[threads] Remove dead field cached_culture_info (#4410)

mcs/class/corlib/System.Threading/Thread.cs

@@ -51,9 +51,7 @@ namespace System.Threading {
 		// stores a thread handle
 		IntPtr handle;
 		IntPtr native_handle; // used only on Win32
-
-		/* Note this is an opaque object (an array), not a CultureInfo */
-		private object cached_culture_info;
+		IntPtr unused3;
 		/* accessed only from unmanaged code */
 		private IntPtr name;
 		private int name_len; 

mono/metadata/appdomain.c

@@ -2543,8 +2543,6 @@ unload_thread_main (void *arg)
 	mono_domain_unlock (domain);
 	mono_loader_unlock ();
 
-	mono_threads_clear_cached_culture (domain);
-
 	domain->state = MONO_APPDOMAIN_UNLOADED;
 
 	/* printf ("UNLOADED %s.\n", domain->friendly_name); */

mono/metadata/object-internals.h

@@ -362,7 +362,7 @@ struct _MonoInternalThread {
 	volatile int lock_thread_id; /* to be used as the pre-shifted thread id in thin locks. Used for appdomain_ref push/pop */
 	MonoThreadHandle *handle;
 	gpointer native_handle;
-	MonoArray  *cached_culture_info;
+	gpointer unused3;
 	gunichar2  *name;
 	guint32	    name_len;
 	guint32	    state;

mono/metadata/threads-types.h

@@ -211,8 +211,6 @@ void mono_thread_push_appdomain_ref (MonoDomain *domain);
 void mono_thread_pop_appdomain_ref (void);
 gboolean mono_thread_has_appdomain_ref (MonoThread *thread, MonoDomain *domain);
 
-void mono_threads_clear_cached_culture (MonoDomain *domain);
-
 MonoException* mono_thread_request_interruption (mono_bool running_managed);
 gboolean mono_thread_interruption_requested (void);
 MonoException* mono_thread_interruption_checkpoint (void);

mono/metadata/threads.c

@@ -114,14 +114,6 @@ typedef struct {
 	StaticDataFreeList *freelist;
 } StaticDataInfo;
 
-/* Number of cached culture objects in the MonoThread->cached_culture_info array
- * (per-type): we use the first NUM entries for CultureInfo and the last for
- * UICultureInfo. So the size of the array is really NUM_CACHED_CULTURES * 2.
- */
-#define NUM_CACHED_CULTURES 4
-#define CULTURES_START_IDX 0
-#define UICULTURES_START_IDX NUM_CACHED_CULTURES
-
 /* Controls access to the 'threads' hash table */
 static void mono_threads_lock (void);
 static void mono_threads_unlock (void);
@@ -1130,17 +1122,6 @@ mono_thread_detach_internal (MonoInternalThread *thread)
 	thread->abort_exc = NULL;
 	thread->current_appcontext = NULL;
 
-	/*
-	 * This is necessary because otherwise we might have
-	 * cross-domain references which will not get cleaned up when
-	 * the target domain is unloaded.
-	 */
-	if (thread->cached_culture_info) {
-		int i;
-		for (i = 0; i < NUM_CACHED_CULTURES * 2; ++i)
-			mono_array_set (thread->cached_culture_info, MonoObject*, i, NULL);
-	}
-
 	/*
 	 * thread->synch_cs can be NULL if this was called after
 	 * ves_icall_System_Threading_InternalThread_Thread_free_internal.
@@ -1231,8 +1212,6 @@ mono_thread_detach_internal (MonoInternalThread *thread)
 	if (thread == mono_thread_internal_current ())
 		mono_thread_pop_appdomain_ref ();
 
-	thread->cached_culture_info = NULL;
-
 	mono_free_static_data (thread->static_data);
 	thread->static_data = NULL;
 	ref_stack_destroy (thread->appdomain_refs);
@@ -3934,39 +3913,6 @@ mono_threads_abort_appdomain_threads (MonoDomain *domain, int timeout)
 	return TRUE;
 }
 
-static void
-clear_cached_culture (gpointer key, gpointer value, gpointer user_data)
-{
-	MonoInternalThread *thread = (MonoInternalThread*)value;
-	MonoDomain *domain = (MonoDomain*)user_data;
-	int i;
-
-	/* No locking needed here */
-	/* FIXME: why no locking? writes to the cache are protected with synch_cs above */
-
-	if (thread->cached_culture_info) {
-		for (i = 0; i < NUM_CACHED_CULTURES * 2; ++i) {
-			MonoObject *obj = mono_array_get (thread->cached_culture_info, MonoObject*, i);
-			if (obj && obj->vtable->domain == domain)
-				mono_array_set (thread->cached_culture_info, MonoObject*, i, NULL);
-		}
-	}
-}
-	
-/*
- * mono_threads_clear_cached_culture:
- *
- *   Clear the cached_current_culture from all threads if it is in the
- * given appdomain.
- */
-void
-mono_threads_clear_cached_culture (MonoDomain *domain)
-{
-	mono_threads_lock ();
-	mono_g_hash_table_foreach (threads, clear_cached_culture, domain);
-	mono_threads_unlock ();
-}
-
 /*
  * mono_thread_get_undeniable_exception:
  *

mono/sgen/sgen-debug.c

@@ -958,12 +958,6 @@ is_xdomain_ref_allowed (GCObject **ptr, GCObject *obj, MonoDomain *domain)
 			offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
 		return TRUE;
 #endif
-	/* Thread.cached_culture_info */
-	if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
-			!strcmp (ref->vtable->klass->name, "CultureInfo") &&
-			!strcmp(o->vtable->klass->name_space, "System") &&
-			!strcmp(o->vtable->klass->name, "Object[]"))
-		return TRUE;
 	/*
 	 *  at System.IO.MemoryStream.InternalConstructor (byte[],int,int,bool,bool) [0x0004d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:121
 	 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81