Merge branch 'master' into release

Change-Id: I56ea2217899e92bdd9d6cb56797ac9895e194fff

cpp/platform_v2/api/condition_variable.h

@@ -16,6 +16,7 @@
 #define PLATFORM_V2_API_CONDITION_VARIABLE_H_
 
 #include "platform_v2/base/exception.h"
+#include "absl/time/clock.h"
 
 namespace location {
 namespace nearby {
@@ -29,10 +30,19 @@ class ConditionVariable {
  public:
   virtual ~ConditionVariable() {}
 
-  // https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#notify--
+  // Notifies all the waiters that condition state has changed.
   virtual void Notify() = 0;
-  // https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait--
-  virtual Exception Wait() = 0;  // throws Exception::kInterrupted
+
+  // Waits indefinitely for Notify to be called.
+  // May return prematurely in case of interrupt, if supported by platform.
+  // Returns kSuccess, or kInterrupted on interrupt.
+  virtual Exception Wait() = 0;
+
+  // Waits while timeout has not expired for Notify to be called.
+  // May return prematurely in case of interrupt, if supported by platform.
+  // Returns kSuccess, or kInterrupted on interrupt.
+  // If Timeout expired, and Notify was not called, returns kTimeout.
+  virtual Exception Wait(absl::Duration timeout) = 0;
 };
 
 }  // namespace api