RFR (S): 8146246: JVMCICompiler::abort_on_pending_exception: assert(!thread->owns_locks()) failed: must release all locks when leaving VM

[Christian Thalinger]

> On Jan 6, 2016, at 9:34 AM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
> 
> I would go with "Java code do the printing”.

Yeah, it might be better.

> You left ttyLocker in case 2) in src/share/vm/runtime/java.cpp

Right.  Thanks for pointing that out.

> 
> Thanks,
> Vladimir
> 
> On 1/6/16 11:19 AM, Christian Thalinger wrote:
>> https://bugs.openjdk.java.net/browse/JDK-8146246
>> 
>> The problem is that https://bugs.openjdk.java.net/browse/JDK-8145435 introduced ttyLocker to synchronize the exception output but java_lang_Throwable::print_stack_trace can call out to Java to get the cause.
>> 
>> There are two solutions:
>> 
>> 1) Remove ttyLocker and deal with some possible scrambling in the rare case of an exception:
>> 
>> diff -r df8d635f2296 -r e87e187552fb src/share/vm/jvmci/jvmciCompiler.cpp
>> --- a/src/share/vm/jvmci/jvmciCompiler.cpp	Tue Dec 29 11:24:01 2015 -0800
>> +++ b/src/share/vm/jvmci/jvmciCompiler.cpp	Thu Dec 31 09:20:16 2015 -0800
>> @@ -162,10 +162,7 @@ void JVMCICompiler::compile_method(const
>>      Handle exception(THREAD, PENDING_EXCEPTION);
>>      CLEAR_PENDING_EXCEPTION;
>> 
>> -    {
>> -      ttyLocker ttyl;
>> -      java_lang_Throwable::print_stack_trace(exception, tty);
>> -    }
>> +    java_lang_Throwable::print_stack_trace(exception, tty);
>> 
>>      // Something went wrong so disable compilation at this level
>>      method->set_not_compilable(CompLevel_full_optimization);
>> @@ -181,11 +178,8 @@ void JVMCICompiler::abort_on_pending_exc
>>    Thread* THREAD = Thread::current();
>>    CLEAR_PENDING_EXCEPTION;
>> 
>> -  {
>> -    ttyLocker ttyl;
>> -    tty->print_raw_cr(message);
>> -    java_lang_Throwable::print_stack_trace(exception, tty);
>> -  }
>> +  tty->print_raw_cr(message);
>> +  java_lang_Throwable::print_stack_trace(exception, tty);
>> 
>>    // Give other aborting threads to also print their stack traces.
>>    // This can be very useful when debugging class initialization
>> diff -r df8d635f2296 -r e87e187552fb src/share/vm/runtime/java.cpp
>> --- a/src/share/vm/runtime/java.cpp	Tue Dec 29 11:24:01 2015 -0800
>> +++ b/src/share/vm/runtime/java.cpp	Thu Dec 31 09:20:16 2015 -0800
>> @@ -432,7 +432,6 @@ void before_exit(JavaThread* thread) {
>>    if (HAS_PENDING_EXCEPTION) {
>>      Handle exception(THREAD, PENDING_EXCEPTION);
>>      CLEAR_PENDING_EXCEPTION;
>> -    ttyLocker ttyl;
>>      java_lang_Throwable::print_stack_trace(exception, tty);
>>    }
>>  #endif
>> 
>> or
>> 
>> 2) Call out to Java and let the Java code do the printing:
>> 
>> diff -r 0fcfe4b07f7e src/share/vm/classfile/javaClasses.cpp
>> --- a/src/share/vm/classfile/javaClasses.cpp	Tue Dec 29 18:30:51 2015 +0100
>> +++ b/src/share/vm/classfile/javaClasses.cpp	Wed Jan 06 09:12:00 2016 -1000
>> @@ -1784,6 +1784,20 @@ void java_lang_Throwable::print_stack_tr
>>    }
>>  }
>> 
>> +/**
>> + * Print the throwable stack trace by calling the Java method java.lang.Throwable.printStackTrace().
>> + */
>> +void java_lang_Throwable::java_printStackTrace(Handle throwable, TRAPS) {
>> +  assert(throwable->is_a(SystemDictionary::Throwable_klass()), "Throwable instance expected");
>> +  JavaValue result(T_VOID);
>> +  JavaCalls::call_virtual(&result,
>> +                          throwable,
>> +                          KlassHandle(THREAD, SystemDictionary::Throwable_klass()),
>> +                          vmSymbols::printStackTrace_name(),
>> +                          vmSymbols::void_method_signature(),
>> +                          THREAD);
>> +}
>> +
>>  void java_lang_Throwable::fill_in_stack_trace(Handle throwable, const methodHandle& method, TRAPS) {
>>    if (!StackTraceInThrowable) return;
>>    ResourceMark rm(THREAD);
>> diff -r 0fcfe4b07f7e src/share/vm/classfile/javaClasses.hpp
>> --- a/src/share/vm/classfile/javaClasses.hpp	Tue Dec 29 18:30:51 2015 +0100
>> +++ b/src/share/vm/classfile/javaClasses.hpp	Wed Jan 06 09:12:00 2016 -1000
>> @@ -554,6 +554,7 @@ class java_lang_Throwable: AllStatic {
>>    // Printing
>>    static void print(Handle throwable, outputStream* st);
>>    static void print_stack_trace(Handle throwable, outputStream* st);
>> +  static void java_printStackTrace(Handle throwable, TRAPS);
>>    // Debugging
>>    friend class JavaClasses;
>>  };
>> diff -r 0fcfe4b07f7e src/share/vm/jvmci/jvmciCompiler.cpp
>> --- a/src/share/vm/jvmci/jvmciCompiler.cpp	Tue Dec 29 18:30:51 2015 +0100
>> +++ b/src/share/vm/jvmci/jvmciCompiler.cpp	Wed Jan 06 09:12:00 2016 -1000
>> @@ -162,10 +162,7 @@ void JVMCICompiler::compile_method(const
>>      Handle exception(THREAD, PENDING_EXCEPTION);
>>      CLEAR_PENDING_EXCEPTION;
>> 
>> -    {
>> -      ttyLocker ttyl;
>> -      java_lang_Throwable::print_stack_trace(exception, tty);
>> -    }
>> +    java_lang_Throwable::java_printStackTrace(exception, THREAD);
>> 
>>      // Something went wrong so disable compilation at this level
>>      method->set_not_compilable(CompLevel_full_optimization);
>> @@ -181,11 +178,7 @@ void JVMCICompiler::abort_on_pending_exc
>>    Thread* THREAD = Thread::current();
>>    CLEAR_PENDING_EXCEPTION;
>> 
>> -  {
>> -    ttyLocker ttyl;
>> -    tty->print_raw_cr(message);
>> -    java_lang_Throwable::print_stack_trace(exception, tty);
>> -  }
>> +  java_lang_Throwable::java_printStackTrace(exception, THREAD);
>> 
>>    // Give other aborting threads to also print their stack traces.
>>    // This can be very useful when debugging class initialization
>> diff -r 0fcfe4b07f7e src/share/vm/runtime/java.cpp
>> --- a/src/share/vm/runtime/java.cpp	Tue Dec 29 18:30:51 2015 +0100
>> +++ b/src/share/vm/runtime/java.cpp	Wed Jan 06 09:12:00 2016 -1000
>> @@ -433,7 +433,7 @@ void before_exit(JavaThread* thread) {
>>      Handle exception(THREAD, PENDING_EXCEPTION);
>>      CLEAR_PENDING_EXCEPTION;
>>      ttyLocker ttyl;
>> -    java_lang_Throwable::print_stack_trace(exception, tty);
>> +    java_lang_Throwable::java_printStackTrace(exception, THREAD);
>>    }
>>  #endif
>>