Make intentional error discards explicit

[onechat] / subagent_run.go

diff --git a/subagent_run.go b/subagent_run.go
index 3ee98a076a22311424b3321e201878ce30e9148e..24e4f8229c975a3f9fca2e7e3002530e7da76a99 100644 (file)
--- a/subagent_run.go
+++ b/subagent_run.go
@@ -2,12 +2,17 @@ package main
 
 import (
        "context"
 
 import (
        "context"

+       "encoding/json"

        "errors"
        "fmt"
        "errors"
        "fmt"

+       "log/slog"
+       "maps"

        "os"
        "os"

+       "path/filepath"

        "slices"
        "strings"
        "sync"
        "slices"
        "strings"
        "sync"

+       "time"

 )
 
 const (
 )
 
 const (


@@ -17,21 +22,43 @@ const (
        // subagentNoteEffort follows subagentNote when the subagent has its own
        // effort.
        subagentNoteEffort = " at effort "
        // subagentNoteEffort follows subagentNote when the subagent has its own
        // effort.
        subagentNoteEffort = " at effort "

+
+       // subagentWorkFileName is the file of the names of the running
+       // subagents in the directory of an agent.
+       subagentWorkFileName = "work.json"
+)
+
+// The statuses of the end of a run, in the work event of its report.
+const (
+       subagentFinished = "finished"
+       subagentStopped  = "stopped"
+       subagentFailed   = "failed"

 )
 
 // errSubagentClosed tells that the runs of the subagents ended with the loop.
 var errSubagentClosed = errors.New("the daemon stops, so no subagent starts")
 
 )
 
 // errSubagentClosed tells that the runs of the subagents ended with the loop.
 var errSubagentClosed = errors.New("the daemon stops, so no subagent starts")
 

-// SubagentRuns runs the subagents of one agent in the background. Each run is
-// a goroutine with its own Chain and its own context, which only Close ends.
-// The first request of each chain holds the view of the agent at the spawn,
-// then the state of the turn, then the whole log of the subagent. The report of
-// the run goes to report: its final answer, or the error of a failed call. At
-// the stop of the daemon the runs end with no report.
+// SubagentRuns runs the subagents of one agent in the background. Each run is a
+// goroutine with its own context, which only Stop and Close end. A run is one
+// or more request chains. The first request of each chain holds the view of the
+// agent at the start of the run, then the state of the turn, then the whole log
+// of the subagent. A message of Tell that comes during a chain joins its next
+// request after the tool results. One that comes after the final answer starts
+// one more chain, which reads the log again. The report of the run goes to
+// report: the final answer of each chain, or the error of a failed call. The
+// logger gets one line at the end of a run: done, failed with the cause, or
+// stopped. Stop ends one run, and its report says that it stopped. At the stop
+// of the daemon the runs end with no report.
+//
+// work.json in the directory of the agent holds the names of the running
+// subagents. Each start and each end of a run writes it whole, but Close does
+// not, so after a stop of the daemon it names the runs that the stop cut, and
+// Resume goes on with them. The logs alone cannot tell this, because a stop can
+// cut a run just after its final reply.

 //
 //

-// Spawn splits the view with the layout of the agent, which has no lock. Spawn
-// is a tool, so it runs in the goroutine of the turns, as each split of a turn
-// does.
+// Spawn and Tell split the view with the layout of the agent, which has no
+// lock. They are tools, so they run in the goroutine of the turns, as each
+// split of a turn does.

 type SubagentRuns struct {
        agent     *Agent
        memory    *Memory
 type SubagentRuns struct {
        agent     *Agent
        memory    *Memory


@@ -39,7 +66,10 @@ type SubagentRuns struct {
        layout    *ViewLayout
        client    ChainClient
        state     func() string
        layout    *ViewLayout
        client    ChainClient
        state     func() string

-       report    func(text string, stopped bool)
+       report    func(name, text, status string)
+       note      func(text string) error
+       fail      func(err error)
+       logger    *slog.Logger

        notify    func(Event)
 
        mutex   sync.Mutex
        notify    func(Event)
 
        mutex   sync.Mutex


@@ -48,6 +78,25 @@ type SubagentRuns struct {
        workers sync.WaitGroup
 }
 
        workers sync.WaitGroup
 }
 

+// SubagentRun is one run of a subagent: the view that its requests get, its
+// effort, the end of its context, the messages of Tell that wait for a request,
+// whether Stop ended it, and the time it started. The mutex of SubagentRuns
+// protects the messages and the stop.
+type SubagentRun struct {
+       subagent *Subagent
+       view     []string
+       effort   string
+       cancel   context.CancelFunc
+       pending  []Message
+       stopped  bool
+       started  time.Time
+}
+
+// SubagentWorkFile is the content of work.json.
+type SubagentWorkFile struct {
+       Running []string `json:"running"`
+}
+

 // Spawn starts one subagent for each task and returns their names at once. It
 // waits until the view has no pending summary, and gives the view to each
 // subagent. A nil effort is the effort of the agent.
 // Spawn starts one subagent for each task and returns their names at once. It
 // waits until the view has no pending summary, and gives the view to each
 // subagent. A nil effort is the effort of the agent.


@@ -57,6 +106,7 @@ func (r *SubagentRuns) Spawn(ctx context.Context, tasks []string, effort *string
        }
 
        r.mutex.Lock()
        }
 
        r.mutex.Lock()

+

        closed := r.closed
        r.mutex.Unlock()
 
        closed := r.closed
        r.mutex.Unlock()
 


@@ -134,23 +184,40 @@ func (r *SubagentRuns) create(ctx context.Context, note, task string, view []str
        })
 }
 
        })
 }
 

-// start runs run in the background. Its context keeps the values of ctx, but
-// only Close ends it.
+// start runs run in the background and logs its start. Its context keeps the
+// values of ctx, but only Stop and Close end it.

 func (r *SubagentRuns) start(ctx context.Context, run *SubagentRun) error {
        ctx, run.cancel = context.WithCancel(context.WithoutCancel(ctx))
 
        r.mutex.Lock()
 func (r *SubagentRuns) start(ctx context.Context, run *SubagentRun) error {
        ctx, run.cancel = context.WithCancel(context.WithoutCancel(ctx))
 
        r.mutex.Lock()

-       if r.closed {
+
+       _, found := r.running[run.subagent.name]
+       if r.closed || found {

                r.mutex.Unlock()
                run.cancel()
 
                r.mutex.Unlock()
                run.cancel()
 

+               if found {
+                       return fmt.Errorf("%s runs already", run.subagent.name)
+               }
+

                return errSubagentClosed
        }
 
        r.running[run.subagent.name] = run
                return errSubagentClosed
        }
 
        r.running[run.subagent.name] = run

+       err := r.save()
+       if err != nil {
+               delete(r.running, run.subagent.name)
+               r.mutex.Unlock()
+               run.cancel()
+
+               return err
+       }
+

        r.workers.Add(1)
        r.mutex.Unlock()
 
        r.workers.Add(1)
        r.mutex.Unlock()
 

+       run.started = r.subagents.clock()
+       r.logger.Info("subagent started", "name", run.subagent.name)

        r.notify(Event{
                Kind: "subagent",
                Text: run.subagent.name,
        r.notify(Event{
                Kind: "subagent",
                Text: run.subagent.name,


@@ -161,35 +228,113 @@ func (r *SubagentRuns) start(ctx context.Context, run *SubagentRun) error {
        return nil
 }
 
        return nil
 }
 

-// run runs the chain of run and reports its end, unless Close ended it.
+// save writes the names of the running subagents to work.json. The caller holds
+// the mutex.
+func (r *SubagentRuns) save() error {
+       file := SubagentWorkFile{
+               Running: append([]string{}, slices.Sorted(maps.Keys(r.running))...),
+       }
+
+       data, err := json.Marshal(file)
+       if err != nil {
+               return fmt.Errorf("encode running subagents: %w", err)
+       }
+
+       err = writeFileAtomic(r.workPath(), append(data, '\n'))
+       if err != nil {
+               return fmt.Errorf("save running subagents: %w", err)
+       }
+
+       return nil
+}
+
+// run runs the chains of run and reports and logs its end with the length of
+// the run, unless Close ended it. A chain follows while messages wait after the
+// final answer of the chain before it, and no chain failed. A chain that Stop
+// ends gives the reply "stopped".

 func (r *SubagentRuns) run(ctx context.Context, run *SubagentRun) {
        defer r.workers.Done()
        defer run.cancel()
 
 func (r *SubagentRuns) run(ctx context.Context, run *SubagentRun) {
        defer r.workers.Done()
        defer run.cancel()
 

-       reply := r.chain(ctx, run)
+       var (
+               replies []string
+               failure error
+       )
+
+       stopped := false
+       status := subagentFinished
+       for more := true; more; {
+               reply, err := r.chain(ctx, run)
+
+               r.mutex.Lock()
+
+               stopped = run.stopped
+               switch {
+               case err != nil && stopped:
+                       reply = "stopped"
+               case err != nil:
+                       reply = "failed: " + err.Error()
+                       status = subagentFailed
+                       failure = err
+               }
+
+               more = err == nil && ctx.Err() == nil && len(run.pending) > 0
+               run.pending = nil

 
 

-       r.mutex.Lock()
-       delete(r.running, run.subagent.name)
-       r.mutex.Unlock()
+               var saveErr error

 
 

-       if ctx.Err() != nil {
+               if !more {
+                       delete(r.running, run.subagent.name)
+
+                       if !r.closed {
+                               saveErr = r.save()
+                       }
+               }
+
+               r.mutex.Unlock()
+
+               if saveErr != nil {
+                       r.fail(saveErr)
+               }
+
+               replies = append(replies, reply)
+       }
+
+       if ctx.Err() != nil && !stopped {

                return
        }
 
                return
        }
 

-       r.report(subagentReport(run.subagent.name, []string{reply}), false)
+       if stopped {
+               status = subagentStopped
+       }
+
+       length := r.subagents.clock().Sub(run.started)
+       switch status {
+       case subagentStopped:
+               r.logger.Info("subagent stopped", "name", run.subagent.name, "after", length)
+       case subagentFailed:
+               r.logger.Error("subagent failed", "name", run.subagent.name, "after", length, "err", failure)
+       default:
+               r.logger.Info("subagent done", "name", run.subagent.name, "after", length)
+       }
+
+       r.report(run.subagent.name, subagentReport(run.subagent.name, replies), status)

 }
 
 }
 

-// chain runs one request chain of run and returns its final answer, or the
-// error of the chain after "failed: ".
-func (r *SubagentRuns) chain(ctx context.Context, run *SubagentRun) string {
+func (r *SubagentRuns) workPath() string {
+       return filepath.Join(r.agent.dir, subagentWorkFileName)
+}
+
+// chain runs one request chain of run and returns its final answer.
+func (r *SubagentRuns) chain(ctx context.Context, run *SubagentRun) (string, error) {

        instructions, err := r.agent.SubagentPrompt()
        if err != nil {
        instructions, err := r.agent.SubagentPrompt()
        if err != nil {

-               return "failed: " + err.Error()
+               return "", err

        }
 
        log, err := run.subagent.Show()
        if err != nil {
        }
 
        log, err := run.subagent.Show()
        if err != nil {

-               return "failed: " + err.Error()
+               return "", err

        }
 
        input := make([]any, 0, len(run.view)+2)
        }
 
        input := make([]any, 0, len(run.view)+2)


@@ -200,11 +345,13 @@ func (r *SubagentRuns) chain(ctx context.Context, run *SubagentRun) string {
        input = append(input, modelUserMessage(r.state()), modelUserMessage(log))
        chain := &Chain{
                client: r.client,
        input = append(input, modelUserMessage(r.state()), modelUserMessage(log))
        chain := &Chain{
                client: r.client,

+               images: r.agent.Images(),

                tools: &Toolbox{
                        log:       run.subagent,
                        chat:      r.memory,
                        subagents: r.subagents,
                        workdir:   run.subagent.WorkDir(),
                tools: &Toolbox{
                        log:       run.subagent,
                        chat:      r.memory,
                        subagents: r.subagents,
                        workdir:   run.subagent.WorkDir(),

+                       images:    r.agent.Images(),

                },
                request: ModelRequest{
                        Model:        r.agent.config.Model,
                },
                request: ModelRequest{
                        Model:        r.agent.config.Model,


@@ -214,39 +361,215 @@ func (r *SubagentRuns) chain(ctx context.Context, run *SubagentRun) string {
                        Agent:        run.subagent.name,
                },
                take: func() []Message {
                        Agent:        run.subagent.name,
                },
                take: func() []Message {

-                       return nil
+                       return r.take(run)

                },
        }
 
                },
        }
 

-       reply, err := chain.Run(ctx, input)
+       return chain.Run(ctx, input)
+}
+
+// take returns the messages of Tell that wait for a request of run, and removes
+// them.
+func (r *SubagentRuns) take(run *SubagentRun) []Message {
+       r.mutex.Lock()
+       defer r.mutex.Unlock()
+
+       messages := run.pending
+       run.pending = nil
+
+       return messages
+}
+
+// Stop ends the run of the subagent name and tells if it ran. The chat gets the
+// note "Stopped by the user: NAME." under the mutex, so the note comes before
+// the report of the run.
+func (r *SubagentRuns) Stop(name string) (bool, error) {
+       r.mutex.Lock()
+       defer r.mutex.Unlock()
+
+       run, found := r.running[name]
+       if !found {
+               return false, nil
+       }
+
+       err := r.note("Stopped by the user: " + name + ".")
+       if err != nil {
+               return true, err
+       }
+
+       run.stopped = true
+       run.cancel()
+
+       return true, nil
+}
+
+// Resume goes on with the runs that a stop of the daemon cut, as work.json
+// names them. The chat gets the note "The daemon restarted, cutting NAMES;
+// nothing was lost: go on.", and each cut subagent gets the same text as a
+// message of Tell. A subagent that cannot go on gets a failed report.
+func (r *SubagentRuns) Resume(ctx context.Context) error {
+       names, err := r.load()
+       if err != nil || len(names) == 0 {
+               return err
+       }
+
+       text := "The daemon restarted, cutting " + strings.Join(names, ", ") + "; nothing was lost: go on."
+       err = r.note(text)
+       if err != nil {
+               return err
+       }
+
+       for _, name := range names {
+               _, err = r.Tell(ctx, name, text)
+               if err != nil {
+                       r.logger.Error("subagent lost at restart", "name", name, "err", err)
+                       r.report(name, subagentReport(name, []string{"failed: " + err.Error()}), subagentFailed)
+               }
+       }
+
+       // A subagent that cannot go on does not run, so work.json no longer
+       // names it, and the next start does not try it again.
+       r.mutex.Lock()
+       defer r.mutex.Unlock()
+
+       return r.save()
+}
+
+// load reads the names of work.json. A missing file names none.
+func (r *SubagentRuns) load() ([]string, error) {
+       data, err := os.ReadFile(r.workPath())
+       if errors.Is(err, os.ErrNotExist) {
+               return nil, nil
+       }
+

        if err != nil {
        if err != nil {

-               return "failed: " + err.Error()
+               return nil, fmt.Errorf("read running subagents: %w", err)

        }
 
        }
 

-       return reply
+       var file SubagentWorkFile
+
+       err = json.Unmarshal(data, &file)
+       if err != nil {
+               return nil, fmt.Errorf("decode running subagents: %w", err)
+       }
+
+       return file.Running, nil
+}
+
+// Tell sends message to the subagent name. A running subagent reads it between
+// its tool calls, and its report answers it. A finished subagent goes on from
+// its log with a new run, with the view of now and the effort of its note.
+func (r *SubagentRuns) Tell(ctx context.Context, name, message string) (string, error) {
+       r.mutex.Lock()
+
+       run, found := r.running[name]
+       if found {
+               defer r.mutex.Unlock()
+
+               told, err := run.subagent.Append("user", message)
+               if err != nil {
+                       return "", err
+               }
+
+               run.pending = append(run.pending, told)
+
+               return "Sent. " + name + " reads it between its tool calls, and its report answers it.", nil
+       }
+
+       closed := r.closed
+       r.mutex.Unlock()
+
+       if closed {
+               return "", errSubagentClosed
+       }
+
+       subagent, err := r.subagents.Get(ctx, name)
+       if err != nil {
+               return "", err
+       }
+
+       effort, err := r.effort(subagent)
+       if err != nil {
+               return "", err
+       }
+
+       err = r.memory.Settle(ctx)
+       if err != nil {
+               return "", fmt.Errorf("wait for the summaries: %w", err)
+       }
+
+       view, err := r.layout.Split(r.memory.ViewLines(nil))
+       if err != nil {
+               return "", err
+       }
+
+       _, err = subagent.Append("user", message)
+       if err == nil {
+               err = subagent.Flush(ctx)
+       }
+
+       if err != nil {
+               return "", err
+       }
+
+       err = r.start(ctx, &SubagentRun{
+               subagent: subagent,
+               view:     view,
+               effort:   effort,
+       })
+       if err != nil {
+               return "", err
+       }
+
+       return "Sent. " + name + "'s reply will reach you as a message.", nil
+}
+
+// effort returns the effort of subagent from the note at the start of its log:
+// the effort of the agent, or the effort that the note names.
+func (r *SubagentRuns) effort(subagent *Subagent) (string, error) {
+       note, err := subagent.First()
+       if err != nil {
+               return "", err
+       }
+
+       effort, own := strings.CutPrefix(note.Text, subagentNote+subagentNoteEffort)
+       switch {
+       case note.Kind != "note":
+       case own:
+               return effort, nil
+       case note.Text == subagentNote:
+               return r.agent.config.Effort, nil
+       }
+
+       return "", fmt.Errorf("the log of %s does not start with a subagent note", subagent.name)
+}
+
+// Snapshot locks the run state, memory, and subagent logs while snapshot reads
+// the agent files. The lock order agrees with Stop, which logs under the run
+// lock.
+func (r *SubagentRuns) Snapshot(ctx context.Context, snapshot func() error) error {
+       r.mutex.Lock()
+       defer r.mutex.Unlock()
+
+       return r.memory.Snapshot(ctx, func() error {
+               return r.subagents.Snapshot(ctx, snapshot)
+       })

 }
 
 // Close ends every run and waits for them. No subagent starts after Close.
 func (r *SubagentRuns) Close() {
        r.mutex.Lock()
 }
 
 // Close ends every run and waits for them. No subagent starts after Close.
 func (r *SubagentRuns) Close() {
        r.mutex.Lock()

+

        r.closed = true
        for _, run := range r.running {
                run.cancel()
        }
        r.closed = true
        for _, run := range r.running {
                run.cancel()
        }

+

        r.mutex.Unlock()
 
        r.workers.Wait()
 }
 
        r.mutex.Unlock()
 
        r.workers.Wait()
 }
 

-// SubagentRun is one run of a subagent: the view that its requests get, its
-// effort, and the end of its context.
-type SubagentRun struct {
-       subagent *Subagent
-       view     []string
-       effort   string
-       cancel   context.CancelFunc
-}
-

 // subagentReport returns the report of the subagent name with its replies: the
 // name in brackets, a new line, the replies, and the zoom that gives its whole
 // chat.
 // subagentReport returns the report of the subagent name with its replies: the
 // name in brackets, a new line, the replies, and the zoom that gives its whole
 // chat.