Avoid race condition in chaining prefined errors

CHANGELOG.md

@@ -7,7 +7,8 @@
   * **Fixes**
 
     - Handle lack of key digests in `BatchExists` command.
-    - Allow and handle nil arguments for `chainError`
+    - Allow and handle nil arguments for `chainError`.
+    - Avoid race condition in chaining prefined errors.
 
 ## May 10 2021: v5.0.0
   This is a major feature release. It is also a major breaking release. We have adopted Go's module system as recommended by the Go authors, so the new release moves the active branch to `v5`.

client.go

@@ -321,7 +321,7 @@ func (clnt *Client) BatchExists(policy *BatchPolicy, keys []*Key) ([]bool, Error
 	cmd := newBatchCommandExists(nil, nil, policy, keys, existsArray)
 	filteredOut, err := clnt.batchExecute(policy, batchNodes, cmd)
 	if filteredOut > 0 {
-		err = chainErrors(ErrFilteredOut, err)
+		err = chainErrors(ErrFilteredOut.err(), err)
 	}
 
 	if err != nil {
@@ -398,7 +398,7 @@ func (clnt *Client) BatchGet(policy *BatchPolicy, keys []*Key, binNames ...strin
 	}
 
 	if filteredOut > 0 {
-		err = chainErrors(ErrFilteredOut, err)
+		err = chainErrors(ErrFilteredOut.err(), err)
 	}
 
 	return records, err
@@ -426,7 +426,7 @@ func (clnt *Client) BatchGetComplex(policy *BatchPolicy, records []*BatchRead) E
 	}
 
 	if filteredOut > 0 {
-		err = chainErrors(ErrFilteredOut, err)
+		err = chainErrors(ErrFilteredOut.err(), err)
 	}
 
 	return err
@@ -456,7 +456,7 @@ func (clnt *Client) BatchGetHeader(policy *BatchPolicy, keys []*Key) ([]*Record,
 	}
 
 	if filteredOut > 0 {
-		err = chainErrors(ErrFilteredOut, err)
+		err = chainErrors(ErrFilteredOut.err(), err)
 	}
 
 	return records, err

client_reflect.go

@@ -121,7 +121,7 @@ func (clnt *Client) BatchGetObjects(policy *BatchPolicy, keys []*Key, objects []
 	}
 
 	if filteredOut > 0 {
-		err = chainErrors(ErrFilteredOut, err)
+		err = chainErrors(ErrFilteredOut.err(), err)
 	}
 
 	return objectsFound, err
@@ -207,7 +207,7 @@ func (clnt *Client) scanNodeObjects(policy *ScanPolicy, node *Node, recordset *R
 // If the policy is nil, the default relevant policy will be used.
 func (clnt *Client) QueryPartitionObjects(policy *QueryPolicy, statement *Statement, objChan interface{}, partitionFilter *PartitionFilter) (*Recordset, Error) {
 	if statement.Filter != nil {
-		return nil, ErrPartitionScanQueryNotSupported
+		return nil, ErrPartitionScanQueryNotSupported.err()
 	}
 
 	policy = clnt.getUsableQueryPolicy(policy)

command.go

@@ -1986,7 +1986,7 @@ func (cmd *baseCommand) executeAt(ifc command, policy *BasePolicy, isRead bool,
 
 		// too many retries
 		if (policy.MaxRetries <= 0 && iterations > 0) || (policy.MaxRetries > 0 && iterations > policy.MaxRetries) {
-			return chainErrors(ErrMaxRetriesExceeded, errChain).iter(iterations).setInDoubt(isRead, commandSentCounter)
+			return chainErrors(ErrMaxRetriesExceeded.err(), errChain).iter(iterations).setInDoubt(isRead, commandSentCounter)
 		}
 
 		// Sleep before trying again, after the first iteration
@@ -2176,7 +2176,7 @@ func (cmd *baseCommand) executeAt(ifc command, policy *BasePolicy, isRead bool,
 	}
 
 	// execution timeout
-	errChain = chainErrors(ErrTimeout, errChain).iter(iterations)
+	errChain = chainErrors(ErrTimeout.err(), errChain).iter(iterations)
 	return errChain
 }
 

error.go

@@ -180,8 +180,6 @@ func (ase *AerospikeError) wrap(err error) Error {
 	return ase
 }
 
-// chain wraps an error inside a new error. The new error cannot be nil.
-// if the old error is nil, the new error will be returned.
 func (ase *AerospikeError) iter(i int) Error {
 	if ase == nil {
 		return nil

node.go

@@ -425,22 +425,22 @@ func (nd *Node) getConnection(deadline time.Time, timeout time.Duration) (conn *
 // This is more or less a copy of the logic in the beginning of newConnection function.
 func (nd *Node) newConnectionAllowed() Error {
 	if !nd.active.Get() {
-		return ErrServerNotAvailable
+		return ErrServerNotAvailable.err()
 	}
 
 	// if connection count is limited and enough connections are already created, don't create a new one
 	cc := nd.connectionCount.IncrementAndGet()
 	defer nd.connectionCount.DecrementAndGet()
 	if nd.cluster.clientPolicy.LimitConnectionsToQueueSize && cc > nd.cluster.clientPolicy.ConnectionQueueSize {
-		return ErrTooManyConnectionsForNode
+		return ErrTooManyConnectionsForNode.err()
 	}
 
 	// Check for opening connection threshold
 	if nd.cluster.clientPolicy.OpeningConnectionThreshold > 0 {
 		ct := nd.cluster.connectionThreshold.IncrementAndGet()
 		defer nd.cluster.connectionThreshold.DecrementAndGet()
 		if ct > nd.cluster.clientPolicy.OpeningConnectionThreshold {
-			return ErrTooManyOpeningConnections
+			return ErrTooManyOpeningConnections.err()
 		}
 	}
 
@@ -537,7 +537,7 @@ func (nd *Node) getConnectionWithHint(deadline time.Time, timeout time.Duration,
 		if err = nd.newConnectionAllowed(); err == nil {
 			go nd.makeConnectionForPool(hint)
 		}
-		return nil, ErrConnectionPoolEmpty
+		return nil, ErrConnectionPoolEmpty.err()
 	}
 
 	if err = conn.SetTimeout(deadline, timeout); err != nil {