[jdk17u-dev] RFR: 8271506: Add ResourceHashtable support for deleting selected entries

[Thomas Stuefe]

On Mon, 31 Jan 2022 08:38:32 GMT, Goetz Lindenmaier <goetz at openjdk.org> wrote:

> I backport this as prerequisite to JDK-8274944 which calls the new method unlink().
> 
> I had to adapt the code to work in jdk17 because ""JDK-8269004: Implement ResizableResourceHashtable" is missing in 17.

Changes requested by stuefe (Reviewer).

src/hotspot/share/utilities/resourceHash.hpp line 203:

> 201:   // the entry is deleted.
> 202:   template<class ITER>
> 203:   void unlink(ITER* iter) const {

Seems very weird to have this as a const method. It clearly modifies the table. Mainline version is not const, why here?

src/hotspot/share/utilities/resourceHash.hpp line 205:

> 203:   void unlink(ITER* iter) const {
> 204:     Node** bucket =  const_cast<Node**>(_table);
> 205:     while (bucket < &_table[SIZE]) {

This is an odd way to iterate over a bucket array, I like the new version more. But I see you did it this way to stay consistent with the other methods.

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PR: https://git.openjdk.java.net/jdk17u-dev/pull/132