fix memory leak in vm_method
This introduces a unified reference_count to clarify who is referencing a method.
This also allows us to treat the refinement method as the def owner since it counts itself as a reference
Co-authored-by: Peter Zhu <peter@peterzhu.ca>
[Bug #19894]
When a copy of a complemented method entry is created, there are two
issues:
1. IMEMO_FL_USER3 is not copied, so the complemented status is not
copied over.
2. In rb_method_entry_clone we increment both alias_count and
complemented_count. However, when we free the method entry in
rb_method_definition_release, we only decrement one of the two
counters, resulting in the rb_method_definition_t being leaked.
Co-authored-by: Adam Hess <adamhess1991@gmail.com>
From Ruby 3.0, refined method invocations are slow because
resolved methods are not cached by inline cache because of
conservertive strategy. However, `using` clears all caches
so that it seems safe to cache resolved method entries.
This patch caches resolved method entries in inline cache
and clear all of inline method caches when `using` is called.
fix [Bug #18572]
```ruby
# without refinements
class C
def foo = :C
end
N = 1_000_000
obj = C.new
require 'benchmark'
Benchmark.bm{|x|
x.report{N.times{
obj.foo; obj.foo; obj.foo; obj.foo; obj.foo;
obj.foo; obj.foo; obj.foo; obj.foo; obj.foo;
obj.foo; obj.foo; obj.foo; obj.foo; obj.foo;
obj.foo; obj.foo; obj.foo; obj.foo; obj.foo;
}}
}
_END__
user system total real
master 0.362859 0.002544 0.365403 ( 0.365424)
modified 0.357251 0.000000 0.357251 ( 0.357258)
```
```ruby
# with refinment but without using
class C
def foo = :C
end
module R
refine C do
def foo = :R
end
end
N = 1_000_000
obj = C.new
require 'benchmark'
Benchmark.bm{|x|
x.report{N.times{
obj.foo; obj.foo; obj.foo; obj.foo; obj.foo;
obj.foo; obj.foo; obj.foo; obj.foo; obj.foo;
obj.foo; obj.foo; obj.foo; obj.foo; obj.foo;
obj.foo; obj.foo; obj.foo; obj.foo; obj.foo;
}}
}
__END__
user system total real
master 0.957182 0.000000 0.957182 ( 0.957212)
modified 0.359228 0.000000 0.359228 ( 0.359238)
```
```ruby
# with using
class C
def foo = :C
end
module R
refine C do
def foo = :R
end
end
N = 1_000_000
using R
obj = C.new
require 'benchmark'
Benchmark.bm{|x|
x.report{N.times{
obj.foo; obj.foo; obj.foo; obj.foo; obj.foo;
obj.foo; obj.foo; obj.foo; obj.foo; obj.foo;
obj.foo; obj.foo; obj.foo; obj.foo; obj.foo;
obj.foo; obj.foo; obj.foo; obj.foo; obj.foo;
}}
}
When aliasing a method to the same name method, set a separate bit
flag on that method definition, instead of the reference count
increment. Although this kind of alias has no actual effect at
runtime, is used as the hack to suppress the method re-definition
warning.
`def` (`rb_method_definition_t`) is shared by multiple callable
method entries (cme, `rb_callable_method_entry_t`).
There are two issues:
* old -> young reference: `cme1->def->mandatory_only_cme = monly_cme`
if `cme1` is young and `monly_cme` is young, there is no problem.
Howevr, another old `cme2` can refer `def`, in this case, old `cme2`
points young `monly_cme` and it violates gengc assumption.
* cme can have different `defined_class` but `monly_cme` only has
one `defined_class`. It does not make sense and `monly_cme`
should be created for a cme (not `def`).
To solve these issues, this patch allocates `monly_cme` per `cme`.
`cme` does not have another room to store a pointer to the `monly_cme`,
so this patch introduces `overloaded_cme_table`, which is weak key map
`[cme] -> [monly_cme]`.
`def::body::iseqptr::monly_cme` is deleted.
The first issue is reported by Alan Wu.
* Lazily create singletons on instance_{exec,eval}
Previously when instance_exec or instance_eval was called on an object,
that object would be given a singleton class so that method
definitions inside the block would be added to the object rather than
its class.
This commit aims to improve performance by delaying the creation of the
singleton class unless/until one is needed for method definition. Most
of the time instance_eval is used without any method definition.
This was implemented by adding a flag to the cref indicating that it
represents a singleton of the object rather than a class itself. In this
case CREF_CLASS returns the object's existing class, but in cases that
we are defining a method (either via definemethod or
VM_SPECIAL_OBJECT_CBASE which is used for undef and alias).
This also happens to fix what I believe is a bug. Previously
instance_eval behaved differently with regards to constant access for
true/false/nil than for all other objects. I don't think this was
intentional.
String::Foo = "foo"
"".instance_eval("Foo") # => "foo"
Integer::Foo = "foo"
123.instance_eval("Foo") # => "foo"
TrueClass::Foo = "foo"
true.instance_eval("Foo") # NameError: uninitialized constant Foo
This also slightly changes the error message when trying to define a method
through instance_eval on an object which can't have a singleton class.
Before:
$ ruby -e '123.instance_eval { def foo; end }'
-e:1:in `block in <main>': no class/module to add method (TypeError)
After:
$ ./ruby -e '123.instance_eval { def foo; end }'
-e:1:in `block in <main>': can't define singleton (TypeError)
IMO this error is a small improvement on the original and better matches
the (both old and new) message when definging a method using `def self.`
$ ruby -e '123.instance_eval{ def self.foo; end }'
-e:1:in `block in <main>': can't define singleton (TypeError)
Co-authored-by: Matthew Draper <matthew@trebex.net>
* Remove "under" argument from yield_under
* Move CREF_SINGLETON_SET into vm_cref_new
* Simplify vm_get_const_base
* Fix leaf VM_SPECIAL_OBJECT_CONST_BASE
Co-authored-by: Matthew Draper <matthew@trebex.net>
Compare with the C methods, A built-in methods written in Ruby is
slower if only mandatory parameters are given because it needs to
check the argumens and fill default values for optional and keyword
parameters (C methods can check the number of parameters with `argc`,
so there are no overhead). Passing mandatory arguments are common
(optional arguments are exceptional, in many cases) so it is important
to provide the fast path for such common cases.
`Primitive.mandatory_only?` is a special builtin function used with
`if` expression like that:
```ruby
def self.at(time, subsec = false, unit = :microsecond, in: nil)
if Primitive.mandatory_only?
Primitive.time_s_at1(time)
else
Primitive.time_s_at(time, subsec, unit, Primitive.arg!(:in))
end
end
```
and it makes two ISeq,
```
def self.at(time, subsec = false, unit = :microsecond, in: nil)
Primitive.time_s_at(time, subsec, unit, Primitive.arg!(:in))
end
def self.at(time)
Primitive.time_s_at1(time)
end
```
and (2) is pointed by (1). Note that `Primitive.mandatory_only?`
should be used only in a condition of an `if` statement and the
`if` statement should be equal to the methdo body (you can not
put any expression before and after the `if` statement).
A method entry with `mandatory_only?` (`Time.at` on the above case)
is marked as `iseq_overload`. When the method will be dispatch only
with mandatory arguments (`Time.at(0)` for example), make another
method entry with ISeq (2) as mandatory only method entry and it
will be cached in an inline method cache.
The idea is similar discussed in https://bugs.ruby-lang.org/issues/16254
but it only checks mandatory parameters or more, because many cases
only mandatory parameters are given. If we find other cases (optional
or keyword parameters are used frequently and it hurts performance),
we can extend the feature.
Before this commit, iclasses were "shady", or not protected by write
barriers. Because of that, the GC needs to spend more time marking these
objects than otherwise.
Applications that make heavy use of modules should see reduction in GC
time as they have a significant number of live iclasses on the heap.
- Put logic for iclass method table ownership into a function
- Remove calls to WB_UNPROTECT and insert write barriers for iclasses
This commit relies on the following invariant: for any non oirigin
iclass `I`, `RCLASS_M_TBL(I) == RCLASS_M_TBL(RBasic(I)->klass)`. This
invariant did not hold prior to 98286e9 for classes and modules that
have prepended modules.
[Feature #16984]
According to MSVC manual (*1), cl.exe can skip including a header file
when that:
- contains #pragma once, or
- starts with #ifndef, or
- starts with #if ! defined.
GCC has a similar trick (*2), but it acts more stricter (e. g. there
must be _no tokens_ outside of #ifndef...#endif).
Sun C lacked #pragma once for a looong time. Oracle Developer Studio
12.5 finally implemented it, but we cannot assume such recent version.
This changeset modifies header files so that each of them include
strictly one #ifndef...#endif. I believe this is the most portable way
to trigger compiler optimizations. [Bug #16770]
*1: https://docs.microsoft.com/en-us/cpp/preprocessor/once
*2: https://gcc.gnu.org/onlinedocs/cppinternals/Guard-Macros.html
This patch contains several ideas:
(1) Disposable inline method cache (IMC) for race-free inline method cache
* Making call-cache (CC) as a RVALUE (GC target object) and allocate new
CC on cache miss.
* This technique allows race-free access from parallel processing
elements like RCU.
(2) Introduce per-Class method cache (pCMC)
* Instead of fixed-size global method cache (GMC), pCMC allows flexible
cache size.
* Caching CCs reduces CC allocation and allow sharing CC's fast-path
between same call-info (CI) call-sites.
(3) Invalidate an inline method cache by invalidating corresponding method
entries (MEs)
* Instead of using class serials, we set "invalidated" flag for method
entry itself to represent cache invalidation.
* Compare with using class serials, the impact of method modification
(add/overwrite/delete) is small.
* Updating class serials invalidate all method caches of the class and
sub-classes.
* Proposed approach only invalidate the method cache of only one ME.
See [Feature #16614] for more details.
Saves comitters' daily life by avoid #include-ing everything from
internal.h to make each file do so instead. This would significantly
speed up incremental builds.
We take the following inclusion order in this changeset:
1. "ruby/config.h", where _GNU_SOURCE is defined (must be the very
first thing among everything).
2. RUBY_EXTCONF_H if any.
3. Standard C headers, sorted alphabetically.
4. Other system headers, maybe guarded by #ifdef
5. Everything else, sorted alphabetically.
Exceptions are those win32-related headers, which tend not be self-
containing (headers have inclusion order dependencies).
Methods and their definitions can be allocated/deallocated on-the-fly.
One pathological situation is when a method is deallocated then another
one is allocated immediately after that. Address of those old/new method
entries/definitions can be the same then, depending on underlying
malloc/free implementation.
So pointer comparison is insufficient. We have to check the contents.
To do so we introduce def->method_serial, which is an integer unique to
that specific method definition.
PS: Note that method_serial being uintptr_t rather than rb_serial_t is
intentional. This is because rb_serial_t can be bigger than a pointer
on a 32bit system (rb_serial_t is at least 64bit). In order to preserve
old packing of struct rb_call_cache, rb_serial_t is inappropriate.
These functions are used from within a compilation unit so we can
make them static, for better binary size. This changeset reduces
the size of generated ruby binary from 26,590,128 bytes to
26,584,472 bytes on my macihne.
Looking at the list of symbols inside of libruby-static.a, I found
hundreds of functions that are defined, but used from nowhere.
There can be reasons for each of them (e.g. some functions are
specific to some platform, some are useful when debugging, etc).
However it seems the functions deleted here exist for no reason.
This changeset reduces the size of ruby binary from 26,671,456
bytes to 26,592,864 bytes on my machine.
Tabs were expanded because previously the file did not have any tab indentation.
Please update your editor config, and use misc/expand_tabs.rb in the pre-commit hook.
This reverts commits: 10d6a3aca78ba48c1b85fba8627dc1dd883de5ba6c6a25feca167e6b48f17cb96d41a53207979278595b3c4fdd1521f7cf89c11c5e69accf336082033632a812c0f56506be0d86427a3219 .
The reason for the revert is that we observe ABA problem around
inline method cache. When a cache misshits, we search for a
method entry. And if the entry is identical to what was cached
before, we reuse the cache. But the commits we are reverting here
introduced situations where a method entry is freed, then the
identical memory region is used for another method entry. An
inline method cache cannot detect that ABA.
Here is a code that reproduce such situation:
```ruby
require 'prime'
class << Integer
alias org_sqrt sqrt
def sqrt(n)
raise
end
GC.stress = true
Prime.each(7*37){} rescue nil # <- Here we populate CC
class << Object.new; end
# These adjacent remove-then-alias maneuver
# frees a method entry, then immediately
# reuses it for another.
remove_method :sqrt
alias sqrt org_sqrt
end
Prime.each(7*37).to_a # <- SEGV
```
Now that we have eliminated most destructive operations over the
rb_method_entry_t / rb_callable_method_entry_t, let's make them
mostly immutabe and mark them const.
One exception is rb_export_method(), which destructively modifies
visibilities of method entries. I have left that operation as is
because I suspect that destructiveness is the nature of that
function.
Tired of rb_method_entry_create(..., rb_method_definition_create(
..., &(rb_method_foo_t) {...})) maneuver. Provide a function that
does the thing to reduce copy&paste.
The deleted function was to destructively overwrite existing method
entries, which is now considered to be a bad idea. Delete it, and
assign a newly created method entry instead.
Most (if not all) of the fields of rb_method_definition_t are never
meant to be modified once after they are stored. Marking them const
makes it possible for compilers to warn on unintended modifications.
For some reason symbols (or classes) are being overridden in trunk
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67598 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This commit adds the new method `GC.compact` and compacting GC support.
Please see this issue for caveats:
https://bugs.ruby-lang.org/issues/15626
[Feature #15626]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67576 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Because hard to specify commits related to r67479 only.
So please commit again.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67499 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This commit adds the new method `GC.compact` and compacting GC support.
Please see this issue for caveats:
https://bugs.ruby-lang.org/issues/15626
[Feature #15626]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67479 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* method.h (rb_add_method): make it void function because
nobody use a return value.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67444 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* vm_insnhelper.c: change `call_cfunc_*` parameters order
and specify a function type for the passed func ptr.
This fix reduce the number of asm instructions, such as:
# before this patch
0000000000000110 <call_cfunc_0>:
110: 48 89 fa mov %rdi,%rdx
113: 31 c0 xor %eax,%eax
115: 48 89 f7 mov %rsi,%rdi
118: ff e2 jmpq *%rdx
11a: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1)
# after this patch
0000000000000110 <call_cfunc_0>:
110: ff e1 jmpq *%rcx
However, this kind of instruction reduction doesn't affect
any performance because of great CPU architectures :p
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67122 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* vm_args.c (refine_sym_proc_call): resolve refinements when the
proc is invoked, instead of resolving at making the proc, to
enable refinements on symbol-proc in ruby-level methods
* vm.c (vm_cref_dup): clear cached symbol-procs when duplicating.
[Bug #15114] [Fix GH-2039]
From: manga_osyo <manga.osyo@gmail.com>
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66439 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* vm_trace.c (rb_tracepoint_enable_for_target): support targetting
TracePoint. [Feature #15289]
Tragetting TracePoint is only enabled on specified method, proc
and so on, example: `tp.enable(target: code)`.
`code` should be consisted of InstructionSeuqnece (iseq)
(RubyVM::InstructionSeuqnece.of(code) should not return nil)
If code is a tree of iseq, TracePoint is enabled on all of
iseqs in a tree.
Enabled tragetting TracePoints can not enabled again with
and without target.
* vm_core.h (rb_iseq_t): introduce `rb_iseq_t::local_hooks`
to store local hooks.
`rb_iseq_t::aux::trace_events` is renamed to
`global_trace_events` to contrast with `local_hooks`.
* vm_core.h (rb_hook_list_t): add `rb_hook_list_t::running`
to represent how many Threads/Fibers are used this list.
If this field is 0, nobody using this hooks and we can
delete it.
This is why we can remove code from cont.c.
* vm_core.h (rb_vm_t): because of above change, we can eliminate
`rb_vm_t::trace_running` field.
Also renamed from `rb_vm_t::event_hooks` to `global_hooks`.
* vm_core.h, vm.c (ruby_vm_event_enabled_global_flags): renamed
from `ruby_vm_event_enabled_flags.
* vm_core.h, vm.c (ruby_vm_event_local_num): added to count
enabled targetting TracePoints.
* vm_core.h, vm_trace.c (rb_exec_event_hooks): accepts
hook list.
* vm_core.h (rb_vm_global_hooks): added for convinience.
* method.h (rb_method_bmethod_t): added to maintain Proc
and `rb_hook_list_t` for bmethod (defined by define_method).
* prelude.rb (TracePoint#enable): extracet a keyword parameter
(because it is easy than writing in C).
It calls `TracePoint#__enable` internal method written in C.
* vm_insnhelper.c (vm_trace): check also iseq->local_hooks.
* vm.c (invoke_bmethod): check def->body.bmethod.hooks.
* vm.c (hook_before_rewind): check iseq->local_hooks
and def->body.bmethod.hooks before rewind by exception.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66003 b2dd03c8-39d4-4d8f-98ff-823fe69b080e