Fix: SDK detects OutOfMemory after device reboot (#3352)

If the host app has been terminated due to device reboot, SentrySDK assumes it as a WatchdogTermination crash. In such cases, mostly, the boot time will be mentioned as "a few seconds before this event". 

![Screenshot 2023-10-19 at 09 52 27](https://github.com/getsentry/sentry-cocoa/assets/1960884/c66f778a-cb4e-4687-991b-646de004b194)

The idea behind this fix is that if the system boot time has been changed since the previous app launch, most likely the app has been terminated due to the reboot and the SentrySDK should not consider it as a WatchdogTermination crash.

Co-authored-by: Dhiogo Brustolin <dhiogo.brustolin@sentry.io>

CHANGELOG.md

@@ -6,6 +6,10 @@
 
 - Enrich error events with any underlying NSErrors reported by Cocoa APIs (#3230)
 
+### Features
+
+- Improve OOM detection by ignoring system reboot (#3352)
+
 ### Fixes
 
 - Missing `mechanism.handled` is not considered crash (#3353)

Sources/Sentry/SentryWatchdogTerminationLogic.m

@@ -60,6 +60,11 @@ - (BOOL)isWatchdogTermination
         return NO;
     }
 
+    // The app may have been terminated due to device reboot
+    if (previousAppState.systemBootTimestamp != currentAppState.systemBootTimestamp) {
+        return NO;
+    }
+
     // This value can change when installing test builds using Xcode or when installing an app
     // on a device using ad-hoc distribution.
     if (![currentAppState.vendorId isEqualToString:previousAppState.vendorId]) {

Tests/SentryTests/Integrations/SentryCrash/SentryCrashIntegrationTests.swift

@@ -13,6 +13,7 @@ class SentryCrashIntegrationTests: NotificationCenterTestCase {
         let sentryCrash: TestSentryCrashWrapper
 
         init() {
+            SentryDependencyContainer.sharedInstance().sysctlWrapper = TestSysctl()
             sentryCrash = TestSentryCrashWrapper.sharedInstance()
             sentryCrash.internalActiveDurationSinceLastCrash = 5.0
             sentryCrash.internalCrashedLastLaunch = true

Tests/SentryTests/Integrations/WatchdogTerminations/SentryWatchdogTerminationsTrackerTests.swift

@@ -216,7 +216,18 @@ class SentryWatchdogTerminationTrackerTests: NotificationCenterTestCase {
         sut.start()
         assertNoOOMSent()
     }
-
+
+    func testDifferentBootTime_NoOOM() {
+        sut = fixture.getSut(usingRealFileManager: true)
+        sut.start()
+        let appState = SentryAppState(releaseName: fixture.options.releaseName ?? "", osVersion: UIDevice.current.systemVersion, vendorId: TestData.someUUID, isDebugging: false, systemBootTimestamp: fixture.sysctl.systemBootTimestamp.addingTimeInterval(1))
+
+        givenPreviousAppState(appState: appState)
+        fixture.mockFileManager.moveAppStateToPreviousAppState()
+        sut.start()
+        assertNoOOMSent()
+    }
+
     func testAppWasInForeground_OOM() {
         sut = fixture.getSut(usingRealFileManager: true)