Safepointing in GC

runtime/vm/pages.cc

Index: runtime/vm/pages.cc
diff --git a/runtime/vm/pages.cc b/runtime/vm/pages.cc
index f45c5b04a95f5715b7f77d3ab3e2ccd2571e8ffe..55e5fa0dcc8f2313b55d54517068f63dcdf52365 100644
--- a/runtime/vm/pages.cc
+++ b/runtime/vm/pages.cc
@@ -11,6 +11,7 @@
 #include "vm/lockers.h"
 #include "vm/object.h"
 #include "vm/os_thread.h"
+#include "vm/thread_registry.h"
 #include "vm/verified_memory.h"
 #include "vm/virtual_memory.h"
 
@@ -768,6 +769,8 @@ void PageSpace::MarkSweep(bool invoke_api_callbacks) {
     set_tasks(1);
   }
 
+  isolate->thread_registry()->SafepointThreads();

[Ivan Posva, 2015/08/25 23:27:15]

// Ensure that all threads for this isolate are at a safepoint (either stopped
or in native code).

[koda, 2015/08/26 01:09:14]

Done.

+
   // Perform various cleanup that relies on no tasks interfering.
   isolate->class_table()->FreeOldTables();
 
@@ -907,6 +910,8 @@ void PageSpace::MarkSweep(bool invoke_api_callbacks) {
     freelist_[HeapPage::kExecutable].Print();
   }
 
+  isolate->thread_registry()->ResumeAllThreads();
+
   // Done, reset the task count.
   {
     MonitorLocker ml(tasks_lock());