Module pool 

Connection pool — LIFO ordering, Condvar-based waiting.

The pool maintains a stack of idle connections. acquire() pops the top (most recently used = warmest caches). On drop, the guard pushes the connection back. If the pool is exhausted, callers wait on a Condvar up to acquire_timeout (default: 5 seconds). Set acquire_timeout to None for fail-fast behavior (immediate error when exhausted).

Structs

Pool

A connection pool with LIFO ordering and fail-fast semantics.

PoolBuilder

Builder for configuring a connection pool.

PoolGuard

A borrowed connection from the pool. Returns to the pool on drop.

PoolStatus

Pool status metrics.

Transaction

A database transaction. Sends ROLLBACK on drop if not committed.