fix: UIWindow being possibly accessed from a background thread in SentryCrashWrapper (#6905)

* fix: UIWindow being possibly accesed from a background thread in SentryCrashWrapper

* Update changelog

* Fix test

* Use `UIWindow.screen.bounds`

* Fix build on visionOS

* Fix build on visionOS

* Fix changelog merge conflict

Author: itaybre

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Fixes
 
+- Fix UIWindow being possibly accessed from a background thread in SentryCrashWrapper (#6905)
 - Ensure SentrySDK.close resets everything on the main thread (#6907)
 - Allow transaction tags to be accessed and modified in `beforeSend` (#6910)
 

Sources/Sentry/SentryDependencyContainerSwiftHelper.m

@@ -13,6 +13,13 @@ @implementation SentryDependencyContainerSwiftHelper
     return [SentryDependencyContainer.sharedInstance.application getWindows];
 }
 
+#    if TARGET_OS_IOS || TARGET_OS_TV
++ (CGSize)activeScreenSize
+{
+    return [SentryDependencyContainer.sharedInstance.application getActiveWindowSize];
+}
+#    endif // TARGET_OS_IOS || TARGET_OS_TV
+
 #endif // SENTRY_HAS_UIKIT
 
 + (NSString *)release:(SentryOptions *)options

Sources/Sentry/include/SentryDependencyContainerSwiftHelper.h

@@ -31,6 +31,10 @@ NS_ASSUME_NONNULL_BEGIN
 
 + (nullable NSArray<UIWindow *> *)windows;
 
+#    if TARGET_OS_IOS || TARGET_OS_TV
++ (CGSize)activeScreenSize;
+#    endif // TARGET_OS_IOS || TARGET_OS_TV
+
 #endif // SENTRY_HAS_UIKIT
 
 + (NSString *_Nullable)release:(SentryOptionsObjC *)options;

Sources/Swift/Helper/SentryApplication.swift

@@ -23,6 +23,10 @@ import UIKit
  */
     func getWindows() -> [UIWindow]?
 
+#if (os(iOS) || os(tvOS))
+    func getActiveWindowSize() -> CGSize
+#endif // os(iOS) || os(tvOS)
+    
     var connectedScenes: Set<UIScene> { get }
 
     var delegate: UIApplicationDelegate? { get }

Sources/Swift/Helper/SentryApplicationExtensions.swift

@@ -13,6 +13,12 @@ import UIKit
         internal_getWindows()
     }
 
+#if (os(iOS) || os(tvOS))
+    @objc public func getActiveWindowSize() -> CGSize {
+        internal_getActiveWindowSize()
+    }
+#endif // os(iOS) || os(tvOS)
+    
     @objc public func relevantViewControllersNames() -> [String]? {
         internal_relevantViewControllersNames()
     }
@@ -55,6 +61,21 @@ extension SentryApplication {
         return Array(windows)
     }
 
+#if (os(iOS) || os(tvOS))
+    public func internal_getActiveWindowSize() -> CGSize {
+        var size = CGSize.zero
+        Dependencies.dispatchQueueWrapper.dispatchSyncOnMainQueue({ [weak self] in
+            guard let self,
+                  let window = self.internal_getWindows()?.first else {
+                return
+            }
+            
+            size = window.screen.bounds.size
+        }, timeout: 0.01)
+        return size
+    }
+#endif // os(iOS) || os(tvOS)
+    
     // This cannot be declared with @objc so until we delete more ObjC code it needs a separate
     // function than the objc visible one.
     public func internal_relevantViewControllersNames() -> [String]? {

Sources/Swift/SentryCrash/SentryCrashWrapper.swift

@@ -265,10 +265,10 @@ public final class SentryCrashWrapper: NSObject {
     private func setScreenDimensions(_ deviceData: inout [String: Any]) {
         // The UIWindowScene is unavailable on visionOS
 #if (os(iOS) || os(tvOS)) && !SENTRY_NO_UIKIT
-        if let appWindows = SentryDependencyContainerSwiftHelper.windows(),
-           let appScreen = appWindows.first?.screen {
-            deviceData["screen_height_pixels"] = appScreen.bounds.size.height
-            deviceData["screen_width_pixels"] = appScreen.bounds.size.width
+        let screenSize = SentryDependencyContainerSwiftHelper.activeScreenSize()
+        if screenSize != CGSize.zero {
+            deviceData["screen_height_pixels"] = screenSize.height
+            deviceData["screen_width_pixels"] = screenSize.width
         }
 #endif // (os(iOS) || os(tvOS)) && !SENTRY_NO_UIKIT
     }

Tests/SentryTests/TestSentryUIApplication.swift

@@ -9,6 +9,12 @@ final class TestSentryUIApplication: SentryApplication {
         return internal_getWindows()
     }
 
+#if (os(iOS) || os(tvOS))
+    func getActiveWindowSize() -> CGSize {
+        return internal_getActiveWindowSize()
+    }
+#endif // os(iOS) || os(tvOS)
+    
     private var _windows: [UIWindow]?
     private(set) var calledOnMainThread = true
     var windows: [UIWindow]? {