event_buffer_watermark_set Set the watermarks for read and write events &reftitle.description; voidevent_buffer_watermark_set resourcebevent intevents intlowmark inthighmark Sets the watermarks for read and write events. Libevent does not invoke read callback unless there is at least lowmark bytes in the input buffer; if the read buffer is beyond the highmark, reading is stopped. On output, the write callback is invoked whenever the buffered data falls below the lowmark. &reftitle.parameters; bevent Valid buffered event resource. events Any combination of EV_READ and EV_WRITE. lowmark Low watermark. highmark High watermark.