func (fo *frameOpen) createRollClientTxn() (*msgs.ClientTxn, map[common.VarUUId]*common.Positions) {
var origWrite *msgs.Action
vUUIdBytes := fo.v.UUId[:]
for idx, l := 0, fo.frameTxnActions.Len(); idx < l; idx++ {
action := fo.frameTxnActions.At(idx)
if bytes.Equal(action.VarId(), vUUIdBytes) {
origWrite = &action
break
}
}
seg := capn.NewBuffer(nil)
ctxn := msgs.NewClientTxn(seg)
ctxn.SetRetry(false)
actions := msgs.NewClientActionList(seg, 1)
ctxn.SetActions(actions)
action := actions.At(0)
action.SetVarId(fo.v.UUId[:])
action.SetRoll()
roll := action.Roll()
roll.SetVersion(fo.frameTxnId[:])
var refs msgs.VarIdPos_List
switch origWrite.Which() {
case msgs.ACTION_WRITE:
ow := origWrite.Write()
roll.SetValue(ow.Value())
refs = ow.References()
case msgs.ACTION_READWRITE:
owr := origWrite.Readwrite()
roll.SetValue(owr.Value())
refs = owr.References()
case msgs.ACTION_CREATE:
oc := origWrite.Create()
roll.SetValue(oc.Value())
refs = oc.References()
case msgs.ACTION_ROLL:
owr := origWrite.Roll()
roll.SetValue(owr.Value())
refs = owr.References()
default:
panic(fmt.Sprintf("%v unexpected action type when building roll: %v", fo.frame, origWrite.Which()))
}
posMap := make(map[common.VarUUId]*common.Positions)
posMap[*fo.v.UUId] = fo.v.positions
refVarList := seg.NewDataList(refs.Len())
roll.SetReferences(refVarList)
for idx, l := 0, refs.Len(); idx < l; idx++ {
ref := refs.At(idx)
vUUId := common.MakeVarUUId(ref.Id())
pos := common.Positions(ref.Positions())
posMap[*vUUId] = &pos
refVarList.Set(idx, vUUId[:])
}
return &ctxn, posMap
}
func (bra *badReadAction) combine(action *msgs.Action, rmBal *rmBallot, txnId *common.TxnId, clockElem uint64) {
newActionType := action.Which()
braActionType := bra.action.Which()
switch {
case braActionType != msgs.ACTION_READ && newActionType != msgs.ACTION_READ:
// They're both writes in some way. Just order the txns
if clockElem > bra.clockElem || (clockElem == bra.clockElem && bra.txnId.LessThan(txnId)) {
bra.set(action, rmBal, txnId, clockElem)
}
case braActionType == msgs.ACTION_READ && newActionType == msgs.ACTION_READ:
braRead := bra.action.Read()
newRead := action.Read()
clockElem--
// If they read the same version, we really don't care.
if !bytes.Equal(braRead.Version(), newRead.Version()) {
// They read different versions, but which version was the latter?
if clockElem > bra.clockElem {
bra.set(action, rmBal, common.MakeTxnId(newRead.Version()), clockElem)
}
}
case braActionType == msgs.ACTION_READ:
if bytes.Equal(bra.txnId[:], txnId[:]) {
// The write will obviously be in the past of the
// existing read, but it's better to have the write
// as we can update the client with the actual
// value.
bra.set(action, rmBal, txnId, clockElem)
} else if clockElem > bra.clockElem {
// The write is after than the read
bra.set(action, rmBal, txnId, clockElem)
}
default: // Existing is not a read, but new is a read.
newRead := action.Read()
clockElem--
// If the read is a read of the existing write, better to keep the write
if !bytes.Equal(bra.txnId[:], newRead.Version()) {
if clockElem > bra.clockElem {
// The read must be of some value which was written after our existing write.
bra.set(action, rmBal, common.MakeTxnId(newRead.Version()), clockElem)
}
}
}
}
func GetTopologyFromLocalDatabase(cm *ConnectionManager, varDispatcher *eng.VarDispatcher, lc *client.LocalConnection) (*server.Topology, error) {
if paxos.IsDatabaseClean(varDispatcher) {
return nil, nil
}
for {
seg := capn.NewBuffer(nil)
txn := msgs.NewTxn(seg)
txn.SetSubmitter(uint32(cm.RMId))
txn.SetSubmitterBootCount(cm.BootCount)
actions := msgs.NewActionList(seg, 1)
txn.SetActions(actions)
action := actions.At(0)
action.SetVarId(server.TopologyVarUUId[:])
action.SetRead()
action.Read().SetVersion(common.VersionZero[:])
allocs := msgs.NewAllocationList(seg, 1)
txn.SetAllocations(allocs)
alloc := allocs.At(0)
alloc.SetRmId(uint32(cm.RMId))
alloc.SetActive(cm.BootCount)
indices := seg.NewUInt16List(1)
alloc.SetActionIndices(indices)
indices.Set(0, 0)
txn.SetFInc(1)
txn.SetTopologyVersion(0)
result, err := lc.RunTransaction(&txn, true, cm.RMId)
if err != nil {
return nil, err
}
if result == nil {
return nil, nil // shutting down
}
if result.Which() == msgs.OUTCOME_COMMIT {
return nil, fmt.Errorf("Internal error: read of topology version 0 failed to abort")
}
abort := result.Abort()
if abort.Which() == msgs.OUTCOMEABORT_RESUBMIT {
continue
}
abortUpdates := abort.Rerun()
if abortUpdates.Len() != 1 {
return nil, fmt.Errorf("Internal error: read of topology version 0 gave multiple updates")
}
update := abortUpdates.At(0)
dbversion := common.MakeTxnId(update.TxnId())
updateActions := update.Actions()
if updateActions.Len() != 1 && updateActions.Len() != 2 {
return nil, fmt.Errorf("Internal error: read of topology version 0 gave multiple actions: %v", updateActions.Len())
}
var updateAction *msgs.Action
for idx, l := 0, updateActions.Len(); idx < l; idx++ {
action := updateActions.At(idx)
if bytes.Equal(action.VarId(), server.TopologyVarUUId[:]) {
updateAction = &action
break
}
}
if updateAction == nil {
return nil, fmt.Errorf("Internal error: unable to find action for topology from read of topology version 0")
}
if updateAction.Which() != msgs.ACTION_WRITE {
return nil, fmt.Errorf("Internal error: read of topology version 0 gave non-write action")
}
write := updateAction.Write()
var rootPtr *msgs.VarIdPos
if refs := write.References(); refs.Len() == 1 {
root := refs.At(0)
rootPtr = &root
}
return server.TopologyDeserialize(dbversion, rootPtr, write.Value())
}
}
func AddSelfToTopology(cm *ConnectionManager, conns map[common.RMId]paxos.Connection, topology *server.Topology, fInc int, active, passive []common.RMId, lc *client.LocalConnection) (*server.Topology, bool, error) {
seg := capn.NewBuffer(nil)
txn := msgs.NewTxn(seg)
txn.SetSubmitter(uint32(cm.RMId))
txn.SetSubmitterBootCount(cm.BootCount)
actions := msgs.NewActionList(seg, 1)
txn.SetActions(actions)
topologyAction := actions.At(0)
topologyAction.SetVarId(server.TopologyVarUUId[:])
topologyAction.SetReadwrite()
rw := topologyAction.Readwrite()
rw.SetVersion(topology.DBVersion[:])
rw.SetValue(topology.Serialize())
if topology.RootVarUUId == nil {
rw.SetReferences(msgs.NewVarIdPosList(seg, 0))
} else {
refs := msgs.NewVarIdPosList(seg, 1)
rw.SetReferences(refs)
varIdPos := refs.At(0)
varIdPos.SetId(topology.RootVarUUId[:])
varIdPos.SetPositions((capn.UInt8List)(*topology.RootPositions))
}
allocs := msgs.NewAllocationList(seg, len(topology.AllRMs))
txn.SetAllocations(allocs)
idx := 0
for listIdx, rmIds := range [][]common.RMId{active, passive} {
for _, rmId := range rmIds {
alloc := allocs.At(idx)
idx++
alloc.SetRmId(uint32(rmId))
if listIdx == 0 {
alloc.SetActive(conns[rmId].BootCount())
} else {
alloc.SetActive(0)
}
indices := seg.NewUInt16List(1)
alloc.SetActionIndices(indices)
indices.Set(0, 0)
}
}
txn.SetFInc(uint8(fInc))
txn.SetTopologyVersion(topology.Version)
result, err := lc.RunTransaction(&txn, true, active...)
if err != nil || result == nil {
return nil, false, err
}
txnId := common.MakeTxnId(result.Txn().Id())
if result.Which() == msgs.OUTCOME_COMMIT {
topology.DBVersion = txnId
server.Log("Topology Txn Committed ok with txnId", topology.DBVersion)
return topology, false, nil
}
abort := result.Abort()
server.Log("Topology Txn Aborted", txnId)
if abort.Which() == msgs.OUTCOMEABORT_RESUBMIT {
return nil, true, nil
}
abortUpdates := abort.Rerun()
if abortUpdates.Len() != 1 {
return nil, false, fmt.Errorf("Internal error: readwrite of topology gave %v updates (1 expected)", abortUpdates.Len())
}
update := abortUpdates.At(0)
dbversion := common.MakeTxnId(update.TxnId())
updateActions := update.Actions()
if updateActions.Len() != 1 && updateActions.Len() != 2 {
return nil, false, fmt.Errorf("Internal error: readwrite of topology gave multiple actions: %v", updateActions.Len())
}
var updateAction *msgs.Action
for idx, l := 0, updateActions.Len(); idx < l; idx++ {
action := updateActions.At(idx)
if bytes.Equal(action.VarId(), server.TopologyVarUUId[:]) {
updateAction = &action
break
}
}
if updateAction == nil {
return nil, false, fmt.Errorf("Internal error: unable to find action for topology from readwrite")
}
if updateAction.Which() != msgs.ACTION_WRITE {
return nil, false, fmt.Errorf("Internal error: readwrite of topology gave non-write action")
}
write := updateAction.Write()
var rootVarPos *msgs.VarIdPos
if refs := write.References(); refs.Len() == 1 {
root := refs.At(0)
rootVarPos = &root
} else if refs.Len() > 1 {
return nil, false, fmt.Errorf("Internal error: readwrite of topology had wrong references: %v", refs.Len())
}
topology, err = server.TopologyDeserialize(dbversion, rootVarPos, write.Value())
if err != nil {
return nil, false, err
}
found := false
for _, rmId := range topology.AllRMs {
if found = rmId == cm.RMId; found {
server.Log("Topology Txn Aborted, but found self in topology.")
return topology, false, nil
}
}
return topology, true, nil
}