JerryLiu369 · Oct 2, 2026
diff --git a/packages/client/src/effect/service.ts b/packages/client/src/effect/service.ts
@@ -84,7 +84,9 @@ export const ensure = Effect.fn("service.ensure")(function* (options: EnsureOpti
         info,
         count: timeouts !== undefined && same(timeouts.info, info) ? timeouts.count + 1 : 1,
       }
-      if (timeouts.count >= 3) {
+      // Require sustained unresponsiveness before evicting: transient Windows probe stalls must
+      // reconnect, never kill a healthy service and abort its sessions.
+      if (timeouts.count >= 5) {
         yield* announce("missing")
         yield* Effect.logWarning("Background service is unresponsive; recovery cannot preserve persistent terminals")
         yield* Effect.tryPromise(() => PtyHandoff.clear(options.file ?? fallback()))
@@ -121,8 +123,10 @@ export const ensure = Effect.fn("service.ensure")(function* (options: EnsureOpti
     }
     finished.forEach((item) => contenders.delete(item))
     if (failure !== undefined && contenders.size === 0) return yield* Effect.fail(failure)
-    // Keep one candidate plus one lock probe so a pre-lock stall cannot block recovery.
-    if (contenders.size < 2 && Date.now() - lastSpawn >= spawnDelay) {
+    // Keep one candidate plus one lock probe so a pre-lock stall cannot block recovery. While health
+    // probes against the registered service keep timing out, wait for eviction instead: a contender
+    // that registers first would take over and leak the hung process terminate() no longer matches.
+    if (timeouts === undefined && contenders.size < 2 && Date.now() - lastSpawn >= spawnDelay) {
       yield* announce("missing")
       contenders.add(yield* spawnContender)
       lastSpawn = Date.now()

diff --git a/packages/client/src/promise/service.ts b/packages/client/src/promise/service.ts
@@ -63,7 +63,9 @@ export async function ensure(options: EnsureOptions = {}): Promise<Endpoint> {
           info: registration.info,
           count: timeouts !== undefined && same(timeouts.info, registration.info) ? timeouts.count + 1 : 1,
         }
-        if (timeouts.count >= 3) {
+        // Require sustained unresponsiveness before evicting: transient Windows probe stalls must
+        // reconnect, never kill a healthy service and abort its sessions.
+        if (timeouts.count >= 5) {
           announce("missing")
           console.warn("Background service is unresponsive; recovery cannot preserve persistent terminals")
           await PtyHandoff.clear(options.file ?? fallback())
@@ -101,8 +103,10 @@ export async function ensure(options: EnsureOptions = {}): Promise<Endpoint> {
         }
         finished.forEach((item) => contenders.delete(item))
         if (failure !== undefined && contenders.size === 0) throw failure
-        // Keep one candidate plus one lock probe so a pre-lock stall cannot block recovery.
-        if (contenders.size < 2 && Date.now() - lastSpawn >= spawnDelay) {
+        // Keep one candidate plus one lock probe so a pre-lock stall cannot block recovery. While health
+        // probes against the registered service keep timing out, wait for eviction instead: a contender
+        // that registers first would take over and leak the hung process terminate() no longer matches.
+        if (timeouts === undefined && contenders.size < 2 && Date.now() - lastSpawn >= spawnDelay) {
           announce("missing")
           contenders.add(await spawnContender())
           lastSpawn = Date.now()

diff --git a/packages/client/src/solid/connection.ts b/packages/client/src/solid/connection.ts
@@ -20,7 +20,8 @@ export type ClientConnectionOptions = {
   readonly pageLifecycle?: boolean
   /**
    * Abort and reconnect a stream that receives no bytes for this long. The server writes a keepalive
-   * comment every 15 seconds, so a quiet but healthy stream never trips this.
+   * comment every 15 seconds, so a quiet but healthy stream never trips this. The default allows six
+   * missed keepalives so transient Windows stalls never look like a dead stream.
    */
   readonly idleTimeout?: number
   readonly log?: {
@@ -32,7 +33,7 @@ export type ClientConnectionOptions = {
 const connectTimeout = 2_000
 const reconnectDelay = 1_000
 const connectionHistoryLimit = 50
-export const defaultIdleTimeout = 45_000
+export const defaultIdleTimeout = 90_000
 // Longer than one server keepalive interval: a stream that is silent this long when the page
 // returns to the foreground is probably half-open after the device slept.
 export const foregroundIdleThreshold = 20_000

diff --git a/packages/client/test/fixture/service.ts b/packages/client/test/fixture/service.ts
@@ -59,6 +59,10 @@ const server = Bun.serve({
       await appendFile(registration + ".requests", process.pid + "\n")
       return new Promise<Response>(() => {})
     }
+    if (mode === "flaky") {
+      await appendFile(registration + ".requests", process.pid + "\n")
+      if (requests <= Number(delay ?? "3")) return new Promise<Response>(() => {})
+    }
     if (mode === "modern" && requests === 1) {
       await writeFile(registration + ".first-request", "")
       while (!(await Bun.file(registration + ".release").exists())) await Bun.sleep(5)

diff --git a/packages/client/test/promise-service.test.ts b/packages/client/test/promise-service.test.ts
@@ -141,12 +141,33 @@ test("evicts an unresponsive registered service before starting its replacement"
   const replacement = await Bun.file(registration).json()
   fixture.track(replacement.pid)
 
-  expect((await Bun.file(registration + ".requests").text()).trim().split("\n")).toHaveLength(3)
+  expect((await Bun.file(registration + ".requests").text()).trim().split("\n")).toHaveLength(5)
   expect(await existing.exited).toBe(0)
   expect(replacement.pid).not.toBe(original.pid)
   expect(endpoint.url).toBe(replacement.url)
 })
 
+test("keeps a registered service that recovers after transient probe stalls", async () => {
+  await using fixture = await serviceFixture()
+  const registration = fixture.registration
+  const existing = fixture.spawn("flaky", "3")
+  await fixture.waitForFile()
+  const original = await Bun.file(registration).json()
+
+  const endpoint = await ensure({
+    file: registration,
+    version: "test",
+    command: fixture.command("delayed", "10"),
+  })
+  const current = await Bun.file(registration).json()
+  fixture.track(current.pid)
+
+  expect((await Bun.file(registration + ".requests").text()).trim().split("\n")).toHaveLength(4)
+  expect(existing.exitCode).toBe(null)
+  expect(current.pid).toBe(original.pid)
+  expect(endpoint.url).toBe(original.url)
+})
+
 test("signals the registered service process", async () => {
   await using fixture = await serviceFixture()
   const registration = fixture.registration

diff --git a/packages/client/test/service.test.ts b/packages/client/test/service.test.ts
@@ -142,13 +142,37 @@ test("evicts an unresponsive registered service before starting its replacement"
   const replacement = await Bun.file(registration).json()
   fixture.track(replacement.pid)
 
-  expect((await Bun.file(registration + ".requests").text()).trim().split("\n")).toHaveLength(3)
+  expect((await Bun.file(registration + ".requests").text()).trim().split("\n")).toHaveLength(5)
   expect(await existing.exited).toBe(0)
   expect(replacement.pid).not.toBe(original.pid)
   expect(endpoint.url).toBe(replacement.url)
   expect(await status(endpoint.url)).toMatchObject({ version: "test", pid: replacement.pid })
 })
 
+test("keeps a registered service that recovers after transient probe stalls", async () => {
+  await using fixture = await serviceFixture()
+  const registration = fixture.registration
+  const existing = fixture.spawn("flaky", "3")
+  await fixture.waitForFile()
+  const original = await Bun.file(registration).json()
+
+  const endpoint = await run(
+    ensure({
+      file: registration,
+      version: "test",
+      command: fixture.command("delayed", "10"),
+    }),
+  )
+  const current = await Bun.file(registration).json()
+  fixture.track(current.pid)
+
+  expect((await Bun.file(registration + ".requests").text()).trim().split("\n")).toHaveLength(4)
+  expect(existing.exitCode).toBe(null)
+  expect(current.pid).toBe(original.pid)
+  expect(endpoint.url).toBe(original.url)
+  expect(await status(endpoint.url)).toMatchObject({ version: "test", pid: original.pid })
+})
+
 test("signals an unresponsive registered service process", async () => {
   await using fixture = await serviceFixture()
   const registration = fixture.registration

diff --git a/packages/client/test/solid-connection.test.ts b/packages/client/test/solid-connection.test.ts
@@ -1,6 +1,6 @@
 import { expect, test } from "bun:test"
 import { createRoot } from "solid-js"
-import { createClientConnection } from "../src/solid"
+import { createClientConnection, defaultIdleTimeout } from "../src/solid"
 import { OpenCode, type OpenCodeEvent } from "../src/promise"
 
 const connected = { id: "evt_connected", created: 1, type: "server.connected", data: {} }
@@ -179,3 +179,9 @@ test("a reconnect does not ask the volatile event stream to replay", async () =>
     ctx.dispose()
   }
 })
+
+test("the default idle timeout spans several server keepalives", () => {
+  // The server writes a keepalive comment every 15 seconds. The default must cover several missed
+  // keepalives so a transient Windows stall triggers a reconnect, never a service replacement.
+  expect(defaultIdleTimeout).toBeGreaterThanOrEqual(6 * 15_000)
+})