[threads] Destroy suspend MonoOSEvent when detaching (#3923)

* [threads] Destroy suspend MonoOSEvent when detaching

It could happen that we destroy the managed InternalThread object, before we actually detach the thread (in mono/tests/threadpool-exceptions1.exe for example).

Fixes https://bugzilla.xamarin.com/show_bug.cgi?id=46536

* [threads] Close thread handle once done with it

diff --git a/mono/metadata/threads.c b/mono/metadata/threads.c
index 083b62f33ac747c1fac21263ee82710cb42c58b0..36bbf09aa110ece179371613bc52f6741c108a85 100644 (file)
--- a/mono/metadata/threads.c
+++ b/mono/metadata/threads.c
@@ -453,6 +453,10 @@ static void thread_cleanup (MonoInternalThread *thread)
                thread->thread_pinning_ref = NULL;
        }
 
+       g_assert (thread->suspended);
+       mono_os_event_destroy (thread->suspended);
+       g_free (thread->suspended);
+       thread->suspended = NULL;
 }
 
 /*
@@ -1288,11 +1292,6 @@ ves_icall_System_Threading_InternalThread_Thread_free_internal (MonoInternalThre
                this_obj->name = NULL;
                g_free (name);
        }
-
-       g_assert (this_obj->suspended);
-       mono_os_event_destroy (this_obj->suspended);
-       g_free (this_obj->suspended);
-       this_obj->suspended = NULL;
 }
 
 void
@@ -3255,8 +3254,8 @@ void mono_thread_suspend_all_other_threads (void)
                             || mono_gc_is_finalizer_internal_thread (thread)
                             || (thread->flags & MONO_THREAD_FLAG_DONT_MANAGE)
                        ) {
-                               //mono_threads_close_thread_handle (wait->handles [i]);
-                               wait->threads [i] = NULL; /* ignore this thread in next loop */
+                               mono_threads_close_thread_handle (wait->handles [i]);
+                               wait->threads [i] = NULL;
                                continue;
                        }
 
@@ -3267,7 +3266,7 @@ void mono_thread_suspend_all_other_threads (void)
                                (thread->state & ThreadState_Stopped) != 0) {
                                UNLOCK_THREAD (thread);
                                mono_threads_close_thread_handle (wait->handles [i]);
-                               wait->threads [i] = NULL; /* ignore this thread in next loop */
+                               wait->threads [i] = NULL;
                                continue;
                        }
 
@@ -3283,6 +3282,9 @@ void mono_thread_suspend_all_other_threads (void)
 
                        /* Signal the thread to suspend + calls UNLOCK_THREAD (thread) */
                        async_suspend_internal (thread, TRUE);
+
+                       mono_threads_close_thread_handle (wait->handles [i]);
+                       wait->threads [i] = NULL;
                }
                if (eventidx <= 0) {
                        /*