Only abort tx's when last connection is closed

Also: convert rest of panic isn't ordinary errors

Author: reductionista

pkg/pg/txdb.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"database/sql"
 	"database/sql/driver"
-	"flag"
 	"fmt"
 	"io"
 	"net/url"
@@ -34,18 +33,14 @@ import (
 // store to use the raw DialectPostgres dialect and setup a one-use database.
 // See heavyweight.FullTestDB() as a convenience function to help you do this,
 // but please use sparingly because as it's name implies, it is expensive.
-func RegisterTxDb(ctx context.Context, dbURL string) error {
+func RegisterTxDb(dbURL string) error {
 	drivers := sql.Drivers()
 	for _, driver := range drivers {
 		if driver == string(TransactionWrappedPostgres) {
 			// TxDB driver already registered
 			return nil
 		}
 	}
-	testing.Init()
-	if !flag.Parsed() {
-		flag.Parse()
-	}
 	if testing.Short() {
 		// -short tests don't need a DB
 		return nil
@@ -60,15 +55,10 @@ func RegisterTxDb(ctx context.Context, dbURL string) error {
 	if !strings.HasSuffix(parsed.Path, "_test") {
 		return fmt.Errorf("cannot run tests against database named `%s`. Note that the test database MUST end in `_test` to differentiate from a possible production DB. HINT: Try postgresql://postgres@localhost:5432/chainlink_test?sslmode=disable", parsed.Path[1:])
 	}
-	abort := make(chan struct{})
-	go func() {
-		<-ctx.Done()
-		abort <- struct{}{} // abort all queries when context is cancelled
-	}()
 
 	name := string(TransactionWrappedPostgres)
 	sql.Register(name, &txDriver{
-		abort: abort,
+		abort: make(chan struct{}),
 		dbURL: dbURL,
 		conns: make(map[string]*conn),
 	})
@@ -85,7 +75,7 @@ var _ driver.SessionResetter = &conn{}
 // When `Close` is called, transaction is rolled back.
 type txDriver struct {
 	sync.Mutex
-	abort <-chan struct{}
+	abort chan struct{}
 	db    *sql.DB
 	conns map[string]*conn
 
@@ -130,6 +120,7 @@ func (d *txDriver) deleteConn(c *conn) error {
 	}
 	delete(d.conns, c.dsn)
 	if len(d.conns) == 0 && d.db != nil {
+		close(d.abort)
 		if err := d.db.Close(); err != nil {
 			return err
 		}
@@ -152,7 +143,7 @@ func (c *conn) Begin() (driver.Tx, error) {
 	c.Lock()
 	defer c.Unlock()
 	if c.closed {
-		panic("conn is closed")
+		return nil, fmt.Errorf("conn is closed")
 	}
 	// Begin is a noop because the transaction was already opened
 	return tx{c.tx}, nil
@@ -177,7 +168,7 @@ func (c *conn) PrepareContext(_ context.Context, query string) (driver.Stmt, err
 	c.Lock()
 	defer c.Unlock()
 	if c.closed {
-		panic("conn is closed")
+		return nil, fmt.Errorf("conn is closed")
 	}
 
 	// It is not safe to give the passed in context to the tx directly
@@ -226,7 +217,7 @@ func (c *conn) QueryContext(ctx context.Context, query string, args []driver.Nam
 	c.Lock()
 	defer c.Unlock()
 	if c.closed {
-		panic("conn is closed")
+		return nil, fmt.Errorf("conn is closed")
 	}
 
 	ctx, cancel := utils.ContextFromChan(c.abort)
@@ -277,38 +268,43 @@ func (c *conn) tryOpen() bool {
 // Drivers must ensure all network calls made by Close
 // do not block indefinitely (e.g. apply a timeout).
 func (c *conn) Close() (err error) {
-	if !c.close() {
-		return
+	newlyClosed, err := c.close()
+	if err != nil {
+		return err
+	}
+	if !newlyClosed {
+		return nil
 	}
+
 	// Wait to remove self to avoid nesting locks.
-	if err := c.removeSelf(); err != nil {
-		panic(err)
+	if err = c.removeSelf(); err != nil {
+		return err
 	}
 	return
 }
 
-func (c *conn) close() bool {
+func (c *conn) close() (bool, error) {
 	c.Lock()
 	defer c.Unlock()
 	if c.closed {
 		// Double close, should be a safe to make this a noop
 		// PGX allows double close
 		// See: https://github.com/jackc/pgx/blob/a457da8bffa4f90ad672fa093ee87f20cf06687b/conn.go#L249
-		return false
+		return false, nil
 	}
 
 	c.opened--
 	if c.opened > 0 {
-		return false
+		return false, nil
 	}
 	if c.tx != nil {
 		if err := c.tx.Rollback(); err != nil {
-			panic(err)
+			return false, err
 		}
 		c.tx = nil
 	}
 	c.closed = true
-	return true
+	return true, nil
 }
 
 type tx struct {
@@ -335,7 +331,7 @@ func (s stmt) Exec(args []driver.Value) (driver.Result, error) {
 	s.conn.Lock()
 	defer s.conn.Unlock()
 	if s.conn.closed {
-		panic("conn is closed")
+		return nil, fmt.Errorf("conn is closed")
 	}
 	return s.st.Exec(mapArgs(args)...)
 }
@@ -345,7 +341,7 @@ func (s *stmt) ExecContext(ctx context.Context, args []driver.NamedValue) (drive
 	s.conn.Lock()
 	defer s.conn.Unlock()
 	if s.conn.closed {
-		panic("conn is closed")
+		return nil, fmt.Errorf("conn is closed")
 	}
 
 	ctx, cancel := utils.ContextFromChan(s.abort)
@@ -370,7 +366,7 @@ func (s stmt) Query(args []driver.Value) (driver.Rows, error) {
 	s.conn.Lock()
 	defer s.conn.Unlock()
 	if s.conn.closed {
-		panic("conn is closed")
+		return nil, fmt.Errorf("conn is closed")
 	}
 	rows, err := s.st.Query(mapArgs(args)...)
 	defer func() {
@@ -387,7 +383,7 @@ func (s *stmt) QueryContext(_ context.Context, args []driver.NamedValue) (driver
 	s.conn.Lock()
 	defer s.conn.Unlock()
 	if s.conn.closed {
-		panic("conn is closed")
+		return nil, fmt.Errorf("conn is closed")
 	}
 
 	ctx, cancel := utils.ContextFromChan(s.abort)