Pass mptest crash.

module.go

@@ -4,6 +4,7 @@ package sqlite3
 import (
 	"context"
 	"crypto/rand"
+	"io"
 	"math"
 	"os"
 	"runtime"
@@ -80,12 +81,13 @@ type module struct {
 	ctx context.Context
 	mem memory
 	api sqliteAPI
+	vfs io.Closer
 }
 
 func newModule(mod api.Module) (m *module, err error) {
 	m = &module{}
 	m.mem = memory{mod}
-	m.ctx = context.Background()
+	m.ctx, m.vfs = vfsContext(context.Background())
 
 	getFun := func(name string) api.Function {
 		f := mod.ExportedFunction(name)
@@ -156,13 +158,15 @@ func newModule(mod api.Module) (m *module, err error) {
 		interrupt:       getVal("sqlite3_interrupt_offset"),
 	}
 	if err != nil {
-		m = nil
+		return nil, err
 	}
-	return
+	return m, nil
 }
 
 func (m *module) close() error {
-	return m.mem.mod.Close(m.ctx)
+	err := m.mem.mod.Close(m.ctx)
+	m.vfs.Close()
+	return err
 }
 
 func (m *module) error(rc uint64, handle uint32, sql ...string) error {
@@ -178,18 +182,18 @@ func (m *module) error(rc uint64, handle uint32, sql ...string) error {
 
 	var r []uint64
 
-	r, _ = m.api.errstr.Call(m.ctx, rc)
+	r = m.call(m.api.errstr, rc)
 	if r != nil {
 		err.str = m.mem.readString(uint32(r[0]), _MAX_STRING)
 	}
 
-	r, _ = m.api.errmsg.Call(m.ctx, uint64(handle))
+	r = m.call(m.api.errmsg, uint64(handle))
 	if r != nil {
 		err.msg = m.mem.readString(uint32(r[0]), _MAX_STRING)
 	}
 
 	if sql != nil {
-		r, _ = m.api.erroff.Call(m.ctx, uint64(handle))
+		r = m.call(m.api.erroff, uint64(handle))
 		if r != nil && r[0] != math.MaxUint32 {
 			err.sql = sql[0][r[0]:]
 		}
@@ -205,6 +209,7 @@ func (m *module) error(rc uint64, handle uint32, sql ...string) error {
 func (m *module) call(fn api.Function, params ...uint64) []uint64 {
 	r, err := fn.Call(m.ctx, params...)
 	if err != nil {
+		m.vfs.Close()
 		panic(err)
 	}
 	return r

tests/mptest/mptest_test.go

@@ -7,6 +7,7 @@ import (
 	"embed"
 	"io"
 	"io/fs"
+	"os"
 	"path/filepath"
 	"runtime"
 	"strconv"
@@ -33,6 +34,9 @@ var scripts embed.FS
 //go:linkname vfsNewEnvModuleBuilder github.com/ncruces/go-sqlite3.vfsNewEnvModuleBuilder
 func vfsNewEnvModuleBuilder(r wazero.Runtime) wazero.HostModuleBuilder
 
+//go:linkname vfsContext github.com/ncruces/go-sqlite3.vfsContext
+func vfsContext(ctx context.Context) (context.Context, io.Closer)
+
 var (
 	rt        wazero.Runtime
 	module    wazero.CompiledModule
@@ -83,40 +87,56 @@ func system(ctx context.Context, mod api.Module, ptr uint32) uint32 {
 	args = args[:len(args)-1]
 
 	cfg := config(ctx).WithArgs(args...)
-	go rt.InstantiateModule(ctx, module, cfg)
+	go func() {
+		ctx, vfs := vfsContext(ctx)
+		rt.InstantiateModule(ctx, module, cfg)
+		vfs.Close()
+	}()
 	return 0
 }
 
 func Test_config01(t *testing.T) {
-	ctx := newContext(t)
+	ctx, vfs := vfsContext(newContext(t))
 	name := filepath.Join(t.TempDir(), "test.db")
 	cfg := config(ctx).WithArgs("mptest", name, "config01.test")
 	_, err := rt.InstantiateModule(ctx, module, cfg)
 	if err != nil {
 		t.Error(err)
 	}
+	vfs.Close()
 }
 
 func Test_config02(t *testing.T) {
-	t.Skip() // TODO: remove
-	ctx := newContext(t)
+	if testing.Short() {
+		t.Skip("skipping in short mode")
+	}
+	if os.Getenv("CI") != "" {
+		t.Skip("skipping in CI")
+	}
+
+	ctx, vfs := vfsContext(newContext(t))
 	name := filepath.Join(t.TempDir(), "test.db")
 	cfg := config(ctx).WithArgs("mptest", name, "config02.test")
 	_, err := rt.InstantiateModule(ctx, module, cfg)
 	if err != nil {
 		t.Error(err)
 	}
+	vfs.Close()
 }
 
 func Test_crash01(t *testing.T) {
-	t.Skip() // TODO: remove
-	ctx := newContext(t)
+	if testing.Short() {
+		t.Skip("skipping in short mode")
+	}
+
+	ctx, vfs := vfsContext(newContext(t))
 	name := filepath.Join(t.TempDir(), "test.db")
 	cfg := config(ctx).WithArgs("mptest", name, "crash01.test")
 	_, err := rt.InstantiateModule(ctx, module, cfg)
 	if err != nil {
 		t.Error(err)
 	}
+	vfs.Close()
 }
 
 func Test_multiwrite01(t *testing.T) {
@@ -124,13 +144,14 @@ func Test_multiwrite01(t *testing.T) {
 		t.Skip("skipping in short mode")
 	}
 
-	ctx := newContext(t)
+	ctx, vfs := vfsContext(newContext(t))
 	name := filepath.Join(t.TempDir(), "test.db")
 	cfg := config(ctx).WithArgs("mptest", name, "multiwrite01.test")
 	_, err := rt.InstantiateModule(ctx, module, cfg)
 	if err != nil {
 		t.Error(err)
 	}
+	vfs.Close()
 }
 
 func newContext(t *testing.T) context.Context {

tests/mptest/testdata/.gitattributes

@@ -1,2 +1,2 @@
 mptest.wasm filter=lfs diff=lfs merge=lfs -text
-*.test* -crlf
+*.*test -crlf

tests/mptest/testdata/build.sh

@@ -19,6 +19,7 @@ zig cc --target=wasm32-wasi -flto -g0 -Os \
 	-mbulk-memory -mreference-types \
 	-mnontrapping-fptoint -msign-ext \
 	-D_HAVE_SQLITE_CONFIG_H \
+	-DSQLITE_DEFAULT_SYNCHRONOUS=0 \
 	-DSQLITE_DEFAULT_LOCKING_MODE=0 \
 	-DHAVE_USLEEP -DSQLITE_NO_SYNC \
 	-DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION \

tests/mptest/testdata/mptest.wasm

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:e155ad9a9723b2eb2c0d187cbd079f4111931064a62ba0cb30ff4e4242bf5efd
-size 1077263
+oid sha256:3960b873a7dab969a66f7859d491cec0dd4e6c0c9f83eab449fb15ec5ebdfd8f
+size 1077281

vfs.go

@@ -232,8 +232,7 @@ func vfsOpen(ctx context.Context, mod api.Module, pVfs, zName, pFile uint32, fla
 		vfsOS.DeleteOnClose(file)
 	}
 
-	id := vfsGetFileID(file)
-	vfsFilePtr{mod, pFile}.SetID(id).SetLock(_NO_LOCK)
+	vfsFileOpen(ctx, mod, pFile, file)
 
 	if pOutFlags != 0 {
 		memory{mod}.writeUint32(pOutFlags, uint32(flags))
@@ -242,8 +241,7 @@ func vfsOpen(ctx context.Context, mod api.Module, pVfs, zName, pFile uint32, fla
 }
 
 func vfsClose(ctx context.Context, mod api.Module, pFile uint32) uint32 {
-	id := vfsFilePtr{mod, pFile}.ID()
-	err := vfsCloseFile(id)
+	err := vfsFileClose(ctx, mod, pFile)
 	if err != nil {
 		return uint32(IOERR_CLOSE)
 	}
@@ -253,7 +251,7 @@ func vfsClose(ctx context.Context, mod api.Module, pFile uint32) uint32 {
 func vfsRead(ctx context.Context, mod api.Module, pFile, zBuf, iAmt uint32, iOfst uint64) uint32 {
 	buf := memory{mod}.view(zBuf, uint64(iAmt))
 
-	file := vfsFilePtr{mod, pFile}.OSFile()
+	file := vfsFileGet(ctx, mod, pFile)
 	n, err := file.ReadAt(buf, int64(iOfst))
 	if n == int(iAmt) {
 		return _OK
@@ -270,7 +268,7 @@ func vfsRead(ctx context.Context, mod api.Module, pFile, zBuf, iAmt uint32, iOfs
 func vfsWrite(ctx context.Context, mod api.Module, pFile, zBuf, iAmt uint32, iOfst uint64) uint32 {
 	buf := memory{mod}.view(zBuf, uint64(iAmt))
 
-	file := vfsFilePtr{mod, pFile}.OSFile()
+	file := vfsFileGet(ctx, mod, pFile)
 	_, err := file.WriteAt(buf, int64(iOfst))
 	if err != nil {
 		return uint32(IOERR_WRITE)
@@ -279,7 +277,7 @@ func vfsWrite(ctx context.Context, mod api.Module, pFile, zBuf, iAmt uint32, iOf
 }
 
 func vfsTruncate(ctx context.Context, mod api.Module, pFile uint32, nByte uint64) uint32 {
-	file := vfsFilePtr{mod, pFile}.OSFile()
+	file := vfsFileGet(ctx, mod, pFile)
 	err := file.Truncate(int64(nByte))
 	if err != nil {
 		return uint32(IOERR_TRUNCATE)
@@ -288,7 +286,7 @@ func vfsTruncate(ctx context.Context, mod api.Module, pFile uint32, nByte uint64
 }
 
 func vfsSync(ctx context.Context, mod api.Module, pFile, flags uint32) uint32 {
-	file := vfsFilePtr{mod, pFile}.OSFile()
+	file := vfsFileGet(ctx, mod, pFile)
 	err := file.Sync()
 	if err != nil {
 		return uint32(IOERR_FSYNC)
@@ -300,7 +298,7 @@ func vfsFileSize(ctx context.Context, mod api.Module, pFile, pSize uint32) uint3
 	// This uses [os.File.Seek] because we don't care about the offset for reading/writing.
 	// But consider using [os.File.Stat] instead (as other VFSes do).
 
-	file := vfsFilePtr{mod, pFile}.OSFile()
+	file := vfsFileGet(ctx, mod, pFile)
 	off, err := file.Seek(0, io.SeekEnd)
 	if err != nil {
 		return uint32(IOERR_SEEK)

vfs_files.go

@@ -1,69 +1,79 @@
 package sqlite3
 
 import (
+	"context"
+	"io"
 	"os"
-	"sync"
 
 	"github.com/tetratelabs/wazero/api"
 )
 
-var (
-	vfsOpenFiles    []*os.File
-	vfsOpenFilesMtx sync.Mutex
-)
+type vfsKey struct{}
 
-func vfsGetFileID(file *os.File) uint32 {
-	vfsOpenFilesMtx.Lock()
-	defer vfsOpenFilesMtx.Unlock()
+type vfsState struct {
+	files []*os.File
+}
+
+func (vfs *vfsState) Close() error {
+	for _, f := range vfs.files {
+		if f != nil {
+			f.Close()
+		}
+	}
+	vfs.files = nil
+	return nil
+}
+
+func vfsContext(ctx context.Context) (context.Context, io.Closer) {
+	vfs := &vfsState{}
+	return context.WithValue(ctx, vfsKey{}, vfs), vfs
+}
+
+func vfsFileNewID(ctx context.Context, file *os.File) uint32 {
+	vfs := ctx.Value(vfsKey{}).(*vfsState)
 
 	// Find an empty slot.
-	for id, ptr := range vfsOpenFiles {
+	for id, ptr := range vfs.files {
 		if ptr == nil {
-			vfsOpenFiles[id] = file
+			vfs.files[id] = file
 			return uint32(id)
 		}
 	}
 
 	// Add a new slot.
-	vfsOpenFiles = append(vfsOpenFiles, file)
-	return uint32(len(vfsOpenFiles) - 1)
+	vfs.files = append(vfs.files, file)
+	return uint32(len(vfs.files) - 1)
 }
 
-func vfsCloseFile(id uint32) error {
-	vfsOpenFilesMtx.Lock()
-	defer vfsOpenFilesMtx.Unlock()
+func vfsFileOpen(ctx context.Context, mod api.Module, pFile uint32, file *os.File) {
+	mem := memory{mod}
+	id := vfsFileNewID(ctx, file)
+	mem.writeUint32(pFile+ptrlen, id)
+	mem.writeUint32(pFile+2*ptrlen, _NO_LOCK)
+}
 
-	file := vfsOpenFiles[id]
-	vfsOpenFiles[id] = nil
+func vfsFileClose(ctx context.Context, mod api.Module, pFile uint32) error {
+	mem := memory{mod}
+	id := mem.readUint32(pFile + ptrlen)
+	vfs := ctx.Value(vfsKey{}).(*vfsState)
+	file := vfs.files[id]
+	vfs.files[id] = nil
 	return file.Close()
 }
 
-type vfsFilePtr struct {
-	api.Module
-	ptr uint32
+func vfsFileGet(ctx context.Context, mod api.Module, pFile uint32) *os.File {
+	mem := memory{mod}
+	id := mem.readUint32(pFile + ptrlen)
+	vfs := ctx.Value(vfsKey{}).(*vfsState)
+	return vfs.files[id]
 }
 
-func (p vfsFilePtr) OSFile() *os.File {
-	id := p.ID()
-	vfsOpenFilesMtx.Lock()
-	defer vfsOpenFilesMtx.Unlock()
-	return vfsOpenFiles[id]
+func vfsFileLockState(ctx context.Context, mod api.Module, pFile uint32) vfsLockState {
+	mem := memory{mod}
+	return vfsLockState(mem.readUint32(pFile + 2*ptrlen))
 }
 
-func (p vfsFilePtr) ID() uint32 {
-	return memory{p}.readUint32(p.ptr + ptrlen)
-}
-
-func (p vfsFilePtr) Lock() vfsLockState {
-	return vfsLockState(memory{p}.readUint32(p.ptr + 2*ptrlen))
-}
-
-func (p vfsFilePtr) SetID(id uint32) vfsFilePtr {
-	memory{p}.writeUint32(p.ptr+ptrlen, id)
-	return p
-}
-
-func (p vfsFilePtr) SetLock(lock vfsLockState) vfsFilePtr {
-	memory{p}.writeUint32(p.ptr+2*ptrlen, uint32(lock))
-	return p
+func vfsFileSetLockState(ctx context.Context, mod api.Module, pFile uint32, lock vfsLockState) {
+	mem := memory{mod}
+	mem.writeUint32(pFile+2*ptrlen, uint32(lock))
 }

vfs_lock.go

@@ -61,9 +61,8 @@ func vfsLock(ctx context.Context, mod api.Module, pFile uint32, eLock vfsLockSta
 		panic(assertErr())
 	}
 
-	ptr := vfsFilePtr{mod, pFile}
-	file := ptr.OSFile()
-	cLock := ptr.Lock()
+	file := vfsFileGet(ctx, mod, pFile)
+	cLock := vfsFileLockState(ctx, mod, pFile)
 
 	switch {
 	case cLock < _NO_LOCK || cLock > _EXCLUSIVE_LOCK:
@@ -95,7 +94,7 @@ func vfsLock(ctx context.Context, mod api.Module, pFile uint32, eLock vfsLockSta
 		if rc := vfsOS.GetSharedLock(file); rc != _OK {
 			return uint32(rc)
 		}
-		ptr.SetLock(_SHARED_LOCK)
+		vfsFileSetLockState(ctx, mod, pFile, _SHARED_LOCK)
 		return _OK
 
 	case _RESERVED_LOCK:
@@ -106,7 +105,7 @@ func vfsLock(ctx context.Context, mod api.Module, pFile uint32, eLock vfsLockSta
 		if rc := vfsOS.GetReservedLock(file); rc != _OK {
 			return uint32(rc)
 		}
-		ptr.SetLock(_RESERVED_LOCK)
+		vfsFileSetLockState(ctx, mod, pFile, _RESERVED_LOCK)
 		return _OK
 
 	case _EXCLUSIVE_LOCK:
@@ -119,12 +118,12 @@ func vfsLock(ctx context.Context, mod api.Module, pFile uint32, eLock vfsLockSta
 			if rc := vfsOS.GetPendingLock(file); rc != _OK {
 				return uint32(rc)
 			}
-			ptr.SetLock(_PENDING_LOCK)
+			vfsFileSetLockState(ctx, mod, pFile, _PENDING_LOCK)
 		}
 		if rc := vfsOS.GetExclusiveLock(file); rc != _OK {
 			return uint32(rc)
 		}
-		ptr.SetLock(_EXCLUSIVE_LOCK)
+		vfsFileSetLockState(ctx, mod, pFile, _EXCLUSIVE_LOCK)
 		return _OK
 
 	default:
@@ -138,9 +137,8 @@ func vfsUnlock(ctx context.Context, mod api.Module, pFile uint32, eLock vfsLockS
 		panic(assertErr())
 	}
 
-	ptr := vfsFilePtr{mod, pFile}
-	file := ptr.OSFile()
-	cLock := ptr.Lock()
+	file := vfsFileGet(ctx, mod, pFile)
+	cLock := vfsFileLockState(ctx, mod, pFile)
 
 	// Connection state check.
 	if cLock < _NO_LOCK || cLock > _EXCLUSIVE_LOCK {
@@ -157,12 +155,12 @@ func vfsUnlock(ctx context.Context, mod api.Module, pFile uint32, eLock vfsLockS
 		if rc := vfsOS.DowngradeLock(file, cLock); rc != _OK {
 			return uint32(rc)
 		}
-		ptr.SetLock(_SHARED_LOCK)
+		vfsFileSetLockState(ctx, mod, pFile, _SHARED_LOCK)
 		return _OK
 
 	case _NO_LOCK:
 		rc := vfsOS.ReleaseLock(file, cLock)
-		ptr.SetLock(_NO_LOCK)
+		vfsFileSetLockState(ctx, mod, pFile, _NO_LOCK)
 		return uint32(rc)
 
 	default:
@@ -171,14 +169,13 @@ func vfsUnlock(ctx context.Context, mod api.Module, pFile uint32, eLock vfsLockS
 }
 
 func vfsCheckReservedLock(ctx context.Context, mod api.Module, pFile, pResOut uint32) uint32 {
-	ptr := vfsFilePtr{mod, pFile}
-	cLock := ptr.Lock()
+	cLock := vfsFileLockState(ctx, mod, pFile)
 
 	if cLock > _SHARED_LOCK {
 		panic(assertErr())
 	}
 
-	file := ptr.OSFile()
+	file := vfsFileGet(ctx, mod, pFile)
 
 	locked, rc := vfsOS.CheckReservedLock(file)
 	var res uint32

vfs_lock_test.go

@@ -38,10 +38,13 @@ func Test_vfsLock(t *testing.T) {
 		pOutput = 32
 	)
 	mem := newMemory(128)
-	vfsFilePtr{mem.mod, pFile1}.SetID(vfsGetFileID(file1)).SetLock(_NO_LOCK)
-	vfsFilePtr{mem.mod, pFile2}.SetID(vfsGetFileID(file2)).SetLock(_NO_LOCK)
+	ctx, vfs := vfsContext(context.TODO())
+	defer vfs.Close()
 
-	rc := vfsCheckReservedLock(context.TODO(), mem.mod, pFile1, pOutput)
+	vfsFileOpen(ctx, mem.mod, pFile1, file1)
+	vfsFileOpen(ctx, mem.mod, pFile2, file2)
+
+	rc := vfsCheckReservedLock(ctx, mem.mod, pFile1, pOutput)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -49,12 +52,12 @@ func Test_vfsLock(t *testing.T) {
 		t.Error("file was locked")
 	}
 
-	rc = vfsLock(context.TODO(), mem.mod, pFile2, _SHARED_LOCK)
+	rc = vfsLock(ctx, mem.mod, pFile2, _SHARED_LOCK)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
 
-	rc = vfsCheckReservedLock(context.TODO(), mem.mod, pFile1, pOutput)
+	rc = vfsCheckReservedLock(ctx, mem.mod, pFile1, pOutput)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -62,16 +65,16 @@ func Test_vfsLock(t *testing.T) {
 		t.Error("file was locked")
 	}
 
-	rc = vfsLock(context.TODO(), mem.mod, pFile2, _RESERVED_LOCK)
+	rc = vfsLock(ctx, mem.mod, pFile2, _RESERVED_LOCK)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
-	rc = vfsLock(context.TODO(), mem.mod, pFile2, _SHARED_LOCK)
+	rc = vfsLock(ctx, mem.mod, pFile2, _SHARED_LOCK)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
 
-	rc = vfsCheckReservedLock(context.TODO(), mem.mod, pFile1, pOutput)
+	rc = vfsCheckReservedLock(ctx, mem.mod, pFile1, pOutput)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -79,12 +82,12 @@ func Test_vfsLock(t *testing.T) {
 		t.Error("file wasn't locked")
 	}
 
-	rc = vfsLock(context.TODO(), mem.mod, pFile2, _EXCLUSIVE_LOCK)
+	rc = vfsLock(ctx, mem.mod, pFile2, _EXCLUSIVE_LOCK)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
 
-	rc = vfsCheckReservedLock(context.TODO(), mem.mod, pFile1, pOutput)
+	rc = vfsCheckReservedLock(ctx, mem.mod, pFile1, pOutput)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -92,12 +95,12 @@ func Test_vfsLock(t *testing.T) {
 		t.Error("file wasn't locked")
 	}
 
-	rc = vfsLock(context.TODO(), mem.mod, pFile1, _SHARED_LOCK)
+	rc = vfsLock(ctx, mem.mod, pFile1, _SHARED_LOCK)
 	if rc == _OK {
 		t.Fatal("returned", rc)
 	}
 
-	rc = vfsCheckReservedLock(context.TODO(), mem.mod, pFile1, pOutput)
+	rc = vfsCheckReservedLock(ctx, mem.mod, pFile1, pOutput)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -105,12 +108,12 @@ func Test_vfsLock(t *testing.T) {
 		t.Error("file wasn't locked")
 	}
 
-	rc = vfsUnlock(context.TODO(), mem.mod, pFile2, _SHARED_LOCK)
+	rc = vfsUnlock(ctx, mem.mod, pFile2, _SHARED_LOCK)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
 
-	rc = vfsCheckReservedLock(context.TODO(), mem.mod, pFile1, pOutput)
+	rc = vfsCheckReservedLock(ctx, mem.mod, pFile1, pOutput)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -118,7 +121,7 @@ func Test_vfsLock(t *testing.T) {
 		t.Error("file was locked")
 	}
 
-	rc = vfsLock(context.TODO(), mem.mod, pFile1, _SHARED_LOCK)
+	rc = vfsLock(ctx, mem.mod, pFile1, _SHARED_LOCK)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}

vfs_test.go

@@ -16,15 +16,17 @@ import (
 
 func Test_vfsExit(t *testing.T) {
 	mem := newMemory(128)
+	ctx := context.TODO()
 	defer func() { _ = recover() }()
-	vfsExit(context.TODO(), mem.mod, 1)
+	vfsExit(ctx, mem.mod, 1)
 	t.Error("want panic")
 }
 
 func Test_vfsLocaltime(t *testing.T) {
 	mem := newMemory(128)
+	ctx := context.TODO()
 
-	rc := vfsLocaltime(context.TODO(), mem.mod, 0, 4)
+	rc := vfsLocaltime(ctx, mem.mod, 0, 4)
 	if rc != 0 {
 		t.Fatal("returned", rc)
 	}
@@ -71,24 +73,26 @@ func Test_vfsRandomness(t *testing.T) {
 }
 
 func Test_vfsSleep(t *testing.T) {
-	start := time.Now()
+	ctx := context.TODO()
 
-	rc := vfsSleep(context.TODO(), 0, 123456)
+	now := time.Now()
+	rc := vfsSleep(ctx, 0, 123456)
 	if rc != 0 {
 		t.Fatal("returned", rc)
 	}
 
 	want := 123456 * time.Microsecond
-	if got := time.Since(start); got < want {
+	if got := time.Since(now); got < want {
 		t.Errorf("got %v, want %v", got, want)
 	}
 }
 
 func Test_vfsCurrentTime(t *testing.T) {
 	mem := newMemory(128)
+	ctx := context.TODO()
 
 	now := time.Now()
-	rc := vfsCurrentTime(context.TODO(), mem.mod, 0, 4)
+	rc := vfsCurrentTime(ctx, mem.mod, 0, 4)
 	if rc != 0 {
 		t.Fatal("returned", rc)
 	}
@@ -101,10 +105,11 @@ func Test_vfsCurrentTime(t *testing.T) {
 
 func Test_vfsCurrentTime64(t *testing.T) {
 	mem := newMemory(128)
+	ctx := context.TODO()
 
 	now := time.Now()
 	time.Sleep(time.Millisecond)
-	rc := vfsCurrentTime64(context.TODO(), mem.mod, 0, 4)
+	rc := vfsCurrentTime64(ctx, mem.mod, 0, 4)
 	if rc != 0 {
 		t.Fatal("returned", rc)
 	}
@@ -119,13 +124,14 @@ func Test_vfsCurrentTime64(t *testing.T) {
 func Test_vfsFullPathname(t *testing.T) {
 	mem := newMemory(128 + _MAX_PATHNAME)
 	mem.writeString(4, ".")
+	ctx := context.TODO()
 
-	rc := vfsFullPathname(context.TODO(), mem.mod, 0, 4, 0, 8)
+	rc := vfsFullPathname(ctx, mem.mod, 0, 4, 0, 8)
 	if rc != uint32(CANTOPEN_FULLPATH) {
 		t.Errorf("returned %d, want %d", rc, CANTOPEN_FULLPATH)
 	}
 
-	rc = vfsFullPathname(context.TODO(), mem.mod, 0, 4, _MAX_PATHNAME, 8)
+	rc = vfsFullPathname(ctx, mem.mod, 0, 4, _MAX_PATHNAME, 8)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -147,8 +153,9 @@ func Test_vfsDelete(t *testing.T) {
 
 	mem := newMemory(128 + _MAX_PATHNAME)
 	mem.writeString(4, name)
+	ctx := context.TODO()
 
-	rc := vfsDelete(context.TODO(), mem.mod, 0, 4, 1)
+	rc := vfsDelete(ctx, mem.mod, 0, 4, 1)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -157,7 +164,7 @@ func Test_vfsDelete(t *testing.T) {
 		t.Fatal("did not delete the file")
 	}
 
-	rc = vfsDelete(context.TODO(), mem.mod, 0, 4, 1)
+	rc = vfsDelete(ctx, mem.mod, 0, 4, 1)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -177,8 +184,9 @@ func Test_vfsAccess(t *testing.T) {
 
 	mem := newMemory(128 + _MAX_PATHNAME)
 	mem.writeString(8, dir)
+	ctx := context.TODO()
 
-	rc := vfsAccess(context.TODO(), mem.mod, 0, 8, _ACCESS_EXISTS, 4)
+	rc := vfsAccess(ctx, mem.mod, 0, 8, _ACCESS_EXISTS, 4)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -186,7 +194,7 @@ func Test_vfsAccess(t *testing.T) {
 		t.Error("directory did not exist")
 	}
 
-	rc = vfsAccess(context.TODO(), mem.mod, 0, 8, _ACCESS_READWRITE, 4)
+	rc = vfsAccess(ctx, mem.mod, 0, 8, _ACCESS_READWRITE, 4)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -195,7 +203,7 @@ func Test_vfsAccess(t *testing.T) {
 	}
 
 	mem.writeString(8, file)
-	rc = vfsAccess(context.TODO(), mem.mod, 0, 8, _ACCESS_READWRITE, 4)
+	rc = vfsAccess(ctx, mem.mod, 0, 8, _ACCESS_READWRITE, 4)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -206,9 +214,11 @@ func Test_vfsAccess(t *testing.T) {
 
 func Test_vfsFile(t *testing.T) {
 	mem := newMemory(128)
+	ctx, vfs := vfsContext(context.TODO())
+	defer vfs.Close()
 
 	// Open a temporary file.
-	rc := vfsOpen(context.TODO(), mem.mod, 0, 0, 4, OPEN_CREATE|OPEN_EXCLUSIVE|OPEN_READWRITE|OPEN_DELETEONCLOSE, 0)
+	rc := vfsOpen(ctx, mem.mod, 0, 0, 4, OPEN_CREATE|OPEN_EXCLUSIVE|OPEN_READWRITE|OPEN_DELETEONCLOSE, 0)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -216,13 +226,13 @@ func Test_vfsFile(t *testing.T) {
 	// Write stuff.
 	text := "Hello world!"
 	mem.writeString(16, text)
-	rc = vfsWrite(context.TODO(), mem.mod, 4, 16, uint32(len(text)), 0)
+	rc = vfsWrite(ctx, mem.mod, 4, 16, uint32(len(text)), 0)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
 
 	// Check file size.
-	rc = vfsFileSize(context.TODO(), mem.mod, 4, 16)
+	rc = vfsFileSize(ctx, mem.mod, 4, 16)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -231,7 +241,7 @@ func Test_vfsFile(t *testing.T) {
 	}
 
 	// Partial read at offset.
-	rc = vfsRead(context.TODO(), mem.mod, 4, 16, uint32(len(text)), 4)
+	rc = vfsRead(ctx, mem.mod, 4, 16, uint32(len(text)), 4)
 	if rc != uint32(IOERR_SHORT_READ) {
 		t.Fatal("returned", rc)
 	}
@@ -240,13 +250,13 @@ func Test_vfsFile(t *testing.T) {
 	}
 
 	// Truncate the file.
-	rc = vfsTruncate(context.TODO(), mem.mod, 4, 4)
+	rc = vfsTruncate(ctx, mem.mod, 4, 4)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
 
 	// Check file size.
-	rc = vfsFileSize(context.TODO(), mem.mod, 4, 16)
+	rc = vfsFileSize(ctx, mem.mod, 4, 16)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -255,7 +265,7 @@ func Test_vfsFile(t *testing.T) {
 	}
 
 	// Read at offset.
-	rc = vfsRead(context.TODO(), mem.mod, 4, 32, 4, 0)
+	rc = vfsRead(ctx, mem.mod, 4, 32, 4, 0)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}
@@ -264,7 +274,7 @@ func Test_vfsFile(t *testing.T) {
 	}
 
 	// Close the file.
-	rc = vfsClose(context.TODO(), mem.mod, 4)
+	rc = vfsClose(ctx, mem.mod, 4)
 	if rc != _OK {
 		t.Fatal("returned", rc)
 	}