[ASan] Refactor thread starting code.

[earthdok]

Summary

Move thread context creation into AsanThread::Create().

[samsonov]

LGTM. Thanks!

lib/asan/asan_interceptors.cc

201

Can we remove CreateThreadContextArgs from asan_thread.h header now?

735

s/stack/&stack

[earthdok]

Committed r223483

lib/asan/asan_interceptors.cc

201

done

735

done

lib/asan/asan_interceptors.cc

INTERCEPTOR(int, pthread_create, void *thread,
   if (attr != 0)
     REAL(pthread_attr_getdetachstate)(attr, &detached);
   ThreadStartParam param;
   atomic_store(&param.t, 0, memory_order_relaxed);
   atomic_store(&param.is_registered, 0, memory_order_relaxed);
   int result = REAL(pthread_create)(thread, attr, asan_thread_start, &param);
   if (result == 0) {
     u32 current_tid = GetCurrentTidOrInvalid();
-    AsanThread *t = AsanThread::Create(start_routine, arg);
-    CreateThreadContextArgs args = { t, &stack };
-    asanThreadRegistry().CreateThread(*reinterpret_cast<uptr *>(t), detached,
-                                      current_tid, &args);
+    AsanThread *t =
+        AsanThread::Create(start_routine, arg, current_tid, &stack, detached);
     atomic_store(&param.t, reinterpret_cast<uptr>(t), memory_order_release);
     // Wait until the AsanThread object is initialized and the ThreadRegistry
     // entry is in "started" state. One reason for this is that after this
     // interceptor exits, the child thread's stack may be the only thing holding
     // the |arg| pointer. This may cause LSan to report a leak if leak checking
     // happens at a point when the interceptor has already exited, but the stack
     // range for the child thread is not yet known.
     while (atomic_load(&param.is_registered, memory_order_acquire) == 0)
INTERCEPTOR_WINAPI(DWORD, CreateThread,
                    void* security, uptr stack_size,
                    DWORD (__stdcall *start_routine)(void*), void* arg,
                    DWORD thr_flags, void* tid) {
   // Strict init-order checking is thread-hostile.
   if (flags()->strict_init_order)
     StopInitOrderChecking();
   GET_STACK_TRACE_THREAD;
   u32 current_tid = GetCurrentTidOrInvalid();
-  AsanThread *t = AsanThread::Create(start_routine, arg);
-  CreateThreadContextArgs args = { t, &stack };
   bool detached = false;  // FIXME: how can we determine it on Windows?
-  asanThreadRegistry().CreateThread(*(uptr*)t, detached, current_tid, &args);
+  AsanThread *t =
+      AsanThread::Create(start_routine, arg, current_tid, stack, detached);
   return REAL(CreateThread)(security, stack_size,
                             asan_thread_start, t, thr_flags, tid);
 }
 
 namespace __asan {
 void InitializeWindowsInterceptors() {
   ASAN_INTERCEPT_FUNC(CreateThread);
   ASAN_INTERCEPT_FUNC(RaiseException);

lib/asan/asan_mac.cc

typedef struct {
   dispatch_function_t func;
   u32 parent_tid;
 } asan_block_context_t;
 
 ALWAYS_INLINE
 void asan_register_worker_thread(int parent_tid, StackTrace *stack) {
   AsanThread *t = GetCurrentThread();
   if (!t) {
-    t = AsanThread::Create(0, 0);
-    CreateThreadContextArgs args = { t, stack };
-    asanThreadRegistry().CreateThread(*(uptr*)t, true, parent_tid, &args);
+    t = AsanThread::Create(/* start_routine */ nullptr, /* arg */ nullptr,
+                           parent_tid, stack, /* detached */ true);
     t->Init();
     asanThreadRegistry().StartThread(t->tid(), 0, 0);
     SetCurrentThread(t);
   }
 }
 
 // For use by only those functions that allocated the context via
 // alloc_asan_context().

lib/asan/asan_rtl.cc

if (common_flags()->coverage) {
     __sanitizer_cov_init();
     Atexit(__sanitizer_cov_dump);
   }
 
   // interceptors
   InitTlsSize();
 
   // Create main thread.
-  AsanThread *main_thread = AsanThread::Create(0, 0);
-  CreateThreadContextArgs create_main_args = { main_thread, 0 };
-  u32 main_tid = asanThreadRegistry().CreateThread(
-      0, true, 0, &create_main_args);
-  CHECK_EQ(0, main_tid);
+  AsanThread *main_thread = AsanThread::Create(
+      /* start_routine */ nullptr, /* arg */ nullptr, /* parent_tid */ 0,
+      /* stack */ nullptr, /* detached */ true);
+  CHECK_EQ(0, main_thread->tid());
   SetCurrentThread(main_thread);
   main_thread->ThreadStart(internal_getpid(),
                            /* signal_thread_is_registered */ nullptr);
   force_interface_symbols();  // no-op.
   SanitizerInitializeUnwinder();
 
 #if CAN_SANITIZE_LEAKS
   __lsan::InitCommonLsan(false);

lib/asan/asan_thread.h

 };
 
 // AsanThreadContext objects are never freed, so we need many of them.
 COMPILER_CHECK(sizeof(AsanThreadContext) <= 256);
 
 // AsanThread are stored in TSD and destroyed when the thread dies.
 class AsanThread {
  public:
-  static AsanThread *Create(thread_callback_t start_routine, void *arg);
+  static AsanThread *Create(thread_callback_t start_routine, void *arg,
+                            u32 parent_tid, StackTrace *stack, bool detached);
   static void TSDDtor(void *tsd);
   void Destroy();
 
   void Init();  // Should be called from the thread itself.
   thread_return_t ThreadStart(uptr os_id,
                               atomic_uintptr_t *signal_thread_is_registered);
 
   uptr stack_top() { return stack_top_; }

lib/asan/asan_thread.cc

 
 AsanThreadContext *GetThreadContextByTidLocked(u32 tid) {
   return static_cast<AsanThreadContext *>(
       asanThreadRegistry().GetThreadLocked(tid));
 }
 
 // AsanThread implementation.
 
-AsanThread *AsanThread::Create(thread_callback_t start_routine,
-                               void *arg) {
+AsanThread *AsanThread::Create(thread_callback_t start_routine, void *arg,
+                               u32 parent_tid, StackTrace *stack,
+                               bool detached) {
   uptr PageSize = GetPageSizeCached();
   uptr size = RoundUpTo(sizeof(AsanThread), PageSize);
   AsanThread *thread = (AsanThread*)MmapOrDie(size, __func__);
   thread->start_routine_ = start_routine;
   thread->arg_ = arg;
+  CreateThreadContextArgs args = { thread, stack };
+  asanThreadRegistry().CreateThread(*reinterpret_cast<uptr *>(thread), detached,
+                                    parent_tid, &args);
 
   return thread;
 }
 
 void AsanThread::TSDDtor(void *tsd) {
   AsanThreadContext *context = (AsanThreadContext*)tsd;
   VReport(1, "T%d TSDDtor\n", context->tid);
   if (context->thread)