Merge branch 'upstream'

Former-commit-id: bd9916021a63d700a72bf8bd6c46f61d072f4241

libgc/dyn_load.c

@@ -396,7 +396,8 @@ GC_bool GC_register_main_static_data()
 
 # if (defined(LINUX) || defined (__GLIBC__) || defined(NACL)) /* Are others OK here, too? */ \
      && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) \
-         || (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && defined(DT_CONFIG))) 
+         || (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && defined(DT_CONFIG))) \
+	 || defined(OPENBSD)
 
 /* We have the header files for a glibc that includes dl_iterate_phdr.	*/
 /* It may still not be available in the library on the target system.   */

libgc/include/gc.h

@@ -835,6 +835,18 @@ typedef GC_PTR (*GC_fn_type) GC_PROTO((GC_PTR client_data));
 GC_API GC_PTR GC_call_with_alloc_lock
         	GC_PROTO((GC_fn_type fn, GC_PTR client_data));
 
+/*
+ * These are similar to GC_do_blocking () in upstream bdwgc. The design is
+ * simpler in that there is no distinction between active and inactive stack
+ * frames; instead, while a thread is in blocking state, it promises to not
+ * interact with the GC at all, and to not keep any pointers to GC memory
+ * around from before entering blocking state. Additionally, these can be
+ * called unbalanced (they simply set a flag internally).
+ */
+GC_API void GC_start_blocking GC_PROTO((void));
+
+GC_API void GC_end_blocking GC_PROTO((void));
+
 /* The following routines are primarily intended for use with a 	*/
 /* preprocessor which inserts calls to check C pointer arithmetic.	*/
 /* They indicate failure by invoking the corresponding _print_proc.	*/

libgc/pthread_support.c

@@ -1245,7 +1245,6 @@ void GC_start_blocking(void) {
     GC_thread me;
     LOCK();
     me = GC_lookup_thread(pthread_self());
-    GC_ASSERT(!(me -> thread_blocked));
 #   ifdef SPARC
 	me -> stop_info.stack_ptr = (ptr_t)GC_save_regs_in_stack();
 #   else
@@ -1273,7 +1272,6 @@ void GC_end_blocking(void) {
     GC_thread me;
     LOCK();   /* This will block if the world is stopped.	*/
     me = GC_lookup_thread(pthread_self());
-    GC_ASSERT(me -> thread_blocked);
     me -> thread_blocked = FALSE;
     UNLOCK();
 }

libgc/win32_threads.c

@@ -48,6 +48,7 @@ struct GC_thread_Rep {
 			/* 0 ==> entry not valid.	*/
 			/* !in_use ==> stack_base == 0	*/
   GC_bool suspended;
+  GC_bool thread_blocked;
 
 # ifdef CYGWIN32
     void *status; /* hold exit value until join in case it's a pointer */
@@ -174,6 +175,7 @@ static GC_thread GC_new_thread(void) {
   /* the world, wait here.  Hopefully this can't happen on any	*/
   /* systems that don't allow us to block here.			*/
   while (GC_please_stop) Sleep(20);
+  GC_ASSERT(!thread_table[i]->thread_blocked);
   return thread_table + i;
 }
 
@@ -223,7 +225,6 @@ static void GC_delete_thread(DWORD thread_id) {
   }
 }
 
-
 #ifdef CYGWIN32
 
 /* Return a GC_thread corresponding to a given pthread_t.	*/
@@ -245,6 +246,20 @@ static GC_thread GC_lookup_thread(pthread_t id)
   return thread_table + i;
 }
 
+#else
+
+static GC_thread GC_lookup_thread(DWORD id)
+{
+  int i;
+  LONG max = GC_get_max_thread_index();
+
+  for (i = 0; i <= max; i++)
+    if (thread_table[i].in_use && thread_table[i].id == id)
+      return &thread_table[i];
+
+  return NULL;
+}
+
 #endif /* CYGWIN32 */
 
 void GC_push_thread_structures GC_PROTO((void))
@@ -264,6 +279,35 @@ void GC_push_thread_structures GC_PROTO((void))
 # endif
 }
 
+/* Wrappers for functions that are likely to block for an appreciable	*/
+/* length of time.  Must be called in pairs, if at all.			*/
+/* Nothing much beyond the system call itself should be executed	*/
+/* between these.							*/
+
+void GC_start_blocking(void) {
+    GC_thread me;
+    LOCK();
+#ifdef CYGWIN32
+    me = GC_lookup_thread(pthread_self());
+#else
+    me = GC_lookup_thread(GetCurrentThreadId());
+#endif
+    me->thread_blocked = TRUE;
+    UNLOCK();
+}
+
+void GC_end_blocking(void) {
+    GC_thread me;
+    LOCK();   /* This will block if the world is stopped.	*/
+#ifdef CYGWIN32
+    me = GC_lookup_thread(pthread_self());
+#else
+    me = GC_lookup_thread(GetCurrentThreadId());
+#endif
+    me->thread_blocked = FALSE;
+    UNLOCK();
+}
+
 /* Defined in misc.c */
 extern CRITICAL_SECTION GC_write_cs;
 
@@ -281,6 +325,8 @@ void GC_stop_world()
   for (i = 0; i <= GC_get_max_thread_index(); i++)
     if (thread_table[i].stack_base != 0
 	&& thread_table[i].id != thread_id) {
+      if (thread_table [i].thread_blocked)
+        continue;
 #     ifdef MSWINCE
         /* SuspendThread will fail if thread is running kernel code */
 	while (SuspendThread(thread_table[i].handle) == (DWORD)-1)