fix: Fixed race condition in ANR Integration (#2045)

bitsandfoxes · web-flow · commit eedc4fa54a7b · 2025-03-03T09:53:50.000+01:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Fixes
+
+- Fixed a potential race condition in the ANR watchdog integration ([2045](https://github.com/getsentry/sentry-unity/pull/2045))
+
 ### Dependencies
 
 - Bump .NET SDK from v5.1.1 to v5.2.0 ([#2040](https://github.com/getsentry/sentry-unity/pull/2040))
diff --git a/src/Sentry.Unity/Integrations/AnrIntegration.cs b/src/Sentry.Unity/Integrations/AnrIntegration.cs
@@ -126,7 +126,7 @@ private IEnumerator UpdateUiStatus()
         yield return waitForSeconds;
         while (!_stop)
         {
-            _ticksSinceUiUpdate = 0;
+            Interlocked.Exchange(ref _ticksSinceUiUpdate, 0);
             _reported = false;
             yield return waitForSeconds;
         }
@@ -144,12 +144,12 @@ private void Run()
 
             while (!_stop)
             {
-                _ticksSinceUiUpdate++;
+                Interlocked.Increment(ref _ticksSinceUiUpdate);
                 Thread.Sleep(SleepIntervalMs);
 
                 if (Paused)
                 {
-                    _ticksSinceUiUpdate = 0;
+                    Interlocked.Exchange(ref _ticksSinceUiUpdate, 0);
                 }
                 else if (_ticksSinceUiUpdate >= reportThreshold && !_reported)
                 {

Original file line number	Diff line number	Diff line change
`@@ -126,7 +126,7 @@ private IEnumerator UpdateUiStatus()`
`126`	`126`	`yield return waitForSeconds;`
`127`	`127`	`while (!_stop)`
`128`	`128`	`{`
`129`		`- _ticksSinceUiUpdate = 0;`
	`129`	`+ Interlocked.Exchange(ref _ticksSinceUiUpdate, 0);`
`130`	`130`	`_reported = false;`
`131`	`131`	`yield return waitForSeconds;`
`132`	`132`	`}`
`@@ -144,12 +144,12 @@ private void Run()`
`144`	`144`
`145`	`145`	`while (!_stop)`
`146`	`146`	`{`
`147`		`- _ticksSinceUiUpdate++;`
	`147`	`+ Interlocked.Increment(ref _ticksSinceUiUpdate);`
`148`	`148`	`Thread.Sleep(SleepIntervalMs);`
`149`	`149`
`150`	`150`	`if (Paused)`
`151`	`151`	`{`
`152`		`- _ticksSinceUiUpdate = 0;`
	`152`	`+ Interlocked.Exchange(ref _ticksSinceUiUpdate, 0);`
`153`	`153`	`}`
`154`	`154`	`else if (_ticksSinceUiUpdate >= reportThreshold && !_reported)`
`155`	`155`	`{`