Modify the stop_timer call to return the time left for the timer to b…

…e stopped. It can be a useful information in some use cases.
lehoff · Mar 7, 2013 · c368680 · c368680
1 parent 409cb0e
commit c368680
Show file tree

Hide file tree

Showing 2 changed files with 5 additions and 3 deletions.
diff --git a/src/chronos.erl b/src/chronos.erl
@@ -66,7 +66,7 @@ stop(ServerName) ->
 start_timer(ServerName, TimerName, Timeout, Callback) ->
     call(ServerName, {start_timer, TimerName, Timeout, Callback}).
 
--spec stop_timer(server_name(), timer_name()) -> 'ok' | 'not_running' | {'error',term()}.
+-spec stop_timer(server_name(), timer_name()) -> {'ok', pos_integer()} | 'not_running' | {'error',term()}.
 stop_timer(ServerName, TimerName) ->
     call(ServerName, {stop_timer, TimerName}).
 
@@ -102,8 +102,8 @@ handle_call({stop_timer, Name}, _From,
             #chronos_state{running=R}=State) ->
     case lists:keytake(Name, 1, R) of
         {value, {_, TRef}, Rnext} ->
-            erlang:cancel_timer(TRef),
-            {reply, ok, State#chronos_state{running=Rnext}};
+            TimeLeft = erlang:cancel_timer(TRef),
+            {reply, {ok, TimeLeft}, State#chronos_state{running=Rnext}};
         false ->
             {reply, not_running, State}
     end.

diff --git a/test/chronos_eqc.erl b/test/chronos_eqc.erl
@@ -79,6 +79,8 @@ postcondition(_S,
     true;
 postcondition(_S, {call, timer_expiry, stop_timer, [_Server, _Timer]}, ok) ->
     true;
+postcondition(_S, {call, timer_expiry, stop_timer, [_Server, _Timer]}, {ok, _TimeLeft}) ->
+    true;
 postcondition(_S, {call, timer_expiry, stop_timer, [Server, Timer]}, {error,{not_running,Timer}}) ->
     valid_stop_timer_status({Server, Timer});
 postcondition(S, {call, ?MODULE, advance_time, [_Duration]}, _) ->