Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit7db1e23

Browse files
committed
Fisx bug in XMIN calculation in DTMD
2 parents58f9465 +4c7fa35 commit7db1e23

File tree

8 files changed

+84
-41
lines changed

8 files changed

+84
-41
lines changed

‎contrib/pg_xtm/README‎

Lines changed: 9 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -39,12 +39,14 @@ libdtm api
3939
void DtmInitSnapshot(Snapshot snapshot);
4040

4141
// Starts a new global transaction of nParticipants size. Returns the
42-
// transaction id and fills the snapshot on success. Returns INVALID_XID
42+
// transaction id, fills the 'snapshot' and 'gxmin' on success. 'gxmin' is the
43+
// smallest xmin among all snapshots known to DTM. Returns INVALID_XID
4344
// otherwise.
44-
TransactionId DtmGlobalStartTransaction(int nParticipants, Snapshotshapshot);
45+
TransactionId DtmGlobalStartTransaction(int nParticipants, Snapshotsnapshot, TransactionId *gxmin);
4546

46-
// Asks the DTM for a fresh snapshot.
47-
void DtmGlobalGetSnapshot(TransactionId xid, Snapshot snapshot);
47+
// Asks the DTM for a fresh snapshot. Fills the 'snapshot' and 'gxmin' on
48+
// success. 'gxmin' is the smallest xmin among all snapshots known to DTM.
49+
void DtmGlobalGetSnapshot(TransactionId xid, Snapshot snapshot, TransactionId *gxmin);
4850

4951
// Commits transaction only once all participants have called this function,
5052
// does not change CLOG otherwise. Set 'wait' to 'true' if you want this call
@@ -135,6 +137,8 @@ The commands:
135137

136138
The DTM replies with '+' followed by a snapshot in the form:
137139

138-
<hex16 xmin><hex16 xmax><hex16 xcnt><hex16 xip[0]>...
140+
<hex16 gxmin><hex16 xmin><hex16 xmax><hex16 xcnt><hex16 xip[0]>...
141+
142+
Where 'gxmin' is the smallest xmin among all available snapshots.
139143

140144
In case of a failure, the DTM replies with '-'.

‎contrib/pg_xtm/dtmd/src/main.c‎

Lines changed: 25 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -225,6 +225,24 @@ static void gen_snapshot(Transaction *t) {
225225
snapshot_sort(s);
226226
}
227227

228+
staticxid_tget_global_xmin() {
229+
inti,j;
230+
xid_txmin=MAX_XID;
231+
Transaction*t;
232+
for (i=0;i<transactions_count;i++) {
233+
t=transactions+i;
234+
j=t->snapshots_count>MAX_SNAPSHOTS_PER_TRANS ?MAX_SNAPSHOTS_PER_TRANS :t->snapshots_count;
235+
while (--j >=0) {
236+
Snapshot*s=transaction_snapshot(t,j);
237+
if (s->xmin<xmin) {
238+
xmin=s->xmin;
239+
}
240+
// minor TODO: Use 'times_sent' to generate a bit greater xmin?
241+
}
242+
}
243+
returnxmin;
244+
}
245+
228246
staticchar*onbegin(void*stream,void*clientdata,cmd_t*cmd) {
229247
CHECK(
230248
transactions_count<MAX_TRANSACTIONS,
@@ -270,8 +288,8 @@ static char *onbegin(void *stream, void *clientdata, cmd_t *cmd) {
270288
returnstrdup("-");
271289
}
272290

273-
charhead[1+16+1];
274-
sprintf(head,"+%016llx",t->xid);
291+
charhead[1+16+16+1];
292+
sprintf(head,"+%016llx%016llx",t->xid,get_global_xmin());
275293

276294
transactions_count++;
277295

@@ -427,14 +445,18 @@ static char *onsnapshot(void *stream, void *clientdata, cmd_t *cmd) {
427445
gen_snapshot(t);
428446
}
429447

448+
charhead[1+16+1];
449+
sprintf(head,"+%016llx",get_global_xmin());
450+
430451
Snapshot*snap=transaction_snapshot(t,CLIENT_SNAPSENT(clientdata)++);
452+
snap->times_sent+=1;
431453
char*snapser=snapshot_serialize(snap);
432454

433455
// FIXME: Remote this assert if you do not have a barrier upon getting
434456
// snapshot in backends. The assert should indicate that situation :)
435457
assert(CLIENT_SNAPSENT(clientdata)==t->snapshots_count);
436458

437-
returndestructive_concat(strdup("+"),snapser);
459+
returndestructive_concat(strdup(head),snapser);
438460
}
439461

440462
staticchar*onstatus(void*stream,void*clientdata,cmd_t*cmd) {

‎contrib/pg_xtm/libdtm.c‎

Lines changed: 13 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -278,12 +278,14 @@ void DtmInitSnapshot(Snapshot snapshot)
278278
}
279279

280280
// Starts a new global transaction of nParticipants size. Returns the
281-
// transaction id and fills the snapshot on success. Returns INVALID_XID
281+
// transaction id, fills the 'snapshot' and 'gxmin' on success. 'gxmin' is the
282+
// smallest xmin among all snapshots known to DTM. Returns INVALID_XID
282283
// otherwise.
283-
TransactionIdDtmGlobalStartTransaction(intnParticipants,Snapshotsnapshot)
284+
TransactionIdDtmGlobalStartTransaction(intnParticipants,Snapshotsnapshot,TransactionId*gxmin)
284285
{
285286
boolok;
286287
xid_txid;
288+
xid_tnumber;
287289
DTMConndtm=GetConnection();
288290

289291
// query
@@ -293,6 +295,8 @@ TransactionId DtmGlobalStartTransaction(int nParticipants, Snapshot snapshot)
293295
if (!dtm_read_bool(dtm,&ok)) gotofailure;
294296
if (!ok) gotofailure;
295297
if (!dtm_read_hex16(dtm,&xid)) gotofailure;
298+
if (!dtm_read_hex16(dtm,&number)) gotofailure;
299+
*gxmin=number;
296300
if (!dtm_read_snapshot(dtm,snapshot)) gotofailure;
297301

298302
returnxid;
@@ -301,10 +305,12 @@ TransactionId DtmGlobalStartTransaction(int nParticipants, Snapshot snapshot)
301305
returnINVALID_XID;
302306
}
303307

304-
// Asks the DTM for a fresh snapshot.
305-
voidDtmGlobalGetSnapshot(TransactionIdxid,Snapshotsnapshot)
308+
// Asks the DTM for a fresh snapshot. Fills the 'snapshot' and 'gxmin' on
309+
// success. 'gxmin' is the smallest xmin among all snapshots known to DTM.
310+
voidDtmGlobalGetSnapshot(TransactionIdxid,Snapshotsnapshot,TransactionId*gxmin)
306311
{
307312
boolok;
313+
xid_tnumber;
308314
DTMConndtm=GetConnection();
309315

310316
assert(snapshot!=NULL);
@@ -316,6 +322,8 @@ void DtmGlobalGetSnapshot(TransactionId xid, Snapshot snapshot)
316322
if (!dtm_read_bool(dtm,&ok)) gotofailure;
317323
if (!ok) gotofailure;
318324

325+
if (!dtm_read_hex16(dtm,&number)) gotofailure;
326+
*gxmin=number;
319327
if (!dtm_read_snapshot(dtm,snapshot)) gotofailure;
320328
return;
321329
failure:
@@ -330,6 +338,7 @@ void DtmGlobalGetSnapshot(TransactionId xid, Snapshot snapshot)
330338
// Commits transaction only once all participants have called this function,
331339
// does not change CLOG otherwise. Set 'wait' to 'true' if you want this call
332340
// to return only after the transaction is considered finished by the DTM.
341+
// Returns the status on success, or -1 otherwise.
333342
XidStatusDtmGlobalSetTransStatus(TransactionIdxid,XidStatusstatus,boolwait)
334343
{
335344
boolok;

‎contrib/pg_xtm/libdtm.h‎

Lines changed: 6 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -11,12 +11,14 @@
1111
voidDtmInitSnapshot(Snapshotsnapshot);
1212

1313
// Starts a new global transaction of nParticipants size. Returns the
14-
// transaction id and fills the snapshot on success. Returns INVALID_XID
14+
// transaction id, fills the 'snapshot' and 'gxmin' on success. 'gxmin' is the
15+
// smallest xmin among all snapshots known to DTM. Returns INVALID_XID
1516
// otherwise.
16-
TransactionIdDtmGlobalStartTransaction(intnParticipants,Snapshotshapshot);
17+
TransactionIdDtmGlobalStartTransaction(intnParticipants,Snapshotsnapshot,TransactionId*gxmin);
1718

18-
// Asks the DTM for a fresh snapshot.
19-
voidDtmGlobalGetSnapshot(TransactionIdxid,Snapshotsnapshot);
19+
// Asks the DTM for a fresh snapshot. Fills the 'snapshot' and 'gxmin' on
20+
// success. 'gxmin' is the smallest xmin among all snapshots known to DTM.
21+
voidDtmGlobalGetSnapshot(TransactionIdxid,Snapshotsnapshot,TransactionId*gxmin);
2022

2123
// Commits transaction only once all participants have called this function,
2224
// does not change CLOG otherwise. Set 'wait' to 'true' if you want this call

‎contrib/pg_xtm/pg_dtm.c‎

Lines changed: 20 additions & 18 deletions
Original file line numberDiff line numberDiff line change
@@ -90,8 +90,8 @@ static TransactionManager DtmTM = { DtmGetTransactionStatus, DtmSetTransactionSt
9090

9191

9292
#defineXTM_TRACE(fmt, ...)
93-
#defineXTM_INFO(fmt, ...) fprintf(stderr, fmt, ## __VA_ARGS__)
94-
//#define XTM_INFO(fmt, ...)
93+
//#define XTM_INFO(fmt, ...) fprintf(stderr, fmt, ## __VA_ARGS__)
94+
#defineXTM_INFO(fmt, ...)
9595

9696
staticvoidDumpSnapshot(Snapshots,char*name)
9797
{
@@ -195,20 +195,24 @@ static void DtmMergeSnapshots(Snapshot dst, Snapshot src)
195195

196196
staticTransactionIdDtmGetOldestXmin(Relationrel,boolignoreVacuum)
197197
{
198-
TransactionIdxmin=GetOldestLocalXmin(rel,ignoreVacuum);
199-
#if0
200-
if (TransactionIdIsValid(DtmSnapshot.xmin)&&TransactionIdPrecedes(DtmSnapshot.xmin,xmin)) {
201-
xmin=DtmSnapshot.xmin;
198+
TransactionIdlocalXmin=GetOldestLocalXmin(rel,ignoreVacuum);
199+
TransactionIdglobalXmin=DtmMinXid;
200+
if (TransactionIdIsValid(globalXmin)) {
201+
globalXmin-=vacuum_defer_cleanup_age;
202+
if (!TransactionIdIsNormal(globalXmin)) {
203+
globalXmin=FirstNormalTransactionId;
204+
}
205+
if (TransactionIdPrecedes(globalXmin,localXmin)) {
206+
localXmin=globalXmin;
207+
}
202208
}
203-
#endif
204-
returnxmin;
209+
returnlocalXmin;
205210
}
206211

207212
staticvoidDtmUpdateRecentXmin(void)
208213
{
209214
TransactionIdxmin=DtmMinXid;//DtmSnapshot.xmin;
210-
211-
XTM_TRACE("XTM: DtmUpdateRecentXmin \n");
215+
XTM_INFO("XTM: DtmUpdateRecentXmin global xmin=%d, snapshot xmin %d\n",DtmMinXid,DtmSnapshot.xmin);
212216

213217
if (TransactionIdIsValid(xmin)) {
214218
xmin-=vacuum_defer_cleanup_age;
@@ -394,7 +398,6 @@ DtmGetNewTransactionId(bool isSubXact)
394398
* Extend pg_subtrans and pg_commit_ts too.
395399
*/
396400
if (TransactionIdFollowsOrEquals(xid,ShmemVariableCache->nextXid)) {
397-
fprintf(stderr,"Extend CLOG to %d\n",xid);
398401
ExtendCLOG(xid);
399402
ExtendCommitTs(xid);
400403
ExtendSUBTRANS(xid);
@@ -477,18 +480,17 @@ DtmGetNewTransactionId(bool isSubXact)
477480

478481
staticSnapshotDtmGetSnapshot(Snapshotsnapshot)
479482
{
480-
481483
if (TransactionIdIsValid(DtmNextXid)) {
482484
if (!DtmHasGlobalSnapshot) {
483485
DtmGlobalGetSnapshot(DtmNextXid,&DtmSnapshot,&DtmMinXid);
484486
}
485487
DtmMergeSnapshots(snapshot,&DtmSnapshot);
486-
if (!IsolationUsesXactSnapshot()) {
487-
DtmHasGlobalSnapshot= false;
488-
}
488+
if (!IsolationUsesXactSnapshot()) {
489+
DtmHasGlobalSnapshot= false;
490+
}
489491
}else {
490-
snapshot=GetLocalSnapshotData(snapshot);
491-
}
492+
snapshot=GetLocalSnapshotData(snapshot);
493+
}
492494
DtmUpdateRecentXmin();
493495
CurrentTransactionSnapshot=snapshot;
494496
returnsnapshot;
@@ -710,7 +712,7 @@ Datum dtm_join_transaction(PG_FUNCTION_ARGS)
710712
Assert(TransactionIdIsValid(DtmNextXid));
711713
XTM_INFO("%d: Join global transaction %d\n",getpid(),DtmNextXid);
712714

713-
DtmGlobalGetSnapshot(DtmNextXid,&DtmSnapshot);
715+
DtmGlobalGetSnapshot(DtmNextXid,&DtmSnapshot,&DtmMinXid);
714716

715717
DtmHasGlobalSnapshot= true;
716718
DtmIsGlobalTransaction= true;

‎src/backend/access/heap/pruneheap.c‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -98,7 +98,7 @@ heap_page_prune_opt(Relation relation, Buffer buffer)
9898
OldestXmin=RecentGlobalXmin;
9999
else
100100
OldestXmin=RecentGlobalDataXmin;
101-
fprintf(stderr,"PRUNEHEAP: xmin=%d\n",OldestXmin);
101+
//fprintf(stderr, "pid=%dPRUNEHEAP: xmin=%d\n", getpid(), OldestXmin);
102102
Assert(TransactionIdIsValid(OldestXmin));
103103

104104
/*

‎src/backend/access/heap/visibilitymap.c‎

Lines changed: 3 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -254,9 +254,10 @@ visibilitymap_set(Relation rel, BlockNumber heapBlk, Buffer heapBuf,
254254
Pagepage;
255255
char*map;
256256

257+
#if0
257258
fprintf(stderr,"Visibilitymap cutoff %d, RecentLocalDataXmin=%d\n",cutoff_xid,RecentGlobalDataXmin);
258-
return;
259-
259+
// return;
260+
#endif
260261
#ifdefTRACE_VISIBILITYMAP
261262
elog(DEBUG1,"vm_set %s %d",RelationGetRelationName(rel),heapBlk);
262263
#endif

‎src/backend/utils/time/tqual.c‎

Lines changed: 7 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -970,7 +970,7 @@ HeapTupleSatisfiesDirty(HeapTuple htup, Snapshot snapshot,
970970
* and more contention on the PGXACT array.
971971
*/
972972
bool
973-
_HeapTupleSatisfiesMVCC(HeapTuplehtup,Snapshotsnapshot,
973+
HeapTupleSatisfiesMVCC(HeapTuplehtup,Snapshotsnapshot,
974974
Bufferbuffer)
975975
{
976976
HeapTupleHeadertuple=htup->t_data;
@@ -1156,15 +1156,18 @@ _HeapTupleSatisfiesMVCC(HeapTuple htup, Snapshot snapshot,
11561156

11571157
return false;
11581158
}
1159-
#if1
1159+
#if0
11601160
bool
11611161
HeapTupleSatisfiesMVCC(HeapTuplehtup,Snapshotsnapshot,
11621162
Bufferbuffer)
11631163
{
11641164
boolresult=_HeapTupleSatisfiesMVCC(htup,snapshot,buffer);
11651165
HeapTupleHeadertuple=htup->t_data;
1166-
fprintf(stderr,"Transaction %d, [%d,%d) visibility check for tuple {%d,%d) = %d\n",
1167-
GetCurrentTransactionId(),snapshot->xmin,snapshot->xmax,HeapTupleHeaderGetRawXmin(tuple),HeapTupleHeaderGetRawXmax(tuple),result);
1166+
TransactionIdcurxid=GetCurrentTransactionId();
1167+
if (TransactionIdIsNormal(curxid)) {
1168+
fprintf(stderr,"pid=%d Transaction %d, [%d,%d) visibility check for tuple {%d,%d) = %d\n",
1169+
getpid(),curxid,snapshot->xmin,snapshot->xmax,HeapTupleHeaderGetRawXmin(tuple),HeapTupleHeaderGetRawXmax(tuple),result);
1170+
}
11681171
returnresult;
11691172
}
11701173
#endif

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp