Allow disabling app hang monitoring in ObjC API

Author: 0xnm

CHANGELOG.md

@@ -1,5 +1,7 @@
 # Unreleased
 
+- [IMPROVEMENT] Allow disabling app hang monitoring in ObjC API. See [#1908][]
+
 # 2.13.0 / 13-06-2024
 
 - [IMPROVEMENT] Bump `IPHONEOS_DEPLOYMENT_TARGET` and `TVOS_DEPLOYMENT_TARGET` from 11 to 12. See [#1891][]
@@ -684,6 +686,7 @@ Release `2.0` introduces breaking changes. Follow the [Migration Guide](MIGRATIO
 [#1835]: https://github.com/DataDog/dd-sdk-ios/pull/1835
 [#1886]: https://github.com/DataDog/dd-sdk-ios/pull/1886
 [#1898]: https://github.com/DataDog/dd-sdk-ios/pull/1898
+[#1908]: https://github.com/DataDog/dd-sdk-ios/pull/1908
 [@00fa9a]: https://github.com/00FA9A
 [@britton-earnin]: https://github.com/Britton-Earnin
 [@hengyu]: https://github.com/Hengyu

DatadogObjc/Sources/RUM/RUM+objc.swift

@@ -378,7 +378,7 @@ public class DDRUMConfiguration: NSObject {
     }
 
     @objc public var appHangThreshold: TimeInterval {
-        set { swiftConfig.appHangThreshold = newValue }
+        set { swiftConfig.appHangThreshold = newValue == 0 ? nil : newValue }
         get { swiftConfig.appHangThreshold ?? 0 }
     }