/*
* NOTE: The ProcArrayLock must already be held.
*/
void
LocalDistribXact_StartOnMaster(
DistributedTransactionTimeStamp newDistribTimeStamp,
DistributedTransactionId newDistribXid,
TransactionId *newLocalXid,
LocalDistribXactData *masterLocalDistribXactRef)
{
LocalDistribXactData *ele = masterLocalDistribXactRef;
TransactionId localXid;
Assert(newDistribTimeStamp != 0);
Assert(newDistribXid != InvalidDistributedTransactionId);
Assert(newLocalXid != NULL);
Assert(masterLocalDistribXactRef != NULL);
localXid = GetNewTransactionId(false, false);
// NOT subtrans, DO NOT Set PROC struct xid;
ele->distribTimeStamp = newDistribTimeStamp;
ele->distribXid = newDistribXid;
ele->state = LOCALDISTRIBXACT_STATE_ACTIVE;
MyProc->xid = localXid;
*newLocalXid = localXid;
}
void
LocalDistribXact_StartOnSegment(
DistributedTransactionTimeStamp newDistribTimeStamp,
DistributedTransactionId newDistribXid,
TransactionId *newLocalXid)
{
LocalDistribXactData *ele = &MyProc->localDistribXactData;
TransactionId localXid;
MIRRORED_LOCK_DECLARE;
Assert(newDistribTimeStamp != 0);
Assert(newDistribXid != InvalidDistributedTransactionId);
Assert(newLocalXid != NULL);
MIRRORED_LOCK;
LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
localXid = GetNewTransactionId(false, false);
// NOT subtrans, DO NOT Set PROC struct xid;
ele->distribTimeStamp = newDistribTimeStamp;
ele->distribXid = newDistribXid;
ele->state = LOCALDISTRIBXACT_STATE_ACTIVE;
MyProc->xid = localXid;
*newLocalXid = localXid;
LWLockRelease(ProcArrayLock);
MIRRORED_UNLOCK;
}
/*
* StartTransaction
*/
static void
StartTransaction(void)
{
TransactionState s = CurrentTransactionState;
/*
* check the current transaction state
*/
if (s->state != TRANS_DEFAULT)
elog(WARNING, "StartTransaction and not in default state");
/*
* set the current transaction state information appropriately during
* start processing
*/
s->state = TRANS_START;
/*
* Make sure we've freed any old snapshot, and reset xact state variables
*/
FreeXactSnapshot();
XactIsoLevel = DefaultXactIsoLevel;
XactReadOnly = DefaultXactReadOnly;
/*
* generate a new transaction id
*/
s->transactionIdData = GetNewTransactionId();
XactLockTableInsert(s->transactionIdData);
/*
* initialize current transaction state fields
*/
s->commandId = FirstCommandId;
s->startTime = GetCurrentAbsoluteTimeUsec(&(s->startTimeUsec));
/*
* initialize the various transaction subsystems
*/
AtStart_Memory();
AtStart_Cache();
AtStart_Locks();
/*
* Tell the trigger manager to we're starting a transaction
*/
DeferredTriggerBeginXact();
/*
* done with start processing, set current transaction state to "in
* progress"
*/
s->state = TRANS_INPROGRESS;
}
/*
* Add local XID for any new distributed transactions.
*/
void
PreallocLocalXidsForOpenDistributedTransactions(DistributedTransactionId *gxidArray, uint32 count)
{
int i;
DistributedTransactionId gxid;
int pageno;
int entryno;
int slotno;
DISTRIBUTEDXIDMAP_ENTRY *ptr;
LWLockAcquire(DistributedXidMapControlLock, LW_EXCLUSIVE);
for (i = 0; i < count; i++)
{
gxid = gxidArray[i];
pageno = DistributedTransactionIdToPage(gxid);
entryno = DistributedTransactionIdToEntry(gxid);
elog((Debug_print_full_dtm ? LOG : DEBUG5), "PreallocLocalXidsForOpenDistributedTransactions: gxidArray[%d] is %u (pageno %d, entryno %d)",
i, gxid, pageno, entryno);
if (pageno > *shmDistributedXidMapHighestPageNo)
{
/*
* Zero out the new page(s).
*/
DistributedXidMapMakeMorePages(pageno);
}
if (*shmMaxDistributedXid < gxid)
{
*shmMaxDistributedXid = gxid;
}
slotno = SimpleLruReadPage(DistributedXidMapCtl, pageno, InvalidTransactionId);
ptr = (DISTRIBUTEDXIDMAP_ENTRY *) DistributedXidMapCtl->shared->page_buffer[slotno];
ptr += entryno;
if (ptr->state == DISTRIBUTEDXIDMAP_STATE_NONE)
{
ptr->state = DISTRIBUTEDXIDMAP_STATE_PREALLOC_FOR_OPEN_TRANS;
ptr->pid = MyProcPid;
ptr->xid = GetNewTransactionId(false, false); // NOT subtrans, DO NOT Set PROC struct xid
DistributedXidMapCtl->shared->page_dirty[slotno] = true;
elog((Debug_print_full_dtm ? LOG : DEBUG5), "PreallocLocalXidsForOpenDistributedTransactions: Allocated local XID = %u for global XID = %u",
ptr->xid, gxid);
}
}
LWLockRelease(DistributedXidMapControlLock);
}
/*
* Get the local XID associated with a distributed transaction. We will
* allocate the local XID and assign its value in the map if necessary.
*/
void
AllocOrGetLocalXidForStartDistributedTransaction(DistributedTransactionId gxid, TransactionId *xid)
{
int pageno = DistributedTransactionIdToPage(gxid);
int entryno = DistributedTransactionIdToEntry(gxid);
int slotno;
DISTRIBUTEDXIDMAP_ENTRY *ptr;
Assert(gxid != InvalidDistributedTransactionId);
Assert(xid != NULL);
elog((Debug_print_full_dtm ? LOG : DEBUG5), "Entering AllocOrGetLocalXidForStartDistributedTransaction with distributed xid = %d (pageno = %d, entryno = %d, DistributedXidMapHighestPageNo = %d)",
gxid, pageno, entryno, *shmDistributedXidMapHighestPageNo);
LWLockAcquire(DistributedXidMapControlLock, LW_EXCLUSIVE);
if (pageno > *shmDistributedXidMapHighestPageNo)
{
/*
* Zero out the new page(s).
*/
DistributedXidMapMakeMorePages(pageno);
}
if (*shmMaxDistributedXid < gxid)
{
*shmMaxDistributedXid = gxid;
}
slotno = SimpleLruReadPage(DistributedXidMapCtl, pageno, InvalidTransactionId);
ptr = (DISTRIBUTEDXIDMAP_ENTRY *) DistributedXidMapCtl->shared->page_buffer[slotno];
ptr += entryno;
if (ptr->state == DISTRIBUTEDXIDMAP_STATE_NONE)
{
/*
* Need to allocate a local XID and assign the map entry.
*/
*xid = GetNewTransactionId(false, false); // NOT subtrans, DO NOT Set PROC struct xid
ptr->state = DISTRIBUTEDXIDMAP_STATE_IN_PROGRESS;
ptr->pid = MyProcPid;
ptr->xid = *xid;
elog((Debug_print_full_dtm ? LOG : DEBUG5), "AllocOrGetLocalXidForStartDistributedTransaction allocated local XID = %d", *xid);
DistributedXidMapCtl->shared->page_dirty[slotno] = true;
}
else if (ptr->state == DISTRIBUTEDXIDMAP_STATE_PREALLOC_FOR_OPEN_TRANS)
{
/*
* The local XID was pre-allocated by another QE when it
* received a distributed snapshot that listed the distributed transaction
* in its in-doubt list.
*/
ptr->state = DISTRIBUTEDXIDMAP_STATE_IN_PROGRESS;
ptr->pid = MyProcPid;
*xid = ptr->xid;
elog((Debug_print_full_dtm ? LOG : DEBUG5), "AllocOrGetLocalXidForStartDistributedTransaction found pre-allocated local XID = %d", *xid);
DistributedXidMapCtl->shared->page_dirty[slotno] = true;
}
else
{
int pid = ptr->pid;
TransactionId reuseXid = ptr->xid;
DistributedMapState state = ptr->state;
LWLockRelease(DistributedXidMapControlLock);
elog(ERROR,"Attempting re-use local xid %u and distributed xid %u again (original start pid was %d, state = %s, pageno %d, entryno %d, slotno %d)",
reuseXid, gxid, pid, DistributedMapStateToString(state), pageno, entryno, slotno);
}
SetProcXid(*xid, gxid);
LWLockRelease(DistributedXidMapControlLock);
}