Demonstrate deadlock involving transactions and prepared statements

db.go

@@ -1,12 +1,16 @@
 package main
 
 import (
+	"context"
 	"log"
 	"math/rand"
 	"os"
 	"path/filepath"
 	"time"
 
+	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/jackc/pgx/v5/stdlib"
+
 	"gorm.io/driver/mysql"
 	"gorm.io/driver/postgres"
 	"gorm.io/driver/sqlite"
@@ -42,20 +46,32 @@ func init() {
 }
 
 func OpenTestConnection() (db *gorm.DB, err error) {
+	config := &gorm.Config{PrepareStmt: true}
+
 	dbDSN := os.Getenv("GORM_DSN")
 	switch os.Getenv("GORM_DIALECT") {
 	case "mysql":
 		log.Println("testing mysql...")
 		if dbDSN == "" {
 			dbDSN = "gorm:gorm@tcp(localhost:9910)/gorm?charset=utf8&parseTime=True&loc=Local"
 		}
-		db, err = gorm.Open(mysql.Open(dbDSN), &gorm.Config{})
+		db, err = gorm.Open(mysql.Open(dbDSN), config)
 	case "postgres":
 		log.Println("testing postgres...")
 		if dbDSN == "" {
-			dbDSN = "user=gorm password=gorm host=localhost dbname=gorm port=9920 sslmode=disable TimeZone=Asia/Shanghai"
+			dbDSN = "user=gorm password=gorm host=localhost dbname=gorm port=9920 sslmode=disable TimeZone=Asia/Shanghai pool_max_conns=2"
+		}
+		var poolConfig *pgxpool.Config
+		if poolConfig, err = pgxpool.ParseConfig(dbDSN); err != nil {
+			break
+		}
+		var pool *pgxpool.Pool
+		if pool, err = pgxpool.NewWithConfig(context.Background(), poolConfig); err != nil {
+			break
 		}
-		db, err = gorm.Open(postgres.Open(dbDSN), &gorm.Config{})
+		conn := stdlib.OpenDBFromPool(pool)
+		dialector := postgres.New(postgres.Config{Conn: conn})
+		db, err = gorm.Open(dialector, config)
 	case "sqlserver":
 		// CREATE LOGIN gorm WITH PASSWORD = 'LoremIpsum86';
 		// CREATE DATABASE gorm;
@@ -66,7 +82,7 @@ func OpenTestConnection() (db *gorm.DB, err error) {
 		if dbDSN == "" {
 			dbDSN = "sqlserver://gorm:LoremIpsum86@localhost:9930?database=gorm"
 		}
-		db, err = gorm.Open(sqlserver.Open(dbDSN), &gorm.Config{})
+		db, err = gorm.Open(sqlserver.Open(dbDSN), config)
 	default:
 		log.Println("testing sqlite3...")
 		db, err = gorm.Open(sqlite.Open(filepath.Join(os.TempDir(), "gorm.db")), &gorm.Config{})

go.mod

@@ -1,41 +1,40 @@
 module gorm.io/playground
 
-go 1.22.0
+go 1.23.0
 
 toolchain go1.23.3
 
 require (
+	github.com/jackc/pgx/v5 v5.7.5
 	gorm.io/driver/mysql v1.5.7
-	gorm.io/driver/postgres v1.5.10
-	gorm.io/driver/sqlite v1.5.6
+	gorm.io/driver/postgres v1.5.11
+	gorm.io/driver/sqlite v1.5.7
 	gorm.io/driver/sqlserver v1.5.4
-	gorm.io/gen v0.3.26
-	gorm.io/gorm v1.25.12
+	gorm.io/gen v0.3.27
+	gorm.io/gorm v1.26.1
 )
 
 require (
 	filippo.io/edwards25519 v1.1.0 // indirect
-	github.com/go-sql-driver/mysql v1.8.1 // indirect
+	github.com/go-sql-driver/mysql v1.9.2 // indirect
 	github.com/golang-sql/civil v0.0.0-20220223132316-b832511892a9 // indirect
 	github.com/golang-sql/sqlexp v0.1.0 // indirect
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
-	github.com/jackc/pgx/v5 v5.7.1 // indirect
 	github.com/jackc/puddle/v2 v2.2.2 // indirect
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect
-	github.com/mattn/go-sqlite3 v1.14.24 // indirect
-	github.com/microsoft/go-mssqldb v1.7.2 // indirect
-	golang.org/x/crypto v0.29.0 // indirect
-	golang.org/x/mod v0.22.0 // indirect
-	golang.org/x/sync v0.9.0 // indirect
-	golang.org/x/sys v0.27.0 // indirect
-	golang.org/x/text v0.20.0 // indirect
-	golang.org/x/tools v0.27.0 // indirect
-	gorm.io/datatypes v1.2.4 // indirect
+	github.com/mattn/go-sqlite3 v1.14.28 // indirect
+	github.com/microsoft/go-mssqldb v1.8.1 // indirect
+	golang.org/x/crypto v0.38.0 // indirect
+	golang.org/x/mod v0.24.0 // indirect
+	golang.org/x/sync v0.14.0 // indirect
+	golang.org/x/text v0.25.0 // indirect
+	golang.org/x/tools v0.33.0 // indirect
+	gorm.io/datatypes v1.2.5 // indirect
 	gorm.io/hints v1.1.2 // indirect
-	gorm.io/plugin/dbresolver v1.5.3 // indirect
+	gorm.io/plugin/dbresolver v1.6.0 // indirect
 )
 
 replace gorm.io/gorm => ./gorm

main_test.go

@@ -1,20 +1,56 @@
 package main
 
 import (
+	"sync"
 	"testing"
+	"time"
+
+	"gorm.io/gorm"
 )
 
 // GORM_REPO: https://github.com/go-gorm/gorm.git
 // GORM_BRANCH: master
-// TEST_DRIVERS: sqlite, mysql, postgres, sqlserver
+// TEST_DRIVERS: postgres
 
 func TestGORM(t *testing.T) {
-	user := User{Name: "jinzhu"}
+	db := DB
+
+	transactionalClients := []string{"Alice", "Bob"}
+	var started, finished sync.WaitGroup
+	started.Add(len(transactionalClients))
+	finished.Add(len(transactionalClients))
+
+	for _, clientName := range transactionalClients {
+		go func() {
+			db.Transaction(func(db *gorm.DB) error {
+				started.Done()
+				defer finished.Done()
 
-	DB.Create(&user)
+				t.Logf("%s has a connection and is thinking...", clientName)
+				doSomeWork()
 
-	var result User
-	if err := DB.First(&result, user.ID).Error; err != nil {
-		t.Errorf("Failed, got error: %v", err)
+				return addTwoNumbers(t, db, clientName)
+			})
+		}()
 	}
+	started.Wait()
+
+	addTwoNumbers(t, db, "Camille")
+	finished.Wait()
+}
+
+func addTwoNumbers(t *testing.T, db *gorm.DB, clientName string) error {
+	t.Logf("%s wants to add two numbers...", clientName)
+	var sum int32
+	err := db.Raw("SELECT $1::int + $2::int", 2, 2).First(&sum).Error
+	if err != nil {
+		t.Errorf("%s failed: %s", clientName, err)
+		return err
+	}
+	t.Logf("%s thinks that 2 + 2 = %v", clientName, sum)
+	return nil
+}
+
+func doSomeWork() {
+	time.Sleep(time.Second)
 }