RFR (Preliminary): 8248194: Need better support for running SA tests on core files

[Leonid Mesnik]

Hi

The idea basically looks good. I think it just make a sense to polish it a little bit to hide "sh" usage from test and get core from OutputAnalyzer.
 
Also, there is a 'CrashApp' in ClhsdbCDSCore.java. Makes it sense to unify it with LingeredApp crasher? Currently, it uses Unsafe to crash application.

Also, crashes are used in other tests, I see some implementations in 
open/test/hotspot/jtreg/vmTestbase/vm/share/vmcrasher

So it would be nice to have some common way to crash hotspot.

Leonid


> On Jun 25, 2020, at 2:41 PM, Chris Plummer <chris.plummer at oracle.com> wrote:
> 
> Hello,
> 
> Please help with a preliminary review of changes to add better support for writing SA tests that work on core files:
> 
> https://bugs.openjdk.java.net/browse/JDK-8248194
> http://cr.openjdk.java.net/~cjplummer/8248194/webrev.00/index.html
> 
> As pointed out, this is a preliminary review. I suspect there will be some feedback for changes/improvements. Also, I still need to work out a final solution for how to get LingeredApp to produce a crash. What I currently have works but is somewhat of a hack w.r.t. the makefile change, so you can ignore the makefiile change for now. I'm working on a more proper solution with the build team.
> 
> As outlined in the CR, these are the 3 main goals of this CR:
> 
> 1. SATestUtils should include support for finding the core file. This includes parsing the output of the crashed process to locate where the core file was saved, and returning this location to the user.
> 
> 2. SATestUtils should include support for adding the "ulimit -c unlimited" prefix to the command that will produce the core file, allowing the overriding of any lower limit so we can be sure the core file will be produced.
> 
> 3. LingeredApp should include support for producing a core file.
> 
> As proof of concept for these 3 changes in test library support, I'm updating the following 3 tests:
> 
> ClhsdbCDSCore.java: Use the SATestUtils support listed above. This test does not use LingeredApp, so those improvements don't apply.
> 
> TestJmapCore.java: Use the SATestUtils support listed above. This test does not use LingeredApp, so those improvements don't apply.
> 
> ClhsdbFindPC.java: Use all the above features, including having LingeredApp produce a core file. This is the only test modified to start testing on core files that didn't previously do so. It still also tests on a live process.
> 
> In the future more Clhsdb tests will be converted to work on core files in a manner similar to ClhsdbFindPC.
> 
> The new SATestUtils code is borrowed from (more like ripped out of) ClhsdbCDSCore.java and TestJmapCore.java. They both had a lot of code dedicated to finding the core file and also applying "ulimit -c unlimitted" if necessary, but didn't do so in quite the same way. Now both these tests share code in SATestUtils.java. One thing I did drop is TestJmapCore.java use of ":KILLED_PID" in the output to help find the core file. It's no longer necessary based on the smarter core locating code I pulled from ClhsdbCDSCore.java.
> 
> thanks,
> 
> Chris