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Make all async events pause the VM
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Aside from consistency, pausing on other events may be useful to show animations, etc.
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@DrJosh9000
DrJosh9000 committed May 8, 2023
1 parent 65f521a commit ffe2578
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Showing 4 changed files with 133 additions and 99 deletions.
69 changes: 42 additions & 27 deletions async_adapter.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -59,10 +59,10 @@ func (s VMState) String() string {
return fmt.Sprintf("(invalid VMState %d)", s)
}

// VMStateMismatchErr is returned when AsyncAdapter is told to do something (either
// by the user calling Go, GoWithChoice, or Abort, or the VM calling a
// DialogueHandler method) but this requires AsyncAdapter to be in a different state
// than the state it is in.
// VMStateMismatchErr is returned when AsyncAdapter is told to do something
// (either by the user calling Go, GoWithChoice, or Abort, or the VM calling a
// DialogueHandler method) but this requires AsyncAdapter to be in a different
// state than the state it is in.
type VMStateMismatchErr struct {
// The VM was in state Got, but we wanted it to be in state Want in order
// to change it to state Next.
Expand All @@ -75,9 +75,8 @@ func (e VMStateMismatchErr) Error() string {

// AsyncAdapter is a DialogueHandler that exposes an interface that is similar
// to the mainline YarnSpinner VM dialogue handler. Instead of manually blocking
// inside the DialogueHandler Line, Options, and Command callbacks, AsyncAdapter
// does this for you, until you call Go, GoWithChoice, or Abort (as
// appropriate).
// inside the DialogueHandler callbacks, AsyncAdapter does this for you, until
// you call Go, GoWithChoice, or Abort (as appropriate).
type AsyncAdapter struct {
state atomic.Int32
handler AsyncDialogueHandler
Expand All @@ -90,9 +89,9 @@ func NewAsyncAdapter(h AsyncDialogueHandler) *AsyncAdapter {
handler: h,
// The user might call Go from within their handler's Line method
// (or however many other ways to try to continue the VM immediately).
// If ch was unbuffered, calling Go would wait forever trying to send on
// the channel, because AsyncAdapter only receives on ch after their method
// returns.
// If msgCh was unbuffered, calling Go would wait forever trying to send
// on the channel, because AsyncAdapter only receives on msgCh after
// their method returns.
msgCh: make(chan asyncMsg, 1),
}
}
Expand All @@ -105,8 +104,8 @@ func (a *AsyncAdapter) State() VMState {
func (a *AsyncAdapter) stateTransition(old, new int32) error {
if !a.state.CompareAndSwap(old, new) {
// This races (between CAS and a.State, something else could switch the
// state around). While I try to make the error maximally useful
// for debugging ... YOLO?
// state around). While I try to make the error maximally useful for
// debugging ... YOLO?
return VMStateMismatchErr{
Got: a.State(),
Want: VMState(old),
Expand All @@ -117,7 +116,8 @@ func (a *AsyncAdapter) stateTransition(old, new int32) error {
}

// Go will continue the VM after it has delivered any event (other than
// Options). If the VM is not waiting for an event, an error will be returned.
// Options). If the VM is not paused following any event other than Options, an
// error will be returned.
func (a *AsyncAdapter) Go() error {
if err := a.stateTransition(VMStatePaused, VMStateRunning); err != nil {
return err
Expand All @@ -127,7 +127,8 @@ func (a *AsyncAdapter) Go() error {
}

// GoWithChoice will continue the VM after it has delivered an Options event.
// Pass
// Pass the ID of the chosen option. If the VM is not paused following an
// Options event, an error will be returned.
func (a *AsyncAdapter) GoWithChoice(id int) error {
if err := a.stateTransition(VMStatePausedOptions, VMStateRunning); err != nil {
return err
Expand All @@ -139,7 +140,8 @@ func (a *AsyncAdapter) GoWithChoice(id int) error {
// Abort stops the VM with the given error as soon as possible (either within
// the current event, or on the next event). If a nil error is passed, Abort
// will replace it with Stop (so that NodeComplete and DialogueComplete still
// fire).
// fire). If the VM is already stopped (either through Abort, or after the
// DialogueComplete event) an error will be returned.
func (a *AsyncAdapter) Abort(err error) error {
if old := a.state.Swap(VMStateStopped); old == VMStateStopped {
return ErrAlreadyStopped
Expand Down Expand Up @@ -183,16 +185,22 @@ func (a *AsyncAdapter) waitForChoice() (int, error) {

// --- DialogueHandler implementation --- \\

// NodeStart is called by the VM and passed through to the
// AsyncDialogueHandler directly.
// NodeStart is called by the VM and blocks until Go or Abort is called.
func (a *AsyncAdapter) NodeStart(nodeName string) error {
return a.handler.NodeStart(nodeName)
if err := a.stateTransition(VMStateRunning, VMStatePaused); err != nil {
return err
}
a.handler.NodeStart(nodeName)
return a.waitForGo()
}

// PrepareForLines is called by the VM and passed through to the
// AsyncDialogueHandler directly.
// PrepareForLines is called by the VM and blocks until Go or Abort is called.
func (a *AsyncAdapter) PrepareForLines(lineIDs []string) error {
return a.handler.PrepareForLines(lineIDs)
if err := a.stateTransition(VMStateRunning, VMStatePaused); err != nil {
return err
}
a.handler.PrepareForLines(lineIDs)
return a.waitForGo()
}

// Line is called by the VM and blocks until Go or Abort is called.
Expand Down Expand Up @@ -222,16 +230,23 @@ func (a *AsyncAdapter) Command(command string) error {
return a.waitForGo()
}

// NodeComplete is called by the VM and passed through to the
// AsyncDialogueHandler directly.
// NodeComplete is called by the VM and blocks until Go or Abort is called.
func (a *AsyncAdapter) NodeComplete(nodeName string) error {
return a.handler.NodeComplete(nodeName)
if err := a.stateTransition(VMStateRunning, VMStatePaused); err != nil {
return err
}
a.handler.NodeComplete(nodeName)
return a.waitForGo()

}

// DialogueComplete is called by the VM and passed through to the
// AsyncDialogueHandler directly.
// DialogueComplete is called by the VM and blocks until Go or Abort is called.
func (a *AsyncAdapter) DialogueComplete() error {
return a.handler.DialogueComplete()
if err := a.stateTransition(VMStateRunning, VMStatePaused); err != nil {
return err
}
a.handler.DialogueComplete()
return a.waitForGo()
}

// --- AsyncAdapter messages --- \\
Expand Down
84 changes: 52 additions & 32 deletions async_adapter_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -31,12 +31,22 @@ type syncAdapter struct {
t *testing.T
}

func (s *syncAdapter) NodeStart(nodeName string) error {
return s.dh.NodeStart(nodeName)
func (s *syncAdapter) NodeStart(nodeName string) {
if err := s.dh.NodeStart(nodeName); err != nil {
s.t.Errorf("syncAdapter.DialogueHandler.NodeStart(%q) = %v", nodeName, err)
}
if err := s.aa.Go(); err != nil {
s.t.Errorf("syncAdapter.AsyncAdapter.Go() = %v", err)
}
}

func (s *syncAdapter) PrepareForLines(lineIDs []string) error {
return s.dh.PrepareForLines(lineIDs)
func (s *syncAdapter) PrepareForLines(lineIDs []string) {
if err := s.dh.PrepareForLines(lineIDs); err != nil {
s.t.Errorf("syncAdapter.DialogueHandler.PrepareForLines(%q) = %v", lineIDs, err)
}
if err := s.aa.Go(); err != nil {
s.t.Errorf("syncAdapter.AsyncAdapter.Go() = %v", err)
}
}

func (s *syncAdapter) Line(line Line) {
Expand Down Expand Up @@ -67,12 +77,22 @@ func (s *syncAdapter) Command(command string) {
}
}

func (s *syncAdapter) NodeComplete(nodeName string) error {
return s.dh.NodeComplete(nodeName)
func (s *syncAdapter) NodeComplete(nodeName string) {
if err := s.dh.NodeComplete(nodeName); err != nil {
s.t.Errorf("syncAdapter.DialogueHandler.NodeComplete(%q) = %v", nodeName, err)
}
if err := s.aa.Go(); err != nil {
s.t.Errorf("syncAdapter.AsyncAdapter.Go() = %v", err)
}
}

func (s *syncAdapter) DialogueComplete() error {
return s.dh.DialogueComplete()
func (s *syncAdapter) DialogueComplete() {
if err := s.dh.DialogueComplete(); err != nil {
s.t.Errorf("syncAdapter.DialogueHandler.DialogueComplete() = %v", err)
}
if err := s.aa.Go(); err != nil {
s.t.Errorf("syncAdapter.AsyncAdapter.Go() = %v", err)
}
}

func TestAllTestPlansAsync(t *testing.T) {
Expand Down Expand Up @@ -191,9 +211,9 @@ func (d *decoupledAsyncHandler) Command(command string) {
}
}

func (d *decoupledAsyncHandler) DialogueComplete() error {
func (d *decoupledAsyncHandler) DialogueComplete() {
close(d.eventCh)
return nil
d.AsyncAdapter.Go()
}

func TestAsyncAdapterWithDecoupledHandler(t *testing.T) {
Expand All @@ -207,6 +227,7 @@ func TestAsyncAdapterWithDecoupledHandler(t *testing.T) {
eventCh: make(chan decoupledEvent),
}
aa := NewAsyncAdapter(dh)
dh.AsyncAdapter = aa

vm := &VirtualMachine{
Program: prog,
Expand All @@ -233,25 +254,24 @@ func TestAsyncAdapterWithDecoupledHandler(t *testing.T) {
// immediateAsyncHandler calls Go and GoWithChoice within each event.
type immediateAsyncHandler struct {
FakeAsyncDialogueHandler
aa *AsyncAdapter
t *testing.T
t *testing.T
}

func (i *immediateAsyncHandler) Line(Line) {
if err := i.aa.Go(); err != nil {
if err := i.AsyncAdapter.Go(); err != nil {
i.t.Errorf("AsyncAdapter.Go() = %v", err)
}
}

func (i *immediateAsyncHandler) Options(options []Option) {
id := options[0].ID
if err := i.aa.GoWithChoice(id); err != nil {
if err := i.AsyncAdapter.GoWithChoice(id); err != nil {
i.t.Errorf("AsyncAdapter.GoWithChoice(%d) = %v", id, err)
}
}

func (i *immediateAsyncHandler) Command(string) {
if err := i.aa.Go(); err != nil {
if err := i.AsyncAdapter.Go(); err != nil {
i.t.Errorf("AsyncAdapter.Go() = %v", err)
}
}
Expand All @@ -263,9 +283,11 @@ func TestAsyncAdapterWithImmediateHandler(t *testing.T) {
t.Fatalf("LoadFiles(%q, en) = error %v", yarnc, err)
}

ah := &immediateAsyncHandler{t: t}
ah := &immediateAsyncHandler{
t: t,
}
aa := NewAsyncAdapter(ah)
ah.aa = aa
ah.AsyncAdapter = aa

vm := &VirtualMachine{
Program: prog,
Expand All @@ -285,8 +307,7 @@ func TestAsyncAdapterWithImmediateHandler(t *testing.T) {
// ones.
type badAsyncHandler struct {
FakeAsyncDialogueHandler
aa *AsyncAdapter
t *testing.T
t *testing.T
}

func (b *badAsyncHandler) Line(Line) {
Expand All @@ -295,11 +316,11 @@ func (b *badAsyncHandler) Line(Line) {
Want: VMStatePausedOptions,
Next: VMStateRunning,
}
if diff := cmp.Diff(b.aa.GoWithChoice(6), want); diff != "" {
if diff := cmp.Diff(b.AsyncAdapter.GoWithChoice(6), want); diff != "" {
b.t.Errorf("AsyncAdapter.GoWithChoice(6) error diff (-got +want):\n%s", diff)
}
// call Go to proceed, otherwise it hangs (it's waiting for Go, duh)
if err := b.aa.Go(); err != nil {
if err := b.AsyncAdapter.Go(); err != nil {
b.t.Errorf("AsyncAdapter.Go() = %v", err)
}
}
Expand All @@ -310,12 +331,12 @@ func (b *badAsyncHandler) Options(options []Option) {
Want: VMStatePaused,
Next: VMStateRunning,
}
if diff := cmp.Diff(b.aa.Go(), want); diff != "" {
if diff := cmp.Diff(b.AsyncAdapter.Go(), want); diff != "" {
b.t.Errorf("AsyncAdapter.Go() error diff (-got +want):\n%s", diff)
}
// call GoWithChoice to proceed, otherwise it hangs
choice := options[0].ID
if err := b.aa.GoWithChoice(choice); err != nil {
if err := b.AsyncAdapter.GoWithChoice(choice); err != nil {
b.t.Errorf("AsyncAdapter.GoWithChoice(%d) = %v", choice, err)
}
}
Expand All @@ -326,11 +347,11 @@ func (b *badAsyncHandler) Command(string) {
Want: VMStatePausedOptions,
Next: VMStateRunning,
}
if diff := cmp.Diff(b.aa.GoWithChoice(0), want); diff != "" {
if diff := cmp.Diff(b.AsyncAdapter.GoWithChoice(0), want); diff != "" {
b.t.Errorf("AsyncAdapter.GoWithChoice(0) error diff (-got +want):\n%s", diff)
}
// pass Go, collect $200
if err := b.aa.Go(); err != nil {
if err := b.AsyncAdapter.Go(); err != nil {
b.t.Errorf("AsyncAdapter.Go() = %v", err)
}
}
Expand All @@ -344,7 +365,7 @@ func TestAsyncAdapterWithBadHandler(t *testing.T) {

bh := &badAsyncHandler{t: t}
aa := NewAsyncAdapter(bh)
bh.aa = aa
bh.AsyncAdapter = aa

vm := &VirtualMachine{
Program: prog,
Expand All @@ -365,24 +386,23 @@ var errDummy = errors.New("abort! abort!")
// abortAsyncHandler calls Abort within each event.
type abortAsyncHandler struct {
FakeAsyncDialogueHandler
aa *AsyncAdapter
t *testing.T
t *testing.T
}

func (a *abortAsyncHandler) Line(Line) {
if err := a.aa.Abort(errDummy); err != nil {
if err := a.AsyncAdapter.Abort(errDummy); err != nil {
a.t.Errorf("AsyncAdapter.Abort(errDummy) = %v", err)
}
}

func (a *abortAsyncHandler) Options(options []Option) {
if err := a.aa.Abort(errDummy); err != nil {
if err := a.AsyncAdapter.Abort(errDummy); err != nil {
a.t.Errorf("AsyncAdapter.Abort(errDummy) = %v", err)
}
}

func (a *abortAsyncHandler) Command(string) {
if err := a.aa.Abort(errDummy); err != nil {
if err := a.AsyncAdapter.Abort(errDummy); err != nil {
a.t.Errorf("AsyncAdapter.Abort(errDummy) = %v", err)
}
}
Expand All @@ -396,7 +416,7 @@ func TestAsyncAdapterWithAbortHandler(t *testing.T) {

bh := &abortAsyncHandler{t: t}
aa := NewAsyncAdapter(bh)
bh.aa = aa
bh.AsyncAdapter = aa

vm := &VirtualMachine{
Program: prog,
Expand Down
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