From 075c87d52a4d90c0f00f8ba7ba849677771a9be3 Mon Sep 17 00:00:00 2001 From: salmonik Date: Fri, 31 Jul 2026 18:08:45 +0200 Subject: vt: defer scrolls and batch framebuffer pushes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Streaming output scrolled one framebuffer push per line (each a ~3-8 MB write-only copy). The vt now scrolls the logical grid instantly in RAM and defers the display shift: N pending scrolls are pushed together as one shift_up_n — one push regardless of batch size. - vt: PENDING_SCROLLS counter; scroll_up shifts CELLS only; flush renders nothing while pending (the diff would otherwise re-rasterise the whole screen per line); sync_scroll() does one gop::shift_up_n + RENDERED mirror + normal diff flush (which re-blits just the newly exposed rows and the cursor). - Sync triggers: batch of 16 rows, ~40 ms of stream pause (100 Hz TICKS), any CSI sequence (full-screen apps like the editor render immediately), clear_all/set_cursor_visible, interactive input (tty read_line/read_byte), and the shell before each prompt. - gop: shift_up → shift_up_n(n) (one shadow memcpy + one push). Verified in QEMU: mmap/hexdump streaming renders in coherent batches with the prompt syncing at the end; clear wipes clean; the editor scrolls and redraws immediately (45-line file, gutter + status bar intact, cursor correct); save/exit/cat round-trip unchanged. Release and dev builds pass. --- shell/src/lib.rs | 3 +++ 1 file changed, 3 insertions(+) (limited to 'shell/src') diff --git a/shell/src/lib.rs b/shell/src/lib.rs index 4601b98..9644f01 100644 --- a/shell/src/lib.rs +++ b/shell/src/lib.rs @@ -20,6 +20,9 @@ pub fn run() -> ! { ); loop { + // Push any deferred scrolls so the prompt renders on a current + // framebuffer (e.g. after a streaming command's batch of output). + rsnix::vt::sync_scroll(); // Print prompt gop_print!("> "); serial_print!("> "); -- cgit v1.2.3