RFR: 8230943: False deadlock detection with -XX:+CIPrintCompileQueue after JDK-8163511

[Tobias Hartmann]

Hi Jie,

this looks good to me. Thanks for fixing!

Best regards,
Tobias

On 14.09.19 05:26, Jie Fu wrote:
> Hi all,
> 
> JBS:    https://bugs.openjdk.java.net/browse/JDK-8230943
> Webrev: http://cr.openjdk.java.net/~jiefu/8230943/webrev.00/
> 
> When dumping the compile queue with CIPrintCompileQueue, the thread will first acquire the
> tty_lock[1] with rank 3 and then may require the JNI weak alloc lock[2] with rank 7, which may break
> the deadlock avoidance rules[3].
> 
> I've learned from David that it seems impossible to assign a tty lock ranking that will always work.
> And I think the stringStream is good enough to fix this specific issue, which was inspired by Kim.
> 
> Thanks David and Kim for your help.
> For more info., please see the comments by them in the JBS.
> 
> Could you please review it and give me some advice?
> 
> Thanks a lot.
> Best regards,
> Jie
> 
> [1]
> http://hg.openjdk.java.net/jdk/jdk/file/79186d82463e/src/hotspot/share/compiler/compileBroker.cpp#l560
> [2]
> http://hg.openjdk.java.net/jdk/jdk/file/79186d82463e/src/hotspot/share/gc/shared/oopStorage.cpp#l913
> [3] http://hg.openjdk.java.net/jdk/jdk/file/79186d82463e/src/hotspot/share/runtime/mutex.cpp#l385
> 
>