fix: Android 5 attachment issues

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Fixes
+
+- The SDK no longer crashes on Android versions 5 and 6 with native support enabled ([#1652](https://github.com/getsentry/sentry-unity/pull/1652))
+
 ### Dependencies
 
 - Bump Cocoa SDK from v8.25.2 to v8.26.0 ([#1648](https://github.com/getsentry/sentry-unity/pull/1648))

src/Sentry.Unity.Android/AndroidJavaScopeObserver.cs

@@ -8,69 +8,85 @@ namespace Sentry.Unity.Android
     /// <see href="https://github.com/getsentry/sentry-java"/>
     public class AndroidJavaScopeObserver : ScopeObserver
     {
-        public AndroidJavaScopeObserver(SentryOptions options) : base("Android", options) { }
+        private readonly JniExecutor _jniExecutor;
+
+        public AndroidJavaScopeObserver(SentryOptions options, JniExecutor jniExecutor) : base("Android", options)
+        {
+            _jniExecutor = jniExecutor;
+        }
 
         private AndroidJavaObject GetSentryJava() => new AndroidJavaClass("io.sentry.Sentry");
 
         public override void AddBreadcrumbImpl(Breadcrumb breadcrumb)
         {
-            AndroidJNI.AttachCurrentThread();
-            using var sentry = GetSentryJava();
-            using var javaBreadcrumb = new AndroidJavaObject("io.sentry.Breadcrumb");
-            javaBreadcrumb.Set("message", breadcrumb.Message);
-            javaBreadcrumb.Set("type", breadcrumb.Type);
-            javaBreadcrumb.Set("category", breadcrumb.Category);
-            using var javaLevel = breadcrumb.Level.ToJavaSentryLevel();
-            javaBreadcrumb.Set("level", javaLevel);
-            sentry.CallStatic("addBreadcrumb", javaBreadcrumb, null);
+            _jniExecutor.Run(() =>
+            {
+                using var sentry = GetSentryJava();
+                using var javaBreadcrumb = new AndroidJavaObject("io.sentry.Breadcrumb");
+                javaBreadcrumb.Set("message", breadcrumb.Message);
+                javaBreadcrumb.Set("type", breadcrumb.Type);
+                javaBreadcrumb.Set("category", breadcrumb.Category);
+                using var javaLevel = breadcrumb.Level.ToJavaSentryLevel();
+                javaBreadcrumb.Set("level", javaLevel);
+                sentry.CallStatic("addBreadcrumb", javaBreadcrumb, null);
+            });
         }
 
         public override void SetExtraImpl(string key, string? value)
         {
-            AndroidJNI.AttachCurrentThread();
-            using var sentry = GetSentryJava();
-            sentry.CallStatic("setExtra", key, value);
+            _jniExecutor.Run(() =>
+            {
+                using var sentry = GetSentryJava();
+                sentry.CallStatic("setExtra", key, value);
+            });
         }
         public override void SetTagImpl(string key, string value)
         {
-            AndroidJNI.AttachCurrentThread();
-            using var sentry = GetSentryJava();
-            sentry.CallStatic("setTag", key, value);
+            _jniExecutor.Run(() =>
+            {
+                using var sentry = GetSentryJava();
+                sentry.CallStatic("setTag", key, value);
+            });
         }
 
         public override void UnsetTagImpl(string key)
         {
-            AndroidJNI.AttachCurrentThread();
-            using var sentry = GetSentryJava();
-            sentry.CallStatic("removeTag", key);
+            _jniExecutor.Run(() =>
+            {
+                using var sentry = GetSentryJava();
+                sentry.CallStatic("removeTag", key);
+            });
         }
 
         public override void SetUserImpl(SentryUser user)
         {
-            AndroidJNI.AttachCurrentThread();
-
-            AndroidJavaObject? javaUser = null;
-            try
+            _jniExecutor.Run(() =>
             {
-                javaUser = new AndroidJavaObject("io.sentry.protocol.User");
-                javaUser.Set("email", user.Email);
-                javaUser.Set("id", user.Id);
-                javaUser.Set("username", user.Username);
-                javaUser.Set("ipAddress", user.IpAddress);
-                using var sentry = GetSentryJava();
-                sentry.CallStatic("setUser", javaUser);
-            }
-            finally
-            {
-                javaUser?.Dispose();
-            }
+                AndroidJavaObject? javaUser = null;
+                try
+                {
+                    javaUser = new AndroidJavaObject("io.sentry.protocol.User");
+                    javaUser.Set("email", user.Email);
+                    javaUser.Set("id", user.Id);
+                    javaUser.Set("username", user.Username);
+                    javaUser.Set("ipAddress", user.IpAddress);
+                    using var sentry = GetSentryJava();
+                    sentry.CallStatic("setUser", javaUser);
+                }
+                finally
+                {
+                    javaUser?.Dispose();
+                }
+            });
         }
 
         public override void UnsetUserImpl()
         {
-            AndroidJNI.AttachCurrentThread();
-            using var sentry = GetSentryJava();
-            sentry.CallStatic("setUser", null);
+            _jniExecutor.Run(() =>
+            {
+                using var sentry = GetSentryJava();
+                sentry.CallStatic("setUser", null);
+            });
         }
     }
 }

src/Sentry.Unity.Android/JniExecutor.cs

@@ -0,0 +1,116 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using UnityEngine;
+
+namespace Sentry.Unity.Android
+{
+    public class JniExecutor
+    {
+        private readonly CancellationTokenSource _shutdownSource;
+        private readonly AutoResetEvent _taskEvent;
+        private Delegate _currentTask = null!; // The current task will always be set together with the task event
+
+        private TaskCompletionSource<object?>? _taskCompletionSource;
+
+        public JniExecutor()
+        {
+            _taskEvent = new AutoResetEvent(false);
+            _shutdownSource = new CancellationTokenSource();
+
+            new Thread(DoWork) { IsBackground = true }.Start();
+        }
+
+        private void DoWork()
+        {
+            AndroidJNI.AttachCurrentThread();
+
+            var waitHandles = new[] { _taskEvent, _shutdownSource.Token.WaitHandle };
+
+            while (true)
+            {
+                var index = WaitHandle.WaitAny(waitHandles);
+                if (index > 0)
+                {
+                    // We only care about the _taskEvent
+                    break;
+                }
+
+                try
+                {
+                    // Matching the type of the `_currentTask` exactly. The result gets cast to the expected type
+                    // when returning from the blocking call.
+                    switch (_currentTask)
+                    {
+                        case Action action:
+                            {
+                                action.Invoke();
+                                _taskCompletionSource?.SetResult(null);
+                                break;
+                            }
+                        case Func<bool?> func1:
+                            {
+                                var result = func1.Invoke();
+                                _taskCompletionSource?.SetResult(result);
+                                break;
+                            }
+                        case Func<string?> func2:
+                            {
+                                var result = func2.Invoke();
+                                _taskCompletionSource?.SetResult(result);
+                                break;
+                            }
+                        default:
+                            throw new ArgumentException("Invalid type for _currentTask.");
+                    }
+                }
+                catch (Exception e)
+                {
+                    _taskCompletionSource?.SetException(e);
+                }
+            }
+
+            AndroidJNI.DetachCurrentThread();
+        }
+
+        public TResult? Run<TResult>(Func<TResult?> jniOperation)
+        {
+            _taskCompletionSource = new TaskCompletionSource<object?>();
+            _currentTask = jniOperation;
+            _taskEvent.Set();
+
+            try
+            {
+                return (TResult?)_taskCompletionSource.Task.GetAwaiter().GetResult();
+            }
+            catch (Exception e)
+            {
+                Debug.unityLogger.Log(LogType.Exception, UnityLogger.LogTag, $"Error during JNI execution: {e}");
+            }
+
+            return default;
+        }
+
+        public void Run(Action jniOperation)
+        {
+            _taskCompletionSource = new TaskCompletionSource<object?>();
+            _currentTask = jniOperation;
+            _taskEvent.Set();
+
+            try
+            {
+                _taskCompletionSource.Task.Wait();
+            }
+            catch (Exception e)
+            {
+                Debug.unityLogger.Log(LogType.Exception, UnityLogger.LogTag, $"Error during JNI execution: {e}");
+            }
+        }
+
+        public void Dispose()
+        {
+            _shutdownSource.Cancel();
+            _taskEvent.Dispose();
+        }
+    }
+}

src/Sentry.Unity.Android/NativeContextWriter.cs

@@ -4,6 +4,13 @@ namespace Sentry.Unity.Android
 {
     internal class NativeContextWriter : ContextWriter
     {
+        private readonly JniExecutor _jniExecutor;
+
+        public NativeContextWriter(JniExecutor jniExecutor)
+        {
+            _jniExecutor = jniExecutor;
+        }
+
         protected override void WriteScope(
             string? AppStartTime,
             string? AppBuildType,
@@ -44,6 +51,7 @@ protected override void WriteScope(
             // the "unity" context, but it doesn't seem so useful and the effort to do is larger because there's no
             // class for it in Java - not sure how we could add a generic context object in Java...
             SentryJava.WriteScope(
+                _jniExecutor,
                 GpuId,
                 GpuName,
                 GpuVendorName,

src/Sentry.Unity.Android/SentryJava.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Threading;
 using UnityEngine;
 
 namespace Sentry.Unity.Android
@@ -13,17 +14,15 @@ namespace Sentry.Unity.Android
     /// <see href="https://github.com/getsentry/sentry-java"/>
     internal static class SentryJava
     {
-        internal static string? GetInstallationId()
+        internal static string? GetInstallationId(JniExecutor jniExecutor)
         {
-            if (!Attach())
+            return jniExecutor.Run(() =>
             {
-                return null;
-            }
-
-            using var sentry = GetSentryJava();
-            using var hub = sentry.CallStatic<AndroidJavaObject>("getCurrentHub");
-            using var options = hub?.Call<AndroidJavaObject>("getOptions");
-            return options?.Call<string>("getDistinctId");
+                using var sentry = GetSentryJava();
+                using var hub = sentry.CallStatic<AndroidJavaObject>("getCurrentHub");
+                using var options = hub?.Call<AndroidJavaObject>("getOptions");
+                return options?.Call<string>("getDistinctId");
+            });
         }
 
         /// <summary>
@@ -36,30 +35,29 @@ internal static class SentryJava
         /// True if the last run terminated in a crash. No otherwise.
         /// If the SDK wasn't able to find this information, null is returned.
         /// </returns>
-        public static bool? CrashedLastRun()
+        public static bool? CrashedLastRun(JniExecutor jniExecutor)
         {
-            if (!Attach())
+            return jniExecutor.Run(() =>
             {
-                return null;
-            }
-            using var sentry = GetSentryJava();
-            using var jo = sentry.CallStatic<AndroidJavaObject>("isCrashedLastRun");
-            return jo?.Call<bool>("booleanValue");
+                using var sentry = GetSentryJava();
+                using var jo = sentry.CallStatic<AndroidJavaObject>("isCrashedLastRun");
+                return jo?.Call<bool>("booleanValue");
+            });
         }
 
-        public static void Close()
+        public static void Close(JniExecutor jniExecutor)
         {
-            if (Attach())
+            jniExecutor.Run(() =>
             {
                 using var sentry = GetSentryJava();
                 sentry.CallStatic("close");
-            }
+            });
         }
 
-        private static bool Attach() => AndroidJNI.AttachCurrentThread() == 0;
         private static AndroidJavaObject GetSentryJava() => new AndroidJavaClass("io.sentry.Sentry");
 
         public static void WriteScope(
+            JniExecutor jniExecutor,
             int? GpuId,
             string? GpuName,
             string? GpuVendorName,
@@ -76,17 +74,17 @@ public static void WriteScope(
             bool? GpuMultiThreadedRendering,
             string? GpuGraphicsShaderLevel)
         {
-            if (Attach())
+            jniExecutor.Run(() =>
             {
                 using var gpu = new AndroidJavaObject("io.sentry.protocol.Gpu");
                 gpu.SetIfNotNull("name", GpuName);
                 gpu.SetIfNotNull("id", GpuId);
-                int intVendorId;
-                if (GpuVendorId is not null && int.TryParse(GpuVendorId, out intVendorId) && intVendorId != 0)
+                if (GpuVendorId is not null && int.TryParse(GpuVendorId, out var intVendorId) && intVendorId != 0)
                 {
                     using var integer = new AndroidJavaObject("java.lang.Integer", intVendorId);
                     gpu.Set("vendorId", integer);
                 }
+
                 gpu.SetIfNotNull("vendorName", GpuVendorName);
                 gpu.SetIfNotNull("memorySize", GpuMemorySize);
                 gpu.SetIfNotNull("apiType", GpuApiType);
@@ -100,7 +98,7 @@ public static void WriteScope(
                     using var contexts = scope.Call<AndroidJavaObject>("getContexts");
                     contexts.Call("setGpu", gpu);
                 }));
-            }
+            });
         }
 
         private static void SetIfNotNull<T>(this AndroidJavaObject javaObject, string property, T? value, string? valueClass = null)