Initial public release of nearby library

Signed-off-by: Alexey Polyudov <apolyudov@google.com>
Change-Id: I85d490e448375aa4eb7b09680757c02fff1420b4

cpp/platform/api/condition_variable.h

@@ -0,0 +1,40 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef PLATFORM_API_CONDITION_VARIABLE_H_
+#define PLATFORM_API_CONDITION_VARIABLE_H_
+
+#include "platform/exception.h"
+
+namespace location {
+namespace nearby {
+
+// The ConditionVariable class is a synchronization primitive that can be used
+// to block a thread, or multiple threads at the same time, until another thread
+// both modifies a shared variable (the condition), and notifies the
+// ConditionVariable.
+class ConditionVariable {
+ public:
+  virtual ~ConditionVariable() {}
+
+  // https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#notify--
+  virtual void notify() = 0;
+  // https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait--
+  virtual Exception::Value wait() = 0;  // throws Exception::INTERRUPTED
+};
+
+}  // namespace nearby
+}  // namespace location
+
+#endif  // PLATFORM_API_CONDITION_VARIABLE_H_