Merge pull request #1176 from bugsnag/nickdowell/app-hang-in-will-ter…

…minate

[PLAT-7151] Do not report fatal app hangs if terminating

Bugsnag/Client/BugsnagClient+Private.h

@@ -136,17 +136,12 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (BugsnagEvent *)generateOutOfMemoryEvent;
 
-/// @return A `BugsnagEvent` if the last run ended with a fatal app hang, `nil` otherwise.
-- (nullable BugsnagEvent *)loadFatalAppHangEvent;
-
 - (void)notifyInternal:(BugsnagEvent *)event block:(nullable BugsnagOnErrorBlock)block;
 
 - (void)removeObserverWithBlock:(BugsnagObserverBlock)block; // Used in BugsnagReactNative
 
 - (void)start;
 
-- (void)startAppHangDetector;
-
 @end
 
 NS_ASSUME_NONNULL_END

Bugsnag/Client/BugsnagClient.m

@@ -433,7 +433,7 @@ - (void)computeDidCrashLastLaunch {
         didCrash = YES;
     }
     // Was the app terminated while the main thread was hung?
-    else if ((self.eventFromLastLaunch = [self loadFatalAppHangEvent])) {
+    else if ((self.eventFromLastLaunch = [self loadAppHangEvent]).unhandled) {
         bsg_log_info(@"Last run terminated during an app hang.");
         didCrash = YES;
     }
@@ -1185,7 +1185,7 @@ - (void)appHangEnded {
     self.appHangEvent = nil;
 }
 
-- (nullable BugsnagEvent *)loadFatalAppHangEvent {
+- (nullable BugsnagEvent *)loadAppHangEvent {
     NSError *error = nil;
     NSDictionary *json = [BSGJSONSerialization JSONObjectWithContentsOfFile:BSGFileLocations.current.appHangEvent options:0 error:&error];
     if (!json) {
@@ -1201,6 +1201,15 @@ - (nullable BugsnagEvent *)loadFatalAppHangEvent {
         return nil;
     }
 
+    // Receipt of the willTerminateNotification indicates that an app hang was not the cause of the termination, so treat as non-fatal.
+    if ([self.systemState.lastLaunchState[SYSTEMSTATE_KEY_APP][SYSTEMSTATE_APP_WAS_TERMINATED] boolValue]) {
+        if (self.configuration.appHangThresholdMillis == BugsnagAppHangThresholdFatalOnly) {
+            return nil;
+        }
+        event.session.handledCount++;
+        return event;
+    }
+
     // Update event to reflect that the app hang was fatal.
     event.errors.firstObject.errorMessage = @"The app was terminated while unresponsive";
     // Cannot set event.severity directly because that sets severityReason.type to "userCallbackSetSeverity"

CHANGELOG.md

@@ -9,6 +9,11 @@ Changelog
   when the thermal state is critical will now be reported as a "Thermal Kill" rather than Out Of Memory error.
   [#1171](https://github.com/bugsnag/bugsnag-cocoa/pull/1171)
 
+### Bug fixes
+
+* Fatal app hangs will no longer be reported if the `willTerminateNotification` is received.
+  [#1176](https://github.com/bugsnag/bugsnag-cocoa/pull/1176)
+
 ## 6.11.0 (2021-08-18)
 
 ### Enhancements

Tests/BugsnagClientMirrorTest.m

@@ -83,7 +83,7 @@ - (void)setUp {
             @"lastOrientation @16@0:8",
             @"lastThermalState q16@0:8",
             @"leaveBreadcrumbForEvent: v24@0:8@16",
-            @"loadFatalAppHangEvent @16@0:8",
+            @"loadAppHangEvent @16@0:8",
             @"metadata @16@0:8",
             @"metadataChanged: v24@0:8@16",
             @"metadataFile @16@0:8",

features/app_hangs.feature

@@ -154,3 +154,16 @@ Feature: App hangs
     And I background the app for 3 seconds
     And I wait to receive an error
     And the exception "message" equals "The app's main thread failed to respond to an event within 2000 milliseconds"
+
+  Scenario: App hangs that occur during app termination should be non-fatal
+    Given I run "AppHangInTerminationScenario"
+    And the app is not running
+    And I relaunch the app
+    And I configure Bugsnag for "AppHangInTerminationScenario"
+    Then I wait to receive an error
+    And the event "severity" equals "warning"
+    And the event "severityReason.type" equals "appHang"
+    And the event "unhandled" is false
+    And the exception "errorClass" equals "App Hang"
+    And the exception "message" equals "The app's main thread failed to respond to an event within 2000 milliseconds"
+    And the exception "type" equals "cocoa"

features/fixtures/ios/iOSTestApp.xcodeproj/project.pbxproj

@@ -29,6 +29,7 @@
 		01E356C026CD5B6A00BE3F64 /* ThermalStateBreadcrumbScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 01E356BF26CD5B6A00BE3F64 /* ThermalStateBreadcrumbScenario.swift */; };
 		01E5EAD225B713990066EA8A /* OOMScenario.m in Sources */ = {isa = PBXBuildFile; fileRef = 01E5EAD125B713990066EA8A /* OOMScenario.m */; };
 		01F1474425F282E600C2DC65 /* AppHangScenarios.swift in Sources */ = {isa = PBXBuildFile; fileRef = 01F1474325F282E600C2DC65 /* AppHangScenarios.swift */; };
+		01FA9EC426D63BB20059FF4A /* AppHangInTerminationScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 01FA9EC326D63BB20059FF4A /* AppHangInTerminationScenario.swift */; };
 		6526A0D4248A83350002E2C9 /* LoadConfigFromFileAutoScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6526A0D3248A83350002E2C9 /* LoadConfigFromFileAutoScenario.swift */; };
 		8A14F0F62282D4AE00337B05 /* (null) in Sources */ = {isa = PBXBuildFile; };
 		8A32DB8222424E3000EDD92F /* NSExceptionShiftScenario.m in Sources */ = {isa = PBXBuildFile; fileRef = 8A32DB8122424E3000EDD92F /* NSExceptionShiftScenario.m */; };
@@ -189,6 +190,7 @@
 		01E5EAD025B713990066EA8A /* OOMScenario.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = OOMScenario.h; sourceTree = "<group>"; };
 		01E5EAD125B713990066EA8A /* OOMScenario.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = OOMScenario.m; sourceTree = "<group>"; };
 		01F1474325F282E600C2DC65 /* AppHangScenarios.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = AppHangScenarios.swift; sourceTree = "<group>"; };
+		01FA9EC326D63BB20059FF4A /* AppHangInTerminationScenario.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppHangInTerminationScenario.swift; sourceTree = "<group>"; };
 		6526A0D3248A83350002E2C9 /* LoadConfigFromFileAutoScenario.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = LoadConfigFromFileAutoScenario.swift; sourceTree = "<group>"; };
 		8A32DB8022424E3000EDD92F /* NSExceptionShiftScenario.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = NSExceptionShiftScenario.h; sourceTree = "<group>"; };
 		8A32DB8122424E3000EDD92F /* NSExceptionShiftScenario.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = NSExceptionShiftScenario.m; sourceTree = "<group>"; };
@@ -583,6 +585,7 @@
 				F49695AE2445476700105DA9 /* Plugin */,
 				0037410E2473CF2300BE41AA /* AppAndDeviceAttributesScenario.swift */,
 				01E0DB0A25E8EBD100A740ED /* AppDurationScenario.swift */,
+				01FA9EC326D63BB20059FF4A /* AppHangInTerminationScenario.swift */,
 				01F1474325F282E600C2DC65 /* AppHangScenarios.swift */,
 				01AF6A52258A112F00FFC803 /* BareboneTestScenarios.swift */,
 				01DE903726CE99B800455213 /* CriticalThermalStateScenario.swift */,
@@ -954,6 +957,7 @@
 				E700EE55247D3204008CFFB6 /* OnSendOverwriteScenario.swift in Sources */,
 				F429538D8941382EC2C857CE /* AsyncSafeThreadScenario.m in Sources */,
 				F42955869D33EE0E510B9651 /* ReadGarbagePointerScenario.m in Sources */,
+				01FA9EC426D63BB20059FF4A /* AppHangInTerminationScenario.swift in Sources */,
 				8AEFC73420F8D1BB00A78779 /* ManualSessionWithUserScenario.m in Sources */,
 				E753F25424937A83001FB671 /* ThreadScenarios.m in Sources */,
 				F4295B56219D228FAA99BC14 /* ObjCExceptionScenario.m in Sources */,

features/fixtures/macos/macOSTestApp.xcodeproj/project.pbxproj

@@ -137,6 +137,7 @@
 		01F47D30254B1B3100B184AD /* AutoContextNSExceptionScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 01F47CBF254B1B3000B184AD /* AutoContextNSExceptionScenario.swift */; };
 		01F47D31254B1B3100B184AD /* OverwriteLinkRegisterScenario.m in Sources */ = {isa = PBXBuildFile; fileRef = 01F47CC0254B1B3000B184AD /* OverwriteLinkRegisterScenario.m */; };
 		01F47D32254B1B3100B184AD /* ResumeSessionOOMScenario.m in Sources */ = {isa = PBXBuildFile; fileRef = 01F47CC1254B1B3000B184AD /* ResumeSessionOOMScenario.m */; };
+		01FA9EC626D64FFF0059FF4A /* AppHangInTerminationScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 01FA9EC526D64FFF0059FF4A /* AppHangInTerminationScenario.swift */; };
 		CBB7878E2578FB3F0071BDE4 /* MarkUnhandledHandledScenario.m in Sources */ = {isa = PBXBuildFile; fileRef = CBB7878C2578FB3F0071BDE4 /* MarkUnhandledHandledScenario.m */; };
 		E780377D264D703500430C11 /* AutoNotifyReenabledScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = E7803779264D703500430C11 /* AutoNotifyReenabledScenario.swift */; };
 		E780377E264D703500430C11 /* AutoNotifyFalseHandledScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = E780377A264D703500430C11 /* AutoNotifyFalseHandledScenario.swift */; };
@@ -346,6 +347,7 @@
 		01F47CC1254B1B3000B184AD /* ResumeSessionOOMScenario.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ResumeSessionOOMScenario.m; sourceTree = "<group>"; };
 		01F47CC2254B1B3000B184AD /* SIGBUSScenario.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SIGBUSScenario.h; sourceTree = "<group>"; };
 		01F47CC3254B1B3100B184AD /* SIGFPEScenario.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SIGFPEScenario.h; sourceTree = "<group>"; };
+		01FA9EC526D64FFF0059FF4A /* AppHangInTerminationScenario.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = AppHangInTerminationScenario.swift; sourceTree = "<group>"; };
 		2C49722B331FF4B0DC477462 /* Pods-macOSTestApp.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-macOSTestApp.release.xcconfig"; path = "Target Support Files/Pods-macOSTestApp/Pods-macOSTestApp.release.xcconfig"; sourceTree = "<group>"; };
 		5C65BFC9838298CFA8A35072 /* Pods_macOSTestApp.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = Pods_macOSTestApp.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		CBB7878C2578FB3F0071BDE4 /* MarkUnhandledHandledScenario.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MarkUnhandledHandledScenario.m; sourceTree = "<group>"; };
@@ -378,6 +380,7 @@
 				01F47C5B254B1B2E00B184AD /* AccessNonObjectScenario.m */,
 				01F47C60254B1B2E00B184AD /* AppAndDeviceAttributesScenario.swift */,
 				01E0DB0425E8E90500A740ED /* AppDurationScenario.swift */,
+				01FA9EC526D64FFF0059FF4A /* AppHangInTerminationScenario.swift */,
 				01F1473925F2817100C2DC65 /* AppHangScenarios.swift */,
 				01018BAA25E417EC000312C6 /* AsyncSafeMallocScenario.m */,
 				01F47C73254B1B2E00B184AD /* AsyncSafeThreadScenario.h */,
@@ -809,6 +812,7 @@
 				01F47CCD254B1B3100B184AD /* NullPointerScenario.m in Sources */,
 				01F47D30254B1B3100B184AD /* AutoContextNSExceptionScenario.swift in Sources */,
 				01F47CE1254B1B3100B184AD /* ManualSessionWithUserScenario.m in Sources */,
+				01FA9EC626D64FFF0059FF4A /* AppHangInTerminationScenario.swift in Sources */,
 				01F47D01254B1B3100B184AD /* SessionCallbackOrderScenario.swift in Sources */,
 				01AF6A84258BB38A00FFC803 /* DispatchCrashScenario.swift in Sources */,
 				01F47D0A254B1B3100B184AD /* CxxExceptionScenario.mm in Sources */,

features/fixtures/shared/scenarios/AppHangInTerminationScenario.swift

@@ -0,0 +1,41 @@
+//
+//  AppHangInTerminationScenario.swift
+//  iOSTestApp
+//
+//  Created by Nick Dowell on 25/08/2021.
+//  Copyright © 2021 Bugsnag. All rights reserved.
+//
+
+#if os(iOS)
+import UIKit
+#elseif os(macOS)
+import AppKit
+#endif
+
+class AppHangInTerminationScenario: Scenario {
+
+    override func startBugsnag() {
+        config.appHangThresholdMillis = 2_000
+        super.startBugsnag()
+    }
+
+    override func run() {
+        #if os(iOS)
+        let willTerminate = UIApplication.willTerminateNotification
+        #elseif os(macOS)
+        let willTerminate = NSApplication.willTerminateNotification
+        #endif
+
+        NotificationCenter.default.addObserver(forName: willTerminate, object: nil, queue: nil) {
+            NSLog("Received \($0.name.rawValue), simulating an app hang...")
+            Thread.sleep(forTimeInterval: 3)
+        }
+
+        #if os(iOS)
+        // Appium is not able to close apps gracefully, so we simulate this using private API
+        UIApplication.shared.perform(Selector(("terminateWithSuccess")))
+        #elseif os(macOS)
+        NSApp.terminate(self)
+        #endif
+    }
+}

features/steps/ios_steps.rb

@@ -105,22 +105,26 @@ def click_if_present(element)
 
 Then('the app is running in the foreground') do
   wait_for_true do
-    status = Maze.driver.execute_script('mobile: queryAppState', {bundleId: 'com.bugsnag.iOSTestApp'})
-    status == 4
+    Maze.driver.app_state('com.bugsnag.iOSTestApp') == :running_in_foreground
   end
 end
 
 Then('the app is running in the background') do
   wait_for_true do
-    status = Maze.driver.execute_script('mobile: queryAppState', {bundleId: 'com.bugsnag.iOSTestApp'})
-    status == 3
+    Maze.driver.app_state('com.bugsnag.iOSTestApp') == :running_in_background
   end
 end
 
 Then('the app is not running') do
   wait_for_true do
-    status = Maze.driver.execute_script('mobile: queryAppState', {bundleId: 'com.bugsnag.iOSTestApp'})
-    status == 1
+    case Maze.driver.capabilities['platformName']
+    when 'iOS'
+      Maze.driver.app_state('com.bugsnag.iOSTestApp') == :not_running
+    when 'Mac'
+      `lsappinfo info -only pid -app com.bugsnag.macOSTestApp`.empty?
+    else
+      raise "Don't know how to query app state on this platform"
+    end
   end
 end