feat: PR3A — Instruments signposts for tunnel lifecycle profiling

FptnVPNTunnel/Diagnostics/TunnelSignposts.swift

@@ -0,0 +1,91 @@
+#if FPTN_SIGNPOSTS
+import OSLog
+
+// PR3A: Instruments signposts for tunnel lifecycle profiling.
+// Compiled only in Debug and Measurement builds.
+// Numeric metadata only — no interpolated strings.
+enum TunnelSignposts {
+    static let signposter = OSSignposter(
+        subsystem: "net.mrmidi.FptnVPN.FptnVPNTunnel",
+        category: "TunnelLifecycle"
+    )
+
+    // MARK: - Intervals
+
+    static func beginTunnelStartup() -> OSSignpostIntervalState {
+        signposter.beginInterval("TunnelStartup")
+    }
+
+    static func endTunnelStartup(_ state: OSSignpostIntervalState) {
+        signposter.endInterval("TunnelStartup", state)
+    }
+
+    static func beginBridgeLifetime(generation: Int) -> (OSSignpostID, OSSignpostIntervalState) {
+        let id = signposter.makeSignpostID()
+        let state = signposter.beginInterval("BridgeLifetime", id: id)
+        return (id, state)
+    }
+
+    static func endBridgeLifetime(_ state: OSSignpostIntervalState, generation: Int) {
+        signposter.endInterval("BridgeLifetime", state)
+    }
+
+    static func beginNativeTeardown(generation: Int) -> (OSSignpostID, OSSignpostIntervalState) {
+        let id = signposter.makeSignpostID()
+        let state = signposter.beginInterval("NativeTeardown", id: id)
+        return (id, state)
+    }
+
+    static func endNativeTeardown(_ state: OSSignpostIntervalState, generation: Int, activeOps: UInt32) {
+        signposter.endInterval("NativeTeardown", state)
+    }
+
+    static func beginTunnelShutdown() -> OSSignpostIntervalState {
+        signposter.beginInterval("TunnelShutdown")
+    }
+
+    static func endTunnelShutdown(_ state: OSSignpostIntervalState) {
+        signposter.endInterval("TunnelShutdown", state)
+    }
+
+    static func beginReconnectDelay(attempt: Int) -> (OSSignpostID, OSSignpostIntervalState) {
+        let id = signposter.makeSignpostID()
+        let state = signposter.beginInterval("ReconnectDelay", id: id)
+        return (id, state)
+    }
+
+    static func endReconnectDelay(_ state: OSSignpostIntervalState, attempt: Int) {
+        signposter.endInterval("ReconnectDelay", state)
+    }
+
+    static func beginReadLoopLifetime() -> OSSignpostIntervalState {
+        signposter.beginInterval("ReadLoopLifetime")
+    }
+
+    static func endReadLoopLifetime(_ state: OSSignpostIntervalState) {
+        signposter.endInterval("ReadLoopLifetime", state)
+    }
+
+    // MARK: - Point events
+
+    static func transportConnected(generation: Int) {
+        signposter.emitEvent("TransportConnected")
+    }
+
+    static func transportDisconnected(generation: Int) {
+        signposter.emitEvent("TransportDisconnected")
+    }
+
+    static func networkPathChanged(satisfied: Bool) {
+        signposter.emitEvent("NetworkPathChanged")
+    }
+
+    static func memoryWarning() {
+        signposter.emitEvent("MemoryWarning")
+    }
+
+    static func invariantViolation() {
+        signposter.emitEvent("InvariantViolation")
+    }
+}
+#endif