feat: release v0.27 unified HTTP limits and safe request shutdown

app/app.go

@@ -33,6 +33,10 @@ type App struct {
 	closeErr         error
 	clientIPResolver *httpx.ClientIPResolver
 	responseEncoder  response.Encoder
+	requests         requestDrain
+	bodyLimits       []routeBodyLimit
+	validateOnce     sync.Once
+	validateErr      error
 }
 
 // Runner is the small lifecycle boundary used by an HTTP server
@@ -100,7 +104,14 @@ func newApp(router httpx.Router, settings config.Config) *App {
 	}
 	middlewares = append(middlewares, middleware.Recovery())
 	application := &App{router: router, config: settings, middlewares: middlewares, clientIPResolver: resolver, responseEncoder: responseEncoder}
-	application.handler = corsPolicy.Wrap(router)
+	application.requests.done = make(chan struct{})
+	application.handler = corsPolicy.Wrap(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.ContentLength > application.hardBodyLimit() {
+			application.adapt(func(*httpx.Context) error { return apierrors.New(413, "BODY_TOO_LARGE", "request body exceeds limit") }).ServeHTTP(w, r)
+			return
+		}
+		router.ServeHTTP(w, r)
+	}))
 	if fallback, ok := router.(httpx.FallbackRouter); ok {
 		adaptError := func(status int, code, message string) http.Handler {
 			return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -113,15 +124,31 @@ func newApp(router httpx.Router, settings config.Config) *App {
 }
 
 // Router exposes the underlying routing contract for advanced registration.
-// Serve requests through App or Engine so application CORS policy is applied.
+// Serve through App or Engine for CORS, hard body limits and shutdown tracking.
 func (a *App) Router() httpx.Router { return a.router }
 
 // Engine is kept as a compatibility name for the old API. It returns a
 // standard http.Handler, so callers do not depend on a router type.
-func (a *App) Engine() http.Handler { return a.handler }
+func (a *App) Engine() http.Handler { return a }
 
 // ServeHTTP implements http.Handler for standard servers and HTTP tests.
 func (a *App) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
+	ctx, work := a.requests.begin(request.Context())
+	if work == nil {
+		// Do not invoke encoders, middleware or loggers after their owners close.
+		http.Error(writer, "server shutting down", http.StatusServiceUnavailable)
+		return
+	}
+	defer a.requests.end(work)
+	a.validateOnce.Do(func() { a.validateErr = a.ValidateHTTP() })
+	if a.validateErr != nil {
+		http.Error(writer, "invalid HTTP configuration", http.StatusServiceUnavailable)
+		return
+	}
+	request = request.WithContext(ctx)
+	if request.Body != nil {
+		request.Body = http.MaxBytesReader(writer, request.Body, a.hardBodyLimit())
+	}
 	a.handler.ServeHTTP(writer, request)
 }
 
@@ -143,7 +170,8 @@ func (a *App) Use(middleware ...httpx.Middleware) *App {
 }
 
 // OnShutdown registers a cleanup function owned by the application. Cleanup
-// functions run in reverse registration order when Close or RunContext ends.
+// functions run in reverse registration order after all handlers have returned.
+// Incomplete draining skips these callbacks and returns ErrResourcesRetained.
 // This keeps omni.New as the only public startup entry point while allowing
 // projects to attach databases, loggers and other resources to its lifecycle.
 func (a *App) OnShutdown(cleanup func() error) *App {
@@ -153,9 +181,21 @@ func (a *App) OnShutdown(cleanup func() error) *App {
 	return a
 }
 
-// Close releases application resources. It is safe to call more than once.
+// Close stops admission, cancels active requests and waits for their handlers
+// to return before releasing resources. It is idempotent. If cancellation grace
+// expires, ErrResourcesRetained is permanent and no cleanup callbacks run.
+// Use RunContext/ServeContext for graceful draining before cancellation. Do not
+// call Close from a handler or cleanup callback; it would wait for itself.
 func (a *App) Close() error {
 	a.closeOnce.Do(func() {
+		timeout := a.config.HTTP.ShutdownCancelTimeout
+		if timeout <= 0 {
+			timeout = 5 * time.Second
+		}
+		if err := a.requests.cancelAndWait(timeout); err != nil {
+			a.closeErr = err
+			return
+		}
 		for index := len(a.closers) - 1; index >= 0; index-- {
 			if err := a.closers[index](); err != nil {
 				a.closeErr = errors.Join(a.closeErr, err)
@@ -177,7 +217,7 @@ func (a *App) Run(address ...string) error {
 // Invalid HTTP options panic; RunContext/ServeContext return validation errors.
 // Use RunContext or ServeContext to apply the configured transport and TLS.
 func (a *App) NewServer(address string) *http.Server {
-	if err := a.config.HTTP.Validate(); err != nil {
+	if err := a.ValidateHTTP(); err != nil {
 		panic(err)
 	}
 	if address == "" {
@@ -187,7 +227,7 @@ func (a *App) NewServer(address string) *http.Server {
 		}
 	}
 	cfg := a.config.HTTP
-	return &http.Server{Addr: address, Handler: a.handler,
+	return &http.Server{Addr: address, Handler: a,
 		ReadHeaderTimeout: cfg.ReadHeaderTimeout, ReadTimeout: cfg.ReadTimeout,
 		WriteTimeout: cfg.WriteTimeout, IdleTimeout: cfg.IdleTimeout,
 		MaxHeaderBytes: cfg.MaxHeaderBytes, ErrorLog: cfg.ErrorLog}
@@ -202,6 +242,8 @@ func (a *App) RunContext(ctx context.Context, address ...string) (runErr error)
 	if ctx.Err() != nil {
 		return a.Close()
 	}
+	stopWatching := a.watchShutdown(ctx)
+	defer stopWatching()
 	serve, err := a.prepareTransport()
 	if err != nil {
 		return errors.Join(err, a.Close())
@@ -228,6 +270,11 @@ func (a *App) RunWith(ctx context.Context, runner Runner, address ...string) (ru
 	if ctx.Err() != nil {
 		return a.Close()
 	}
+	if err := a.ValidateHTTP(); err != nil {
+		return errors.Join(err, a.Close())
+	}
+	stopWatching := a.watchShutdown(ctx)
+	defer stopWatching()
 	return errors.Join(runner.Run(ctx, a, a.listenAddress(address...)), a.Close())
 }
 
@@ -261,12 +308,16 @@ func (a *App) serveContext(ctx context.Context, server *http.Server, listener ne
 
 	select {
 	case err := <-serveErr:
+		// Serve returning only proves the accept loop ended. Cancel any remaining
+		// connections before the application completion barrier and cleanup.
+		_ = server.Close()
 		closeErr := a.Close()
 		if err == http.ErrServerClosed {
 			return closeErr
 		}
 		return errors.Join(err, closeErr)
 	case <-ctx.Done():
+		a.requests.stop()
 		shutdownTimeout := a.config.ShutdownTimeout
 		if shutdownTimeout <= 0 {
 			shutdownTimeout = 10 * time.Second
@@ -275,8 +326,8 @@ func (a *App) serveContext(ctx context.Context, server *http.Server, listener ne
 		defer cancel()
 		shutdownErr := server.Shutdown(shutdownCtx)
 		if shutdownErr != nil {
-			// Shutdown leaves active connections open on timeout. Close them so
-			// request contexts are canceled before releasing shared resources.
+			// Closing sockets requests cancellation; App.Close separately waits
+			// for the actual handler return before releasing shared resources.
 			shutdownErr = errors.Join(shutdownErr, server.Close())
 		}
 		if err := <-serveErr; err != nil && err != http.ErrServerClosed {

app/body.go

@@ -1,11 +1,68 @@
 package app
 
 import (
-	"git.yuntuo.hk/k2safe/go-omni/httpx"
-	"git.yuntuo.hk/k2safe/go-omni/response"
+	"fmt"
 	"net/http"
+	"strings"
+
+	"git.yuntuo.hk/k2safe/go-omni/config"
+	"git.yuntuo.hk/k2safe/go-omni/httpx"
+	"git.yuntuo.hk/k2safe/go-omni/internal/httplimits"
+	"git.yuntuo.hk/k2safe/go-omni/response"
 )
 
+type routeBodyLimit struct {
+	method, path string
+	maxBytes     int64
+}
+
+func (a *App) hardBodyLimit() int64 {
+	if a.config.HTTP.MaxBodyBytes > 0 {
+		return a.config.HTTP.MaxBodyBytes
+	}
+	return httplimits.MaxBodyBytes
+}
+
+func (a *App) defaultBodyLimit() int64 {
+	limit := a.config.HTTP.DefaultMaxBodyBytes
+	if limit <= 0 {
+		limit = httplimits.DefaultBodyBytes
+	}
+	if limit > a.hardBodyLimit() {
+		limit = a.hardBodyLimit()
+	}
+	// Invalid configuration is rejected at startup or the first external request.
+	if limit > httplimits.MaxBodyBytes {
+		limit = httplimits.MaxBodyBytes
+	}
+	return limit
+}
+
+// ValidateHTTP checks HTTP settings and registered route body limits without
+// opening a listener. Call after registration when hosting App/Engine externally.
+// Built-in serving entry points and RunWith perform this check automatically.
+func (a *App) ValidateHTTP() error {
+	if err := a.config.HTTP.Validate(); err != nil {
+		return err
+	}
+	for _, route := range a.bodyLimits {
+		if route.maxBytes > a.hardBodyLimit() {
+			return &config.ConfigError{Field: "http.maxBodyBytes", Message: fmt.Sprintf("route %s %s maxBytes=%d exceeds service hard limit=%d; raise http.maxBodyBytes or lower the route limit", route.method, route.path, route.maxBytes, a.hardBodyLimit())}
+		}
+	}
+	return nil
+}
+
+func joinRoutePath(prefix, path string) string {
+	if path == "" {
+		if prefix == "" {
+			return "/"
+		}
+		return prefix
+	}
+	return strings.TrimSuffix(prefix, "/") + "/" + strings.TrimPrefix(path, "/")
+}
+
 func (a *App) bodyHandler(maxBytes int64, encoder response.Encoder, handler httpx.Handler, middleware ...httpx.Middleware) http.Handler {
 	checked := httpx.LimitBody(maxBytes)(handler)
 	if encoder == nil {
@@ -25,8 +82,10 @@ func (a *App) bodyHandler(maxBytes int64, encoder response.Encoder, handler http
 // the response policy, including auth failures and parameter errors.
 func (a *App) HandleWithBodyLimit(method, path string, maxBytes int64, encoder response.Encoder, handler httpx.Handler, middleware ...httpx.Middleware) {
 	a.router.Handle(method, path, a.bodyHandler(maxBytes, encoder, handler, middleware...))
+	a.bodyLimits = append(a.bodyLimits, routeBodyLimit{method, path, maxBytes})
 }
 func (g *RouterGroup) HandleWithBodyLimit(method, path string, maxBytes int64, encoder response.Encoder, handler httpx.Handler, middleware ...httpx.Middleware) {
 	combined := append(append([]httpx.Middleware{}, g.middlewares...), middleware...)
 	g.group.Handle(method, path, g.app.bodyHandler(maxBytes, encoder, handler, combined...))
+	g.app.bodyLimits = append(g.app.bodyLimits, routeBodyLimit{method, joinRoutePath(g.prefix, path), maxBytes})
 }

app/bodyPolicy_test.go

@@ -0,0 +1,224 @@
+package app
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"io"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"git.yuntuo.hk/k2safe/go-omni/config"
+	"git.yuntuo.hk/k2safe/go-omni/httpx"
+	"git.yuntuo.hk/k2safe/go-omni/internal/testutil"
+	"git.yuntuo.hk/k2safe/go-omni/response"
+)
+
+func serveBodyPolicy(t *testing.T, a *App, transport string) (string, *http.Client) {
+	t.Helper()
+	cert, key, clientTLS := testutil.CertificateFiles(t)
+	a.config.Transport = transport
+	a.config.TLS = config.TLSConfig{CertFile: cert, KeyFile: key}
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	done := make(chan error, 1)
+	go func() { done <- a.ServeContext(ctx, l) }()
+	client := &http.Client{Timeout: 5 * time.Second, Transport: &http.Transport{TLSClientConfig: clientTLS, ForceAttemptHTTP2: transport == config.TransportHTTP2}}
+	t.Cleanup(func() {
+		client.CloseIdleConnections()
+		cancel()
+		select {
+		case err := <-done:
+			if err != nil {
+				t.Error(err)
+			}
+		case <-time.After(5 * time.Second):
+			t.Error("server did not stop")
+		}
+	})
+	return "https://" + l.Addr().String(), client
+}
+
+func consumeBody(c *httpx.Context) error {
+	_, err := io.Copy(io.Discard, c.Request().Body)
+	if err != nil {
+		return err
+	}
+	return c.Text(200, "accepted")
+}
+
+func TestUploadPolicyAcrossTransports(t *testing.T) {
+	for _, transport := range []string{config.TransportNetHTTP, config.TransportNative, config.TransportHTTP2} {
+		t.Run(transport, func(t *testing.T) {
+			a := New()
+			a.POST("/default", consumeBody)
+			a.HandleWithBodyLimit("POST", "/large", 16<<20, nil, consumeBody)
+			a.Group("/v1").Group("files").HandleWithBodyLimit("POST", "/large", 16<<20, nil, consumeBody)
+			base, client := serveBodyPolicy(t, a, transport)
+			payload := bytes.Repeat([]byte{'x'}, 9<<20)
+			for _, chunked := range []bool{false, true} {
+				for _, path := range []string{"/default", "/large", "/v1/files/large"} {
+					var body io.Reader = bytes.NewReader(payload)
+					if chunked {
+						body = struct{ io.Reader }{body}
+					}
+					req, _ := http.NewRequest("POST", base+path, body)
+					res, err := client.Do(req)
+					if err != nil {
+						t.Fatal(err)
+					}
+					data, err := io.ReadAll(res.Body)
+					res.Body.Close()
+					if err != nil {
+						t.Fatal(err)
+					}
+					want := 200
+					if path == "/default" {
+						want = 413
+					}
+					if res.StatusCode != want || (want == 413 && !strings.Contains(string(data), "BODY_TOO_LARGE")) {
+						t.Fatalf("%s unknownLength=%v: %d %s", path, chunked, res.StatusCode, data)
+					}
+					if transport == config.TransportHTTP2 && res.ProtoMajor != 2 {
+						t.Fatal("HTTP/2 not negotiated")
+					}
+				}
+			}
+		})
+	}
+}
+
+func TestConfiguredBodyPolicyBeforeMiddleware(t *testing.T) {
+	for _, transport := range []string{config.TransportNetHTTP, config.TransportNative, config.TransportHTTP2} {
+		t.Run(transport, func(t *testing.T) {
+			a := New(config.WithHTTPConfig(config.HTTPConfig{DefaultMaxBodyBytes: 32, MaxBodyBytes: 128}))
+			var calls atomic.Int32
+			a.Use(func(next httpx.Handler) httpx.Handler {
+				return func(c *httpx.Context) error {
+					data, err := io.ReadAll(c.Request().Body)
+					if err != nil {
+						return err
+					}
+					c.Request().Body = io.NopCloser(bytes.NewReader(data))
+					return next(c)
+				}
+			})
+			h := func(c *httpx.Context) error { calls.Add(1); return consumeBody(c) }
+			a.POST("/default", h)
+			a.HandleWithBodyLimit("POST", "/override", 64, nil, h)
+			a.HandleWithBodyLimit("POST", "/hard", 128, nil, h)
+			base, client := serveBodyPolicy(t, a, transport)
+			for _, tc := range []struct {
+				path         string
+				size, status int
+			}{
+				{"/default", 32, 200}, {"/default", 33, 413}, {"/override", 64, 200}, {"/override", 65, 413}, {"/hard", 128, 200}, {"/hard", 129, 413},
+			} {
+				for _, unknown := range []bool{false, true} {
+					before := calls.Load()
+					var body io.Reader = strings.NewReader(strings.Repeat("a", tc.size))
+					if unknown {
+						body = struct{ io.Reader }{body}
+					}
+					res, err := client.Post(base+tc.path, "application/octet-stream", body)
+					if err != nil {
+						t.Fatal(err)
+					}
+					data, err := io.ReadAll(res.Body)
+					res.Body.Close()
+					if err != nil || res.StatusCode != tc.status {
+						t.Fatalf("%+v unknown=%v: %d %s %v", tc, unknown, res.StatusCode, data, err)
+					}
+					if tc.status == 413 && (calls.Load() != before || !strings.Contains(string(data), "BODY_TOO_LARGE")) {
+						t.Fatal("oversize reached business or lost error", string(data))
+					}
+				}
+			}
+		})
+	}
+}
+
+func TestBodyHardLimitConflictBeforeServing(t *testing.T) {
+	for _, entry := range []string{"RunContext", "ServeContext", "RunWith", "NewServer", "Engine"} {
+		t.Run(entry, func(t *testing.T) {
+			a := New(config.WithHTTPConfig(config.HTTPConfig{MaxBodyBytes: 8 << 20}))
+			a.Group("/v1").Group("files").HandleWithBodyLimit("POST", "/upload/", 16<<20, nil, consumeBody)
+			closed := 0
+			a.OnShutdown(func() error { closed++; return nil })
+			if err := a.ValidateHTTP(); err == nil {
+				t.Fatal("external preflight accepted conflicting route limit")
+			}
+			var err error
+			switch entry {
+			case "RunContext":
+				err = a.RunContext(context.Background(), "bad address")
+			case "ServeContext":
+				l, e := net.Listen("tcp", "127.0.0.1:0")
+				if e != nil {
+					t.Fatal(e)
+				}
+				err = a.ServeContext(context.Background(), l)
+				if _, e = l.Accept(); !errors.Is(e, net.ErrClosed) {
+					t.Fatal("listener leaked", e)
+				}
+			case "RunWith":
+				err = a.RunWith(context.Background(), runnerFunc(func(context.Context, http.Handler, string) error { t.Error("runner started"); return nil }))
+			case "NewServer":
+				func() {
+					defer func() {
+						if p := recover(); p != nil {
+							err, _ = p.(error)
+						}
+					}()
+					a.NewServer("")
+				}()
+				_ = a.Close()
+			case "Engine":
+				w := httptest.NewRecorder()
+				a.Engine().ServeHTTP(w, httptest.NewRequest("POST", "/v1/files/upload/", nil))
+				if w.Code != 503 {
+					t.Fatal(w.Code)
+				}
+				err = a.validateErr
+				_ = a.Close()
+			}
+			for _, part := range []string{"POST /v1/files/upload/", "16777216", "8388608", "http.maxBodyBytes"} {
+				if err == nil || !strings.Contains(err.Error(), part) {
+					t.Fatalf("missing %q: %v", part, err)
+				}
+			}
+			if closed != 1 {
+				t.Fatal("cleanup count", closed)
+			}
+		})
+	}
+}
+
+func TestDefaultBodyLimitRegistrationPaths(t *testing.T) {
+	a := New(config.WithHTTPConfig(config.HTTPConfig{DefaultMaxBodyBytes: 4, MaxBodyBytes: 16}))
+	h := func(*httpx.Context) error { t.Error("oversize reached business"); return nil }
+	encoder, _ := response.New(response.Config{})
+	a.Handle("POST", "/handle", h)
+	a.HandleWithResponse("POST", "/response", encoder, h)
+	a.Any("/any", h)
+	g := a.Group("/group")
+	g.POST("/post", h)
+	g.Any("/any", h)
+	g.HandleWithResponse("POST", "/response", encoder, h)
+	for _, path := range []string{"/handle", "/response", "/any", "/group/post", "/group/any", "/group/response"} {
+		w := httptest.NewRecorder()
+		r := httptest.NewRequest("POST", path, strings.NewReader("12345"))
+		a.ServeHTTP(w, r)
+		if w.Code != 413 {
+			t.Fatal(path, w.Code, w.Body.String())
+		}
+	}
+}

app/requests.go

@@ -0,0 +1,88 @@
+package app
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sync"
+	"time"
+
+	"git.yuntuo.hk/k2safe/go-omni/lifecycle"
+)
+
+// Admission and completion share a lock: once stopped, no request can enter
+// between observing zero active handlers and releasing their dependencies.
+type requestDrain struct {
+	mu      sync.Mutex
+	stopped bool
+	active  map[*requestWork]struct{}
+	done    chan struct{}
+}
+
+type requestWork struct{ cancel context.CancelFunc }
+
+func (d *requestDrain) begin(ctx context.Context) (context.Context, *requestWork) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	if d.stopped {
+		return ctx, nil
+	}
+	ctx, cancel := context.WithCancel(ctx)
+	w := &requestWork{cancel: cancel}
+	if d.active == nil {
+		d.active = make(map[*requestWork]struct{})
+	}
+	d.active[w] = struct{}{}
+	return ctx, w
+}
+
+func (d *requestDrain) end(w *requestWork) {
+	w.cancel()
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	delete(d.active, w)
+	if d.stopped && len(d.active) == 0 {
+		close(d.done)
+	}
+}
+
+func (d *requestDrain) stop() {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	if d.stopped {
+		return
+	}
+	d.stopped = true
+	if len(d.active) == 0 {
+		close(d.done)
+	}
+}
+
+func (d *requestDrain) cancelAndWait(timeout time.Duration) error {
+	d.stop()
+	d.mu.Lock()
+	for w := range d.active {
+		w.cancel()
+	}
+	d.mu.Unlock()
+	timer := time.NewTimer(timeout)
+	defer timer.Stop()
+	select {
+	case <-d.done:
+		return nil
+	case <-timer.C:
+		select {
+		case <-d.done:
+			return nil
+		default:
+		}
+		return fmt.Errorf("go-omni: HTTP handlers did not finish within cancellation grace %s: %w", timeout,
+			errors.Join(context.DeadlineExceeded, lifecycle.ErrResourcesRetained))
+	}
+}
+
+// watchShutdown stops admission on the early signal without canceling accepted
+// work. The transport retains its graceful drain budget before Close cancels.
+func (a *App) watchShutdown(ctx context.Context) func() bool {
+	return context.AfterFunc(ctx, a.requests.stop)
+}

app/requests_test.go

@@ -0,0 +1,167 @@
+package app
+
+import (
+	"context"
+	"errors"
+	"io"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"git.yuntuo.hk/k2safe/go-omni/config"
+	"git.yuntuo.hk/k2safe/go-omni/httpx"
+	"git.yuntuo.hk/k2safe/go-omni/internal/testutil"
+	"git.yuntuo.hk/k2safe/go-omni/lifecycle"
+)
+
+func TestShutdownWaitsForCancellationCleanup(t *testing.T) {
+	for _, transport := range []string{config.TransportNetHTTP, config.TransportNative, config.TransportHTTP2} {
+		t.Run(transport, func(t *testing.T) {
+			cert, key, tlsClient := testutil.CertificateFiles(t)
+			a := New(config.WithTransport(transport), config.WithTLS(cert, key), config.WithShutdownTimeout(30*time.Millisecond), config.WithHTTPConfig(config.HTTPConfig{ShutdownCancelTimeout: time.Second}))
+			started, canceled, release := make(chan struct{}), make(chan struct{}), make(chan struct{})
+			var once sync.Once
+			unblock := func() { once.Do(func() { close(release) }) }
+			defer unblock()
+			var closed atomic.Int32
+			a.OnShutdown(func() error { closed.Add(1); return nil })
+			a.GET("/work", func(c *httpx.Context) error {
+				close(started)
+				<-c.Context().Done()
+				close(canceled)
+				<-release
+				if closed.Load() != 0 {
+					t.Error("dependency closed during cancellation cleanup")
+				}
+				return nil
+			})
+			l, err := net.Listen("tcp", "127.0.0.1:0")
+			if err != nil {
+				t.Fatal(err)
+			}
+			ctx, cancel := context.WithCancel(context.Background())
+			defer cancel()
+			done := make(chan error, 1)
+			go func() { done <- a.ServeContext(ctx, l) }()
+			client := &http.Client{Timeout: 3 * time.Second, Transport: &http.Transport{TLSClientConfig: tlsClient, ForceAttemptHTTP2: true}}
+			defer client.CloseIdleConnections()
+			requestDone := make(chan struct{})
+			go func() {
+				defer close(requestDone)
+				res, err := client.Get("https://" + l.Addr().String() + "/work")
+				if err == nil {
+					io.Copy(io.Discard, res.Body)
+					res.Body.Close()
+				}
+			}()
+			await(t, started)
+			cancel()
+			await(t, canceled)
+			if closed.Load() != 0 {
+				t.Fatal("dependency closed on cancellation")
+			}
+			select {
+			case err := <-done:
+				t.Fatal("returned before handler cleanup", err)
+			default:
+			}
+			// Even an in-memory invocation through Engine must now be rejected.
+			w := httptest.NewRecorder()
+			a.Engine().ServeHTTP(w, httptest.NewRequest("GET", "/work", nil))
+			if w.Code != 503 {
+				t.Fatal(w.Code)
+			}
+			unblock()
+			select {
+			case err := <-done:
+				if !errors.Is(err, context.DeadlineExceeded) || errors.Is(err, lifecycle.ErrResourcesRetained) {
+					t.Fatal(err)
+				}
+			case <-time.After(3 * time.Second):
+				t.Fatal("shutdown stuck")
+			}
+			await(t, requestDone)
+			if closed.Load() != 1 {
+				t.Fatal("cleanup count", closed.Load())
+			}
+		})
+	}
+}
+
+func TestExternalServingEntriesRetainActiveResources(t *testing.T) {
+	for _, entry := range []string{"App", "Engine", "NewServer", "RunWith"} {
+		t.Run(entry, func(t *testing.T) {
+			a := New(config.WithHTTPConfig(config.HTTPConfig{ShutdownCancelTimeout: 30 * time.Millisecond}))
+			started, release, returned := make(chan struct{}), make(chan struct{}), make(chan struct{})
+			var closed atomic.Int32
+			a.OnShutdown(func() error { closed.Add(1); return nil })
+			a.GET("/", func(*httpx.Context) error {
+				close(started)
+				<-release
+				if closed.Load() != 0 {
+					t.Error("closed while active")
+				}
+				return nil
+			})
+			var h http.Handler = a
+			if entry == "Engine" {
+				h = a.Engine()
+			}
+			if entry == "NewServer" {
+				h = a.NewServer("").Handler
+			}
+			invoke := func(h http.Handler) {
+				defer close(returned)
+				h.ServeHTTP(httptest.NewRecorder(), httptest.NewRequest("GET", "/", nil))
+			}
+			defer func() { close(release); await(t, returned) }()
+			var err error
+			if entry == "RunWith" {
+				err = a.RunWith(context.Background(), runnerFunc(func(_ context.Context, h http.Handler, _ string) error { go invoke(h); await(t, started); return nil }))
+			} else {
+				go invoke(h)
+				await(t, started)
+				err = a.Close()
+			}
+			if !errors.Is(err, lifecycle.ErrResourcesRetained) || closed.Load() != 0 {
+				t.Fatal("retention failed", err, closed.Load())
+			}
+			if err = a.Close(); !errors.Is(err, lifecycle.ErrResourcesRetained) {
+				t.Fatal("repeat close lost retention", err)
+			}
+		})
+	}
+}
+
+func TestRequestAdmissionAndCloseRace(t *testing.T) {
+	for attempt := 0; attempt < 20; attempt++ {
+		a := New()
+		var closed atomic.Bool
+		a.OnShutdown(func() error { closed.Store(true); return nil })
+		a.GET("/", func(c *httpx.Context) error {
+			if closed.Load() {
+				t.Error("handler admitted after resource release")
+			}
+			return nil
+		})
+		start := make(chan struct{})
+		var wg sync.WaitGroup
+		for i := 0; i < 20; i++ {
+			wg.Add(1)
+			go func() {
+				defer wg.Done()
+				<-start
+				a.ServeHTTP(httptest.NewRecorder(), httptest.NewRequest("GET", "/", nil))
+			}()
+		}
+		close(start)
+		if err := a.Close(); err != nil {
+			t.Fatal(err)
+		}
+		wg.Wait()
+	}
+}

app/router.go

@@ -10,7 +10,7 @@ import (
 )
 
 func (a *App) handle(routes httpx.RouterGroup, method, path string, handler httpx.Handler, middleware []httpx.Middleware) {
-	routes.Handle(method, path, a.adapt(handler, middleware...))
+	routes.Handle(method, path, a.bodyHandler(a.defaultBodyLimit(), nil, handler, middleware...))
 }
 
 func (a *App) adapt(handler httpx.Handler, middleware ...httpx.Middleware) http.Handler {
@@ -62,7 +62,7 @@ func (a *App) HandleWithResponse(method, path string, encoder response.Encoder,
 	if encoder == nil {
 		encoder = a.responseEncoder
 	}
-	a.router.Handle(method, path, a.adaptResponse(encoder, handler, middleware...))
+	a.router.Handle(method, path, a.bodyHandler(a.defaultBodyLimit(), encoder, handler, middleware...))
 }
 
 func (a *App) GET(path string, handler httpx.Handler, middleware ...httpx.Middleware) {
@@ -86,18 +86,19 @@ func (a *App) DELETE(path string, handler httpx.Handler, middleware ...httpx.Mid
 }
 
 func (a *App) Any(path string, handler httpx.Handler, middleware ...httpx.Middleware) {
-	a.router.Any(path, a.adapt(handler, middleware...))
+	a.router.Any(path, a.bodyHandler(a.defaultBodyLimit(), nil, handler, middleware...))
 }
 
 // RouterGroup scopes a route prefix and optional middleware.
 type RouterGroup struct {
+	prefix      string
 	group       httpx.RouterGroup
 	app         *App
 	middlewares []httpx.Middleware
 }
 
 func (a *App) Group(path string, middleware ...httpx.Middleware) *RouterGroup {
-	return &RouterGroup{group: a.router.Group(path), app: a, middlewares: middleware}
+	return &RouterGroup{group: a.router.Group(path), app: a, middlewares: middleware, prefix: joinRoutePath("", path)}
 }
 
 func (g *RouterGroup) Use(middleware ...httpx.Middleware) *RouterGroup {
@@ -108,7 +109,7 @@ func (g *RouterGroup) Use(middleware ...httpx.Middleware) *RouterGroup {
 func (g *RouterGroup) Group(path string, middleware ...httpx.Middleware) *RouterGroup {
 	combined := append([]httpx.Middleware{}, g.middlewares...)
 	combined = append(combined, middleware...)
-	return &RouterGroup{group: g.group.Group(path), app: g.app, middlewares: combined}
+	return &RouterGroup{group: g.group.Group(path), app: g.app, middlewares: combined, prefix: joinRoutePath(g.prefix, path)}
 }
 
 func (g *RouterGroup) route(method, path string, handler httpx.Handler, middleware []httpx.Middleware) {
@@ -128,7 +129,7 @@ func (g *RouterGroup) HandleWithResponse(method, path string, encoder response.E
 	}
 	combined := append([]httpx.Middleware{}, g.middlewares...)
 	combined = append(combined, middleware...)
-	g.group.Handle(method, path, g.app.adaptResponse(encoder, handler, combined...))
+	g.group.Handle(method, path, g.app.bodyHandler(g.app.defaultBodyLimit(), encoder, handler, combined...))
 }
 
 func (g *RouterGroup) GET(path string, handler httpx.Handler, middleware ...httpx.Middleware) {
@@ -154,5 +155,5 @@ func (g *RouterGroup) DELETE(path string, handler httpx.Handler, middleware ...h
 func (g *RouterGroup) Any(path string, handler httpx.Handler, middleware ...httpx.Middleware) {
 	combined := append([]httpx.Middleware{}, g.middlewares...)
 	combined = append(combined, middleware...)
-	g.group.Any(path, g.app.adapt(handler, combined...))
+	g.group.Any(path, g.app.bodyHandler(g.app.defaultBodyLimit(), nil, handler, combined...))
 }

app/transport.go

@@ -10,13 +10,14 @@ import (
 	"time"
 
 	"git.yuntuo.hk/k2safe/go-omni/config"
+	"git.yuntuo.hk/k2safe/go-omni/internal/httplimits"
 	h2transport "git.yuntuo.hk/k2safe/go-omni/transport/http2"
 	"git.yuntuo.hk/k2safe/go-omni/transport/native"
 )
 
 // ServeContext serves a caller-created listener using the configured transport
 // and TLS. App takes ownership of the listener, including on startup failure,
-// and runs resource cleanup after the server has stopped.
+// and runs resource cleanup only after admitted handlers have returned.
 func (a *App) ServeContext(ctx context.Context, listener net.Listener) (runErr error) {
 	defer func() { runErr = shutdownResult(ctx, runErr) }()
 	if listener == nil {
@@ -30,6 +31,8 @@ func (a *App) ServeContext(ctx context.Context, listener net.Listener) (runErr e
 		_ = listener.Close()
 		return a.Close()
 	}
+	stopWatching := a.watchShutdown(ctx)
+	defer stopWatching()
 	serve, err := a.prepareTransport()
 	if err != nil {
 		_ = listener.Close()
@@ -39,6 +42,9 @@ func (a *App) ServeContext(ctx context.Context, listener net.Listener) (runErr e
 }
 
 func (a *App) prepareTransport() (func(context.Context, net.Listener) error, error) {
+	if err := a.ValidateHTTP(); err != nil {
+		return nil, err
+	}
 	if err := a.config.ValidateTransport(); err != nil {
 		return nil, err
 	}
@@ -57,6 +63,9 @@ func (a *App) prepareTransport() (func(context.Context, net.Listener) error, err
 	switch a.config.Transport {
 	case config.TransportNative:
 		server := native.New(a)
+		// App enforces the service/route policy after routing. Keep only the
+		// supported framing ceiling here, never a hidden smaller transport cap.
+		server.MaxBodyBytes = httplimits.MaxBodyBytes
 		server.ShutdownTimeout = shutdownTimeout
 		cfg := a.config.HTTP
 		if cfg.ReadHeaderTimeout > 0 {
@@ -82,6 +91,7 @@ func (a *App) prepareTransport() (func(context.Context, net.Listener) error, err
 		return server.Serve, nil
 	case config.TransportHTTP2:
 		server := h2transport.New(a)
+		server.MaxBodyBytes = httplimits.MaxBodyBytes
 		server.ShutdownTimeout = shutdownTimeout
 		if a.config.HTTP.IdleTimeout > 0 {
 			server.IdleTimeout = a.config.HTTP.IdleTimeout

app/transport_test.go

@@ -15,6 +15,7 @@ import (
 	"git.yuntuo.hk/k2safe/go-omni/config"
 	"git.yuntuo.hk/k2safe/go-omni/httpx"
 	"git.yuntuo.hk/k2safe/go-omni/internal/testutil"
+	"git.yuntuo.hk/k2safe/go-omni/lifecycle"
 )
 
 func TestConfiguredTransportLifecycle(t *testing.T) {
@@ -269,7 +270,9 @@ func TestConfiguredShutdownDoesNotWaitForUncooperativeHandler(t *testing.T) {
 	for _, transport := range []string{config.TransportNetHTTP, config.TransportNative, config.TransportHTTP2} {
 		t.Run(transport, func(t *testing.T) {
 			cert, key, tlsClient := testutil.CertificateFiles(t)
-			application := New(config.WithTransport(transport), config.WithTLS(cert, key), config.WithShutdownTimeout(80*time.Millisecond))
+			application := New(config.WithTransport(transport), config.WithTLS(cert, key), config.WithShutdownTimeout(80*time.Millisecond), config.WithHTTPConfig(config.HTTPConfig{ShutdownCancelTimeout: 40 * time.Millisecond}))
+			var cleaned atomic.Int32
+			application.OnShutdown(func() error { cleaned.Add(1); return nil })
 			started := make(chan context.Context, 1)
 			release, finished := make(chan struct{}), make(chan struct{})
 			application.GET("/blocked", func(ctx *httpx.Context) error {
@@ -304,11 +307,17 @@ func TestConfiguredShutdownDoesNotWaitForUncooperativeHandler(t *testing.T) {
 				close(release)
 				t.Fatal("handler did not start")
 			}
-			defer func() { close(release); await(t, finished) }()
+			defer func() {
+				close(release)
+				await(t, finished)
+				if err := application.Close(); !errors.Is(err, lifecycle.ErrResourcesRetained) || cleaned.Load() != 0 {
+					t.Fatalf("late handler return must not trigger cleanup: %v count=%d", err, cleaned.Load())
+				}
+			}()
 			cancel()
 			select {
 			case err := <-done:
-				if !errors.Is(err, context.DeadlineExceeded) {
+				if !errors.Is(err, context.DeadlineExceeded) || !errors.Is(err, lifecycle.ErrResourcesRetained) || cleaned.Load() != 0 {
 					t.Fatalf("shutdown: %v", err)
 				}
 			case <-time.After(2 * time.Second):