Check if the thread suspend correctly. Fixes shutdown race in mono testsuite.

diff --git a/mono/metadata/threads.c b/mono/metadata/threads.c
index f65f890749eeb81b928f36e060ee002b0673536d..5b9ca001b1536fb255d9815fa37e2e5d120b45a0 100644 (file)
--- a/mono/metadata/threads.c
+++ b/mono/metadata/threads.c
@@ -4465,6 +4465,8 @@ static MonoJitInfo*
 mono_thread_info_get_last_managed (MonoThreadInfo *info)
 {
        MonoJitInfo *ji = NULL;
+       if (!info)
+               return NULL;
        mono_get_eh_callbacks ()->mono_walk_stack_with_state (last_managed, &info->suspend_state, MONO_UNWIND_SIGNAL_SAFE, &ji);
        return ji;
 }
@@ -4571,10 +4573,18 @@ suspend_thread_internal (MonoInternalThread *thread, gboolean interrupt)
                transition_to_suspended (thread);
                mono_thread_info_self_suspend ();
        } else {
-               MonoThreadInfo *info = mono_thread_info_safe_suspend_sync ((MonoNativeThreadId)(gsize)thread->tid, interrupt);
-               MonoJitInfo *ji = mono_thread_info_get_last_managed (info);
-               gboolean protected_wrapper = ji && mono_threads_is_critical_method (ji->method);
-               gboolean running_managed = mono_jit_info_match (ji, MONO_CONTEXT_GET_IP (&info->suspend_state.ctx));
+               MonoThreadInfo *info;
+               MonoJitInfo *ji;
+               gboolean protected_wrapper;
+               gboolean running_managed;
+
+               /*A null info usually means the thread is already dead. */
+               if (!(info = mono_thread_info_safe_suspend_sync ((MonoNativeThreadId)(gsize)thread->tid, interrupt)))
+                       return;
+
+               ji = mono_thread_info_get_last_managed (info);
+               protected_wrapper = ji && mono_threads_is_critical_method (ji->method);
+               running_managed = mono_jit_info_match (ji, MONO_CONTEXT_GET_IP (&info->suspend_state.ctx));
 
                if (running_managed && !protected_wrapper) {
                        transition_to_suspended (thread);