RFR: 8282573: ByteBufferTest.java: replace endless recursion with RuntimeException in void ck(double x, double y)

[Tobias Hartmann]

On Thu, 3 Mar 2022 11:24:04 GMT, Emanuel Peter <duke at openjdk.java.net> wrote:

> There are two functions that check for equality.
> void ck(long x, long y): already throws a RuntimeException if we observe inequality
> void ck(double x, double y): called itself, leading to endless recursion and a StackOverflowError.
> 
> Instead of the recursion, I now also throw a RuntimeException.
> 
> This can currently be triggered with
> `path-to-jtreg/jtreg -va -s -jdk:jdk-path -javaoptions:"-XX:+UnlockDiagnosticVMOptions -XX:-TieredCompilation -XX:+StressGCM -XX:+OptoScheduling -XX:StressSeed=293843391" test/hotspot/jtreg/compiler/intrinsics/unsafe/HeapByteBufferTest.java `
> (see bug [JDK-8282555](https://bugs.openjdk.java.net/browse/JDK-8282555))
> 
> This way I could verify that instead of StackOverflowError we now get RuntimeException, as desired.
> Ran some basic tests to ensure I didn't break things.

test/hotspot/jtreg/compiler/intrinsics/unsafe/ByteBufferTest.java line 219:

> 217: 
> 218:     void ck(double x, double y) {
> 219:         if (x == x && y == y && x != y) {

What are the `x == x` and `y == y` checks good for?

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PR: https://git.openjdk.java.net/jdk/pull/7674