- Add and enable concurrent sweeper.

runtime/vm/heap.cc

Index: runtime/vm/heap.cc
===================================================================
--- runtime/vm/heap.cc	(revision 39568)
+++ runtime/vm/heap.cc	(working copy)
@@ -8,6 +8,7 @@
 #include "platform/utils.h"
 #include "vm/flags.h"
 #include "vm/isolate.h"
+#include "vm/lockers.h"
 #include "vm/object.h"
 #include "vm/object_set.h"
 #include "vm/os.h"
@@ -81,12 +82,22 @@
   ASSERT(isolate()->no_gc_scope_depth() == 0);
   uword addr = old_space_->TryAllocate(size, type);
   if (addr == 0) {
-    CollectAllGarbage();
-    addr = old_space_->TryAllocate(size, type, PageSpace::kForceGrowth);
+    {
+      MonitorLocker ml(old_space_->tasks_lock());
+      addr = old_space_->TryAllocate(size, type);
+      while ((addr == 0) && (old_space_->tasks())) {

[koda, 2014/08/26 23:34:48]

Add missing "> 0" (or, per my other comment, "has_tasks()")

[Ivan Posva, 2014/08/27 01:00:22]

Uiuiuiui! That should not have happened.

+        ml.Wait();
+        addr = old_space_->TryAllocate(size, type);
+      }
+    }
     if (addr == 0) {
-      OS::PrintErr("Exhausted heap space, trying to allocate %" Pd " bytes.\n",
-                   size);
-      return 0;
+      CollectAllGarbage();
+      addr = old_space_->TryAllocate(size, type, PageSpace::kForceGrowth);

[koda, 2014/08/26 23:34:48]

Explain why there's no point in waiting for sweepers here.

[Ivan Posva, 2014/08/27 01:00:22]

We should be waiting for sweepers here, but I missed it during refactoring of
this code. Thanks!

+      if (addr == 0) {
+        OS::PrintErr(
+            "Exhausted heap space, trying to allocate %" Pd " bytes.\n", size);
+        return 0;
+      }
     }
   }
   return addr;