structs that will be reallocated to new backends.
@@ -185,6 +150,14 @@ struct PGPROC
*/
XLogRecPtr waitLSN; /* waiting for this LSN or higher */
int syncRepState; /* wait state for sync rep */
+
+ /*
+ * This is a variable in duality with PGXACT.delayChkpt, but placed here to
+ * prevent ABI breakage by moving other struct members of the two structs
+ * around.
+ */
+ bool delayChkptEnd; /* true if this proc delays checkpoint end */
+
SHM_QUEUE syncRepLinks; /* list link if process is in syncrep queue */
/*
@@ -267,7 +240,8 @@ typedef struct PGXACT
uint8 vacuumFlags; /* vacuum-related flags, see above */
bool overflowed;
- int delayChkpt; /* for DELAY_CHKPT_* flags */
+ bool delayChkpt; /* true if this proc delays checkpoint start;
+ * previously called InCommit */
uint8 nxids;
} PGXACT;
diff --git a/src/include/storage/procarray.h b/src/include/storage/procarray.h
index d9ca460efc..88161e280a 100644
--- a/src/include/storage/procarray.h
+++ b/src/include/storage/procarray.h
@@ -92,9 +92,11 @@ extern TransactionId GetOldestXmin(Relation rel, int flags);
extern TransactionId GetOldestActiveTransactionId(void);
extern TransactionId GetOldestSafeDecodingTransactionId(bool catalogOnly);
-extern VirtualTransactionId *GetVirtualXIDsDelayingChkpt(int *nvxids, int type);
-extern bool HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids,
- int nvxids, int type);
+extern VirtualTransactionId *GetVirtualXIDsDelayingChkpt(int *nvxids);
+extern bool HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids);
+extern VirtualTransactionId *GetVirtualXIDsDelayingChkptEnd(int *nvxids);
+extern bool HaveVirtualXIDsDelayingChkptEnd(VirtualTransactionId *vxids,
+ int nvxids);
extern PGPROC *BackendPidGetProc(int pid);
extern PGPROC *BackendPidGetProcWithLock(int pid);
--
2.27.0
>From f1b507270ceb6d4ab4a4e86ad9fcba473a788ec1 Mon Sep 17 00:00:00 2001
From: Kyotaro Horiguchi <horikyota....@gmail.com>
Date: Tue, 12 Apr 2022 17:53:01 +0900
Subject: [PATCH v2] Fix ABI/API break
Commit 118f1a332b caused ABI break by changing the type and width of
PGXACT.delayChkpt and API break by changing the signature of some
public functions. Restore the member and function signature to
previous state, and add delayChkptEnd to an existing gap in PGPROC
struct instead of PGXACT since there's no room for the new variable in
PGXACT.
Backpatch to 10, all supported branches.
---
src/backend/access/transam/multixact.c | 6 +--
src/backend/access/transam/twophase.c | 13 +++---
src/backend/access/transam/xact.c | 5 +-
src/backend/access/transam/xlog.c | 10 ++--
src/backend/access/transam/xloginsert.c | 2 +-
src/backend/catalog/storage.c | 6 +--
src/backend/storage/buffer/bufmgr.c | 6 +--
src/backend/storage/ipc/procarray.c | 61 +++++++++++++++++++------
src/backend/storage/lmgr/proc.c | 6 ++-
src/include/storage/proc.h | 46 ++++---------------
src/include/storage/procarray.h | 8 ++--
11 files changed, 87 insertions(+), 82 deletions(-)
diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c
index 5612db0e21..ad9e7ff8f0 100644
--- a/src/backend/access/transam/multixact.c
+++ b/src/backend/access/transam/multixact.c
@@ -3069,8 +3069,8 @@ TruncateMultiXact(MultiXactId newOldestMulti, Oid newOldestMultiDB)
* crash/basebackup, even though the state of the data directory would
* require it.
*/
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) == 0);
- MyPgXact->delayChkpt |= DELAY_CHKPT_START;
+ Assert(!MyPgXact->delayChkpt);
+ MyPgXact->delayChkpt = true;
/* WAL log truncation */
WriteMTruncateXlogRec(newOldestMultiDB,
@@ -3096,7 +3096,7 @@ TruncateMultiXact(MultiXactId newOldestMulti, Oid newOldestMultiDB)
/* Then offsets */
PerformOffsetsTruncation(oldestMulti, newOldestMulti);
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = false;
END_CRIT_SECTION();
LWLockRelease(MultiXactTruncationLock);
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 769a5fd714..9f1e00608c 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -476,7 +476,8 @@ MarkAsPreparingGuts(GlobalTransaction gxact, TransactionId xid, const char *gid,
}
pgxact->xid = xid;
pgxact->xmin = InvalidTransactionId;
- pgxact->delayChkpt = 0;
+ pgxact->delayChkpt = false;
+ proc->delayChkptEnd = false;
pgxact->vacuumFlags = 0;
proc->pid = 0;
proc->databaseId = databaseid;
@@ -1175,8 +1176,7 @@ EndPrepare(GlobalTransaction gxact)
START_CRIT_SECTION();
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) == 0);
- MyPgXact->delayChkpt |= DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = true;
XLogBeginInsert();
for (record = records.head; record != NULL; record = record->next)
@@ -1219,7 +1219,7 @@ EndPrepare(GlobalTransaction gxact)
* checkpoint starting after this will certainly see the gxact as a
* candidate for fsyncing.
*/
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = false;
/*
* Remember that we have this GlobalTransaction entry locked for us. If
@@ -2353,8 +2353,7 @@ RecordTransactionCommitPrepared(TransactionId xid,
START_CRIT_SECTION();
/* See notes in RecordTransactionCommit */
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) == 0);
- MyPgXact->delayChkpt |= DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = true;
/*
* Emit the XLOG commit record. Note that we mark 2PC commits as
@@ -2402,7 +2401,7 @@ RecordTransactionCommitPrepared(TransactionId xid,
TransactionIdCommitTree(xid, nchildren, children);
/* Checkpoint can proceed now */
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = false;
END_CRIT_SECTION();
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5a86b6575e..e32b05d17f 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -1239,9 +1239,8 @@ RecordTransactionCommit(void)
* This makes checkpoint's determination of which xacts are delayChkpt
* a bit fuzzy, but it doesn't matter.
*/
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) == 0);
START_CRIT_SECTION();
- MyPgXact->delayChkpt |= DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = true;
SetCurrentTransactionStopTimestamp();
@@ -1342,7 +1341,7 @@ RecordTransactionCommit(void)
*/
if (markXidCommitted)
{
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = false;
END_CRIT_SECTION();
}
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index cc0229b934..5de7143f65 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -9064,27 +9064,25 @@ CreateCheckPoint(int flags)
* and we will correctly flush the update below. So we cannot miss any
* xacts we need to wait for.
*/
- vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_START);
+ vxids = GetVirtualXIDsDelayingChkpt(&nvxids);
if (nvxids > 0)
{
do
{
pg_usleep(10000L); /* wait for 10 msec */
- } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
- DELAY_CHKPT_START));
+ } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids));
}
pfree(vxids);
CheckPointGuts(checkPoint.redo, flags);
- vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_COMPLETE);
+ vxids = GetVirtualXIDsDelayingChkptEnd(&nvxids);
if (nvxids > 0)
{
do
{
pg_usleep(10000L); /* wait for 10 msec */
- } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
- DELAY_CHKPT_COMPLETE));
+ } while (HaveVirtualXIDsDelayingChkptEnd(vxids, nvxids));
}
pfree(vxids);
diff --git a/src/backend/access/transam/xloginsert.c b/src/backend/access/transam/xloginsert.c
index a8c140b06f..c033e7bd4c 100644
--- a/src/backend/access/transam/xloginsert.c
+++ b/src/backend/access/transam/xloginsert.c
@@ -899,7 +899,7 @@ XLogSaveBufferForHint(Buffer buffer, bool buffer_std)
/*
* Ensure no checkpoint can change our view of RedoRecPtr.
*/
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) != 0);
+ Assert(MyPgXact->delayChkpt);
/*
* Update RedoRecPtr so that we can make the right decision
diff --git a/src/backend/catalog/storage.c b/src/backend/catalog/storage.c
index 5d6f456c70..76a75a46b8 100644
--- a/src/backend/catalog/storage.c
+++ b/src/backend/catalog/storage.c
@@ -262,8 +262,8 @@ RelationTruncate(Relation rel, BlockNumber nblocks)
* the blocks to not exist on disk at all, but not for them to have the
* wrong contents.
*/
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_COMPLETE) == 0);
- MyPgXact->delayChkpt |= DELAY_CHKPT_COMPLETE;
+ Assert(!MyProc->delayChkptEnd);
+ MyProc->delayChkptEnd = true;
/*
* We WAL-log the truncation before actually truncating, which means
@@ -311,7 +311,7 @@ RelationTruncate(Relation rel, BlockNumber nblocks)
smgrtruncate(rel->rd_smgr, MAIN_FORKNUM, nblocks);
/* We've done all the critical work, so checkpoints are OK now. */
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_COMPLETE;
+ MyProc->delayChkptEnd = false;
}
/*
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 027d5067a0..459151519a 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -3471,9 +3471,7 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
* essential that CreateCheckpoint waits for virtual transactions
* rather than full transactionids.
*/
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) == 0);
- MyPgXact->delayChkpt |= DELAY_CHKPT_START;
- delayChkpt = true;
+ MyPgXact->delayChkpt = delayChkpt = true;
lsn = XLogSaveBufferForHint(buffer, buffer_std);
}
@@ -3506,7 +3504,7 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
UnlockBufHdr(bufHdr, buf_state);
if (delayChkpt)
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = false;
if (dirtied)
{
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index d88d955091..99ba68b4a3 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -171,6 +171,10 @@ static void KnownAssignedXidsReset(void);
static inline void ProcArrayEndTransactionInternal(PGPROC *proc,
PGXACT *pgxact, TransactionId latestXid);
static void ProcArrayGroupClearXid(PGPROC *proc, TransactionId latestXid);
+static VirtualTransactionId *GetVirtualXIDsDelayingChkptGuts(int *nvxids,
+ bool start);
+static bool HaveVirtualXIDsDelayingChkptGuts(VirtualTransactionId *vxids,
+ int nvxids, bool start);
/*
* Report shared-memory space needed by CreateSharedProcArray.
@@ -434,8 +438,9 @@ ProcArrayEndTransaction(PGPROC *proc, TransactionId latestXid)
/* must be cleared with xid/xmin: */
pgxact->vacuumFlags &= ~PROC_VACUUM_STATE_MASK;
- /* be sure this is cleared in abort */
- pgxact->delayChkpt = 0;
+ /* be sure these are cleared in abort */
+ pgxact->delayChkpt = false;
+ proc->delayChkptEnd = false;
proc->recoveryConflictPending = false;
@@ -459,8 +464,9 @@ ProcArrayEndTransactionInternal(PGPROC *proc, PGXACT *pgxact,
/* must be cleared with xid/xmin: */
pgxact->vacuumFlags &= ~PROC_VACUUM_STATE_MASK;
- /* be sure this is cleared in abort */
- pgxact->delayChkpt = 0;
+ /* be sure these are cleared in abort */
+ pgxact->delayChkpt = false;
+ proc->delayChkptEnd = false;
proc->recoveryConflictPending = false;
@@ -626,6 +632,7 @@ ProcArrayClearTransaction(PGPROC *proc)
/* redundant, but just in case */
pgxact->vacuumFlags &= ~PROC_VACUUM_STATE_MASK;
pgxact->delayChkpt = false;
+ proc->delayChkptEnd = false;
/* Clear the subtransaction-XID cache too */
pgxact->nxids = 0;
@@ -2273,8 +2280,10 @@ GetOldestSafeDecodingTransactionId(bool catalogOnly)
* delaying checkpoint because they have critical actions in progress.
*
* Constructs an array of VXIDs of transactions that are currently in commit
- * critical sections, as shown by having specified delayChkpt bits set in their
- * PGXACT.
+ * critical sections, as shown by having the corresponding flag set in their
+ * PGPROC or PGXACT. GetVirtualXIDsDelayingChkpt checks PGXACT.delayChkpt, and
+ * GetVirtualXIDsDelayingChkptEnd checks PGPROC.delayChkptEnd. See PGPROC for
+ * the reason for the placement.
*
* Returns a palloc'd array that should be freed by the caller.
* *nvxids is the number of valid entries.
@@ -2288,15 +2297,25 @@ GetOldestSafeDecodingTransactionId(bool catalogOnly)
* for clearing of delayChkpt to propagate is unimportant for correctness.
*/
VirtualTransactionId *
-GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
+GetVirtualXIDsDelayingChkpt(int *nvxids)
+{
+ return GetVirtualXIDsDelayingChkptGuts(nvxids, true);
+}
+
+VirtualTransactionId *
+GetVirtualXIDsDelayingChkptEnd(int *nvxids)
+{
+ return GetVirtualXIDsDelayingChkptGuts(nvxids, false);
+}
+
+static VirtualTransactionId *
+GetVirtualXIDsDelayingChkptGuts(int *nvxids, bool start)
{
VirtualTransactionId *vxids;
ProcArrayStruct *arrayP = procArray;
int count = 0;
int index;
- Assert(type != 0);
-
/* allocate what's certainly enough result space */
vxids = (VirtualTransactionId *)
palloc(sizeof(VirtualTransactionId) * arrayP->maxProcs);
@@ -2309,7 +2328,7 @@ GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
volatile PGPROC *proc = &allProcs[pgprocno];
volatile PGXACT *pgxact = &allPgXact[pgprocno];
- if ((pgxact->delayChkpt & type) != 0)
+ if (start ? pgxact->delayChkpt : proc->delayChkptEnd)
{
VirtualTransactionId vxid;
@@ -2331,18 +2350,32 @@ GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
* This is used with the results of GetVirtualXIDsDelayingChkpt to see if any
* of the specified VXIDs are still in critical sections of code.
*
+ * HaveVirtualXIDsDelayingChkptEnd corresponds to
+ * GetVirtualXIDsDelayingChkptEnd above.
+ *
* Note: this is O(N^2) in the number of vxacts that are/were delaying, but
* those numbers should be small enough for it not to be a problem.
*/
bool
-HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids, int type)
+HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids)
+{
+ return HaveVirtualXIDsDelayingChkptGuts(vxids, nvxids, true);
+}
+
+bool
+HaveVirtualXIDsDelayingChkptEnd(VirtualTransactionId *vxids, int nvxids)
+{
+ return HaveVirtualXIDsDelayingChkptGuts(vxids, nvxids, false);
+}
+
+static bool
+HaveVirtualXIDsDelayingChkptGuts(VirtualTransactionId *vxids, int nvxids,
+ bool start)
{
bool result = false;
ProcArrayStruct *arrayP = procArray;
int index;
- Assert(type != 0);
-
LWLockAcquire(ProcArrayLock, LW_SHARED);
for (index = 0; index < arrayP->numProcs; index++)
@@ -2354,7 +2387,7 @@ HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids, int type)
GET_VXID_FROM_PGPROC(vxid, *proc);
- if ((pgxact->delayChkpt & type) != 0 &&
+ if ((start ? pgxact->delayChkpt : proc->delayChkptEnd) &&
VirtualTransactionIdIsValid(vxid))
{
int i;
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index aaecfa67b7..b0b63d4c99 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -380,7 +380,8 @@ InitProcess(void)
MyProc->roleId = InvalidOid;
MyProc->tempNamespaceId = InvalidOid;
MyProc->isBackgroundWorker = IsBackgroundWorker;
- MyPgXact->delayChkpt = 0;
+ MyPgXact->delayChkpt = false;
+ MyProc->delayChkptEnd = false;
MyPgXact->vacuumFlags = 0;
/* NB -- autovac launcher intentionally does not set IS_AUTOVACUUM */
if (IsAutoVacuumWorkerProcess())
@@ -562,7 +563,8 @@ InitAuxiliaryProcess(void)
MyProc->roleId = InvalidOid;
MyProc->tempNamespaceId = InvalidOid;
MyProc->isBackgroundWorker = IsBackgroundWorker;
- MyPgXact->delayChkpt = 0;
+ MyPgXact->delayChkpt = false;
+ MyProc->delayChkptEnd = false;
MyPgXact->vacuumFlags = 0;
MyProc->lwWaiting = false;
MyProc->lwWaitMode = 0;
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index e76ca8a11e..8cec3d74f4 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -76,41 +76,6 @@ struct XidCache
*/
#define INVALID_PGPROCNO PG_INT32_MAX
-/*
- * Flags for PGPROC.delayChkpt
- *
- * These flags can be used to delay the start or completion of a checkpoint
- * for short periods. A flag is in effect if the corresponding bit is set in
- * the PGPROC of any backend.
- *
- * For our purposes here, a checkpoint has three phases: (1) determine the
- * location to which the redo pointer will be moved, (2) write all the
- * data durably to disk, and (3) WAL-log the checkpoint.
- *
- * Setting DELAY_CHKPT_START prevents the system from moving from phase 1
- * to phase 2. This is useful when we are performing a WAL-logged modification
- * of data that will be flushed to disk in phase 2. By setting this flag
- * before writing WAL and clearing it after we've both written WAL and
- * performed the corresponding modification, we ensure that if the WAL record
- * is inserted prior to the new redo point, the corresponding data changes will
- * also be flushed to disk before the checkpoint can complete. (In the
- * extremely common case where the data being modified is in shared buffers
- * and we acquire an exclusive content lock on the relevant buffers before
- * writing WAL, this mechanism is not needed, because phase 2 will block
- * until we release the content lock and then flush the modified data to
- * disk.)
- *
- * Setting DELAY_CHKPT_COMPLETE prevents the system from moving from phase 2
- * to phase 3. This is useful if we are performing a WAL-logged operation that
- * might invalidate buffers, such as relation truncation. In this case, we need
- * to ensure that any buffers which were invalidated and thus not flushed by
- * the checkpoint are actaully destroyed on disk. Replay can cope with a file
- * or block that doesn't exist, but not with a block that has the wrong
- * contents.
- */
-#define DELAY_CHKPT_START (1<<0)
-#define DELAY_CHKPT_COMPLETE (1<<1)
-
/*
* Each backend has a PGPROC struct in shared memory. There is also a list of
* currently-unused PGPROC structs that will be reallocated to new backends.
@@ -185,6 +150,14 @@ struct PGPROC
*/
XLogRecPtr waitLSN; /* waiting for this LSN or higher */
int syncRepState; /* wait state for sync rep */
+
+ /*
+ * This is a variable in duality with PGXACT.delayChkpt, but placed here to
+ * prevent ABI breakage by moving other struct members of the two structs
+ * around.
+ */
+ bool delayChkptEnd; /* true if this proc delays checkpoint end */
+
SHM_QUEUE syncRepLinks; /* list link if process is in syncrep queue */
/*
@@ -267,7 +240,8 @@ typedef struct PGXACT
uint8 vacuumFlags; /* vacuum-related flags, see above */
bool overflowed;
- int delayChkpt; /* for DELAY_CHKPT_* flags */
+ bool delayChkpt; /* true if this proc delays checkpoint start;
+ * previously called InCommit */
uint8 nxids;
} PGXACT;
diff --git a/src/include/storage/procarray.h b/src/include/storage/procarray.h
index a69632a70c..0c669c7965 100644
--- a/src/include/storage/procarray.h
+++ b/src/include/storage/procarray.h
@@ -92,9 +92,11 @@ extern TransactionId GetOldestXmin(Relation rel, int flags);
extern TransactionId GetOldestActiveTransactionId(void);
extern TransactionId GetOldestSafeDecodingTransactionId(bool catalogOnly);
-extern VirtualTransactionId *GetVirtualXIDsDelayingChkpt(int *nvxids, int type);
-extern bool HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids,
- int nvxids, int type);
+extern VirtualTransactionId *GetVirtualXIDsDelayingChkpt(int *nvxids);
+extern bool HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids);
+extern VirtualTransactionId *GetVirtualXIDsDelayingChkptEnd(int *nvxids);
+extern bool HaveVirtualXIDsDelayingChkptEnd(VirtualTransactionId *vxids,
+ int nvxids);
extern PGPROC *BackendPidGetProc(int pid);
extern PGPROC *BackendPidGetProcWithLock(int pid);
--
2.27.0
>From 9656334d2dd6a85fde9c79736bd6615bb060e371 Mon Sep 17 00:00:00 2001
From: Kyotaro Horiguchi <horikyota....@gmail.com>
Date: Tue, 12 Apr 2022 17:54:25 +0900
Subject: [PATCH v2] Fix ABI/API break
Commit 57f618310f caused ABI break by changing the type and width of
PGXACT.delayChkpt and API break by changing the signature of some
public functions. Restore the member and function signature to
previous state, and add delayChkptEnd to an existing gap in PGPROC
struct instead of PGXACT since there's no room for the new variable in
PGXACT.
Backpatch to 10, all supported branches.
---
src/backend/access/transam/multixact.c | 6 +--
src/backend/access/transam/twophase.c | 13 +++---
src/backend/access/transam/xact.c | 5 +-
src/backend/access/transam/xlog.c | 10 ++--
src/backend/access/transam/xloginsert.c | 2 +-
src/backend/catalog/storage.c | 6 +--
src/backend/storage/buffer/bufmgr.c | 6 +--
src/backend/storage/ipc/procarray.c | 61 +++++++++++++++++++------
src/backend/storage/lmgr/proc.c | 6 ++-
src/include/storage/proc.h | 46 ++++---------------
src/include/storage/procarray.h | 8 ++--
11 files changed, 87 insertions(+), 82 deletions(-)
diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c
index 1e52972bbf..cdaf499348 100644
--- a/src/backend/access/transam/multixact.c
+++ b/src/backend/access/transam/multixact.c
@@ -3069,8 +3069,8 @@ TruncateMultiXact(MultiXactId newOldestMulti, Oid newOldestMultiDB)
* crash/basebackup, even though the state of the data directory would
* require it.
*/
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) == 0);
- MyPgXact->delayChkpt |= DELAY_CHKPT_START;
+ Assert(!MyPgXact->delayChkpt);
+ MyPgXact->delayChkpt = true;
/* WAL log truncation */
WriteMTruncateXlogRec(newOldestMultiDB,
@@ -3096,7 +3096,7 @@ TruncateMultiXact(MultiXactId newOldestMulti, Oid newOldestMultiDB)
/* Then offsets */
PerformOffsetsTruncation(oldestMulti, newOldestMulti);
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = false;
END_CRIT_SECTION();
LWLockRelease(MultiXactTruncationLock);
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index c61b2736a1..26a4faf388 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -478,7 +478,8 @@ MarkAsPreparingGuts(GlobalTransaction gxact, TransactionId xid, const char *gid,
}
pgxact->xid = xid;
pgxact->xmin = InvalidTransactionId;
- pgxact->delayChkpt = 0;
+ pgxact->delayChkpt = false;
+ proc->delayChkptEnd = false;
pgxact->vacuumFlags = 0;
proc->pid = 0;
proc->databaseId = databaseid;
@@ -1159,8 +1160,7 @@ EndPrepare(GlobalTransaction gxact)
START_CRIT_SECTION();
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) == 0);
- MyPgXact->delayChkpt |= DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = true;
XLogBeginInsert();
for (record = records.head; record != NULL; record = record->next)
@@ -1192,7 +1192,7 @@ EndPrepare(GlobalTransaction gxact)
* checkpoint starting after this will certainly see the gxact as a
* candidate for fsyncing.
*/
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = false;
/*
* Remember that we have this GlobalTransaction entry locked for us. If
@@ -2285,8 +2285,7 @@ RecordTransactionCommitPrepared(TransactionId xid,
START_CRIT_SECTION();
/* See notes in RecordTransactionCommit */
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) == 0);
- MyPgXact->delayChkpt |= DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = true;
/*
* Emit the XLOG commit record. Note that we mark 2PC commits as
@@ -2334,7 +2333,7 @@ RecordTransactionCommitPrepared(TransactionId xid,
TransactionIdCommitTree(xid, nchildren, children);
/* Checkpoint can proceed now */
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = false;
END_CRIT_SECTION();
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index ccd99c38c2..25a3a4f97e 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -1247,9 +1247,8 @@ RecordTransactionCommit(void)
* This makes checkpoint's determination of which xacts are delayChkpt
* a bit fuzzy, but it doesn't matter.
*/
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) == 0);
START_CRIT_SECTION();
- MyPgXact->delayChkpt |= DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = true;
SetCurrentTransactionStopTimestamp();
@@ -1350,7 +1349,7 @@ RecordTransactionCommit(void)
*/
if (markXidCommitted)
{
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = false;
END_CRIT_SECTION();
}
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 51efc106a2..be6d9b239a 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -9022,27 +9022,25 @@ CreateCheckPoint(int flags)
* and we will correctly flush the update below. So we cannot miss any
* xacts we need to wait for.
*/
- vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_START);
+ vxids = GetVirtualXIDsDelayingChkpt(&nvxids);
if (nvxids > 0)
{
do
{
pg_usleep(10000L); /* wait for 10 msec */
- } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
- DELAY_CHKPT_START));
+ } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids));
}
pfree(vxids);
CheckPointGuts(checkPoint.redo, flags);
- vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_COMPLETE);
+ vxids = GetVirtualXIDsDelayingChkptEnd(&nvxids);
if (nvxids > 0)
{
do
{
pg_usleep(10000L); /* wait for 10 msec */
- } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
- DELAY_CHKPT_COMPLETE));
+ } while (HaveVirtualXIDsDelayingChkptEnd(vxids, nvxids));
}
pfree(vxids);
diff --git a/src/backend/access/transam/xloginsert.c b/src/backend/access/transam/xloginsert.c
index 6ff19814d4..579d8de775 100644
--- a/src/backend/access/transam/xloginsert.c
+++ b/src/backend/access/transam/xloginsert.c
@@ -899,7 +899,7 @@ XLogSaveBufferForHint(Buffer buffer, bool buffer_std)
/*
* Ensure no checkpoint can change our view of RedoRecPtr.
*/
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) != 0);
+ Assert(MyPgXact->delayChkpt);
/*
* Update RedoRecPtr so that we can make the right decision
diff --git a/src/backend/catalog/storage.c b/src/backend/catalog/storage.c
index 729fb92c5f..9497e1d88d 100644
--- a/src/backend/catalog/storage.c
+++ b/src/backend/catalog/storage.c
@@ -263,8 +263,8 @@ RelationTruncate(Relation rel, BlockNumber nblocks)
* the blocks to not exist on disk at all, but not for them to have the
* wrong contents.
*/
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_COMPLETE) == 0);
- MyPgXact->delayChkpt |= DELAY_CHKPT_COMPLETE;
+ Assert(!MyProc->delayChkptEnd);
+ MyProc->delayChkptEnd = true;
/*
* We WAL-log the truncation before actually truncating, which means
@@ -312,7 +312,7 @@ RelationTruncate(Relation rel, BlockNumber nblocks)
smgrtruncate(rel->rd_smgr, MAIN_FORKNUM, nblocks);
/* We've done all the critical work, so checkpoints are OK now. */
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_COMPLETE;
+ MyProc->delayChkptEnd = false;
}
/*
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 0b7bdb8634..bafe91ab0d 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -3469,9 +3469,7 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
* essential that CreateCheckpoint waits for virtual transactions
* rather than full transactionids.
*/
- Assert((MyPgXact->delayChkpt & DELAY_CHKPT_START) == 0);
- MyPgXact->delayChkpt |= DELAY_CHKPT_START;
- delayChkpt = true;
+ MyPgXact->delayChkpt = delayChkpt = true;
lsn = XLogSaveBufferForHint(buffer, buffer_std);
}
@@ -3504,7 +3502,7 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
UnlockBufHdr(bufHdr, buf_state);
if (delayChkpt)
- MyPgXact->delayChkpt &= ~DELAY_CHKPT_START;
+ MyPgXact->delayChkpt = false;
if (dirtied)
{
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index 134b63f28b..9f5b26f201 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -171,6 +171,10 @@ static void KnownAssignedXidsReset(void);
static inline void ProcArrayEndTransactionInternal(PGPROC *proc,
PGXACT *pgxact, TransactionId latestXid);
static void ProcArrayGroupClearXid(PGPROC *proc, TransactionId latestXid);
+static VirtualTransactionId *GetVirtualXIDsDelayingChkptGuts(int *nvxids,
+ bool start);
+static bool HaveVirtualXIDsDelayingChkptGuts(VirtualTransactionId *vxids,
+ int nvxids, bool start);
/*
* Report shared-memory space needed by CreateSharedProcArray.
@@ -434,8 +438,9 @@ ProcArrayEndTransaction(PGPROC *proc, TransactionId latestXid)
/* must be cleared with xid/xmin: */
pgxact->vacuumFlags &= ~PROC_VACUUM_STATE_MASK;
- /* be sure this is cleared in abort */
- pgxact->delayChkpt = 0;
+ /* be sure these are cleared in abort */
+ pgxact->delayChkpt = false;
+ proc->delayChkptEnd = false;
proc->recoveryConflictPending = false;
@@ -459,8 +464,9 @@ ProcArrayEndTransactionInternal(PGPROC *proc, PGXACT *pgxact,
/* must be cleared with xid/xmin: */
pgxact->vacuumFlags &= ~PROC_VACUUM_STATE_MASK;
- /* be sure this is cleared in abort */
- pgxact->delayChkpt = 0;
+ /* be sure these are cleared in abort */
+ pgxact->delayChkpt = false;
+ proc->delayChkptEnd = false;
proc->recoveryConflictPending = false;
@@ -626,6 +632,7 @@ ProcArrayClearTransaction(PGPROC *proc)
/* redundant, but just in case */
pgxact->vacuumFlags &= ~PROC_VACUUM_STATE_MASK;
pgxact->delayChkpt = false;
+ proc->delayChkptEnd = false;
/* Clear the subtransaction-XID cache too */
pgxact->nxids = 0;
@@ -2265,8 +2272,10 @@ GetOldestSafeDecodingTransactionId(bool catalogOnly)
* delaying checkpoint because they have critical actions in progress.
*
* Constructs an array of VXIDs of transactions that are currently in commit
- * critical sections, as shown by having specified delayChkpt bits set in their
- * PGXACT.
+ * critical sections, as shown by having the corresponding flag set in their
+ * PGPROC or PGXACT. GetVirtualXIDsDelayingChkpt checks PGXACT.delayChkpt, and
+ * GetVirtualXIDsDelayingChkptEnd checks PGPROC.delayChkptEnd. See PGPROC for
+ * the reason for the placement.
*
* Returns a palloc'd array that should be freed by the caller.
* *nvxids is the number of valid entries.
@@ -2280,15 +2289,25 @@ GetOldestSafeDecodingTransactionId(bool catalogOnly)
* for clearing of delayChkpt to propagate is unimportant for correctness.
*/
VirtualTransactionId *
-GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
+GetVirtualXIDsDelayingChkpt(int *nvxids)
+{
+ return GetVirtualXIDsDelayingChkptGuts(nvxids, true);
+}
+
+VirtualTransactionId *
+GetVirtualXIDsDelayingChkptEnd(int *nvxids)
+{
+ return GetVirtualXIDsDelayingChkptGuts(nvxids, false);
+}
+
+static VirtualTransactionId *
+GetVirtualXIDsDelayingChkptGuts(int *nvxids, bool start)
{
VirtualTransactionId *vxids;
ProcArrayStruct *arrayP = procArray;
int count = 0;
int index;
- Assert(type != 0);
-
/* allocate what's certainly enough result space */
vxids = (VirtualTransactionId *)
palloc(sizeof(VirtualTransactionId) * arrayP->maxProcs);
@@ -2301,7 +2320,7 @@ GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
volatile PGPROC *proc = &allProcs[pgprocno];
volatile PGXACT *pgxact = &allPgXact[pgprocno];
- if ((pgxact->delayChkpt & type) != 0)
+ if (start ? pgxact->delayChkpt : proc->delayChkptEnd)
{
VirtualTransactionId vxid;
@@ -2323,18 +2342,32 @@ GetVirtualXIDsDelayingChkpt(int *nvxids, int type)
* This is used with the results of GetVirtualXIDsDelayingChkpt to see if any
* of the specified VXIDs are still in critical sections of code.
*
+ * HaveVirtualXIDsDelayingChkptEnd corresponds to
+ * GetVirtualXIDsDelayingChkptEnd above.
+ *
* Note: this is O(N^2) in the number of vxacts that are/were delaying, but
* those numbers should be small enough for it not to be a problem.
*/
bool
-HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids, int type)
+HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids)
+{
+ return HaveVirtualXIDsDelayingChkptGuts(vxids, nvxids, true);
+}
+
+bool
+HaveVirtualXIDsDelayingChkptEnd(VirtualTransactionId *vxids, int nvxids)
+{
+ return HaveVirtualXIDsDelayingChkptGuts(vxids, nvxids, false);
+}
+
+static bool
+HaveVirtualXIDsDelayingChkptGuts(VirtualTransactionId *vxids, int nvxids,
+ bool start)
{
bool result = false;
ProcArrayStruct *arrayP = procArray;
int index;
- Assert(type != 0);
-
LWLockAcquire(ProcArrayLock, LW_SHARED);
for (index = 0; index < arrayP->numProcs; index++)
@@ -2346,7 +2379,7 @@ HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids, int type)
GET_VXID_FROM_PGPROC(vxid, *proc);
- if ((pgxact->delayChkpt & type) != 0 &&
+ if ((start ? pgxact->delayChkpt : proc->delayChkptEnd) &&
VirtualTransactionIdIsValid(vxid))
{
int i;
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index e5370df019..0efee8411e 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -377,7 +377,8 @@ InitProcess(void)
MyProc->databaseId = InvalidOid;
MyProc->roleId = InvalidOid;
MyProc->isBackgroundWorker = IsBackgroundWorker;
- MyPgXact->delayChkpt = 0;
+ MyPgXact->delayChkpt = false;
+ MyProc->delayChkptEnd = false;
MyPgXact->vacuumFlags = 0;
/* NB -- autovac launcher intentionally does not set IS_AUTOVACUUM */
if (IsAutoVacuumWorkerProcess())
@@ -550,7 +551,8 @@ InitAuxiliaryProcess(void)
MyProc->databaseId = InvalidOid;
MyProc->roleId = InvalidOid;
MyProc->isBackgroundWorker = IsBackgroundWorker;
- MyPgXact->delayChkpt = 0;
+ MyPgXact->delayChkpt = false;
+ MyProc->delayChkptEnd = false;
MyPgXact->vacuumFlags = 0;
MyProc->lwWaiting = false;
MyProc->lwWaitMode = 0;
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index d8dd7bf5e1..e6d0f74458 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -75,41 +75,6 @@ struct XidCache
*/
#define INVALID_PGPROCNO PG_INT32_MAX
-/*
- * Flags for PGPROC.delayChkpt
- *
- * These flags can be used to delay the start or completion of a checkpoint
- * for short periods. A flag is in effect if the corresponding bit is set in
- * the PGPROC of any backend.
- *
- * For our purposes here, a checkpoint has three phases: (1) determine the
- * location to which the redo pointer will be moved, (2) write all the
- * data durably to disk, and (3) WAL-log the checkpoint.
- *
- * Setting DELAY_CHKPT_START prevents the system from moving from phase 1
- * to phase 2. This is useful when we are performing a WAL-logged modification
- * of data that will be flushed to disk in phase 2. By setting this flag
- * before writing WAL and clearing it after we've both written WAL and
- * performed the corresponding modification, we ensure that if the WAL record
- * is inserted prior to the new redo point, the corresponding data changes will
- * also be flushed to disk before the checkpoint can complete. (In the
- * extremely common case where the data being modified is in shared buffers
- * and we acquire an exclusive content lock on the relevant buffers before
- * writing WAL, this mechanism is not needed, because phase 2 will block
- * until we release the content lock and then flush the modified data to
- * disk.)
- *
- * Setting DELAY_CHKPT_COMPLETE prevents the system from moving from phase 2
- * to phase 3. This is useful if we are performing a WAL-logged operation that
- * might invalidate buffers, such as relation truncation. In this case, we need
- * to ensure that any buffers which were invalidated and thus not flushed by
- * the checkpoint are actaully destroyed on disk. Replay can cope with a file
- * or block that doesn't exist, but not with a block that has the wrong
- * contents.
- */
-#define DELAY_CHKPT_START (1<<0)
-#define DELAY_CHKPT_COMPLETE (1<<1)
-
/*
* Each backend has a PGPROC struct in shared memory. There is also a list of
* currently-unused PGPROC structs that will be reallocated to new backends.
@@ -181,6 +146,14 @@ struct PGPROC
*/
XLogRecPtr waitLSN; /* waiting for this LSN or higher */
int syncRepState; /* wait state for sync rep */
+
+ /*
+ * This is a variable in duality with PGXACT.delayChkpt, but placed here to
+ * prevent ABI breakage by moving other struct members of the two structs
+ * around.
+ */
+ bool delayChkptEnd; /* true if this proc delays checkpoint end */
+
SHM_QUEUE syncRepLinks; /* list link if process is in syncrep queue */
/*
@@ -252,7 +225,8 @@ typedef struct PGXACT
uint8 vacuumFlags; /* vacuum-related flags, see above */
bool overflowed;
- int delayChkpt; /* for DELAY_CHKPT_* flags */
+ bool delayChkpt; /* true if this proc delays checkpoint start;
+ * previously called InCommit */
uint8 nxids;
} PGXACT;
diff --git a/src/include/storage/procarray.h b/src/include/storage/procarray.h
index 2b60b27604..9a139c5f61 100644
--- a/src/include/storage/procarray.h
+++ b/src/include/storage/procarray.h
@@ -92,9 +92,11 @@ extern TransactionId GetOldestXmin(Relation rel, int flags);
extern TransactionId GetOldestActiveTransactionId(void);
extern TransactionId GetOldestSafeDecodingTransactionId(bool catalogOnly);
-extern VirtualTransactionId *GetVirtualXIDsDelayingChkpt(int *nvxids, int type);
-extern bool HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids,
- int nvxids, int type);
+extern VirtualTransactionId *GetVirtualXIDsDelayingChkpt(int *nvxids);
+extern bool HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids);
+extern VirtualTransactionId *GetVirtualXIDsDelayingChkptEnd(int *nvxids);
+extern bool HaveVirtualXIDsDelayingChkptEnd(VirtualTransactionId *vxids,
+ int nvxids);
extern PGPROC *BackendPidGetProc(int pid);
extern PGPROC *BackendPidGetProcWithLock(int pid);
--
2.27.0
