Fix idle ping spin loop from exhausted AsyncStream iterator

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - Fix macOS HIG compliance: system colors, accessibility labels, theme tokens, localization
+- Fix idle ping spin loop caused by exhausted AsyncStream iterator (#618)
 
 ## [0.28.0] - 2026-04-07
 

TablePro/Core/Database/ConnectionHealthMonitor.swift

@@ -48,7 +48,8 @@ actor ConnectionHealthMonitor {
 
     private var state: HealthState = .healthy
     private var monitoringTask: Task<Void, Never>?
-    private var wakeUpContinuation: AsyncStream<Void>.Continuation?
+    private var pingCount: Int = 0
+    private var lastPingTime: ContinuousClock.Instant?
 
     // MARK: - Initialization
 
@@ -92,42 +93,16 @@ actor ConnectionHealthMonitor {
 
         Self.logger.trace("Starting health monitoring for connection \(self.connectionId)")
 
-        let (wakeUpStream, continuation) = AsyncStream<Void>.makeStream(bufferingPolicy: .bufferingNewest(1))
-        self.wakeUpContinuation = continuation
-
         monitoringTask = Task { [weak self] in
             guard let self else { return }
 
             let initialDelay = Double.random(in: 0 ... 10)
             try? await Task.sleep(for: .seconds(initialDelay))
             guard !Task.isCancelled else { return }
 
-            // Create the iterator ONCE — reusing it across loop iterations
-            // prevents buffered yields from causing back-to-back instant pings.
-            var wakeIterator = wakeUpStream.makeAsyncIterator()
-
             while !Task.isCancelled {
-                await Task.yield()
-
-                // Race between the normal ping interval and an early wake-up signal
-                await withTaskGroup(of: Bool.self) { group in
-                    group.addTask {
-                        try? await Task.sleep(for: .seconds(Self.pingInterval))
-                        return false // normal timer fired
-                    }
-                    group.addTask {
-                        _ = await wakeIterator.next()
-                        return true // woken up early
-                    }
-
-                    // Wait for whichever finishes first, cancel the other
-                    if await group.next() != nil {
-                        group.cancelAll()
-                    }
-                }
-
+                try? await Task.sleep(for: .seconds(Self.pingInterval))
                 guard !Task.isCancelled else { break }
-
                 await self.performHealthCheck()
             }
 
@@ -145,16 +120,6 @@ actor ConnectionHealthMonitor {
         monitoringTask = nil
         task?.cancel()
         await task?.value
-        wakeUpContinuation?.finish()
-        wakeUpContinuation = nil
-    }
-
-    /// Triggers an immediate health check, interrupting the normal 30-second sleep.
-    ///
-    /// Call this after a query failure to get faster feedback on connection health
-    /// instead of waiting for the next scheduled ping.
-    func checkNow() {
-        wakeUpContinuation?.yield()
     }
 
     /// Resets the monitor to `.healthy` after the user manually reconnects.
@@ -178,6 +143,22 @@ actor ConnectionHealthMonitor {
             return
         }
 
+        pingCount += 1
+        let now = ContinuousClock.now
+        if let last = lastPingTime {
+            let interval = (now - last) / .seconds(1)
+            if interval < 5.0 {
+                Self.logger.warning(
+                    "Ping #\(self.pingCount) fired only \(String(format: "%.2f", interval))s after previous for \(self.connectionId)"
+                )
+            } else {
+                Self.logger.debug("Ping #\(self.pingCount) for \(self.connectionId) (interval: \(String(format: "%.1f", interval))s)")
+            }
+        } else {
+            Self.logger.debug("First ping (#\(self.pingCount)) for \(self.connectionId)")
+        }
+        lastPingTime = now
+
         await transitionTo(.checking)
 
         let isAlive = await pingHandler()

TablePro/Core/Database/DatabaseManager+Health.swift

@@ -15,6 +15,7 @@ import TableProPluginKit
 extension DatabaseManager {
     /// Start health monitoring for a connection
     internal func startHealthMonitor(for connectionId: UUID) async {
+        Self.logger.info("startHealthMonitor called for \(connectionId) (existing monitors: \(self.healthMonitors.count))")
         // Stop any existing monitor
         await stopHealthMonitor(for: connectionId)
 
@@ -30,18 +31,20 @@ extension DatabaseManager {
                     let maxStale = max(queryTimeout, 300) // At least 5 minutes
                     if let startTime = await self.queryStartTimes[connectionId],
                        Date().timeIntervalSince(startTime) < maxStale {
+                        Self.logger.debug("Ping skipped — query in-flight for \(connectionId)")
                         return true // Query still within expected time
                     }
-                    // Query appears stuck — fall through to ping
+                    Self.logger.warning("Ping proceeding despite in-flight query (stale after \(maxStale)s) for \(connectionId)")
                 }
                 guard let mainDriver = await self.activeSessions[connectionId]?.driver else {
+                    Self.logger.debug("Ping skipped — no active driver for \(connectionId)")
                     return false
                 }
                 do {
                     _ = try await mainDriver.execute(query: "SELECT 1")
                     return true
                 } catch {
-                    Self.logger.debug("Ping failed: \(error.localizedDescription)")
+                    Self.logger.debug("Ping failed for \(connectionId): \(error.localizedDescription)")
                     return false
                 }
             },
@@ -149,6 +152,7 @@ extension DatabaseManager {
     /// Stop health monitoring for a connection
     internal func stopHealthMonitor(for connectionId: UUID) async {
         if let monitor = healthMonitors.removeValue(forKey: connectionId) {
+            Self.logger.info("stopHealthMonitor: stopping monitor for \(connectionId) (remaining: \(self.healthMonitors.count))")
             await monitor.stopMonitoring()
         }
     }