RFR: Fix NullPointerException on a parallel run [v3]

[Dmitry Bessonov]

On Thu, 1 Sep 2022 00:42:10 GMT, Jonathan Gibbons <jjg at openjdk.org> wrote:

>> Jan Kratochvil has refreshed the contents of this pull request, and previous commits have been removed. The incremental views will show differences compared to the previous content of the PR. The pull request contains one new commit since the last revision:
>> 
>>   Fix NullPointerException on a parallel run
>>   
>>   Error: Unexpected exception occurred! java.lang.NullPointerException
>>   java.lang.NullPointerException
>>   	at com.sun.javatest.regtest.config.TestProperties$Cache.getEntryInternal(TestProperties.java:515)
>>   	at com.sun.javatest.regtest.config.TestProperties$Cache.getEntryInternal(TestProperties.java:515)
>>   	at com.sun.javatest.regtest.config.TestProperties$Cache.getEntry(TestProperties.java:502)
>>   	at com.sun.javatest.regtest.config.TestProperties.getEntry(TestProperties.java:170)
>>   	at com.sun.javatest.regtest.config.TestProperties.getTestNGRoot(TestProperties.java:123)
>>   	at com.sun.javatest.regtest.config.RegressionTestFinder.scanFile(RegressionTestFinder.java:143)
>>   	at com.sun.javatest.finder.TagTestFinder.scan(TagTestFinder.java:115)
>>   	at com.sun.javatest.TestFinder.read(TestFinder.java:433)
>>   	at com.sun.javatest.TRT_TreeNode.processFile(TRT_TreeNode.java:1259)
>>   	at com.sun.javatest.TRT_TreeNode.scanIfNeeded(TRT_TreeNode.java:807)
>>   	at com.sun.javatest.TRT_TreeNode.getTreeNode(TRT_TreeNode.java:616)
>>   	at com.sun.javatest.TestResultTable.findNode(TestResultTable.java:400)
>>   	at com.sun.javatest.TestResultTable.lookupNode(TestResultTable.java:533)
>>   	at com.sun.javatest.TestResultTable.lookupInitURL(TestResultTable.java:571)
>>   	at com.sun.javatest.TestResultTable.validatePath(TestResultTable.java:1000)
>>   	at com.sun.javatest.regtest.config.TestManager.validatePath(TestManager.java:299)
>>   	at com.sun.javatest.regtest.config.TestManager.getTests(TestManager.java:271)
>>   	at com.sun.javatest.regtest.tool.Tool.createParameters(Tool.java:1659)
>>   	at com.sun.javatest.regtest.tool.Tool.run(Tool.java:1293)
>>   	at com.sun.javatest.regtest.tool.Tool.run(Tool.java:1082)
>>   	at com.sun.javatest.regtest.tool.Tool.main(Tool.java:155)
>>   	at com.sun.javatest.regtest.Main.main(Main.java:46)
>>   
>>   Some debug output showing the problem:
>>   	scanIfNeeded getRootRelativePath= separator=/ filesToScan[i]=resultdir
>>   	processFile file=/resultdir isAbsolute=true
>>   	TestFinder.java read file=/resultdir isAbsolute=true
>>   	scanFile caller file=/resultdir
>>   	scanFile File=/resultdir
>>   	TestProperties.java:dir=/ rootDir=/home/azul/azul/zulu11-git/test/hotspot/jtreg file2=/resultdir file2.getParentFile()=/
>>   	TestProperties.java:dir=null rootDir=/home/azul/azul/zulu11-git/test/hotspot/jtreg file2=/resultdir file2.getParentFile()=/
>>   
>>   This happens with jtreg using -w:resultdir . getRootRelativePath()
>>   returns empty "" path. Other option would be to return "." but in such
>>   case it broke some other code.
>>   
>>   This problem does not happen during a single run. It happens only when
>>   jtreg is being run in parallel, in my case:
>>   	seq 1 100000|xargs -n1 -P64 ./runtest
>>   	#! /bin/bash
>>   	dir=result-test$$
>>   	rm -rf $dir
>>   	mkdir $dir
>>   	set -o pipefail
>>   	(JAVA_HOME=$HOME/azul/zulu11-git/build/linux-x86_64-normal-server-release/images/jdk/; $JAVA_HOME/bin/java -classpath $HOME/azul/jtreg/build/images/jtreg/lib/jtreg.jar:$HOME/azul/jtreg/build/images/jtreg/lib/javatest.jar:$HOME/azul/jtreg/build/images/jtreg/lib/asmtools.jar com.sun.javatest.regtest.Main -testjdk:$JAVA_HOME -othervm -verbose -ignore:quiet -retain:all -a -conc:1 -timeout:10 -vmoptions:-XX:+UnlockExperimentalVMOptions -w:$dir -noreport -dir:$JAVA_HOME/../../../../test/jdk/ -nativepath:$JAVA_HOME/../test/hotspot/jtreg/native ../hotspot/jtreg/vmTestbase/nsk/jdi/stress/serial/heapwalking001/TestDescription.java |& tee $dir/err) || exit 255
>>   	rm -rf $dir
>
> src/com/sun/javatest/TRT_TreeNode.java line 808:
> 
>> 806:                     String path = TestResultTable.getRootRelativePath(this);
>> 807:                     processFile(new File( "".equals(path) // Zero length string if the node is a root
>> 808:                                           ? filesToScan[i] : (path + File.separator + filesToScan[i]) ));
> 
> Pretty ugly code, containing a complex expression inside the `new File`, and even path string computation instead of using a better `File` constructor.
> 
> I suggest something like:
> 
> 
> processFile(path.isEmpty() // Zero length string if the node is a root
>     ? new File(filesToScan[i]) 
>     : new File(path, filesToScan[i]));

What if `path` is null ?

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PR: https://git.openjdk.org/jtharness/pull/35