Unix locks.

tests/parallel_test.go

@@ -0,0 +1,113 @@
+package tests
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+	"time"
+
+	"golang.org/x/sync/errgroup"
+
+	"github.com/ncruces/go-sqlite3"
+	_ "github.com/ncruces/go-sqlite3/embed"
+)
+
+func TestParallel(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip()
+	}
+
+	dir, err := os.MkdirTemp("", "sqlite3-")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	writer := func() error {
+		db, err := sqlite3.Open(filepath.Join(dir, "test.db"))
+		if err != nil {
+			return err
+		}
+		defer db.Close()
+
+		err = db.Exec(`
+			PRAGMA locking_mode = NORMAL;
+			PRAGMA busy_timeout = 1000;
+		`)
+		if err != nil {
+			return err
+		}
+
+		err = db.Exec(`CREATE TABLE IF NOT EXISTS users (id INT, name VARCHAR(10))`)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		err = db.Exec(`INSERT INTO users(id, name) VALUES(0, 'go'), (1, 'zig'), (2, 'whatever')`)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		return db.Close()
+	}
+
+	reader := func() error {
+		db, err := sqlite3.Open(filepath.Join(dir, "test.db"))
+		if err != nil {
+			return err
+		}
+		defer db.Close()
+
+		err = db.Exec(`
+			PRAGMA locking_mode = NORMAL;
+			PRAGMA busy_timeout = 1000;
+		`)
+		if err != nil {
+			return err
+		}
+
+		stmt, _, err := db.Prepare(`SELECT id, name FROM users`)
+		if err != nil {
+			return err
+		}
+
+		row := 0
+		for stmt.Step() {
+			row++
+		}
+		if err := stmt.Err(); err != nil {
+			return err
+		}
+		if row%3 != 0 {
+			t.Errorf("got %d rows, want multiple of 3", row)
+		}
+
+		err = stmt.Close()
+		if err != nil {
+			return err
+		}
+
+		return db.Close()
+	}
+
+	err = writer()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var group errgroup.Group
+	group.SetLimit(4)
+	for i := 0; i < 32; i++ {
+		if i&7 != 7 {
+			group.Go(reader)
+		} else {
+			group.Go(writer)
+		}
+		time.Sleep(time.Microsecond)
+	}
+	err = group.Wait()
+	if err != nil {
+		t.Fatal(err)
+	}
+}