fix: Deadlock during cost calculation

[dadrus]

Unfortunately, the implementation, I've done in #152 can cause a deadlock during cost calculation:

The update method of the Item locks an RW lock and calls the item.calculateCost(item), which if configured, may make use of the available getter functions of the item object. All these functions make however use of the R lock - thus we have a deadlock.

This PR updates the implementation of the Item and performs the calculation of the item cost on a snapshot rather the actual update.

The test has been updated as well to use a public method. Without the update to the Item implementation the corresponding test will run into a deadlock

[coveralls]

Pull Request Test Coverage Report for Build 15467277810

Details

• 15 of 15 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.001%) to 99.733%

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Totals
Change from base Build 15260220298:	0.001%
Covered Lines:	747
Relevant Lines:	749

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💛 - Coveralls

[dadrus]

@swithek: Would you please review?

[swithek]

@dadrus thanks for the PR. I'll try to review it by the end of this week.

[swithek]

Looks good, one small change is needed. Also, you might need to merge/rebase your branch on the latest v3 branch, because there have been some changes there that might affect some of your code (at least the tests).

[davseby]

Seems good, waiting for @swithek.

[swithek]

Thanks for the change @dadrus Quality work as always 👍

[dadrus]

Thank you @swithek and @davseby !

Just a side question: Do you have any specific time frame when you plan to release the next version?