Fix WAL flakiness on Windows (#253)

Author: ncruces

util/osutil/open.go

@@ -1,3 +1,4 @@
+// Package osutil implements operating system utilities.
 package osutil
 
 import (
@@ -19,7 +20,7 @@ type FS struct{}
 
 // Open implements [fs.FS].
 func (FS) Open(name string) (fs.File, error) {
-	return OpenFile(name, os.O_RDONLY, 0)
+	return os.OpenFile(name, os.O_RDONLY, 0)
 }
 
 // ReadFileFS implements [fs.StatFS].
@@ -31,3 +32,10 @@ func (FS) Stat(name string) (fs.FileInfo, error) {
 func (FS) ReadFile(name string) ([]byte, error) {
 	return os.ReadFile(name)
 }
+
+// OpenFile behaves the same as [os.OpenFile].
+//
+// Deprecated: use os.OpenFile instead.
+func OpenFile(name string, flag int, perm fs.FileMode) (*os.File, error) {
+	return os.OpenFile(name, flag, perm)
+}

util/osutil/open_windows.go

@@ -6,9 +6,8 @@ import (
 	"io/fs"
 	"os"
 	"path/filepath"
+	"runtime"
 	"syscall"
-
-	"github.com/ncruces/go-sqlite3/util/osutil"
 )
 
 type vfsOS struct{}
@@ -40,7 +39,7 @@ func (vfsOS) Delete(path string, syncDir bool) error {
 	if err != nil {
 		return err
 	}
-	if canSyncDirs && syncDir {
+	if isUnix && syncDir {
 		f, err := os.Open(filepath.Dir(path))
 		if err != nil {
 			return _OK
@@ -96,7 +95,7 @@ func (vfsOS) OpenFilename(name *Filename, flags OpenFlag) (File, OpenFlag, error
 	if name == nil {
 		f, err = os.CreateTemp(os.Getenv("SQLITE_TMPDIR"), "*.db")
 	} else {
-		f, err = osutil.OpenFile(name.String(), oflags, 0666)
+		f, err = os.OpenFile(name.String(), oflags, 0666)
 	}
 	if err != nil {
 		if name == nil {
@@ -118,7 +117,7 @@ func (vfsOS) OpenFilename(name *Filename, flags OpenFlag) (File, OpenFlag, error
 			return nil, flags, _IOERR_FSTAT
 		}
 	}
-	if flags&OPEN_DELETEONCLOSE != 0 {
+	if isUnix && flags&OPEN_DELETEONCLOSE != 0 {
 		os.Remove(f.Name())
 	}
 
@@ -127,7 +126,8 @@ func (vfsOS) OpenFilename(name *Filename, flags OpenFlag) (File, OpenFlag, error
 		psow:     true,
 		atomic:   osBatchAtomic(f),
 		readOnly: flags&OPEN_READONLY != 0,
-		syncDir:  canSyncDirs && isCreate && isJournl,
+		syncDir:  isUnix && isCreate && isJournl,
+		delete:   !isUnix && flags&OPEN_DELETEONCLOSE != 0,
 		shm:      NewSharedMemory(name.String()+"-shm", flags),
 	}
 	return &file, flags, nil
@@ -141,6 +141,7 @@ type vfsFile struct {
 	keepWAL  bool
 	syncDir  bool
 	atomic   bool
+	delete   bool
 	psow     bool
 }
 
@@ -154,6 +155,9 @@ var (
 )
 
 func (f *vfsFile) Close() error {
+	if f.delete {
+		defer os.Remove(f.Name())
+	}
 	if f.shm != nil {
 		f.shm.Close()
 	}
@@ -177,7 +181,7 @@ func (f *vfsFile) Sync(flags SyncFlag) error {
 	if err != nil {
 		return err
 	}
-	if canSyncDirs && f.syncDir {
+	if isUnix && f.syncDir {
 		f.syncDir = false
 		d, err := os.Open(filepath.Dir(f.File.Name()))
 		if err != nil {
@@ -208,6 +212,9 @@ func (f *vfsFile) DeviceCharacteristics() DeviceCharacteristic {
 	if f.psow {
 		ret |= IOCAP_POWERSAFE_OVERWRITE
 	}
+	if runtime.GOOS == "windows" {
+		ret |= IOCAP_UNDELETABLE_WHEN_OPEN
+	}
 	return ret
 }
 
@@ -216,6 +223,9 @@ func (f *vfsFile) SizeHint(size int64) error {
 }
 
 func (f *vfsFile) HasMoved() (bool, error) {
+	if runtime.GOOS == "windows" {
+		return false, nil
+	}
 	fi, err := f.Stat()
 	if err != nil {
 		return false, err

util/osutil/osfs.go

@@ -8,8 +8,8 @@ import (
 )
 
 const (
+	isUnix      = false
 	_O_NOFOLLOW = 0
-	canSyncDirs = false
 )
 
 func osAccess(path string, flags AccessFlag) error {

util/osutil/osutil.go

@@ -10,8 +10,8 @@ import (
 )
 
 const (
+	isUnix      = true
 	_O_NOFOLLOW = unix.O_NOFOLLOW
-	canSyncDirs = true
 )
 
 func osAccess(path string, flags AccessFlag) error {

vfs/file.go

@@ -179,14 +179,13 @@ func osLockExTimeout(file *os.File, flags, start, len uint32, timeout time.Durat
 	if err != windows.ERROR_IO_PENDING {
 		return err
 	}
+	defer windows.CancelIoEx(fd, overlapped)
 
 	ms := (timeout + time.Millisecond - 1) / time.Millisecond
 	rc, err := windows.WaitForSingleObject(event, uint32(ms))
 	if rc == windows.WAIT_OBJECT_0 {
 		return nil
 	}
-	defer windows.CancelIoEx(fd, overlapped)
-
 	if err != nil {
 		return err
 	}

vfs/os_std.go

@@ -7,14 +7,12 @@ import (
 	"io"
 	"os"
 	"sync"
-	"syscall"
 	"time"
 
 	"github.com/tetratelabs/wazero/api"
 	"golang.org/x/sys/windows"
 
 	"github.com/ncruces/go-sqlite3/internal/util"
-	"github.com/ncruces/go-sqlite3/util/osutil"
 )
 
 type vfsShm struct {
@@ -33,7 +31,7 @@ type vfsShm struct {
 	sync.Mutex
 }
 
-// var _ blockingSharedMemory = &vfsShm{}
+var _ blockingSharedMemory = &vfsShm{}
 
 func (s *vfsShm) Close() error {
 	// Unmap regions.
@@ -48,12 +46,19 @@ func (s *vfsShm) Close() error {
 
 func (s *vfsShm) shmOpen() _ErrorCode {
 	if s.File == nil {
-		f, err := osutil.OpenFile(s.path,
-			os.O_RDWR|os.O_CREATE|syscall.O_NONBLOCK, 0666)
+		path, err := windows.UTF16PtrFromString(s.path)
 		if err != nil {
 			return _CANTOPEN
 		}
-		s.File = f
+		h, err := windows.CreateFile(path,
+			windows.GENERIC_READ|windows.GENERIC_WRITE,
+			windows.FILE_SHARE_READ|windows.FILE_SHARE_WRITE,
+			nil, windows.OPEN_ALWAYS,
+			windows.FILE_ATTRIBUTE_NORMAL|windows.FILE_FLAG_OVERLAPPED, 0)
+		if err != nil {
+			return _CANTOPEN
+		}
+		s.File = os.NewFile(uintptr(h), s.path)
 	}
 	if s.fileLock {
 		return _OK
@@ -185,6 +190,6 @@ func (s *vfsShm) shmUnmap(delete bool) {
 	}
 }
 
-// func (s *vfsShm) shmEnableBlocking(block bool) {
-// 	s.blocking = block
-// }
+func (s *vfsShm) shmEnableBlocking(block bool) {
+	s.blocking = block
+}