fix(keyring): cache availability probe with OnceLock to prevent repeated keychain dialogs (#2651)

src/openhuman/app_state/ops.rs

@@ -535,7 +535,17 @@ pub async fn snapshot() -> Result<RpcOutcome<AppStateSnapshot>, String> {
     // snapshot. On Windows this doubled the surface area for the
     // "Timed out waiting for auth profile lock" failure reported in
     // Sentry against `openhuman.app_state_snapshot`.
-    let session_profile = load_app_session_profile(&config)?;
+    //
+    // `load_app_session_profile` calls `acquire_lock()`, which busy-waits
+    // with `thread::sleep` for up to ~35s when the lock is contended. Calling
+    // it directly on a tokio worker thread blocks that thread for the entire
+    // wait, exhausting the thread pool under concurrent snapshot calls and
+    // triggering `ERR_CONNECTION_TIMED_OUT` on all RPC connections.
+    let config_for_profile = config.clone();
+    let session_profile =
+        tokio::task::spawn_blocking(move || load_app_session_profile(&config_for_profile))
+            .await
+            .unwrap_or_else(|e| Err(format!("[app_state] auth profile load task panicked: {e}")))?;
     let mut auth = session_state_from_profile(session_profile.as_ref());
     let session_token = session_token_from_profile(session_profile.as_ref());
     let stored_user = sanitize_snapshot_user(auth.user.clone());

src/openhuman/keyring/mod.rs

@@ -50,3 +50,6 @@ pub use store::init_workspace;
 #[cfg(test)]
 #[allow(unused_imports)]
 pub(crate) use ops::force_backend_for_test;
+
+#[cfg(test)]
+mod tests;

src/openhuman/keyring/ops.rs

@@ -3,12 +3,21 @@
 //! All public functions delegate to the active backend selected by [`crate::openhuman::keyring::store`].
 
 use std::path::Path;
+use std::sync::OnceLock;
 
 use chacha20poly1305::aead::{rand_core::RngCore, OsRng};
 
 use crate::openhuman::keyring::error::KeyringError;
 use crate::openhuman::keyring::store::backend;
 
+// Cached result of the one-time keychain probe. Running the probe on every
+// `is_available()` call means 4 OS-keychain round-trips (delete / set / get /
+// delete) per call, which triggers repeated macOS access-permission dialogs
+// and starves callers that poll frequently (e.g. snapshot, wallet guards).
+// The backend selection is already frozen in a OnceLock, so the probe result
+// is stable for the lifetime of the process — caching it here is safe.
+static AVAILABILITY_CACHE: OnceLock<bool> = OnceLock::new();
+
 // ── Outcome type ─────────────────────────────────────────────────────────────
 
 /// Outcome of a file-to-keychain migration attempt.
@@ -82,7 +91,16 @@ pub fn delete(user_id: &str, key: &str) -> Result<(), KeyringError> {
 /// For the `file` and `mock` backends this always returns `true`.  For the
 /// `os` backend on Linux headless systems (no Secret Service daemon) this
 /// returns `false`; callers should fall back to file-based storage.
+///
+/// The result is cached after the first call — the probe runs exactly once
+/// per process lifetime. This prevents repeated OS-keychain round-trips (and
+/// the macOS access-permission dialogs they trigger) when polled by
+/// wallet guards or snapshot loops.
 pub fn is_available() -> bool {
+    *AVAILABILITY_CACHE.get_or_init(probe_availability)
+}
+
+fn probe_availability() -> bool {
     const PROBE_USER: &str = "__probe__";
     const PROBE_KEY: &str = "__openhuman_keyring_probe__";
     const PROBE_VALUE: &str = "__probe_value__";
@@ -100,6 +118,11 @@ pub fn is_available() -> bool {
     }
 
     let result = (|| -> Result<bool, KeyringError> {
+        // Delete any leftover probe key from a previous launch before writing.
+        // Without this, `set` fails with "item already exists" (-25299) on
+        // every launch after the first, causing `is_available` to incorrectly
+        // return false even when the keychain is fully functional.
+        let _ = delete(PROBE_USER, PROBE_KEY);
         set(PROBE_USER, PROBE_KEY, PROBE_VALUE)?;
         let readback = get(PROBE_USER, PROBE_KEY)?;
         delete(PROBE_USER, PROBE_KEY)?;

src/openhuman/keyring/tests.rs

@@ -380,6 +380,165 @@ fn get_or_create_random_idempotent_file_backend() {
     assert_eq!(first, second, "idempotent read-back");
 }
 
+// ── is_available probe: idempotency regression tests ─────────────────────────
+//
+// The probe in `is_available()` must return `true` on every launch, not just the
+// first one. Before the fix, `set()` was called blindly: on macOS the Keychain
+// returns `-25299 "item already exists"` when the probe key survives from a
+// prior launch, flipping `is_available` to `false` even though the keychain is
+// fully functional. The fix deletes the probe key first so the write always
+// lands clean.
+//
+// We verify this with a `StrictSetBackend` — a `FileBackend` wrapper that
+// rejects `set()` on an already-existing key, exactly matching the Keychain
+// semantics that exposed the bug. This lets the regression run in CI without
+// the `OPENHUMAN_TEST_OS_KEYCHAIN=1` gate.
+
+/// Wraps `FileBackend` but fails `set` with `KeyringError::Backend` when the
+/// key already exists, mirroring macOS Keychain's `-25299` behaviour.
+struct StrictSetBackend {
+    inner: FileBackend,
+}
+
+impl StrictSetBackend {
+    fn new(dir: &std::path::Path) -> Self {
+        Self {
+            inner: FileBackend::new(dir),
+        }
+    }
+}
+
+impl KeyringBackend for StrictSetBackend {
+    fn get(&self, key: &str) -> Result<Option<String>, KeyringError> {
+        self.inner.get(key)
+    }
+    fn set(&self, key: &str, value: &str) -> Result<(), KeyringError> {
+        if self.inner.get(key)?.is_some() {
+            return Err(KeyringError::Backend(
+                "Platform secure storage failure: The specified item already exists in the keychain. (OSStatus -25299)".into(),
+            ));
+        }
+        self.inner.set(key, value)
+    }
+    fn delete(&self, key: &str) -> Result<(), KeyringError> {
+        self.inner.delete(key)
+    }
+    fn name(&self) -> &'static str {
+        "strict-set-mock"
+    }
+}
+
+/// Run the OLD (broken) probe logic against any backend.
+/// Returns `true` only if the round-trip succeeded.
+fn old_probe<B: KeyringBackend>(b: &B) -> bool {
+    const KEY: &str = "__probe__:__openhuman_keyring_probe__";
+    const VAL: &str = "__probe_value__";
+    if b.set(KEY, VAL).is_err() {
+        return false;
+    }
+    let ok = b.get(KEY).ok().flatten().as_deref() == Some(VAL);
+    let _ = b.delete(KEY);
+    ok
+}
+
+/// Run the NEW (fixed) probe logic against any backend.
+/// Deletes any residue before writing, making the probe idempotent.
+fn new_probe<B: KeyringBackend>(b: &B) -> bool {
+    const KEY: &str = "__probe__:__openhuman_keyring_probe__";
+    const VAL: &str = "__probe_value__";
+    let _ = b.delete(KEY);
+    if b.set(KEY, VAL).is_err() {
+        return false;
+    }
+    let ok = b.get(KEY).ok().flatten().as_deref() == Some(VAL);
+    let _ = b.delete(KEY);
+    ok
+}
+
+#[test]
+fn probe_old_logic_fails_when_key_preexists() {
+    // Demonstrates the bug: old probe returns false the second time because
+    // `set` on an already-existing key fails with "item already exists".
+    let dir = TempDir::new().expect("tempdir");
+    let b = StrictSetBackend::new(dir.path());
+
+    // First probe: key absent → succeeds.
+    assert!(old_probe(&b), "first probe should succeed");
+
+    // Key was deleted by the probe — re-seed it to simulate a leftover from a
+    // previous launch (e.g. the app was force-quit after writing but before
+    // the delete could run, or a previous `is_available` call left it behind).
+    b.inner
+        .set("__probe__:__openhuman_keyring_probe__", "stale")
+        .unwrap();
+
+    // Second probe with residue: `set` hits "already exists" → returns false.
+    assert!(
+        !old_probe(&b),
+        "old probe must fail when probe key pre-exists (regression target)"
+    );
+}
+
+#[test]
+fn probe_new_logic_succeeds_even_when_key_preexists() {
+    // Verifies the fix: new probe deletes any residue first, so it always
+    // succeeds regardless of leftover state.
+    let dir = TempDir::new().expect("tempdir");
+    let b = StrictSetBackend::new(dir.path());
+
+    assert!(new_probe(&b), "first probe should succeed");
+
+    // Re-seed to simulate a leftover key (same scenario as the bug test).
+    b.inner
+        .set("__probe__:__openhuman_keyring_probe__", "stale")
+        .unwrap();
+
+    assert!(
+        new_probe(&b),
+        "new probe must succeed even when probe key pre-exists"
+    );
+}
+
+#[test]
+fn probe_new_logic_is_idempotent_across_multiple_runs() {
+    // New probe must return true on every consecutive call.
+    let dir = TempDir::new().expect("tempdir");
+    let b = StrictSetBackend::new(dir.path());
+
+    for i in 0..5 {
+        assert!(new_probe(&b), "probe run {i} should succeed");
+    }
+}
+
+#[test]
+fn is_available_returns_true_on_repeated_calls_os_backend() {
+    // End-to-end: the real `is_available()` must return true on consecutive
+    // calls even when the OS backend retains the probe key between runs.
+    // Guarded by OPENHUMAN_TEST_OS_KEYCHAIN=1 to avoid blocking CI on a
+    // Keychain permission dialog.
+    if !os_keychain_available() {
+        eprintln!("skip: set OPENHUMAN_TEST_OS_KEYCHAIN=1 to run OS keychain tests");
+        return;
+    }
+    // Use the OsBackend directly to simulate the cross-launch residue.
+    let b = backend::OsBackend;
+    let probe_key = "__probe__:__openhuman_keyring_probe__";
+    // Pre-seed to mimic a leftover from a previous app launch.
+    let _ = b.set(probe_key, "__probe_value__");
+    // `is_available()` must still return true.
+    assert!(
+        super::ops::is_available(),
+        "is_available must return true even with pre-existing probe key in OS keychain"
+    );
+    // Repeated call should also stay true (exercises the OnceLock cached path).
+    assert!(
+        super::ops::is_available(),
+        "is_available must remain true on repeated calls (cached result)"
+    );
+    // Cleanup.
+    let _ = b.delete(probe_key);
+}
+
 // ── migrate_from_file (via module functions, requires OS keychain or file backend) ──
 
 #[test]