Function with_thread_local 

pub fn with_thread_local<F, R>(f: F) -> R
where
    F: FnOnce(&mut PerfContext) -> R,

Runs f with a reusable thread-local PerfContext.

The context is reset before each call. This avoids allocating and destroying the C wrapper for every measurement.

Panics

Panics if called reentrantly or while a manually created PerfContext is alive on the same thread. RocksDB returns the same underlying context to all wrappers on a thread, so resetting it would discard the manual measurement.