OutOfMemoryError while constructing a NameError in the context of a large object #8384
Description
Causing a NameError within the scope of a large Object results in an OutOfMemoryError instead of the NameError, hiding the actual user space code location of the NameError and potentially crashing the process.
Environment Information
- jruby 9.4.8.0 (3.1.4) 2024-07-02 4d41e55 OpenJDK 64-Bit Server VM 17.0.12+7-Ubuntu-1ubuntu222.04 on 17.0.12+7-Ubuntu-1ubuntu222.04 +jit [x86_64-linux]
Linux 6.8.0-47-generic #47~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Wed Oct 2 16:16:55 UTC 2 x86_64 x86_64 x86_64 GNU/Linux
Expected Behavior
The NameError should be shown.
Actual Behavior
All the memory of the process gets filled while collecting an inspect string of the large object. If not enough memory is available, an OutOfMemoryError is shown, hiding the actual NameError location.
Minimal Example
class Test
def initialize()
@obj = {}
for t in 1..800000 do
@obj[t.to_s] = Random.rand(10000000).to_s
end
end
def error
nameerror
end
end
puts("generating large obj")
test = Test.new
puts("done")
test.error
Running with jruby -w -J-Xmx250M test2.rb results in:
generating large obj
done
Error: Your application used more memory than the safety cap of 250M.
Specify -J-Xmx####M to increase it (#### = cap size in MB).
java.lang.OutOfMemoryError: Java heap space
at org.jruby.dist/org.jruby.util.ByteList.ensure(ByteList.java:362)
at org.jruby.dist/org.jruby.util.io.EncodingUtils.strBufCat(EncodingUtils.java:1883)
at org.jruby.dist/org.jruby.util.io.EncodingUtils.strBufCat(EncodingUtils.java:1868)
at org.jruby.dist/org.jruby.util.io.EncodingUtils.encCrStrBufCat(EncodingUtils.java:1991)
at org.jruby.dist/org.jruby.util.io.EncodingUtils.encStrBufCat(EncodingUtils.java:1894)
at org.jruby.dist/org.jruby.RubyBasicObject.inspectObj(RubyBasicObject.java:1145)
at org.jruby.dist/org.jruby.RubyBasicObject.hashyInspect(RubyBasicObject.java:1088)
at org.jruby.dist/org.jruby.RubyBasicObject.inspect(RubyBasicObject.java:1072)
at org.jruby.dist/org.jruby.RubyKernel.inspect(RubyKernel.java:2362)
at org.jruby.dist/org.jruby.RubyKernel$INVOKER$s$0$0$inspect.call(RubyKernel$INVOKER$s$0$0$inspect.gen)
at org.jruby.dist/org.jruby.runtime.callsite.CachingCallSite.cacheAndCall(CachingCallSite.java:456)
at org.jruby.dist/org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:195)
at org.jruby.dist/org.jruby.RubyBasicObject.rbInspect(RubyBasicObject.java:1097)
at org.jruby.dist/org.jruby.RubyObject.inspect(RubyObject.java:452)
at org.jruby.dist/org.jruby.RubyNameError$RubyNameErrorMessage.to_str(RubyNameError.java:129)
at org.jruby.dist/org.jruby.RubyNameError$RubyNameErrorMessage$INVOKER$i$0$0$to_str.call(RubyNameError$RubyNameErrorMessage$INVOKER$i$0$0$to_str.gen)
at org.jruby.dist/org.jruby.RubyClass.checkFuncallDefault(RubyClass.java:685)
at org.jruby.dist/org.jruby.RubyClass.finvokeChecked(RubyClass.java:629)
at org.jruby.dist/org.jruby.runtime.Helpers.invokeChecked(Helpers.java:757)
at org.jruby.dist/org.jruby.RubyBasicObject.checkCallMethod(RubyBasicObject.java:341)
at org.jruby.dist/org.jruby.util.TypeConverter.convertToType(TypeConverter.java:97)
at org.jruby.dist/org.jruby.util.TypeConverter.convertToType(TypeConverter.java:128)
at org.jruby.dist/org.jruby.RubyBasicObject.convertToString(RubyBasicObject.java:722)
at org.jruby.dist/org.jruby.RubyNameError.to_s(RubyNameError.java:264)
at org.jruby.dist/org.jruby.RubyNameError$INVOKER$i$0$0$to_s.call(RubyNameError$INVOKER$i$0$0$to_s.gen)
at org.jruby.dist/org.jruby.internal.runtime.methods.JavaMethod$JavaMethodN.call(JavaMethod.java:841)
at org.jruby.dist/org.jruby.ir.runtime.IRRuntimeHelpers.unresolvedSuper(IRRuntimeHelpers.java:1488)
at org.jruby.dist/org.jruby.ir.instructions.UnresolvedSuperInstr.interpret(UnresolvedSuperInstr.java:123)
at org.jruby.dist/org.jruby.ir.interpreter.InterpreterEngine.processCall(InterpreterEngine.java:363)
at org.jruby.dist/org.jruby.ir.interpreter.StartupInterpreterEngine.interpret(StartupInterpreterEngine.java:66)
at org.jruby.dist/org.jruby.ir.interpreter.InterpreterEngine.interpret(InterpreterEngine.java:76)
at org.jruby.dist/org.jruby.internal.runtime.methods.MixedModeIRMethod.INTERPRET_METHOD(MixedModeIRMethod.java:164)
This will be fixed regularly in JRuby 10 (ruby 3.3), this issue is for a potential fix in JRuby 9.4 with compatibility to ruby 3.1.
See also #216
best