asyncmachine.dev

To read about am-dbg, go to /tools/cmd/am-dbg. This package is about the implementation, not the end-user application.

/tools/debugger is a cview TUI app with a single state-machine consisting of:

input events (7 states)
external state (25 states)
actions (18 states)

This state machine features a decent amount of relations within a large number of states and 5 state groups. It’s also a good example to see how easily an AM-based program can be controller with a script in /internal/cmd/am-dbg-video.

See machine schema and relations

// States map defines relations and properties of states.
var States = am.Schema{

    // ///// Input events

    ClientMsg:       {Multi: true},
    ConnectEvent:    {Multi: true},
    DisconnectEvent: {Multi: true},

    // user scrolling tx / steps
    UserFwd: {
        Add:    S{Fwd},
        Remove: GroupPlaying,
    },
    UserBack: {
        Add:    S{Back},
        Remove: GroupPlaying,
    },
    UserFwdStep: {
        Add:     S{FwdStep},
        Require: S{ClientSelected},
        Remove:  SAdd(GroupPlaying, S{LogUserScrolled}),
    },
    UserBackStep: {
        Add:     S{BackStep},
        Require: S{ClientSelected},
        Remove:  SAdd(GroupPlaying, S{LogUserScrolled}),
    },

    // ///// Read-only states (e.g. UI)

    // focus group

    TreeFocused:          {Remove: GroupFocused},
    LogFocused:           {Remove: GroupFocused},
    ClientListFocused:    {Remove: GroupFocused},
    TimelineTxsFocused:   {Remove: GroupFocused},
    TimelineStepsFocused: {Remove: GroupFocused},
    MatrixFocused:        {Remove: GroupFocused},
    DialogFocused:        {Remove: GroupFocused},
    Toolbar1Focused:      {Remove: GroupFocused},
    Toolbar2Focused:      {Remove: GroupFocused},
    LogReaderFocused: {
        Require: S{LogReaderVisible},
        Remove:  GroupFocused,
    },
    AddressFocused: {Remove: GroupFocused},

    TimelineHidden:      {Require: S{TimelineStepsHidden}},
    TimelineStepsHidden: {},
    NarrowLayout: {
        Require: S{Ready},
        Remove:  S{ClientListVisible},
    },
    ClientListVisible: {
        Require: S{Ready},
        Auto:    true,
    },
    StateNameSelected:     {Require: S{ClientSelected}},
    TimelineStepsScrolled: {Require: S{ClientSelected}},
    HelpDialog:            {Remove: GroupDialog},
    ExportDialog: {
        Require: S{ClientSelected},
        Remove:  GroupDialog,
    },
    LogUserScrolled: {
        Remove: S{Playing, TailMode},
        Require: S{LogFocused},
    },
    Ready: {Require: S{Start}},
    FilterAutoTx:      {},
    FilterCanceledTx:  {},
    FilterEmptyTx:     {},
    FilterSummaries:   {},
    FilterHealthcheck: {},

    // ///// Actions

    Start: {Add: S{FilterSummaries, FilterHealthcheck, FilterEmptyTx}},
    Healthcheck: {
        Multi:   true,
        Require: S{Start},
    },
    GcMsgs: {Remove: S{SelectingClient, SwitchedClientTx, ScrollToTx,
        ScrollToMutTx}},
    TreeLogView: {
        Auto:    true,
        Require: S{Start},
        Remove:  SAdd(GroupViews, S{TreeMatrixView, MatrixView, MatrixRain}),
    },
    MatrixView:     {Remove: GroupViews},
    TreeMatrixView: {Remove: GroupViews},
    TailMode: {
        Require: S{ClientSelected},
        Remove:  SAdd(GroupPlaying, S{LogUserScrolled}),
    },
    Playing: {
        Require: S{ClientSelected},
        Remove:  SAdd(GroupPlaying, S{LogUserScrolled}),
    },
    Paused: {
        Auto:    true,
        Require: S{ClientSelected},
        Remove:  GroupPlaying,
    },
    ToggleTool: {},
    SwitchingClientTx: {
        Require: S{Ready},
        Remove:  GroupSwitchedClientTx,
    },
    SwitchedClientTx: {
        Require: S{Ready},
        Remove:  GroupSwitchedClientTx,
    },
    ScrollToMutTx: {Require: S{ClientSelected}},
    MatrixRain: {},
    LogReaderVisible: {
        Auto:    true,
        Require: S{TreeLogView, LogReaderEnabled},
    },
    LogReaderEnabled: {},
    UpdateLogReader:  {Require: S{LogReaderEnabled}},

    // tx / steps back / fwd

    Fwd: {
        Require: S{ClientSelected},
    },
    Back: {
        Require: S{ClientSelected},
    },
    FwdStep: {
        Require: S{ClientSelected},
    },
    BackStep: {
        Require: S{ClientSelected},
    },

    ScrollToTx: {
        Require: S{ClientSelected},
        Remove:  S{TailMode, Playing, TimelineStepsScrolled},
    },
    ScrollToStep: {
        Require: S{ClientSelected},
        Remove:  S{TailMode, Playing},
    },

    // client selection

    SelectingClient: {
        Require: S{Start},
        Remove:  S{ClientSelected},
    },
    ClientSelected: {
        Require: S{Start},
        Remove:  S{SelectingClient},
    },
    RemoveClient: {Require: S{ClientSelected}},

    SetCursor: {
        Multi:   true,
        Require: S{Ready},
    },
    GraphsScheduled: {
        Multi:   true,
        Require: S{Ready},
    },
    GraphsRendering: {
        Require: S{Ready},
    },

    InitClient: {Multi: true},
}

You can read the source at /tools/debugger and states at /tools/debugger/states.

Integration Tests

/tools/debugger/test contains integration tests which use a local worker instance, which is then controlled with Add1Block and Add1AsyncBlock from /pkg/helpers to perform test scenarios. None of the tests ever calls time.Sleep, as everything is synchronized via asyncmachine’s clock. The local test worker doesn’t have UI and uses tcell.SimulationScreen instead.

Remote Worker

/tools/debugger/test/remote contains integration tests which use a remote worker to execute the same suite. The worker has to be started separately using task am-dbg-worker, and because it’s a regular TUI app, this one has a UI which can be seen and controlled by the user (on top of the test suite itself).

Debugging Workers

Because both local and remote workers are state machines, they can export telemetry to a debugger instance. In aRPC Tutorial one can find a video demo presenting a debugging session of a remote worker. To activate remote debugging, please set AM_TEST_DEBUG=1 and run task am-dbg-dbg prior to tests. Remote tests are run via task test-debugger-remote.

Schema

State schema from /tools/debugger/states/ss_dbg.go.

schema

/tools/debugger/README.md

Integration Tests

Remote Worker

Debugging Workers

Schema