an opinionated terminal multiplexer in C with programmable pane chrome https://git.sl0p.foo/slosh.git/atom/include/proto.h?h=master 2026-09-02T12:51:02Z 2026-09-02T12:51:02Z Ingmar Steen iksteen@gmail.com 2026-08-31T12:43:32Z urn:sha1:29061a4aca5e3d645c0e23b885342036ac48f97b Last input wins, canvas size is adjusted to active connection. 2026-08-26T14:48:17Z Peter Geissler peter@haxx.in 2026-08-26T14:44:33Z urn:sha1:9d5f9d2a1c3b8d0948a8efa8443a36847aa2107b Everything the server said went out through msg_send(), which loops on sendmsg() until the kernel has taken all of it. That is a blocking write to whoever is attached. A display whose reader has paused -- C-s at the terminal, a stopped ssh, a client being swapped -- fills its socket buffer, and then the *server* sits inside that loop: every other pane, the config watcher, the control socket and every other connection stop with it. A session that is supposed to outlive its client hangs on one. macOS is where this showed up, because its socket buffers are a fraction of Linux's 64K and it wedges within a screenful rather than after a few hundred. `make test-live` could not get past the forty-connection probe in test_session.py: the server was blocked writing to a pty nobody was draining, so `slosh cmd panes` timed out and took the suite with it. So connections are non-blocking and output is queued, flushed when poll() says the socket will take more. The queue is capped: past 4MB we are not buffering a slow reader any more, we are storing a screen nobody is looking at, and the connection is dropped -- a display that comes back reattaches and gets a full repaint, which is what happens after any detach anyway. Measured, with a pane running `yes` and a display that never reads: before, the first control command hung forever; after, 40 of 40 are answered, the session stays listed, and the server's RSS is flat. 2026-08-19T11:46:57Z user user@clank 2026-08-19T11:46:57Z urn:sha1:42b3c10995eb67778d9dd3aa2fd80624896acd5f The out-of-the-box look, rethought as one piece: - the compiled-in palette calms down: muted blue #7aa2f7 on the same neutral darks, with the colours that mean something kept semantic -- amber bell, red-orange dead. sl0p stays one include away as the house style, and contrib/themes/default.kdl is the starting point written down (theme-tour shows it). - derived state defaults now actually follow the theme: the scrolled wash is rebuilt from scroll_bg after the theme block (it used to bake the compiled accent), and declaring a state -- in any file of an include chain -- still wins. The dump writes derived states as comments so C-a e cannot pin what is meant to keep following. - a bell you can see: the frame blinks three times in theme's bell colour then breathes until answered, and a soft diagonal shimmer -- the bell colour halved towards default_fg, width breathing on a sine -- crosses the body for the same 900ms. bell_indicator false silences all of it; states { bell { } } replaces it like any state. since carries the clock dependency, so an idle session pays nothing. - scrollback says where it continues: while scrolled, the viewport's top and bottom rows melt towards an edge with content past it and turn solid at the buffer's end. New expression variables above/below (lines hidden past each edge, own dependency bit, cached per scroll position), carried in shade_ctx_t -- SLOSH_SHADER_ABI 3 -> 4. - expressions survive the dump: a program keeps its source and cb_chain writes it back, so amount="(y % 2) * 40" no longer dumps as a number. - headers move to include/, -Iinclude everywhere; the plugin Makefile's SLOSH var becomes SLOSH_DIR because slosh exports SLOSH=1 into every pane it runs, and building from inside a session read that as a path. - comment drift culled where features outran the prose, and the derivation boilerplate folded into derived_pass()/ctx_scroll().