RFR: 8282475: SafeFetch should not rely on existence of Thread::current [v6]

Fri Mar 11 09:53:40 UTC 2022

On Fri, 11 Mar 2022 09:33:40 GMT, Andrew Haley <aph at openjdk.org> wrote:

> But we don't need to speculate. If thread-local variables are cheap on MacOS, and there is no reason why they should be expensive, then we can stop worrying and just use a thread-local variable for WX state. We can measure how long it takes, and we only have to care about one platform, MacOS/AArch64.

According to https://forums.swift.org/t/concurrencys-use-of-thread-local-variables/48654: "these accesses are just a move from a system register plus a load/store at a constant offset."

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PR: https://git.openjdk.java.net/jdk/pull/7727