dbg_cstate
dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
dbg_cstate(COMMIT_REQUIRED));
dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
dbg_cstate(COMMIT_RUNNING_REQUIRED));
dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
dbg_cstate(COMMIT_BACKGROUND));
const char *dbg_cstate(int cmt_state);