diff options
| author | Jean Boussier <[email protected]> | 2022-12-06 12:56:51 +0100 |
|---|---|---|
| committer | Jean Boussier <[email protected]> | 2022-12-08 18:46:16 +0100 |
| commit | 73771e4b192f3db62efb854affdfc95babba1d35 (patch) | |
| tree | 6f15d7fea885b5e639c82b51d5c3fd50b9200735 /ext/objspace/lib/objspace.rb | |
| parent | b19490f75dd790f2f886df2c05ed8fba947326a9 (diff) | |
ObjectSpace.dump_all: dump shapes as well
I see several arguments in doing so.
First they use a non trivial amount of memory, so for various memory
profiling/mapping tools it is relevant to have visibility of the space
occupied by shapes.
Then, some pathological code can create a tons of shape, so it is
valuable to have a way to have a way to observe shapes without having
to compile Ruby with `SHAPE_DEBUG=1`.
And additionally it's likely much faster to dump then this way than
to use `RubyVM::Shape`.
There are however a few open questions:
- Shapes can't respect the `since:` argument. Not sure what to do when
it is provided. Would probably make sense to not dump them.
- Maybe it would make more sense to have a separate `ObjectSpace.dump_shapes`?
- Maybe instead `dump_all` should take a `shapes: false` argument?
Additionally, `ObjectSpace.dump_shapes` is added for the use case of
debugging the evolution of the shape tree.
Notes
Notes:
Merged: https://github.com/ruby/ruby/pull/6868
Diffstat (limited to 'ext/objspace/lib/objspace.rb')
| -rw-r--r-- | ext/objspace/lib/objspace.rb | 65 |
1 files changed, 60 insertions, 5 deletions
diff --git a/ext/objspace/lib/objspace.rb b/ext/objspace/lib/objspace.rb index 0298b0646c..f8a66d8d32 100644 --- a/ext/objspace/lib/objspace.rb +++ b/ext/objspace/lib/objspace.rb @@ -6,6 +6,7 @@ module ObjectSpace class << self private :_dump private :_dump_all + private :_dump_shapes end module_function @@ -53,23 +54,38 @@ module ObjectSpace # # Dump the contents of the ruby heap as JSON. # + #. _full__ must be a boolean. If true all heap slots are dumped including the empty ones (T_NONE). + # # _since_ must be a non-negative integer or +nil+. # # If _since_ is a positive integer, only objects of that generation and # newer generations are dumped. The current generation can be accessed using - # GC::count. - # - # Objects that were allocated without object allocation tracing enabled + # GC::count. Objects that were allocated without object allocation tracing enabled # are ignored. See ::trace_object_allocations for more information and # examples. # # If _since_ is omitted or is +nil+, all objects are dumped. # + # _shapes_ must be a boolean or a non-negative integer. + # + # If _shapes_ is a positive integer, only shapes newer than the provided + # shape id are dumped. The current shape_id can be accessed using +RubyVM.stat(:next_shape_id)+. + # + # If _shapes_ is +false+, no shapes are dumped. + # + # To only dump objects allocated past a certain point you can combine _since_ and _shapes_: + # ObjectSpace.trace_object_allocations + # GC.start + # gc_generation = GC.count + # shape_generation = RubyVM.stat(:next_shape_id) + #. call_method_to_instrument + # ObjectSpace.dump_all(since: gc_generation, shapes: shape_generation) + # # This method is only expected to work with C Ruby. # This is an experimental method and is subject to change. # In particular, the function signature and output format are # not guaranteed to be compatible in future versions of ruby. - def dump_all(output: :file, full: false, since: nil) + def dump_all(output: :file, full: false, since: nil, shapes: true) out = case output when :file, nil require 'tempfile' @@ -84,7 +100,46 @@ module ObjectSpace raise ArgumentError, "wrong output option: #{output.inspect}" end - ret = _dump_all(out, full, since) + shapes = 0 if shapes == true + ret = _dump_all(out, full, since, shapes) + return nil if output == :stdout + ret + end + + # call-seq: + # ObjectSpace.dump_shapes([output: :file]) # => #<File:/tmp/rubyshapes20131125-88469-laoj3v.json> + # ObjectSpace.dump_shapes(output: :stdout) # => nil + # ObjectSpace.dump_shapes(output: :string) # => "{...}\n{...}\n..." + # ObjectSpace.dump_shapes(output: + # File.open('shapes.json','w')) # => #<File:shapes.json> + # ObjectSpace.dump_all(output: :string, + # since: 42) # => "{...}\n{...}\n..." + # + # Dump the contents of the ruby shape tree as JSON. + # + # If _shapes_ is a positive integer, only shapes newer than the provided + # shape id are dumped. The current shape_id can be accessed using +RubyVM.stat(:next_shape_id)+. + # + # This method is only expected to work with C Ruby. + # This is an experimental method and is subject to change. + # In particular, the function signature and output format are + # not guaranteed to be compatible in future versions of ruby. + def dump_shapes(output: :file, since: 0) + out = case output + when :file, nil + require 'tempfile' + Tempfile.create(%w(rubyshapes .json)) + when :stdout + STDOUT + when :string + +'' + when IO + output + else + raise ArgumentError, "wrong output option: #{output.inspect}" + end + + ret = _dump_shapes(out, since) return nil if output == :stdout ret end |