From edd8aa2f4ed6a781382d91d387036b4e151b07db Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Sat, 30 May 2026 19:21:17 -0400
Subject: [PATCH] fix(agents): clamp embedded run drain polling

---
 src/agents/embedded-agent-runner/runs.test.ts | 22 +++++++++++++++++++
 src/agents/embedded-agent-runner/runs.ts      |  2 +-
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/agents/embedded-agent-runner/runs.test.ts b/src/agents/embedded-agent-runner/runs.test.ts
index 5bf19a9e99e..dab7e153bfc 100644
--- a/src/agents/embedded-agent-runner/runs.test.ts
+++ b/src/agents/embedded-agent-runner/runs.test.ts
@@ -393,6 +393,28 @@ describe("embedded-agent runner run registry", () => {
     }
   });
 
+  it("clamps oversized active-run drain poll intervals", async () => {
+    vi.useFakeTimers();
+    try {
+      const setTimeoutSpy = vi.spyOn(globalThis, "setTimeout");
+      const handle = createRunHandle();
+      setActiveEmbeddedRun("session-a", handle);
+
+      const waitPromise = waitForActiveEmbeddedRuns(undefined, {
+        pollMs: Number.MAX_SAFE_INTEGER,
+      });
+      await Promise.resolve();
+
+      expect(setTimeoutSpy).toHaveBeenCalledWith(expect.any(Function), MAX_TIMER_TIMEOUT_MS);
+      clearActiveEmbeddedRun("session-a", handle);
+      await vi.advanceTimersByTimeAsync(MAX_TIMER_TIMEOUT_MS);
+      await expect(waitPromise).resolves.toEqual({ drained: true });
+    } finally {
+      await vi.runOnlyPendingTimersAsync();
+      vi.useRealTimers();
+    }
+  });
+
   it("shares active run state across distinct module instances", async () => {
     const runsA = await importFreshModule<typeof import("./runs.js")>(
       import.meta.url,
diff --git a/src/agents/embedded-agent-runner/runs.ts b/src/agents/embedded-agent-runner/runs.ts
index a2a3a832d00..446a8aa4409 100644
--- a/src/agents/embedded-agent-runner/runs.ts
+++ b/src/agents/embedded-agent-runner/runs.ts
@@ -617,7 +617,7 @@ export async function waitForActiveEmbeddedRuns(
   opts?: { pollMs?: number },
 ): Promise<{ drained: boolean }> {
   const pollMsRaw = opts?.pollMs ?? 250;
-  const pollMs = Math.max(10, Math.floor(pollMsRaw));
+  const pollMs = resolveTimerTimeoutMs(pollMsRaw, 250, 10);
   if (timeoutMs !== undefined && timeoutMs <= 0) {
     return { drained: getActiveEmbeddedRunCount() === 0 };
   }