Implement safepointing of threads

runtime/vm/heap.cc

Index: runtime/vm/heap.cc
diff --git a/runtime/vm/heap.cc b/runtime/vm/heap.cc
index 71109eeaee5589d5d9766799c6c94baa84fd627f..f6c35eee2c2040e83a4f4526ca6c90e856151b37 100644
--- a/runtime/vm/heap.cc
+++ b/runtime/vm/heap.cc
@@ -97,11 +97,12 @@ uword Heap::AllocateOld(intptr_t size, HeapPage::PageType type) {
   }
   // If we are in the process of running a sweep wait for the sweeper to free

[zra, 2016/01/08 23:32:07]

sweep, wait

[siva, 2016/01/12 21:26:22]

Done.

   // memory.
+  Thread* thread = Thread::Current();
   {
     MonitorLocker ml(old_space_.tasks_lock());
     addr = old_space_.TryAllocate(size, type);
     while ((addr == 0) && (old_space_.tasks() > 0)) {
-      ml.Wait();
+      ml.WaitWithSafepointCheck(thread);
       addr = old_space_.TryAllocate(size, type);
     }
   }
@@ -119,7 +120,7 @@ uword Heap::AllocateOld(intptr_t size, HeapPage::PageType type) {
     MonitorLocker ml(old_space_.tasks_lock());
     addr = old_space_.TryAllocate(size, type);
     while ((addr == 0) && (old_space_.tasks() > 0)) {
-      ml.Wait();
+      ml.WaitWithSafepointCheck(thread);
       addr = old_space_.TryAllocate(size, type);
     }
   }
@@ -136,7 +137,7 @@ uword Heap::AllocateOld(intptr_t size, HeapPage::PageType type) {
   {
     MonitorLocker ml(old_space_.tasks_lock());
     while (old_space_.tasks() > 0) {
-      ml.Wait();
+      ml.WaitWithSafepointCheck(thread);
     }
   }
   addr = old_space_.TryAllocate(size, type, PageSpace::kForceGrowth);