[mini] Use atomics, instead of loader lock, for JIT wrappers #100925
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lambdageek
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Apr 11, 2024
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| gconstpointer wrapper__; | ||
| gconstpointer trampoline__; |
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Ignore the renamed fields. I will remove this. Just want to see the build fail if there's any #ifdef uses of these that I missed
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This was referenced Apr 11, 2024
kg
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Apr 11, 2024
| @@ -7243,6 +7243,8 @@ mono_create_icall_signatures (void) | |||
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| } | |||
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| /* LOCKING: does not take locks. does not use an atomic write to info->wrapper | |||
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I'll add to the comment. Because it's called single-threaded early during startup.
Related to dotnet#93686 While this doesn't eliminate all deadlocks related to the global loader lock and managed locks, it removes one unneeded use of the loader lock. The wrapper (and trampoline) of a JIT icall are only ever set from NULL to non-NULL. We can use atomics to deal with races instad of double checked locking. This was not the case historically, because the JIT info was dynamically allocated - so we used the loader lock to protect the integrity of the hash table
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Related to #93686
While this doesn't eliminate all deadlocks related to the global loader lock and managed locks, it removes one unneeded use of the loader lock.
The wrapper (and trampoline) of a JIT icall are only ever set from NULL to non-NULL. We can use atomics to deal with races instad of double checked locking. This was not the case historically, because the JIT info was dynamically allocated - so we used the loader lock to protect the integrity of the hash table