iv_index_tbl manages instance variable indexes (ID -> index).
This data structure should be synchronized with other ractors
so introduce some VM locks.
This patch also introduced atomic ivar cache used by
set/getinlinecache instructions. To make updating ivar cache (IVC),
we changed iv_index_tbl data structure to manage (ID -> entry)
and an entry points serial and index. IVC points to this entry so
that cache update becomes atomically.
Buggy native extensions could have mark functions that cause stack
overflow. When a stack overflow happens during GC, Ruby used to recover
by raising an exception, which runs the interpreter. It's not safe to
run the interpreter during GC since the GC is in an inconsistent state.
This could cause object allocation during GC, for example.
Instead of running the interpreter and potentially causing a crash down
the line, fail fast and abort.
generic_ivtbl is a process global table to maintain instance variables
for non T_OBJECT/T_CLASS/... objects. So we need to protect them
for multi-Ractor exection.
Hint: we can make them Ractor local for unshareable objects, but
now it is premature optimization.
The changes here include:
* Using `FL_TEST_RAW` instead of `FL_TEST` in the first check in
`vm_search_super_method`. While the profile showed us spending a fair
amount of time here, the subsequent benchmarks didn't show much
improvement when adding this. Regardless, we know this does less work
than `FL_TEST` and we know that `FL_TEST_RAW` is safe due to the
previous check so it's a small but accurate optimization.
* Set `mid` only once. Both `vm_ci_new_runtime` and `vm_ci_mid` were
getting the `original_id` for the method entry. We can do this once
and pass the variable to the 2 callers that need it. This also doesn't
have a huge performance improvement but cleans up the code a bit.
Benchmark:
```
| |compare-ruby|built-ruby|
|:----------------|-----------:|---------:|
|vm_iclass_super | 3.540M| 3.940M|
| | -| 1.11x|
```
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
This PR improves the performance of `super` calls. While working on some
Rails optimizations jhawthorn discovered that `super` calls were slower
than expected.
The changes here do the following:
1) Adds a check for whether the call frame is not equal to the method
entry iseq. This avoids the `rb_obj_is_kind_of` check on the next line
which is quite slow. If the current call frame is equal to the method
entry we know we can't have an instance eval, etc.
2) Changes `FL_TEST` to `FL_TEST_RAW`. This is safe because we've
already done the check for `T_ICLASS` above.
3) Adds a benchmark for `T_ICLASS` super calls.
4) Note: makes a chage for `method_entry_cref` to use `const`.
On master the benchmarks showed that `super` is 1.76x slower. Our
changes improved the performance so that it is now only 1.36x slower.
Benchmark IPS:
```
Warming up --------------------------------------
super 244.918k i/100ms
method call 383.007k i/100ms
Calculating -------------------------------------
super 2.280M (± 6.7%) i/s - 11.511M in 5.071758s
method call 3.834M (± 4.9%) i/s - 19.150M in 5.008444s
Comparison:
method call: 3833648.3 i/s
super: 2279837.9 i/s - 1.68x (± 0.00) slower
```
With changes:
```
Warming up --------------------------------------
super 308.777k i/100ms
method call 375.051k i/100ms
Calculating -------------------------------------
super 2.951M (± 5.4%) i/s - 14.821M in 5.039592s
method call 3.551M (± 4.9%) i/s - 18.002M in 5.081695s
Comparison:
method call: 3551372.7 i/s
super: 2950557.9 i/s - 1.20x (± 0.00) slower
```
Ruby VM benchmarks also showed an improvement:
Existing `vm_super` benchmark`.
```
$ make benchmark ITEM=vm_super
| |compare-ruby|built-ruby|
|:---------|-----------:|---------:|
|vm_super | 21.555M| 37.819M|
| | -| 1.75x|
```
New `vm_iclass_super` benchmark:
```
$ make benchmark ITEM=vm_iclass_super
| |compare-ruby|built-ruby|
|:----------------|-----------:|---------:|
|vm_iclass_super | 1.669M| 3.683M|
| | -| 2.21x|
```
This is the benchmark script used for the benchmark-ips benchmarks:
```ruby
require "benchmark/ips"
class Foo
def zuper; end
def top; end
last_method = "top"
("A".."M").each do |module_name|
eval <<-EOM
module #{module_name}
def zuper; super; end
def #{module_name.downcase}
#{last_method}
end
end
prepend #{module_name}
EOM
last_method = module_name.downcase
end
end
foo = Foo.new
Benchmark.ips do |x|
x.report "super" do
foo.zuper
end
x.report "method call" do
foo.m
end
x.compare!
end
```
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
Co-authored-by: John Hawthorn <john@hawthorn.email>
This reverts commit eeef16e190.
This also reverts the spec change.
Preventing the SystemStackError would be nice, but there is valid
code that the fix breaks, and it is probably more common than cases
that cause the SystemStackError.
Fixes [Bug #17182]
This commit introduces Ractor mechanism to run Ruby program in
parallel. See doc/ractor.md for more details about Ractor.
See ticket [Feature #17100] to see the implementation details
and discussions.
[Feature #17100]
This commit does not complete the implementation. You can find
many bugs on using Ractor. Also the specification will be changed
so that this feature is experimental. You will see a warning when
you make the first Ractor with `Ractor.new`.
I hope this feature can help programmers from thread-safety issues.
Previously, Method#super_method looked at the called_id to
determine the method id to use, but that isn't correct for
aliased methods, because the super target depends on the
original method id, not the called_id.
Additionally, aliases can reference methods defined in other
classes and modules, and super lookup needs to start in the
super of the defined class in such cases.
This adds tests for Method#super_method for both types of
aliases, one that uses VM_METHOD_TYPE_ALIAS and another that
does not. Both check that the results for calling super
methods return the expected values.
To find the defined class for alias methods, add an rb_ prefix
to find_defined_class_by_owner in vm_insnhelper.c and make it
non-static, so that it can be called from method_super_method
in proc.c.
This bug was original discovered while researching [Bug #11189].
Fixes [Bug #17130]
Without this, if a refinement defines a method that calls super and
includes a module with a module that calls super and has a activated
refinement at the point super is called, the module method super call
will end up calling back into the refinement method, creating a loop.
Fixes [Bug #17007]
Struct assignment using a compound literal is more readable than before,
to me at least. It seems compilers reorder assignments anyways.
Neither speedup nor slowdown is observed on my machine.
Use ID instead of GENTRY for gvars.
Global variables are compiled into GENTRY (a pointer to struct
rb_global_entry). This patch replace this GENTRY to ID and
make the code simple.
We need to search GENTRY from ID every time (st_lookup), so
additional overhead will be introduced.
However, the performance of accessing global variables is not
important now a day and this simplicity helps Ractor development.
for opt_* insns.
opt_eq handles rb_obj_equal inside opt_eq, and all other cfunc is
handled by opt_send_without_block. Therefore we can't decide which insn
should be generated by checking whether it's cfunc cc or not.
```
$ benchmark-driver -v --rbenv 'before --jit;after --jit' benchmark/mjit_opt_cc_insns.yml --repeat-count=4
before --jit: ruby 2.8.0dev (2020-06-26T05:21:43Z master 9dbc2294a6) +JIT [x86_64-linux]
after --jit: ruby 2.8.0dev (2020-06-26T06:30:18Z master 75cece1b0b) +JIT [x86_64-linux]
last_commit=Decide JIT-ed insn based on cached cfunc
Calculating -------------------------------------
before --jit after --jit
mjit_nil?(1) 73.878M 74.021M i/s - 40.000M times in 0.541432s 0.540391s
mjit_not(1) 72.635M 74.601M i/s - 40.000M times in 0.550702s 0.536187s
mjit_eq(1, nil) 7.331M 7.445M i/s - 8.000M times in 1.091211s 1.074596s
mjit_eq(nil, 1) 49.450M 64.711M i/s - 8.000M times in 0.161781s 0.123627s
Comparison:
mjit_nil?(1)
after --jit: 74020528.4 i/s
before --jit: 73878185.9 i/s - 1.00x slower
mjit_not(1)
after --jit: 74600882.0 i/s
before --jit: 72634507.6 i/s - 1.03x slower
mjit_eq(1, nil)
after --jit: 7444657.4 i/s
before --jit: 7331304.3 i/s - 1.02x slower
mjit_eq(nil, 1)
after --jit: 64710790.6 i/s
before --jit: 49449507.4 i/s - 1.31x slower
```
This callcache is on stack, must not be GCed. However its contents are
copied from other materials, which can be an ordinal object. Should
set a flag to make sure it is properly skipped by the GC.
This changeset reduces the generated binary of
vm_call_method_missing_body from 604 bytes to 532 bytes on my machine.
Should reduce GC pressure as well.
Koichi Sasada
Alan Wu
eileencodes
Jeremy Evans
Benoit Daloze
Nobuyoshi Nakada
卜部昌平
Takashi Kokubun