8202449: overflow handling in Random.doubles

[rgiulietti]

Extend the range of Random.doubles(double, double) and similar methods.

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Progress

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• Commit message must refer to an issue
• Change requires a CSR request to be approved

Issues

• JDK-8202449: overflow handling in Random.doubles
• JDK-8287026: Changes related to overflow handling in Random.doubles (CSR)

Reviewers

• Joe Darcy (@jddarcy - Reviewer)

Reviewing

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[bridgekeeper]

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[openjdk]

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[mlbridge]

Webrevs

• 02: Full - Incremental (954d1ea2)
• 01: Full - Incremental (62322ac1)
• 00: Full (936a5bc1)

[rgiulietti]

Random.doubles(double, double) and similar methods depend on RandomGenerator.nextDouble(double, double).

Currently, this method is specified to throw when the range [origin, bound) given by the arguments is so large that its size (bound - origin) overflows. Since the proposed implementation doesn't suffer from this limitation, the specification needs to be modified, thus the need for a CSR.

[rgiulietti]

Hi,

the major code changes are in RandomSupport in methods

checkRange(float,float)
checkRange(double,double)

where the checks are more tolerant, and in

boundedNextDouble(RandomGenerator,double,double)
boundedNextFloat(RandomGenerator,float,float)

that extend the accepted range. In case the range size overflows, the methods half the range, generate a value inside the reduced range and finally double the outcome.

[jddarcy]

This could be done in double arithmetic, but I think it is better to keep it in float arithmetic for similarity with the code in the double version of the method.

[openjdk]

@rgiulietti This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8202449: overflow handling in Random.doubles

Reviewed-by: darcy

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 298 new commits pushed to the master branch:

• 230726e: 8287735: Provide separate event category for dll operations
• ecf0078: 8287442: Reduce list to array conversions in java.lang.invoke.MethodHandles
• 5c39a36: 8287522: StringConcatFactory: Add in prependers and mixers in batches
• 47d3c2a: 8287980: Build is broken due to SuperWordMaxVectorSize when C2 is disabled after JDK-8287697
• bf0e625: 8286451: C2: assert(nb == 1) failed: only when the head is not shared
• 0960ecc: 8287700: C2 Crash running eclipse benchmark from Dacapo
• 590337e: 8286625: C2 fails with assert(!n->is_Store() && !n->is_LoadStore()) failed: no node with a side effect
• 4662e06: 8277307: Pre shared key sent under both session_ticket and pre_shared_key extensions
• 7df48f9: 8287353: Use snippet tag instead of pre tag in Javadoc of InterruptedException
• 32dd1ee: 8287967: Update golden test files after JDK-8287886
• ... and 288 more: https://git.openjdk.java.net/jdk/compare/47500b2429c8e09f322ec3ff95ff09293db26a9a...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

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➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

[rgiulietti]

/integrate

[openjdk]

@rgiulietti
Your change (at version 954d1ea) is now ready to be sponsored by a Committer.

[jddarcy]

/sponsor

[openjdk]

Going to push as commit c8cff1b.
Since your change was applied there have been 310 commits pushed to the master branch:

• c15e10f: 8233760: Result of BigDecimal.toString throws overflow exception on new BigDecimal(str)
• b92ce26: 8281001: Class::forName(String) defaults to system class loader if the caller is null
• c68419f: 8286990: Add compiler name to warning messages in Compiler Directive
• 6fb84e2: 8287541: Files.writeString fails to throw IOException for charset "windows-1252"
• a9b9831: 8286663: Resolve IDE warnings in WTrayIconPeer and SystemTray
• b021d37: 8283383: [macos] a11y : Screen magnifier shows extra characters (0) at the end JButton accessibility name
• 78d3712: 8287432: C2: assert(tn->in(0) != __null) failed: must have live top node
• f7791ad: 8287895: Some langtools tests fail on msys2
• 5ad6286: 8287970: riscv: jdk/incubator/vector/*VectorTests failing
• a9d46f3: 8287894: Use fixed timestamp as an alternative of DATE macro in jdk.jdi to make Windows build reproducible
• ... and 300 more: https://git.openjdk.java.net/jdk/compare/47500b2429c8e09f322ec3ff95ff09293db26a9a...master

Your commit was automatically rebased without conflicts.

[openjdk]

@jddarcy @rgiulietti Pushed as commit c8cff1b.

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