Basic tag infrastructure

runtime/vm/isolate.h

Index: runtime/vm/isolate.h
diff --git a/runtime/vm/isolate.h b/runtime/vm/isolate.h
index 5410ab82d7c7f5c87ac8161d5ea1f9d043913d18..62edc51d37c3fafdf30e849518cbd8d86da1f566 100644
--- a/runtime/vm/isolate.h
+++ b/runtime/vm/isolate.h
@@ -14,6 +14,7 @@
 #include "vm/megamorphic_cache_table.h"
 #include "vm/random.h"
 #include "vm/store_buffer.h"
+#include "vm/tags.h"
 #include "vm/timer.h"
 
 namespace dart {
@@ -445,6 +446,14 @@ class Isolate : public BaseIsolate {
     return thread_state_;
   }
 
+  uword vm_tag() const {
+    return vm_tag_;
+  }
+  void set_vm_tag(uword tag) {
+    ASSERT(tag != VMTag::kInvalidTagId);
+    vm_tag_ = tag;
+  }
+
 #if defined(DEBUG)
 #define REUSABLE_HANDLE_SCOPE_ACCESSORS(object)                                \
   void set_reusable_##object##_handle_scope_active(bool value) {               \
@@ -523,6 +532,7 @@ class Isolate : public BaseIsolate {
   IsolateProfilerData* profiler_data_;
   Mutex profiler_data_mutex_;
   InterruptableThreadState* thread_state_;
+  uword vm_tag_;

[siva, 2014/03/13 23:18:47]

you may have to put this and the accessor method above in BaseIsolate (see
comment in class VMTagScope)

 
   // Isolate list next pointer.
   Isolate* next_;