feat: Disable SIGTERM reporting by default

.github/workflows/lint.yml

@@ -4,24 +4,24 @@ on:
     branches:
       - main
     paths:
-      - 'Sources/**'
-      - 'Tests/**'
-      - 'test-server/**'
-      - 'Samples/**'
-      - '.github/workflows/lint.yml'
-      - 'scripts/ci-select-xcode.sh'
+      - "Sources/**"
+      - "Tests/**"
+      - "test-server/**"
+      - "Samples/**"
+      - ".github/workflows/lint.yml"
+      - "scripts/ci-select-xcode.sh"
 
   pull_request:
     paths:
-      - 'Sources/**'
-      - 'Tests/**'
-      - 'test-server/**'
-      - 'Samples/**'
-      - '.github/workflows/lint.yml'
-      - 'scripts/ci-select-xcode.sh'
-      - 'Sentry.xcodeproj/**'
-      - '*.podspec'
-      - 'Gemfile.lock'
+      - "Sources/**"
+      - "Tests/**"
+      - "test-server/**"
+      - "Samples/**"
+      - ".github/workflows/lint.yml"
+      - "scripts/ci-select-xcode.sh"
+      - "Sentry.xcodeproj/**"
+      - "*.podspec"
+      - "Gemfile.lock"
 
 # https://docs.github.com/en/actions/using-jobs/using-concurrency#example-using-a-fallback-value
 concurrency:
@@ -50,10 +50,11 @@ jobs:
     name: pod lint ${{ matrix.podspec}} ${{ matrix.library_type }} ${{ matrix.platform}}
     runs-on: macos-13
     strategy:
+      fail-fast: false
       matrix:
-        podspec: ['Sentry', 'SentrySwiftUI']
-        platform: ['ios', 'macos', 'tvos', 'watchos']
-        library_type: ['dynamic', 'static']
+        podspec: ["Sentry", "SentrySwiftUI"]
+        platform: ["ios", "macos", "tvos", "watchos"]
+        library_type: ["dynamic", "static"]
 
     steps:
       - uses: actions/checkout@v4

CHANGELOG.md

@@ -8,6 +8,11 @@
 - Add start time to network request breadcrumbs (#4008)
 - Add C++ exception support for `__cxa_rethrow` (#3996)
 - Add beforeCaptureScreenshot callback (#4016)
+- Disable SIGTERM reporting by default (#4025). We added support
+for SIGTERM reporting in the last release and enabled it by default.
+For some users, SIGTERM events were verbose and not actionable.
+Therefore, we disable it per default in this release. If you'd like
+to receive SIGTERM events, set the option `enableSigtermReporting = true`.
 
 ### Improvements
 

Samples/iOS-Swift/iOS-Swift/AppDelegate.swift

@@ -22,6 +22,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
             options.beforeSend = { event in
                 return event
             }
+            options.enableSigtermReporting = true
             options.beforeCaptureScreenshot = { _ in
                 return true
             }

Sources/Sentry/Public/SentryOptions.h

@@ -74,6 +74,23 @@ NS_SWIFT_NAME(Options)
  */
 @property (nonatomic, assign) BOOL enableCrashHandler;
 
+#if !TARGET_OS_WATCH
+
+/**
+ * When enabled, the SDK reports SIGTERM signals to Sentry.
+ *
+ * It's crucial for developers to understand that the OS sends a SIGTERM to their app as a prelude
+ * to a graceful shutdown, before resorting to a SIGKILL. This SIGKILL, which your app can't catch
+ * or ignore, is a direct order to terminate your app's process immediately. Developers should be
+ * aware that their app can receive a SIGTERM in various scenarios, such as  CPU or disk overuse,
+ * watchdog terminations, or when the OS updates your app.
+ *
+ * @note The default value is @c NO.
+ */
+@property (nonatomic, assign) BOOL enableSigtermReporting;
+
+#endif // !TARGET_OS_WATCH
+
 /**
  * How many breadcrumbs do you want to keep in memory?
  * @note Default is @c 100 .

Sources/Sentry/SentryCrashIntegration.m

@@ -1,5 +1,7 @@
 #import "SentryCrashIntegration.h"
 #import "SentryCrashInstallationReporter.h"
+
+#include "SentryCrashMonitor_Signal.h"
 #import "SentryCrashWrapper.h"
 #import "SentryDispatchQueueWrapper.h"
 #import "SentryEvent.h"
@@ -87,7 +89,13 @@ - (BOOL)installWithOptions:(nonnull SentryOptions *)options
     self.scopeObserver =
         [[SentryCrashScopeObserver alloc] initWithMaxBreadcrumbs:options.maxBreadcrumbs];
 
-    [self startCrashHandler:options.cacheDirectoryPath];
+    BOOL enableSigtermReporting = NO;
+#if !TARGET_OS_WATCH
+    enableSigtermReporting = options.enableSigtermReporting;
+#endif // !TARGET_OS_WATCH
+
+    [self startCrashHandler:options.cacheDirectoryPath
+        enableSigtermReporting:enableSigtermReporting];
 
     [self configureScope];
 
@@ -100,6 +108,7 @@ - (SentryIntegrationOption)integrationOptions
 }
 
 - (void)startCrashHandler:(NSString *)cacheDirectory
+    enableSigtermReporting:(BOOL)enableSigtermReporting
 {
     void (^block)(void) = ^{
         BOOL canSendReports = NO;
@@ -116,6 +125,8 @@ - (void)startCrashHandler:(NSString *)cacheDirectory
             canSendReports = YES;
         }
 
+        sentrycrashcm_setEnableSigtermReporting(enableSigtermReporting);
+
         [installation install:cacheDirectory];
 
         // We need to send the crashed event together with the crashed session in the same envelope

Sources/Sentry/SentryOptions.m

@@ -87,6 +87,9 @@ - (instancetype)init
         self.enabled = YES;
         self.shutdownTimeInterval = 2.0;
         self.enableCrashHandler = YES;
+#if !TARGET_OS_WATCH
+        self.enableSigtermReporting = NO;
+#endif // !TARGET_OS_WATCH
         self.diagnosticLevel = kSentryLevelDebug;
         self.debug = NO;
         self.maxBreadcrumbs = defaultMaxBreadcrumbs;
@@ -316,6 +319,11 @@ - (BOOL)validateOptions:(NSDictionary<NSString *, id> *)options
     [self setBool:options[@"enableCrashHandler"]
             block:^(BOOL value) { self->_enableCrashHandler = value; }];
 
+#if !TARGET_OS_WATCH
+    [self setBool:options[@"enableSigtermReporting"]
+            block:^(BOOL value) { self->_enableSigtermReporting = value; }];
+#endif // !TARGET_OS_WATCH
+
     if ([options[@"maxBreadcrumbs"] isKindOfClass:[NSNumber class]]) {
         self.maxBreadcrumbs = [options[@"maxBreadcrumbs"] unsignedIntValue];
     }

Sources/SentryCrash/Recording/Monitors/SentryCrashMonitor_Signal.c

@@ -49,6 +49,7 @@
 // ============================================================================
 
 static volatile bool g_isEnabled = false;
+static bool g_isSigtermReportingEnabled = false;
 
 static SentryCrash_MonitorContext g_monitorContext;
 static SentryCrashStackCursor g_stackCursor;
@@ -163,6 +164,11 @@ installSignalHandler(void)
     action.sa_sigaction = &handleSignal;
 
     for (int i = 0; i < fatalSignalsCount; i++) {
+        if (fatalSignals[i] == SIGTERM && !g_isSigtermReportingEnabled) {
+            SentryCrashLOG_DEBUG("SIGTERM handling disabled. Skipping assigning handler.");
+            continue;
+        }
+
         SentryCrashLOG_DEBUG("Assigning handler for signal %d", fatalSignals[i]);
         if (sigaction(fatalSignals[i], &action, &g_previousSignalHandlers[i]) != 0) {
             char sigNameBuff[30];
@@ -203,6 +209,11 @@ uninstallSignalHandler(void)
     int fatalSignalsCount = sentrycrashsignal_numFatalSignals();
 
     for (int i = 0; i < fatalSignalsCount; i++) {
+        if (fatalSignals[i] == SIGTERM && !g_isSigtermReportingEnabled) {
+            SentryCrashLOG_DEBUG("SIGTERM handling disabled. Skipping restoring handler.");
+            continue;
+        }
+
         SentryCrashLOG_DEBUG("Restoring original handler for signal %d", fatalSignals[i]);
         sigaction(fatalSignals[i], &g_previousSignalHandlers[i], NULL);
     }
@@ -246,6 +257,14 @@ addContextualInfoToEvent(struct SentryCrash_MonitorContext *eventContext)
 
 #endif
 
+void
+sentrycrashcm_setEnableSigtermReporting(bool enabled)
+{
+#if SentryCrashCRASH_HAS_SIGNAL
+    g_isSigtermReportingEnabled = enabled;
+#endif
+}
+
 SentryCrashMonitorAPI *
 sentrycrashcm_signal_getAPI(void)
 {

Sources/SentryCrash/Recording/Monitors/SentryCrashMonitor_Signal.h

@@ -37,6 +37,10 @@ extern "C" {
 
 #include "SentryCrashMonitor.h"
 
+/** Wether to assign the signal handler for SIGTERM or not.
+ */
+void sentrycrashcm_setEnableSigtermReporting(bool enabled);
+
 /** Access the Monitor API.
  */
 SentryCrashMonitorAPI *sentrycrashcm_signal_getAPI(void);

Sources/SentryCrash/Recording/Tools/SentryCrashSignalInfo.c

@@ -126,7 +126,7 @@ static const int g_fatalSignals[] = {
     // SIGTERM can be caught and is usually sent by iOS and variants
     // when Apple wants to try and gracefully shutdown the app
     // before sending a SIGKILL (which can't be caught).
-    // Some areas I've seen this happen are:
+    // Some areas this might happen are:
     // - When the OS updates an app.
     // - In some circumstances for Watchdog Events.
     // - Resource overuse (CPU, Disk, ...).

Tests/SentryTests/SentryOptionsTest.m

@@ -155,6 +155,11 @@ - (void)testDiagnosticlevelWith:(NSObject *)level expected:(SentryLevel)expected
     XCTAssertEqual(expected, options.diagnosticLevel);
 }
 
+- (void)testEnableSigtermReporting
+{
+    [self testBooleanField:@"enableSigtermReporting" defaultValue:NO];
+}
+
 - (void)testValidEnabled
 {
     [self testEnabledWith:@YES expected:YES];