Remove some obsolete context handling

batch.go

@@ -84,11 +84,6 @@ func (b *Batch) Send(ctx context.Context) error {
 
 	b.ctx = ctx
 
-	err := b.conn.waitForPreviousCancelQuery(ctx)
-	if err != nil {
-		return err
-	}
-
 	batch := &pgconn.Batch{}
 
 	for _, bi := range b.items {

conn.go

@@ -76,8 +76,7 @@ type Conn struct {
 	status       byte // One of connStatus* constants
 	causeOfDeath error
 
-	cancelQueryCompleted chan struct{}
-	lastStmtSent         bool
+	lastStmtSent bool
 
 	// context support
 	ctxInProgress bool
@@ -190,8 +189,6 @@ func connect(ctx context.Context, config *ConnConfig, connInfo *pgtype.ConnInfo)
 	}
 
 	c.preparedStatements = make(map[string]*PreparedStatement)
-	c.cancelQueryCompleted = make(chan struct{})
-	close(c.cancelQueryCompleted)
 	c.doneChan = make(chan struct{})
 	c.closedChan = make(chan error)
 	c.wbuf = make([]byte, 0, 1024)
@@ -487,11 +484,6 @@ func (c *Conn) Prepare(name, sql string) (ps *PreparedStatement, err error) {
 // name and sql arguments. This allows a code path to PrepareEx and Query/Exec without
 // concern for if the statement has already been prepared.
 func (c *Conn) PrepareEx(ctx context.Context, name, sql string, opts *PrepareExOptions) (ps *PreparedStatement, err error) {
-	err = c.waitForPreviousCancelQuery(ctx)
-	if err != nil {
-		return nil, err
-	}
-
 	if name != "" {
 		if ps, ok := c.preparedStatements[name]; ok && ps.SQL == sql {
 			return ps, nil
@@ -552,21 +544,7 @@ func (c *Conn) Deallocate(name string) error {
 
 // TODO - consider making this public
 func (c *Conn) deallocateContext(ctx context.Context, name string) (err error) {
-	err = c.waitForPreviousCancelQuery(ctx)
-	if err != nil {
-		return err
-	}
-
-	err = c.initContext(ctx)
-	if err != nil {
-		return err
-	}
-	defer func() {
-		err = c.termContext(err)
-	}()
-
 	delete(c.preparedStatements, name)
-
 	_, err = c.pgConn.Exec(ctx, "deallocate "+quoteIdentifier(name)).ReadAll()
 	return err
 }
@@ -740,81 +718,6 @@ func (c *Conn) Ping(ctx context.Context) error {
 	return err
 }
 
-func (c *Conn) initContext(ctx context.Context) error {
-	if c.ctxInProgress {
-		return errors.New("ctx already in progress")
-	}
-
-	if ctx.Done() == nil {
-		return nil
-	}
-
-	select {
-	case <-ctx.Done():
-		return ctx.Err()
-	default:
-	}
-
-	c.ctxInProgress = true
-
-	go c.contextHandler(ctx)
-
-	return nil
-}
-
-func (c *Conn) termContext(opErr error) error {
-	if !c.ctxInProgress {
-		return opErr
-	}
-
-	var err error
-
-	select {
-	case err = <-c.closedChan:
-		if opErr == nil {
-			err = nil
-		}
-	case c.doneChan <- struct{}{}:
-		err = opErr
-	}
-
-	c.ctxInProgress = false
-	return err
-}
-
-func (c *Conn) contextHandler(ctx context.Context) {
-	select {
-	case <-ctx.Done():
-		c.closedChan <- ctx.Err()
-	case <-c.doneChan:
-	}
-}
-
-// WaitUntilReady will return when the connection is ready for another query
-func (c *Conn) WaitUntilReady(ctx context.Context) error {
-	err := c.waitForPreviousCancelQuery(ctx)
-	if err != nil {
-		return err
-	}
-	return nil
-}
-
-func (c *Conn) waitForPreviousCancelQuery(ctx context.Context) error {
-	c.mux.Lock()
-	completeCh := c.cancelQueryCompleted
-	c.mux.Unlock()
-	select {
-	case <-completeCh:
-		if err := c.pgConn.Conn().SetDeadline(time.Time{}); err != nil {
-			c.Close() // Close connection if unable to disable deadline
-			return err
-		}
-		return nil
-	case <-ctx.Done():
-		return ctx.Err()
-	}
-}
-
 func connInfoFromRows(rows *Rows, err error) (map[string]pgtype.OID, error) {
 	if err != nil {
 		return nil, err
@@ -854,10 +757,6 @@ func (c *Conn) LastStmtSent() bool {
 // positionally from the sql string as $1, $2, etc.
 func (c *Conn) Exec(ctx context.Context, sql string, arguments ...interface{}) (pgconn.CommandTag, error) {
 	c.lastStmtSent = false
-	err := c.waitForPreviousCancelQuery(ctx)
-	if err != nil {
-		return "", err
-	}
 
 	if err := c.lock(); err != nil {
 		return "", err

query.go

@@ -356,12 +356,6 @@ func (c *Conn) Query(ctx context.Context, sql string, optionsAndArgs ...interfac
 		args:      args,
 	}
 
-	err = c.waitForPreviousCancelQuery(ctx)
-	if err != nil {
-		rows.fatal(err)
-		return rows, err
-	}
-
 	if err := c.lock(); err != nil {
 		rows.fatal(err)
 		return rows, err