fix: 隔离 Pod 与 VM 并发容量

cmd/gitea-dynamic-runner/controller.go

@@ -91,7 +91,6 @@ func runController(ctx context.Context) error {
 		return err
 	}
 	registry := runnerfacade.NewRegistry()
-	gate := taskscheduler.NewSingleFlightGate()
 	var podExecutorBackend *podbackend.Backend
 	var vmExecutorBackend *opensandboxbackend.Backend
 	giteaClient := giteaactions.NewClient(giteaactions.DefaultHTTPClient(), config.GiteaURL, config.GiteaUUID, config.GiteaToken)
@@ -114,7 +113,6 @@ func runController(ctx context.Context) error {
 					return err
 				}
 			}
-			gate.Release()
 			return nil
 		},
 	}
@@ -131,7 +129,7 @@ func runController(ctx context.Context) error {
 		labels = append(labels, string(taskassignment.BackendVM))
 	}
 	poller := taskscheduler.Poller{
-		Client: giteaClient, Gate: gate,
+		Client: giteaClient,
 		Scheduler: &taskscheduler.Scheduler{TrustDomain: config.TrustDomain, Dispatcher: assignmentqueue.Publisher{
 			JetStream: producerJS, SubjectBase: config.SubjectBase,
 		}},

docs/runner-protocol-roadmap.md

@@ -80,9 +80,9 @@ facade，并严格校验 facade 的 SPIFFE ID。这样无需修改 runner 或把
 - consumer 在 executor 使用上述 facade 成功 claim task 后确认 assignment；无需把完整
   task 写入 Pod annotation、OpenSandbox metadata 或环境变量。
 - Pod 与 VM 共享 task/executor 协议，只有环境创建和销毁实现不同。
-- 首次生产 canary 使用 controller 进程内 single-flight gate：只有官方 runner 的终态
-  `UpdateTask` 已被 Gitea 接受后才允许 Fetch 下一条任务。它把未知故障收敛为停止领取，
-  而不是在 backlog 下连续创建 executor；后续容量调度必须以 backend 实际运行资源为准。
+- scheduler 在 assignment 持久化到 JetStream 后即可继续领取；Pod 与 VM 分别由 durable
+  consumer 的 capacity 限制并发，不共享全局执行槽位。未知后端故障由对应 consumer 的
+  NAK/redelivery 收敛，不能阻塞另一种 backend。
 - 两种 backend 都注入同一份 runner bootstrap 环境；Pod 仍由 homelab Kubernetes 原生
   创建，只有 VM 经 OpenSandbox 创建，bootstrap 机制不改变 backend 边界。
 

internal/taskscheduler/gate.go

@@ -1,31 +0,0 @@
-package taskscheduler
-
-import "context"
-
-// SingleFlightGate keeps at most one fetched task in flight. Release is
-// idempotent so repeated terminal updates cannot increase capacity.
-type SingleFlightGate struct {
-	token chan struct{}
-}
-
-func NewSingleFlightGate() *SingleFlightGate {
-	gate := &SingleFlightGate{token: make(chan struct{}, 1)}
-	gate.token <- struct{}{}
-	return gate
-}
-
-func (g *SingleFlightGate) Acquire(ctx context.Context) error {
-	select {
-	case <-g.token:
-		return nil
-	case <-ctx.Done():
-		return ctx.Err()
-	}
-}
-
-func (g *SingleFlightGate) Release() {
-	select {
-	case g.token <- struct{}{}:
-	default:
-	}
-}

internal/taskscheduler/gate_test.go

@@ -1,29 +0,0 @@
-package taskscheduler
-
-import (
-	"context"
-	"testing"
-	"time"
-)
-
-func TestSingleFlightGateBlocksUntilTerminalRelease(t *testing.T) {
-	gate := NewSingleFlightGate()
-	if err := gate.Acquire(context.Background()); err != nil {
-		t.Fatal(err)
-	}
-	blocked, cancel := context.WithTimeout(context.Background(), 20*time.Millisecond)
-	defer cancel()
-	if err := gate.Acquire(blocked); err == nil {
-		t.Fatal("second task acquired capacity before release")
-	}
-	gate.Release()
-	gate.Release()
-	if err := gate.Acquire(context.Background()); err != nil {
-		t.Fatal(err)
-	}
-	blockedAgain, cancelAgain := context.WithTimeout(context.Background(), 20*time.Millisecond)
-	defer cancelAgain()
-	if err := gate.Acquire(blockedAgain); err == nil {
-		t.Fatal("duplicate terminal release increased capacity")
-	}
-}

internal/taskscheduler/poller.go

@@ -26,7 +26,6 @@ type PollerConfig struct {
 type Poller struct {
 	Client    PollClient
 	Scheduler *Scheduler
-	Gate      *SingleFlightGate
 	Config    PollerConfig
 	OnError   func(error)
 }
@@ -51,14 +50,7 @@ func (p Poller) Run(ctx context.Context) error {
 		errorBackoff = 5 * time.Second
 	}
 	var tasksVersion int64
-	haveLease := false
 	for {
-		if p.Gate != nil && !haveLease {
-			if err := p.Gate.Acquire(ctx); err != nil {
-				return nil
-			}
-			haveLease = true
-		}
 		response, err := p.Client.FetchTask(ctx, tasksVersion)
 		if err != nil {
 			if ctx.Err() != nil {
@@ -80,10 +72,6 @@ func (p Poller) Run(ctx context.Context) error {
 		tasksVersion = response.GetTasksVersion()
 		task := response.GetTask()
 		if task == nil {
-			if p.Gate != nil {
-				p.Gate.Release()
-				haveLease = false
-			}
 			if !wait(ctx, emptyBackoff) {
 				return nil
 			}
@@ -91,7 +79,6 @@ func (p Poller) Run(ctx context.Context) error {
 		}
 		for {
 			if err := p.Scheduler.Run(ctx, task); err == nil {
-				haveLease = false
 				break
 			} else {
 				if ctx.Err() != nil {