impr: Stop sending empty thread names

CHANGELOG.md

@@ -6,6 +6,10 @@
 
 - Add thread id and name to span data (#3359)
 
+### Improvements
+
+- Stop sending empty thread names (#3361)
+
 ## 8.14.2
 
 ### Features

Sources/Sentry/SentryCrashDefaultMachineContextWrapper.m

@@ -41,11 +41,11 @@ - (SentryCrashThread)getThread:(struct SentryCrashMachineContext *)context withI
     return thread;
 }
 
-- (void)getThreadName:(const SentryCrashThread)thread
+- (BOOL)getThreadName:(const SentryCrashThread)thread
             andBuffer:(char *const)buffer
          andBufLength:(int)bufLength;
 {
-    sentrycrashthread_getThreadName(thread, buffer, bufLength);
+    return sentrycrashthread_getThreadName(thread, buffer, bufLength) == true;
 }
 
 - (BOOL)isMainThread:(SentryCrashThread)thread

Sources/Sentry/SentrySpan.m

@@ -43,11 +43,8 @@ - (instancetype)initWithContext:(SentrySpanContext *)context
         if ([NSThread isMainThread]) {
             _data[SPAN_DATA_THREAD_NAME] = @"main";
         } else {
-            NSString *threadName = [SentryDependencyContainer.sharedInstance.threadInspector
+            _data[SPAN_DATA_THREAD_NAME] = [SentryDependencyContainer.sharedInstance.threadInspector
                 getThreadName:currentThread];
-            if (threadName.length > 0) {
-                _data[SPAN_DATA_THREAD_NAME] = threadName;
-            }
         }
 
         _tags = [[NSMutableDictionary alloc] init];

Sources/Sentry/SentryThreadInspector.m

@@ -202,17 +202,24 @@ - (SentryStacktrace *)stacktraceForCurrentThreadAsyncUnsafe
     return threads;
 }
 
-- (NSString *)getThreadName:(SentryCrashThread)thread
+- (nullable NSString *)getThreadName:(SentryCrashThread)thread
 {
-    char buffer[128];
+    int bufferLength = 128;
+    char buffer[bufferLength];
     char *const pBuffer = buffer;
-    [self.machineContextWrapper getThreadName:thread andBuffer:pBuffer andBufLength:128];
 
-    NSString *threadName = [NSString stringWithCString:pBuffer encoding:NSUTF8StringEncoding];
-    if (nil == threadName) {
-        threadName = @"";
+    BOOL didGetThreadNameSucceed = [self.machineContextWrapper getThreadName:thread
+                                                                   andBuffer:pBuffer
+                                                                andBufLength:bufferLength];
+
+    if (didGetThreadNameSucceed == YES) {
+        NSString *threadName = [NSString stringWithCString:pBuffer encoding:NSUTF8StringEncoding];
+        if (threadName.length > 0) {
+            return threadName;
+        }
     }
-    return threadName;
+
+    return nil;
 }
 
 @end

Sources/Sentry/include/SentryCrashMachineContextWrapper.h

@@ -14,7 +14,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (SentryCrashThread)getThread:(struct SentryCrashMachineContext *)context withIndex:(int)index;
 
-- (void)getThreadName:(const SentryCrashThread)thread
+- (BOOL)getThreadName:(const SentryCrashThread)thread
             andBuffer:(char *const)buffer
          andBufLength:(int)bufLength;
 

Sources/Sentry/include/SentryThreadInspector.h

@@ -31,7 +31,7 @@ SENTRY_NO_INIT
  */
 - (NSArray<SentryThread *> *)getCurrentThreadsWithStackTrace;
 
-- (NSString *)getThreadName:(SentryCrashThread)thread;
+- (nullable NSString *)getThreadName:(SentryCrashThread)thread;
 
 @end
 

Tests/SentryTests/Protocol/SentryThreadTests.swift

@@ -18,6 +18,15 @@ class SentryThreadTests: XCTestCase {
         XCTAssertTrue(actual["main"] as! Bool)
     }
 
+    func testSerialize_ThreadNameNil() {
+        let thread = TestData.thread
+        thread.name = nil
+
+        let actual = thread.serialize()
+
+        XCTAssertNil(actual["name"])
+    }
+
     func testSerialize_Bools() {
         let thread = SentryThread(threadId: 0)
 

Tests/SentryTests/SentryCrash/SentryThreadInspectorTests.swift

@@ -182,15 +182,27 @@ class SentryThreadInspectorTests: XCTestCase {
         XCTAssertEqual(threadName, actual[0].name)
     }
 
-    func testThreadNameIsNull() {
-        fixture.testMachineContextWrapper.threadName = nil
+    func testGetThreadName_EmptyThreadName() {
+        fixture.testMachineContextWrapper.threadName = ""
         fixture.testMachineContextWrapper.threadCount = 1
 
         let actual = fixture.getSut().getCurrentThreads()
         XCTAssertEqual(1, actual.count)
 
         let thread = actual[0]
-        XCTAssertEqual("", thread.name)
+        XCTAssertNil(thread.name)
+    }
+
+    func testGetThreadNameFails() {
+        fixture.testMachineContextWrapper.threadName = ""
+        fixture.testMachineContextWrapper.getThreadNameSucceeds = false
+        fixture.testMachineContextWrapper.threadCount = 1
+
+        let actual = fixture.getSut().getCurrentThreads()
+        XCTAssertEqual(1, actual.count)
+
+        let thread = actual[0]
+        XCTAssertNil(thread.name)
     }
 
     func testLongThreadName() {
@@ -270,16 +282,22 @@ private class TestMachineContextWrapper: NSObject, SentryCrashMachineContextWrap
         mockThreads?[Int(index)].threadId ?? 0
     }
 
-    var threadName: String? = ""
-    func getThreadName(_ thread: SentryCrashThread, andBuffer buffer: UnsafeMutablePointer<Int8>, andBufLength bufLength: Int32) {
+    var threadName: String = ""
+    var getThreadNameSucceeds = true
+    func getThreadName(_ thread: SentryCrashThread, andBuffer buffer: UnsafeMutablePointer<Int8>, andBufLength bufLength: Int32) -> Bool {
         if let mocks = mockThreads, let index = mocks.firstIndex(where: { $0.threadId == thread }) {
             strcpy(buffer, mocks[index].name)
-        } else if threadName != nil {
+            return true
+        }
+
+        if getThreadNameSucceeds {
             strcpy(buffer, threadName)
+            return true
         } else {
             _ = Array(repeating: 0, count: Int(bufLength)).withUnsafeBufferPointer { bufferPointer in
                 strcpy(buffer, bufferPointer.baseAddress)
             }
+            return false
         }
     }