diff options
Diffstat (limited to 'library/std/src/sys/common/thread_local/mod.rs')
| -rw-r--r-- | library/std/src/sys/common/thread_local/mod.rs | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/library/std/src/sys/common/thread_local/mod.rs b/library/std/src/sys/common/thread_local/mod.rs index 951d509ec95..77f64588310 100644 --- a/library/std/src/sys/common/thread_local/mod.rs +++ b/library/std/src/sys/common/thread_local/mod.rs @@ -1,5 +1,10 @@ #![unstable(feature = "thread_local_internals", reason = "should not be necessary", issue = "none")] +// There are three thread-local implementations: "static", "fast", "OS". +// The "OS" thread local key type is accessed via platform-specific API calls and is slow, while the +// "fast" key type is accessed via code generated via LLVM, where TLS keys are set up by the linker. +// "static" is for single-threaded platforms where a global static is sufficient. + cfg_if::cfg_if! { if #[cfg(all(target_family = "wasm", not(target_feature = "atomics")))] { #[doc(hidden)] |