1 files changed, 72 insertions, 0 deletions
diff --git a/base/revocable_store.cc b/base/revocable_store.cc
new file mode 100644
index 0000000..2974792
--- /dev/null
+++ b/base/revocable_store.cc
@@ -0,0 +1,72 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "base/revocable_store.h"
+
+#include "base/logging.h"
+
+RevocableStore::Revocable::Revocable(RevocableStore* store)
+    : store_reference_(store->owning_reference_) {
+  // We AddRef() the owning reference.
+  DCHECK(store_reference_->store());
+  store_reference_->store()->Add(this);
+}
+
+RevocableStore::Revocable::~Revocable() {
+  if (!revoked()) {
+    // Notify the store of our destruction.
+    --(store_reference_->store()->count_);
+  }
+}
+
+RevocableStore::RevocableStore() : count_(0) {
+  // Create a new owning reference.
+  owning_reference_ = new StoreRef(this);
+}
+
+RevocableStore::~RevocableStore() {
+  // Revoke all the items in the store.
+  owning_reference_->set_store(NULL);
+}
+
+void RevocableStore::Add(Revocable* item) {
+  DCHECK(!item->revoked());
+  ++count_;
+}
+
+void RevocableStore::RevokeAll() {
+  // We revoke all the existing items in the store and reset our count.
+  owning_reference_->set_store(NULL);
+  count_ = 0;
+
+  // Then we create a new owning reference for new items that get added.
+  // This Release()s the old owning reference, allowing it to be freed after
+  // all the items that were in the store are eventually destroyed.
+  owning_reference_ = new StoreRef(this);
+}