Made use of edm::RefCore thread-safe #9114
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…cache The cachePtr_ is used to hold either an EDProductGetter or the results of getting data from the getter. Previously the state was encoded in one of the bits in ProcessIndex. However, that structure makes it difficult to change RefCore to be thread safe. Consolidating the address and the state into one memory address makes it possible to use an std::atomic. This design makes the assumption that the RefCore must be aligned on at least an even byte boundary. This is definitely true for all the systems we use since the 64 bit pointer requires that the class be aligned on a 64 bit boundary.
Made how edm::RefCore switches its cached value from an EDProductGetter to the value obtained from the getter to be thread safe via an atomic update. Updated all DataFormats/Common classes which use edm::RefCore to also be thread safe on cache changes.
There was a bug in ROOT 6 which was requiring a dictionary be generated for a class which was only used as a transient data member. The bug was fixed so the workaround can be removed.��
Made the necessary code changes to be able to compile using ROOT 5.
The RefCore code was changed to be thread-safe. This meant that calling productPtr() could change its answer. This change properly handles that possibility.
Add a unit test for edm::Ref which uses multiple threads to dereference the same edm::Ref.
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A new Pull Request was created by @Dr15Jones (Chris Jones) for CMSSW_7_5_X. Made use of edm::RefCore thread-safe It involves the following packages: DataFormats/Common @nclopezo, @cvuosalo, @cmsbuild, @Dr15Jones, @slava77 can you please review it and eventually sign? Thanks. |
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please test |
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+1 |
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The tests are being triggered in jenkins. |
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This pull request is fully signed and it will be integrated in one of the next CMSSW_7_5_X IBs unless changes (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @davidlange6, @nclopezo, @smuzaffar |
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+1 |
Made use of edm::RefCore thread-safe
The internal caching done by an edm::RefCore is now thread safe. All uses of edm::RefCore were also changed to be thread-safe.