Function killRDBChild

app/redis-6.2.6/src/rdb.c:2850–2858

Kill the RDB saving child using SIGUSR1 (so that the parent will know * the child did not exit for an error, but because we wanted), and performs * the cleanup needed. */

 * the child did not exit for an error, but because we wanted), and performs
 * the cleanup needed. */
void killRDBChild(void) {
    kill(server.child_pid, SIGUSR1);
    /* Because we are not using here waitpid (like we have in killAppendOnlyChild
     * and TerminateModuleForkChild), all the cleanup operations is done by
     * checkChildrenDone, that later will find that the process killed.
     * This includes:
     * - resetChildState
     * - rdbRemoveTempFile */
}

/* Spawn an RDB child that writes the RDB to the sockets of the slaves
 * that are currently in SLAVE_STATE_WAIT_BGSAVE_START state. */