SetFinalizer.go

func (h *boringHMAC) Reset() {
 if h.needCleanup {
  C._goboringcrypto_HMAC_CTX_cleanup(&h.ctx)
 } else {
  h.needCleanup = true
  // Note: Because of the finalizer, any time h.ctx is passed to cgo,
  // that call must be followed by a call to runtime.KeepAlive(h),
  // to make sure h is not collected (and finalized) before the cgo
  // call returns.
  runtime.SetFinalizer(h, (*boringHMAC).finalize)
 }
}
func (h *boringHMAC) finalize() {
 C._goboringcrypto_HMAC_CTX_cleanup(&h.ctx)
}