[K/N] Add utilities to check if thread is registered now

kotlin-native/runtime/src/main/cpp/Porting.cpp

@@ -192,13 +192,17 @@ struct DestructorRecord {
 
 static void onThreadExitCallback(void* value) {
   DestructorRecord* record = reinterpret_cast<DestructorRecord*>(value);
+  pthread_setspecific(terminationKey, nullptr);
   while (record != nullptr) {
     record->destructor(record->destructorParameter);
     auto next = record->next;
     free(record);
     record = next;
   }
-  pthread_setspecific(terminationKey, nullptr);
+}
+
+bool isOnThreadExitNotSetOrAlreadyStarted() {
+    return terminationKey != 0 && pthread_getspecific(terminationKey) == nullptr;
 }
 
 #if KONAN_LINUX

kotlin-native/runtime/src/main/cpp/Porting.h

@@ -41,6 +41,7 @@ RUNTIME_NORETURN void exit(int32_t status);
 
 // Thread control.
 void onThreadExit(void (*destructor)(void*), void* destructorParameter);
+bool isOnThreadExitNotSetOrAlreadyStarted();
 
 // String/byte operations.
 // memcpy/memmove/memcmp are not here intentionally, as frequently implemented/optimized

kotlin-native/runtime/src/mm/cpp/ThreadRegistry.cpp

@@ -20,7 +20,7 @@ mm::ThreadRegistry::Node* mm::ThreadRegistry::RegisterCurrentThread() noexcept {
     auto* threadDataNode = list_.Emplace(pthread_self());
     AssertThreadState(threadDataNode->Get(), ThreadState::kNative);
     Node*& currentDataNode = currentThreadDataNode_;
-    RuntimeAssert(currentDataNode == nullptr, "This thread already had some data assigned to it.");
+    RuntimeAssert(!IsCurrentThreadRegistered(), "This thread already had some data assigned to it.");
     currentDataNode = threadDataNode;
     return threadDataNode;
 }

kotlin-native/runtime/src/mm/cpp/ThreadRegistry.hpp

@@ -41,6 +41,8 @@ public:
     ALWAYS_INLINE ThreadData* CurrentThreadData() const noexcept;
     Node* CurrentThreadDataNode() const noexcept { return currentThreadDataNode_; }
 
+    bool IsCurrentThreadRegistered() const noexcept { return currentThreadDataNode_ != nullptr; }
+
     class TestSupport {
     public:
         static void ClearCurrentThreadData() { currentThreadDataNode_ = nullptr; }