RFR [XS]: 8239462: jdk.hotspot.agent misses some ReleaseStringUTFChars calls in case of early returns

[Baesken, Matthias]

Hi Alex , 

new webrev :

http://cr.openjdk.java.net/~mbaesken/webrevs/8239462.2/

Best Regards, Matthias


> 
> Hi Matthias,
> 
> Looks good in general, but I think it makes sense to fix #2 cases (at
> least I see them in LinuxDebuggerLocal). If GetStringUTFChars fails, the
> code will crash.
> Also I see GetStringUTFChars(str, JNI_FALSE). This look bad as well -
> 2nd arg is a pointer, so it should be NULL or nullptr.
> 
> As for #1 and #3 - AFAIU they are both right ways.
> If GetStringUTFChars fails, it throws OOM and return NULL.
> 
> And one more thing to consider.
> LinuxDebuggerLocal_attach0 function looks terrible - 7
> ReleaseStringUTFChars calls for 2 GetStringUTFChars.
> Maybe it make sense to introduce simple wrapper like AutoJavaString in
> src/jdk.hotspot.agent/windows/native/libsaproc/sawindbg.cpp
> It would make the code simpler and less error prone.
> 
> --alex
>