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| author | Fred Hebert <mononcqc@ferd.ca> | 2019-03-29 08:55:59 -0400 |
|---|---|---|
| committer | Fred Hebert <mononcqc@ferd.ca> | 2019-03-29 09:03:25 -0400 |
| commit | 9f81a5754e0dc4d3ce968d02facdfa5c87dcea3c (patch) | |
| tree | a6c7f50e7baa1484f7b059507bb0ca724cda48aa /src/rebar_compiler_erl.erl | |
| parent | ae0af35e8c8707ea8e60467a422d815bd549b55b (diff) | |
Fix Parallel Compilation
This patch does two things:
1. it broadens the interface for the compiler module so that
non-first-file modules can possibly be parallelized. This is done by
dynamically switching on `[ListOfFiles]`, which remains sequential as
before, or `{[SeqPriority], [Parallel]}`, which divides regular files
between higher priority ones and those that can be in parallel
2. implements this mechanism in the rebar compiler, based on the erl
file digraph. If a file has an in-neighbour, it is depended on by
another file. The mechanism therefore makes it so all files that have
dependants get compiled in their strict relative sequential order
first, and then the undepended-on files get compiled together in
parallel.
By running:
./rebar3 ct --suite test/rebar_compile_SUITE.erl --case \
recompile_when_parse_transform_inline_changes --repeat 50
the previous iteration of this would rapidly fail, and this one succeeds
every time.
Diffstat (limited to 'src/rebar_compiler_erl.erl')
| -rw-r--r-- | src/rebar_compiler_erl.erl | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/src/rebar_compiler_erl.erl b/src/rebar_compiler_erl.erl index 759305c..1ad16d8 100644 --- a/src/rebar_compiler_erl.erl +++ b/src/rebar_compiler_erl.erl @@ -55,7 +55,14 @@ needed_files(Graph, FoundFiles, _, AppInfo) -> {ErlFirstFiles, ErlOptsFirst} = erl_first_files(RebarOpts, ErlOpts, Dir, NeededErlFiles), SubGraph = digraph_utils:subgraph(Graph, NeededErlFiles), DepErlsOrdered = digraph_utils:topsort(SubGraph), - OtherErls = lists:reverse(DepErlsOrdered), + %% Break out the files required by other modules from those + %% that none other depend of; the former must be sequentially + %% built, the rest is parallelizable. + OtherErls = lists:partition( + fun(Erl) -> digraph:in_degree(Graph, Erl) > 0 end, + lists:reverse([Dep || Dep <- DepErlsOrdered, + not lists:member(Dep, ErlFirstFiles)]) + ), PrivIncludes = [{i, filename:join(OutDir, Src)} || Src <- rebar_dir:all_src_dirs(RebarOpts, ["src"], [])], @@ -64,8 +71,7 @@ needed_files(Graph, FoundFiles, _, AppInfo) -> true = digraph:delete(SubGraph), {{ErlFirstFiles, ErlOptsFirst ++ AdditionalOpts}, - {[Erl || Erl <- OtherErls, - not lists:member(Erl, ErlFirstFiles)], ErlOpts ++ AdditionalOpts}}. + {OtherErls, ErlOpts ++ AdditionalOpts}}. dependencies(Source, SourceDir, Dirs) -> {ok, Fd} = file:open(Source, [read]), |