1 files changed, 70 insertions, 0 deletions
diff --git a/helium/refcount.cpp b/helium/refcount.cpp
new file mode 100644
index 0000000..3378df9
--- /dev/null
+++ b/helium/refcount.cpp
@@ -0,0 +1,70 @@
+// Copyright 2006 Google Inc.
+// All Rights Reserved.
+// Author: <renn@google.com> (Marius Renn)
+//
+
+// Local includes
+#include "debugging.h"
+#include "refcount.h"
+
+// C includes
+#include <stddef.h>
+
+using namespace helium;
+
+int ReferenceCounted::number_of_allocations_ = 0;
+
+ReferenceCounted::ReferenceCounted() : ref_count_(new int(1)) {
+  number_of_allocations_++;
+}
+
+ReferenceCounted::ReferenceCounted(const ReferenceCounted& other) 
+  : ref_count_(other.ref_count_) {
+  (*ref_count_)++; 
+}
+
+ReferenceCounted::~ReferenceCounted() {
+  if (ShouldDelete())
+    DeleteData();
+  else if (ref_count_)
+    (*ref_count_)--;
+}
+
+void ReferenceCounted::Retain() {
+  ASSERT(ref_count_ && (*ref_count_) > 0);
+  (*ref_count_)++;
+}
+
+void ReferenceCounted::Release() {
+  if (!ref_count_) return;
+  (*ref_count_)--;
+  if ((*ref_count_) == 0) DeleteData();
+}
+
+bool ReferenceCounted::ShouldDelete() {
+  // Assert that we still have a reference counter, and that it will reach
+  // 0 due to this object being deconstructed.
+  if (ref_count_ && (*ref_count_ == 1)) {
+    *ref_count_ = 0;  // Mark data as deleted
+    return true;
+  }
+  return false;
+}
+
+void ReferenceCounted::Realloc() {
+  Release();                  // Release old data
+  ref_count_ = new int(1);    // Re-init reference counter
+  number_of_allocations_++;   // Count the new allocation
+}
+
+void ReferenceCounted::DeleteData() {
+  delete ref_count_;          // Delete and invalidate reference counter
+  ref_count_ = NULL;
+  number_of_allocations_--;  
+}
+
+void ReferenceCounted::operator=(const ReferenceCounted& other) {
+  Release();  // Release old object
+  ref_count_ = other.ref_count_;
+  Retain();   // Retain new object
+}