Completely remove InterruptableThreadState and Fix ThreadRegistry leak

runtime/vm/thread.h

Index: runtime/vm/thread.h
diff --git a/runtime/vm/thread.h b/runtime/vm/thread.h
index 44b804013e7b6ec3c85ff4c0d8ef290d7ac88ca5..ccf7435f75252605e9366357b5c2969b0c9e32ca 100644
--- a/runtime/vm/thread.h
+++ b/runtime/vm/thread.h
@@ -39,6 +39,26 @@ class Zone;
   CACHED_VM_OBJECTS_LIST(V)                                                    \
   CACHED_ADDRESSES_LIST(V)
 
+struct InterruptedThreadState {
+  ThreadId tid;
+  uintptr_t pc;
+  uintptr_t csp;
+  uintptr_t dsp;
+  uintptr_t fp;
+  uintptr_t lr;
+};
+
+// When a thread is interrupted the thread specific interrupt callback will be
+// invoked. Each callback is given an InterruptedThreadState and the user data
+// pointer. When inside a thread interrupt callback doing any of the following
+// is forbidden:
+//   * Accessing TLS -- Because on Windows the callback will be running in a
+//                      different thread.
+//   * Allocating memory -- Because this takes locks which may already be held,
+//                          resulting in a dead lock.
+//   * Taking a lock -- See above.
+typedef void (*ThreadInterruptCallback)(const InterruptedThreadState& state,
+                                        void* data);
 
 // A VM thread; may be executing Dart code or performing helper tasks like
 // garbage collection or compilation. The Thread structure associated with
@@ -233,9 +253,22 @@ CACHED_CONSTANTS_LIST(DEFINE_OFFSET_METHOD)
     state_.long_jump_base = value;
   }
 
+  ThreadId id() const {
+    ASSERT(id_ != OSThread::kInvalidThreadId);
+    return id_;
+  }
+
+  void SetThreadInterrupter(ThreadInterruptCallback callback, void* data);
+
+  bool IsThreadInterrupterEnabled(ThreadInterruptCallback* callback,
+                                  void** data) const;
+
  private:
   static ThreadLocalKey thread_key_;
 
+  const ThreadId id_;
+  ThreadInterruptCallback thread_interrupt_callback_;
+  void* thread_interrupt_data_;
   Isolate* isolate_;
   Heap* heap_;
   State state_;