Method CompareAndSwapUsed

internal/pool/conn.go:327–346

Used - State machine based implementation CompareAndSwapUsed atomically compares and swaps the used flag (lock-free). This method is kept for backwards compatibility. This is the preferred method for acquiring a connection from the pool, as it ensures that only one goroutine marks the connection as

(old, new bool)

// Returns true if the swap was successful (old value matched), false otherwise.
// Deprecated: Use GetStateMachine().TryTransition() directly for better state management.
func (cn *Conn) CompareAndSwapUsed(old, new bool) bool {
	if old == new {
		// No change needed
		currentState := cn.stateMachine.GetState()
		currentUsed := (currentState == StateInUse)
		return currentUsed == old
	}

	if !old && new {
		// Acquiring: IDLE → IN_USE
		// Use predefined slice to avoid allocation
		_, err := cn.stateMachine.TryTransition(validFromCreatedOrIdle, StateInUse)
		return err == nil
	} else {
		// Releasing: IN_USE → IDLE
		// Use predefined slice to avoid allocation
		_, err := cn.stateMachine.TryTransition(validFromInUse, StateIdle)
		return err == nil
	}
}

// IsUsed returns true if the connection is currently in use (lock-free).
//