Return incomplete ranges as well, and make this configurable

Author: chrzaszcz

src/tr.erl

@@ -138,12 +138,17 @@
 %% Source of traces: an ETS table or a list of traces. Default: `tab()'.
 
 -type range_options() :: #{tab => tr_source(),
-                           max_depth => limit()}.
+                           max_depth => limit(),
+                           output => range_output()}.
 %% Options for trace ranges.
 %%
 %% Optional `limit' is the maximum depth of calls in the returned ranges.
 %% All traces (including messages) exceeding that depth are skipped.
 
+-type range_output() :: complete | incomplete | all.
+%% Which ranges to return. Incomplete ranges are missing at least one return.
+%% By default, all ranges are returned.
+
 -type tb_options() :: #{tab => tr_source(),
                         output => tb_output(),
                         format => tb_format(),
@@ -424,10 +429,21 @@ ranges(PredF) ->
 -spec ranges(pred(), range_options()) -> [[tr()]].
 ranges(PredF, Options) when is_map(Options) ->
     Tab = maps:get(tab, Options, tab()),
+    Output = maps:get(output, Options, all),
     InitialState = maps:merge(#{traces => [], pid_states => #{}, max_depth => infinity}, Options),
-    #{traces := Traces} = foldl(fun(T, S) -> range_step(PredF, T, S) end, InitialState, Tab),
+    FinalState = foldl(fun(T, S) -> range_step(PredF, T, S) end, InitialState, Tab),
+    complete_ranges(FinalState, Output) ++ incomplete_ranges(FinalState, Output).
+
+complete_ranges(#{}, incomplete) ->
+    [];
+complete_ranges(#{traces := Traces}, Output) when Output =:= all;  Output =:= complete ->
     lists:reverse(Traces).
 
+incomplete_ranges(#{}, complete) ->
+    [];
+incomplete_ranges(#{pid_states := States}, Output) when Output =:= all; Output =:= incomplete ->
+    lists:sort([Range || #{trace := Range} <- maps:values(States)]).
+
 %% @doc Prints sorted call time statistics for the selected traces from `tab()'.
 %%
 %% The statistics are sorted according to `t:acc_time()', descending.

test/tr_SUITE.erl

@@ -44,7 +44,8 @@ groups() ->
      {range, [ranges,
               ranges_max_depth,
               range,
-              ranges_with_messages]},
+              ranges_with_messages,
+              incomplete_ranges]},
      {traceback, [single_tb,
                   single_tb_with_messages,
                   tb,
@@ -243,6 +244,37 @@ ranges_with_messages(_Config) ->
     Range1 = [hd(Traces), lists:last(Traces)],
     [Range1] = tr:ranges(fun(#tr{}) -> true end, #{max_depth => 1}).
 
+incomplete_ranges(_Config) ->
+    Self = self(),
+    tr:trace(#{modules => [MFA = {?MODULE, wait_and_reply, 1}]}),
+    Pid1 = spawn_link(?MODULE, wait_and_reply, [self()]),
+    Pid2 = spawn_link(?MODULE, wait_and_reply, [self()]),
+    receive {started, Pid1} -> ok end,
+    receive {started, Pid2} -> ok end,
+    Pid2 ! reply,
+    receive {finished, Pid2} -> ok end,
+
+    %% Pid1 finished, but Pid1 didn't
+    wait_for_traces(3),
+    tr:stop_tracing(),
+    Pid1 ! reply,
+    receive {finished, Pid1} -> ok end,
+
+    [#tr{index = 1, pid = Pid1, event = call, mfa = MFA, data = [Self]},
+     #tr{index = 2, pid = Pid2, event = call, mfa = MFA, data = [Self]},
+     #tr{index = 3, pid = Pid2, event = return, mfa = MFA, data = {finished, Pid2}}] =
+        [T1, T2, T3] = tr:select(),
+
+    %% Ranges with missing returns are included at the end
+    [[T2, T3], [T1]] = tr:ranges(fun(#tr{}) -> true end),
+    [[T2, T3], [T1]] = tr:ranges(fun(#tr{}) -> true end, #{output => all}),
+
+    %% Skip ranges with missing returns
+    [[T2, T3]] = tr:ranges(fun(#tr{}) -> true end, #{output => complete}),
+
+    %% Skip ranges with missing returns
+    [[T1]] = tr:ranges(fun(#tr{}) -> true end, #{output => incomplete}).
+
 do(_Config) ->
     tr:trace([{?MODULE, fib, 1}]),
     ?MODULE:fib(2),