Workaround Thread Sanitizer (TSan) false positive warnings (partially)

This patch covers only data race false positive warnings reported in
async_set_pht_entry_from_index, GC_clear_stack, GC_invoke_finalizers,
GC_lock, GC_noop1, GC_notify_or_invoke_finalizers, GC_pthread_create,
GC_suspend_handler_inner, I_DONT_HOLD_LOCK.

* finalize.c (GC_should_invoke_finalizers): Add
GC_ATTR_NO_SANITIZE_THREAD.
* mark.c (GC_noop1): Likewise.
* os_dep.c [MPROTECT_VDB && THREADS && AO_HAVE_test_and_set_acquire]
(async_set_pht_entry_from_index): Likewise.
* finalize.c (GC_invoke_finalizers, GC_notify_or_invoke_finalizers):
Call GC_should_invoke_finalizers() instead of
GC_fnlz_roots.finalize_now!=NULL.
* include/private/gc_locks.h [(GC_WIN32_THREADS && !USE_PTHREAD_LOCKS
|| GC_PTHREADS) && GC_ASSERTIONS && THREAD_SANITIZER]
(I_DONT_HOLD_LOCK): Define to TRUE; add comment.
* include/private/gc_locks.h [!GC_ALWAYS_MULTITHREADED
&& THREAD_SANITIZER] (set_need_to_lock): Do not set GC_need_to_lock if
already set; add comment.
* include/private/gc_priv.h [!GC_ATTR_NO_SANITIZE_THREAD]
(GC_ATTR_NO_SANITIZE_THREAD): New macro.
* include/private/gcconfig.h [__has_feature &&
__has_feature(thread_sanitizer)] (THREAD_SANITIZER): Define.
* misc.c [THREADS] (next_random_no): New static function (with
GC_ATTR_NO_SANITIZE_THREAD).
* pthread_stop_world.c [!GC_OPENBSD_UTHREADS && !NACL]
(update_last_stop_count): Likewise.
* pthread_support.c [THREAD_SANITIZER && (USE_SPIN_LOCK
|| !NO_PTHREAD_TRYLOCK)] (is_collecting): Likewise.
* pthread_support.c [USE_SPIN_LOCK] (set_last_spins_and_high_spin_max,
reset_spin_max): Likewise.
* misc.c [THREADS] (GC_clear_stack): Remove random_no static variable;
use next_random_no() instead of ++random_no%13.
* pthread_stop_world.c [!GC_OPENBSD_UTHREADS && !NACL]
(GC_suspend_handler_inner): Call update_last_stop_count() instead of
me->stop_info.last_stop_count=my_stop_count.
* pthread_support.c [USE_SPIN_LOCK || !NO_PTHREAD_TRYLOCK] (SPIN_MAX):
Define only if not yet.
* pthread_support.c [USE_SPIN_LOCK || !NO_PTHREAD_TRYLOCK]
(GC_collecting): Initialize to FALSE instead of 0.
* pthread_support.c [!(THREAD_SANITIZER && (USE_SPIN_LOCK
|| !NO_PTHREAD_TRYLOCK))] (is_collecting): Define as a macro.
* pthread_support.c [USE_SPIN_LOCK] (low_spin_max, high_spin_max,
spin_max, last_spins): Move definition out of GC_lock().
* pthread_support.c (GC_lock): Use is_collecting(),
set_last_spins_and_high_spin_max() and reset_spin_max().

1 files changed, 4 insertions, 2 deletions

diff --git a/finalize.c b/finalize.c
index 88ce2ebc..0c39b54d 100644
--- a/finalize.c
+++ b/finalize.c
@@ -1183,6 +1183,7 @@ GC_INNER void GC_finalize(void)
 /* finalizers can only be called from some kind of "safe state" and     */
 /* getting into that safe state is expensive.)                          */
 GC_API int GC_CALL GC_should_invoke_finalizers(void)
+                                                GC_ATTR_NO_SANITIZE_THREAD
 {
   return GC_fnlz_roots.finalize_now != NULL;
 }
@@ -1195,7 +1196,7 @@ GC_API int GC_CALL GC_invoke_finalizers(void)
     word bytes_freed_before = 0; /* initialized to prevent warning. */
     DCL_LOCK_STATE;
 
-    while (GC_fnlz_roots.finalize_now != NULL) {
+    while (GC_should_invoke_finalizers()) {
         struct finalizable_object * curr_fo;
 
 #       ifdef THREADS
@@ -1244,7 +1245,8 @@ GC_INNER void GC_notify_or_invoke_finalizers(void)
 #   if defined(THREADS) && !defined(KEEP_BACK_PTRS) \
        && !defined(MAKE_BACK_GRAPH)
       /* Quick check (while unlocked) for an empty finalization queue.  */
-      if (NULL == GC_fnlz_roots.finalize_now) return;
+      if (!GC_should_invoke_finalizers())
+        return;
 #   endif
     LOCK();