RFR: 8244010: Simplify usages of ProcessTools.createJavaProcessBuilder in our tests

[Igor Ignatyev]

Hi Stefan,

the patch looks good to me.

-- Igor

> On Apr 28, 2020, at 9:37 AM, Leonid Mesnik <leonid.mesnik at oracle.com> wrote:
> 
> Hi
> 
> The changes look good.
> 
> The only small nit. Why don't  restrict arguments to "List<String>" instead of "Collection<String>"? The unordered collections like Set<String> shouldn't be used here. It is a just proposal, no need for new review if you going to fix it.
> 
> Leonid
> 
> On 4/28/20 6:54 AM, Stefan Karlsson wrote:
>> Hi again,
>> 
>> I realized that we probably want to give ProcessTools.executeTestJvm the same treatment.
>> 
>> Side-note: It's very awkard that createJavaProcessBuilder defaults to not adding user-specifed flags, but executeTestJvm does. I think it would be good to unify this as a separate RFE. I think *a lot* of callers to createJavaProcessBuilder could be simplified by either using executeTestJvm directly, or a simplified version of that.
>> 
>> I'm running testing through mach5 and found a few things to fix, I might find more when the testing has proceeded further.
>> 
>> This is the current patch:
>> https://cr.openjdk.java.net/~stefank/8244010/webrev.02.delta
>> https://cr.openjdk.java.net/~stefank/8244010/webrev.02
>> 
>> Thanks,
>> StefanK
>> 
>> On 2020-04-28 13:58, Stefan Karlsson wrote:
>>> Hi all,
>>> 
>>> Please review this patch to simplify usages of ProcessTools.createJavaProcessBuilder in our tests.
>>> 
>>> https://cr.openjdk.java.net/~stefank/8244010/webrev.01/
>>> https://bugs.openjdk.java.net/browse/JDK-8244010
>>> 
>>> I saw all this code when reviewing changes to how we pass flags in our tests. There are a many places where arguments are converted and passed back and forth in String[] and Collections.
>>> 
>>> For example:
>>>   ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
>>>           argsList.toArray(new String[argsList.size()]));
>>> 
>>> If we add an overload the createJavaProcessBuilder, that takes a Collection<String> as an argument, then we can write the code above as:
>>>    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(argsList);
>>> 
>>> Other places temporarily put the flags in a String[], where most calls simply lists the arguments in the call:
>>>   String[] opts = {Xmx, "-XX:NativeMemoryTracking=detail", "-XX:+UseParallelGC", "-version"};
>>>   ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(opts);
>>> 
>>> And some places put the args in a temporary Collection:
>>>   LinkedList<String> vmOptions = new LinkedList<>();
>>>   vmOptions.add(gc);
>>>   vmOptions.add("-Xmx" + minMaxHeap);
>>>   vmOptions.add("-XX:+PrintFlagsFinal");
>>>   vmOptions.add(VerifyHeapSize.class.getName());
>>> 
>>>   ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(vmOptions.toArray(new String[0]));
>>> 
>>> I'd like to cleanup, simplify, and unify many of these usages.
>>> 
>>> I've tested this by running all the changed tests locally.
>>> 
>>> Thanks,
>>> StefanK
>>