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-rw-r--r--lib/observer/src/crashdump_viewer.erl155
-rw-r--r--lib/observer/test/crashdump_helper.erl21
2 files changed, 134 insertions, 42 deletions
diff --git a/lib/observer/src/crashdump_viewer.erl b/lib/observer/src/crashdump_viewer.erl
index 14b086ff58..276b209ce5 100644
--- a/lib/observer/src/crashdump_viewer.erl
+++ b/lib/observer/src/crashdump_viewer.erl
@@ -1594,31 +1594,92 @@ read_heap(Fd,Pid,DecodeOpts,Dict0) ->
Dict0
end.
-read_heap(DecodeOpts,Dict0) ->
- %% This function is never called if the dump is truncated in {?proc_heap,Pid}
- case get(fd) of
- end_of_heap ->
+read_heap(DecodeOpts, Dict0) ->
+ %% This function is never called if the dump is truncated in
+ %% {?proc_heap,Pid}.
+ %%
+ %% It is not always possible to reconstruct the heap terms
+ %% in a single pass, especially if maps are involved.
+ %% See crashdump_helper:literal_map/0 for an example.
+ %%
+ %% Therefore, we need two passes. In the first pass
+ %% we collect all lines without parsing them, and in the
+ %% second pass we parse them.
+ %%
+ %% The first pass follows.
+
+ Lines0 = read_heap_lines(),
+
+ %% Save a map of all unprocessed lines so that deref_ptr() can
+ %% access any line when there are references to terms not yet
+ %% built.
+
+ LineMap = maps:from_list(Lines0),
+ put(line_map, LineMap),
+
+ %% Refc binaries (tag "Yc") must be processed before any sub
+ %% binaries (tag "Ys") referencing them, so we make sure to
+ %% process all the refc binaries first.
+ %%
+ %% The other lines can be processed in any order, but processing
+ %% them in the reverse order compared to how they are printed in
+ %% the crash dump seems to minimize the number of references to
+ %% terms that have not yet been built. That happens to be the
+ %% order of the line list as returned by read_heap_lines/0.
+
+ RefcBins = [Refc || {_,<<"Yc",_/binary>>}=Refc <- Lines0],
+ Lines = RefcBins ++ Lines0,
+
+ %% Second pass.
+
+ init_progress("Processing terms", map_size(LineMap)),
+ Dict = parse_heap_terms(Lines, DecodeOpts, Dict0),
+ erase(line_map),
+ end_progress(),
+ Dict.
+
+read_heap_lines() ->
+ read_heap_lines_1(get(fd), []).
+
+read_heap_lines_1(Fd, Acc) ->
+ case bytes(Fd) of
+ "=" ++ _next_tag ->
end_progress(),
- Dict0;
- Fd ->
- case bytes(Fd) of
- "=" ++ _next_tag ->
- end_progress(),
- put(fd, end_of_heap),
- Dict0;
- Line ->
- update_progress(length(Line)+1),
- Dict = parse(Line,DecodeOpts,Dict0),
- read_heap(DecodeOpts,Dict)
- end
+ put(fd, end_of_heap),
+ Acc;
+ Line0 ->
+ update_progress(length(Line0)+1),
+ {Addr,":"++Line1} = get_hex(Line0),
+
+ %% Reduce the memory consumption by converting the
+ %% line to a binary. Measurements show that it may also
+ %% be benefical for performance, too, because it makes the
+ %% garbage collections cheaper.
+
+ Line = list_to_binary(Line1),
+ read_heap_lines_1(Fd, [{Addr,Line}|Acc])
end.
-parse(Line0, DecodeOpts, Dict0) ->
- {Addr,":"++Line1} = get_hex(Line0),
- {_Term,Line,Dict} = parse_heap_term(Line1, Addr, DecodeOpts, Dict0),
- [] = skip_blanks(Line),
+parse_heap_terms([{Addr,Line0}|T], DecodeOpts, Dict0) ->
+ case gb_trees:is_defined(Addr, Dict0) of
+ true ->
+ %% Already parsed (by a recursive call from do_deref_ptr()
+ %% to parse_line()). Nothing to do.
+ parse_heap_terms(T, DecodeOpts, Dict0);
+ false ->
+ %% Parse this previously unparsed term.
+ Dict = parse_line(Addr, Line0, DecodeOpts, Dict0),
+ parse_heap_terms(T, DecodeOpts, Dict)
+ end;
+parse_heap_terms([], _DecodeOpts, Dict) ->
Dict.
+parse_line(Addr, Line0, DecodeOpts, Dict0) ->
+ update_progress(1),
+ Line1 = binary_to_list(Line0),
+ {_Term,Line,Dict} = parse_heap_term(Line1, Addr, DecodeOpts, Dict0),
+ [] = skip_blanks(Line), %Assertion.
+ Dict.
%%-----------------------------------------------------------------
%% Page with one port
@@ -2871,16 +2932,18 @@ parse_atom_translation_table(N, Line0, As) ->
deref_ptr(Ptr, Line, DecodeOpts, D) ->
- Lookup = fun(D0) ->
- gb_trees:lookup(Ptr, D0)
- end,
+ Lookup0 = fun(D0) ->
+ gb_trees:lookup(Ptr, D0)
+ end,
+ Lookup = wrap_line_map(Ptr, Lookup0),
do_deref_ptr(Lookup, Line, DecodeOpts, D).
deref_bin(Binp0, Offset, Sz, Line, DecodeOpts, D) ->
Binp = Binp0 bor DecodeOpts#dec_opts.bin_addr_adj,
- Lookup = fun(D0) ->
- lookup_binary(Binp, Offset, Sz, D0)
- end,
+ Lookup0 = fun(D0) ->
+ lookup_binary(Binp, Offset, Sz, D0)
+ end,
+ Lookup = wrap_line_map(Binp, Lookup0),
do_deref_ptr(Lookup, Line, DecodeOpts, D).
lookup_binary(Binp, Offset, Sz, D) ->
@@ -2899,26 +2962,36 @@ lookup_binary(Binp, Offset, Sz, D) ->
end
end.
+wrap_line_map(Ptr, Lookup) ->
+ wrap_line_map_1(get(line_map), Ptr, Lookup).
+
+wrap_line_map_1(#{}=LineMap, Ptr, Lookup) ->
+ fun(D) ->
+ case Lookup(D) of
+ {value,_}=Res ->
+ Res;
+ none ->
+ case LineMap of
+ #{Ptr:=Line} ->
+ {line,Ptr,Line};
+ #{} ->
+ none
+ end
+ end
+ end;
+wrap_line_map_1(undefined, _Ptr, Lookup) ->
+ Lookup.
+
do_deref_ptr(Lookup, Line, DecodeOpts, D0) ->
case Lookup(D0) of
{value,Term} ->
{Term,Line,D0};
none ->
- case get(fd) of
- end_of_heap ->
- put(incomplete_heap,true),
- {['#CDVIncompleteHeap'],Line,D0};
- Fd ->
- case bytes(Fd) of
- "="++_ ->
- put(fd, end_of_heap),
- do_deref_ptr(Lookup, Line, DecodeOpts, D0);
- L ->
- update_progress(length(L)+1),
- D = parse(L, DecodeOpts, D0),
- do_deref_ptr(Lookup, Line, DecodeOpts, D)
- end
- end
+ put(incomplete_heap, true),
+ {['#CDVIncompleteHeap'],Line,D0};
+ {line,Addr,NewLine} ->
+ D = parse_line(Addr, NewLine, DecodeOpts, D0),
+ do_deref_ptr(Lookup, Line, DecodeOpts, D)
end.
get_hex(L) ->
diff --git a/lib/observer/test/crashdump_helper.erl b/lib/observer/test/crashdump_helper.erl
index 145ff56b71..d8f4e046ae 100644
--- a/lib/observer/test/crashdump_helper.erl
+++ b/lib/observer/test/crashdump_helper.erl
@@ -142,4 +142,23 @@ create_maps() ->
Map3 = lists:foldl(fun(I, A) ->
A#{I=>I*I}
end, Map2, lists:seq(-10, 0)),
- #{a=>Map0,b=>Map1,c=>Map2,d=>Map3,e=>#{}}.
+ #{a=>Map0,b=>Map1,c=>Map2,d=>Map3,e=>#{},literal=>literal_map()}.
+
+literal_map() ->
+ %% A literal map such as the one below will produce a heap dump
+ %% like this:
+ %%
+ %% Address1:t4:H<Address3>,H<Address4>,H<Address5>,H<Address6>
+ %% Address2:Mf4:H<Adress1>:I1,I2,I3,I4
+ %% Address3: ... % "one"
+ %% Address4: ... % "two"
+ %% Address5: ... % "three"
+ %% Address6: ... % "four"
+ %%
+ %% The map cannot be reconstructed in a single sequential pass.
+ %%
+ %% To reconstruct the map, first the string keys "one"
+ %% through "four" must be reconstructed, then the tuple at
+ %% Adress1, then the map at Address2.
+
+ #{"one"=>1,"two"=>2,"three"=>3,"four"=>4}.
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 13:25:18 +0000