RFR 8030115: [parfait] warnings from b119 for jdk.src.share.native.sun.tracing.dtrace: JNI exception pending

[Jaroslav Bachorik]

A few readability improvements suggested by Dmitry

http://cr.openjdk.java.net/~jbachorik/8030115/webrev.04

-JB-


--- snipped for brevity ---

>>>>> On 2014-07-24 15:07, Jaroslav Bachorik wrote:
>>>>>> Please, review the change for the fix of the following problem
>>>>>>
>>>>>> In jdk/src/share/native/sun/tracing/dtrace/JVM.c the following
>>>>>> code is
>>>>>> invoked in loop
>>>>>>
>>>>>> 198     for (i = 0; i < num_providers; ++i) {
>>>>>> 199         JVM_DTraceProvider* p = &(jvm_providers[i]);
>>>>>> 200         jobject provider = (*env)->GetObjectArrayElement(
>>>>>> 201             env, providers, i);
>>>>>> 202         readProviderData(env, provider, p);
>>>>>> 203     }
>>>>>>
>>>>>> The first problem is that GetGetObjectArrayElement() call on L200 may
>>>>>> throw an exception which is not checked subsequently. On L202 the
>>>>>> call
>>>>>> to readProviderData() can also raise a Java exception without
>>>>>> appropriate after-check. When getting back to the beginning of the
>>>>>> loop
>>>>>> GetObjectArrayElement() may be called with a pending exception
>>>>>> which is
>>>>>> deemed unsafe.
>>>>>>
>>>>>> The fix extracts the inner part of the loop into a separate function
>>>>>> where the result of each step is properly checked for pending
>>>>>> exceptions. If there is a pending exception the loop will be
>>>>>> interrupted, resources cleaned and
>>>>>> Java_sun_tracing_dtrace_JVM_activate0() function will return 0
>>>>>> with the
>>>>>> pending exception recorded in env.
>>>>>>
>>>>>>
>>>>>> Webrev: http://cr.openjdk.java.net/~jbachorik/8030115/webrev.00
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> -JB-
>>>>>
>>>>>
>>>>
>>>
>>
>>
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