Register global variables to the GC #91
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yosiat
approved these changes
Feb 15, 2021
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Context
Ruby 2.7 introduced GC compaction. This means that objects can me moved from on GC slot to another. Since then C extensions must declare all the
VALUEthey keep in global variables withrb_global_variable. This allow the GC to update the references held by C extensions.Ruby 3.0 added
GC.verify_compaction_referenceswhich makes it easier to test that all references are properly declared. All objects are moved to new heap pages, so after than any attempt to use undeclared global variable is extremly likely to segfault.This PR
I simply declare all the global variables and add Ruby 3.0 to the test matrix.