//! libpardes — the static library the native macOS app links against. //! //! The split, which is the whole design: Zig keeps the core, the ptys, every //! effect and the worker threads; Swift owns NSApplication, the window, input //! translation and drawing. src/macos/pardes.h is the contract between them and //! docs/macos.md argues for the shape. //! //! This is deliberately src/web.zig's boundary with the wasm removed. Both //! hosts are the same animal — someone else owns the clock, feeds events in //! through flat functions and reads one packed cell buffer out — and the //! browser already proved the shape works. The one real divergence is that the //! browser has no processes, so it forwards every effect to JavaScript, whereas //! forkpty is right here and this file performs them. //! //! Everything below is main-thread only. The single exception is the `wakeup` //! callback, which a pty reader task calls; the host's job is to hop to the //! main thread and call pardes_tick. //! //! The Zig half is ordinary POSIX and builds/tests on Linux — see the dev-loop //! section of docs/macos.md. Only the Swift app needs a Mac. const std = @import("std"); const builtin = @import("builtin"); const posix = std.posix; const libc = std.c; const pardes = @import("pardes.zig"); const look = @import("look.zig"); const temp_file = @import("temp_file.zig"); const shell_bin = @import("shell_bin.zig"); const message = @import("message.zig"); const user_config = @import("user_config.zig"); extern "c" fn forkpty(amaster: *c_int, name: ?[*:0]u8, termp: ?*const anyopaque, winp: ?*const posix.winsize) c_int; extern "c" fn execv(path: [*:0]const u8, argv: [*:null]const ?[*:0]const u8) c_int; extern "c" fn chdir(path: [*:0]const u8) c_int; extern "c" fn _exit(status: c_int) noreturn; extern "c" fn setenv(name: [*:0]const u8, value: [*:0]const u8, overwrite: c_int) c_int; // TIOCSWINSZ: absent from std.c.T on darwin — _IOW('t', 103, winsize). Same // constant the tty and gui shells spell for the same reason. const TIOCSWINSZ: c_int = @bitCast(@as(u32, if (@hasDecl(posix.T, "IOCSWINSZ")) posix.T.IOCSWINSZ else 0x80087467)); // A library linked into an AppKit process has no terminal to garble, but it // does share the app's stderr with Console.app. Same filter as src/main.zig: // ghostty-vt narrates every unimplemented escape a child writes, and nobody // wants that in a crash report. PARDES_LOG=1 gets the real logger back. pub const std_options: std.Options = .{ .logFn = logFn }; fn logFn( comptime level: std.log.Level, comptime scope: @EnumLiteral(), comptime format: []const u8, args: anytype, ) void { if (scope != .macos and scope != .dump and std.c.getenv("PARDES_LOG") == null) return; std.log.defaultLog(level, scope, format, args); } const log = std.log.scoped(.macos); // ---------------------------------------------------------------- boundary /// Sync with: pardes_cell_s. The identical encoding is spelled a second time /// for the browser as WebCell in src/web.zig. /// /// ponytail: two copies of a fifteen-line pure encoder, not a shared module. /// The web ABI is snapshot-tested through a headless Chrome that does not run /// here, so extracting it would refactor a backend I cannot exercise to save /// thirty lines. Merge them the day a third host wants the same bytes. pub const Cell = extern struct { text: [8]u8, fg: u32, bg: u32, attrs: u16, len: u8, flags: u8, }; /// Sync with: pardes_runtime_s. Two callbacks, because everything else the /// core asks for it already does itself — it owns the ptys, and look.openLink /// hands URLs to /usr/bin/open. Both are optional at the ABI level: a host that /// passes null simply does without, rather than trapping inside the library. pub const Runtime = extern struct { userdata: ?*anyopaque = null, wakeup: ?*const fn (?*anyopaque) callconv(.c) void = null, set_clipboard: ?*const fn (?*anyopaque, [*]const u8, usize) callconv(.c) void = null, }; const color_default: u32 = 0x01000000; const color_indexed: u32 = 0x02000000; const cell_flag_default: u8 = 1; // ---------------------------------------------------------------- state /// One pty, and the task draining it. `gen` is the per-slot spawn generation: /// the core reuses pane ids and has no close effect, so a respawned slot must /// ignore the previous shell's late bytes rather than feed them to the new one. const Pty = struct { file: std.Io.File, pid: posix.pid_t, gen: u32, reader: std.Io.Future(anyerror!void), }; /// What a reader task hands the main thread. `gen` travels with the message so /// a shell that was replaced while its read was in flight cannot have its /// stragglers parsed into the pty that took its slot. const Msg = union(enum) { output: struct { pane: u8, gen: u32, bytes: []u8 }, eof: struct { pane: u8, gen: u32 }, fn free(m: Msg, gpa: std.mem.Allocator) void { switch (m) { .output => |o| gpa.free(o.bytes), .eof => {}, } } }; /// 0.16 has no std.Thread.Mutex, and the gui shell's queue already settled /// this: spin on the lock-free std.atomic.Mutex, and keep the critical section /// to a pointer append. The reader allocates its chunk BEFORE taking the lock /// for exactly that reason — a screenful of output must not make a keystroke /// spin through a 64 KiB copy. /// /// ponytail: unbounded. `yes` in a pane can enqueue faster than the host /// drains, and nothing throttles the reader — the tty shell gets that for free /// from vaxis's 512-slot queue, whose post blocks when full, and the SDL shell /// has the same hole this does. Bound it on queued bytes the day someone /// watches RSS climb; the trap to avoid is a wait that teardown cannot cancel. const Inbox = struct { mutex: std.atomic.Mutex = .unlocked, items: std.ArrayList(Msg) = .empty, /// Set when a wakeup has been delivered and not yet answered by a tick. /// Without it a busy shell posts one wakeup per 64 KiB chunk, and each one /// is a block on the host's main queue — a screenful of output becomes /// thousands of scheduled pumps that all find the same drained inbox. wake_pending: std.atomic.Value(bool) = .init(false), fn lock(q: *Inbox) void { // Bounded, unlike the gui shell's otherwise identical spin. AppKit's // main thread runs at a higher QoS than these reader tasks and a raw // CAS spin donates no priority, so a reader preempted inside the append // (which can realloc) would have the highest-priority thread in the // process spinning on it. Yielding hands the core back. var spins: u8 = 0; while (!q.mutex.tryLock()) { spins +%= 1; if (spins == 0) std.Thread.yield() catch {} else std.atomic.spinLoopHint(); } } fn push(q: *Inbox, gpa: std.mem.Allocator, m: Msg) void { q.lock(); defer q.mutex.unlock(); q.items.append(gpa, m) catch m.free(gpa); } }; const State = struct { gpa: std.mem.Allocator, threaded: *std.Io.Threaded, io: std.Io, core: *pardes.Pardes, arena: std.heap.ArenaAllocator, runtime: Runtime, cells: std.ArrayList(Cell) = .empty, /// The grid `cells` actually holds. Not read back off the core: a render /// can move screen_w/screen_h and then fail, and a host that sized its /// loops from those would walk off the buffer. frame_cols: u16 = 0, frame_rows: u16 = 0, ptys: [pardes.MAX_PANES]?Pty = @splat(null), inbox: Inbox = .{}, /// Per-slot spawn generation, owned by the main thread. A reader carries a /// copy in every message it posts; anything that no longer matches belongs /// to a shell this slot has already replaced. gens: [pardes.MAX_PANES]u32 = @splat(0), /// Sub-row wheel distance the core has not been told about yet. The core /// moves a whole row at a time, so fractional trackpad travel accumulates /// here and is spent as wheel presses — see pardes_scroll. scroll_lag: f32 = 0, /// Swapped with the inbox under the lock, so draining it costs one pointer /// exchange and neither side reallocates once capacities have settled. tick_msgs: std.ArrayList(Msg) = .empty, /// Owns the bytes of the user config, which Options only borrows. config_arena: std.heap.ArenaAllocator, }; var state: ?State = null; // ---------------------------------------------------------------- lifecycle export fn pardes_init(runtime: ?*const Runtime, cols_arg: u16, rows_arg: u16) c_int { if (state != null) return 1; // already up; deinit first initCore(runtime, cols_arg, rows_arg) catch |err| { log.err("init failed: {t}", .{err}); return 2; }; return 0; } /// The body is split out purely so the cleanup below is real: `errdefer` fires /// on an error return and nothing else, so writing this inside an export that /// returns c_int would leave every one of these as dead code — and a half-built /// init leaks an arena, leaves zstbi pointing at a dead allocator, and (because /// Io.Threaded installs process-wide SIGIO/SIGPIPE handlers that only its /// deinit restores) hands those handlers permanently to the host app. fn initCore(runtime: ?*const Runtime, cols_arg: u16, rows_arg: u16) !void { const gpa = std.heap.smp_allocator; const threaded = try gpa.create(std.Io.Threaded); errdefer gpa.destroy(threaded); threaded.* = .init(gpa, .{}); errdefer threaded.deinit(); const io = threaded.io(); var config_arena: std.heap.ArenaAllocator = .init(gpa); errdefer config_arena.deinit(); var opts: pardes.Options = .{ .tty_only = true }; // Native shells opt into the user config, and every builtin in it must have // run before the host can render a frame — so it is read here, before // Pardes.init, exactly as src/main.zig does it. The env map is rebuilt from // libc's environ because a library has no std.process.Init to inherit one. if (captureEnv(config_arena.allocator())) |*env| opts.startup_config = user_config.load(io, config_arena.allocator(), env); // stb_image's allocator shim, for image panes. pardes.image.start(io, gpa); errdefer pardes.image.stop(); const core = try pardes.Pardes.init(gpa, opts); errdefer core.deinit(); // Shells emit OSC 133 prompt marks through these, which is what makes // prompt hiding and click-to-move work. writeFile(shell_bin.bash_rc_path, shell_bin.bash_rc); writeFile(shell_bin.fish_rc_path, shell_bin.fish_rc); // Apple's bash 3.2 prints the zsh-deprecation banner into every pane unless // this is in the environment BEFORE bash starts — the rc file is too late. if (comptime builtin.os.tag.isDarwin()) _ = setenv("BASH_SILENCE_DEPRECATION_WARNING", "1", 1); state = .{ .gpa = gpa, .threaded = threaded, .io = io, .core = core, .arena = .init(gpa), .config_arena = config_arena, .runtime = if (runtime) |r| r.* else .{}, }; const st = &state.?; // The real grid, delivered as an EVENT and not as Options.cols/rows: the // core defers each shell's greeting until it has seen a resize, and the // first forkpty below takes its winsize straight off the core. const cols = @max(1, cols_arg); const rows = @max(1, rows_arg); core.update(.{ .resize = .{ .cols = cols, .rows = rows } }); // The initial spawns happen before any reader task exists, mirroring the // tty shell. Note the difference in what that buys: tty.zig runs from // main() and really is single-threaded there, whereas this is called from // applicationDidFinishLaunching, by which point AppKit and libdispatch // have long since spawned threads. What keeps the fork safe is the child // itself — chdir and execv, raw syscalls with nothing allocated between // fork and exec — not the thread count. Ordering it this way anyway keeps // the two backends readable side by side. _ = drainEffects(st, false); for (&st.ptys, 0..) |*slot, id| if (slot.*) |*pt| startReader(st, pt, @intCast(id)); } export fn pardes_deinit() void { const st = &(state orelse return); // Every reader is joined here, before anything it touches is freed. The // runtime joins its tasks on exit, so a reader left parked in read(2) would // hang the process instead of the app quitting. for (0..pardes.MAX_PANES) |pane| reap(st, @intCast(pane)); // Only now is the inbox quiet. Anything still queued owns gpa bytes and // would show up as a leak rather than as the shutdown it actually is. for (st.inbox.items.items) |msg| msg.free(st.gpa); st.inbox.items.deinit(st.gpa); for (st.tick_msgs.items) |msg| msg.free(st.gpa); st.tick_msgs.deinit(st.gpa); st.cells.deinit(st.gpa); st.core.deinit(); st.arena.deinit(); st.config_arena.deinit(); pardes.image.stop(); st.threaded.deinit(); st.gpa.destroy(st.threaded); state = null; } export fn pardes_should_quit() bool { const st = &(state orelse return true); return st.core.quit; } export fn pardes_animating() bool { const st = &(state orelse return false); return st.core.themeAnimationActive(); } /// Drain what the reader tasks collected into the core, then perform whatever /// the core queued in response. Returns whether anything moved, so an idle /// wakeup does not cost the host a repaint. export fn pardes_tick() bool { const st = &(state orelse return false); // Cleared BEFORE the swap: a reader that pushes while this drain is running // must be able to schedule the tick that will collect it. st.inbox.wake_pending.store(false, .release); st.inbox.lock(); std.mem.swap(std.ArrayList(Msg), &st.inbox.items, &st.tick_msgs); st.inbox.mutex.unlock(); var changed = st.tick_msgs.items.len > 0; for (st.tick_msgs.items) |msg| { defer msg.free(st.gpa); switch (msg) { .output => |o| { if (st.gens[o.pane] != o.gen) continue; st.core.update(.{ .output = .{ .pane = o.pane, .bytes = o.bytes } }); }, .eof => |e| { if (st.gens[e.pane] != e.gen) continue; // The shell is gone: join its reader (a completed future that // is never awaited leaks its allocation), close the master and // free the slot. Without this the slot is only ever reaped by a // later spawn INTO it — and the core emits spawn from newPane // alone, so a pane that becomes a file pane instead would hold // the dead fd for the life of the app. reap(st, e.pane); st.core.update(.{ .eof = .{ .pane = e.pane } }); }, } } st.tick_msgs.clearRetainingCapacity(); if (drainEffects(st, true)) changed = true; // A live theme transition repaints on its own clock; say so, or the host // stops ticking and the fade freezes half-applied. if (st.core.themeAnimationActive()) changed = true; return changed; } // ---------------------------------------------------------------- events in export fn pardes_key(cp_arg: u32, text_ptr: ?[*]const u8, len: usize, mods: u32) void { const st = &(state orelse return); if (cp_arg > std.math.maxInt(u21)) return; const text: []const u8 = if (text_ptr) |p| p[0..len] else ""; st.core.update(.{ .key = .{ .cp = @intCast(cp_arg), .text = text, .ctrl = mods & 1 != 0, .alt = mods & 2 != 0, .shift = mods & 4 != 0, } }); } export fn pardes_paste(text_ptr: ?[*]const u8, len: usize) void { const st = &(state orelse return); const text: []const u8 = if (text_ptr) |p| p[0..len] else ""; st.core.update(.{ .paste = text }); } /// Button and kind arrive as their boundary ordinals. An out-of-range value is /// dropped rather than reaching an unchecked enum cast — same rule the browser /// ABI keeps, for the same reason: the host is not part of this build. export fn pardes_mouse(button_arg: c_int, kind_arg: c_int, col: u16, row: u16, mods: u32) void { const st = &(state orelse return); const button: pardes.Mouse.Button = switch (button_arg) { 0 => .left, 1 => .middle, 2 => .right, 3 => .wheel_up, 4 => .wheel_down, 5 => .wheel_left, 6 => .wheel_right, 7 => .none, else => return, }; const kind: pardes.Mouse.Kind = switch (kind_arg) { 0 => .press, 1 => .release, 2 => .motion, 3 => .drag, else => return, }; st.core.update(.{ .mouse = .{ .button = button, .kind = kind, .col = col, .row = row, .ctrl = mods & 1 != 0, } }); } export fn pardes_scroll(delta_rows: f32, col: u16, row: u16) void { const st = &(state orelse return); const ticks = takeScrollTicks(&st.scroll_lag, delta_rows); var left = ticks; while (left != 0) { const down = left > 0; left += if (down) -1 else 1; st.core.update(.{ .mouse = .{ .button = if (down) .wheel_down else .wheel_up, .kind = .press, .col = col, .row = row, } }); } } export fn pardes_resize(cols_arg: u16, rows_arg: u16, cell_w: u16, cell_h: u16) void { const st = &(state orelse return); const cols = @max(1, cols_arg); const rows = @max(1, rows_arg); st.core.update(.{ .resize = .{ .cols = cols, .rows = rows, .cell_pixels = if (@hasField(pardes.CellPixels, "w")) .{ .w = @max(1, cell_w), .h = @max(1, cell_h) } else .{}, } }); } // ---------------------------------------------------------------- frame out export fn pardes_frame() u32 { const st = &(state orelse return 0); _ = st.arena.reset(.retain_capacity); // The three accessors below must never describe a different frame than the // count this returns, so a failure empties all of them together rather than // leaving last frame's buffer behind a fresh cols/rows. st.cells.clearRetainingCapacity(); st.frame_cols = 0; st.frame_rows = 0; const surface = st.core.render(st.arena.allocator()) catch |err| { log.err("render failed: {t}", .{err}); return 0; }; const count: usize = @as(usize, surface.cols) * surface.rows; st.cells.resize(st.gpa, count) catch return 0; st.frame_cols = surface.cols; st.frame_rows = surface.rows; for (surface.cells, st.cells.items) |cell, *out| { out.* = .{ .text = @splat(0), .fg = encodeColor(cell.style.fg), .bg = encodeColor(cell.style.bg), .attrs = encodeAttrs(cell.style), .len = if (cell.default) 1 else cell.len, .flags = @intFromBool(cell.default), }; if (cell.default) out.text[0] = ' ' else @memcpy(out.text[0..cell.len], cell.grapheme()); } return @intCast(count); } export fn pardes_frame_cells() ?[*]const Cell { const st = &(state orelse return null); return if (st.cells.items.len == 0) null else st.cells.items.ptr; } export fn pardes_frame_cols() u16 { const st = &(state orelse return 0); return st.frame_cols; } export fn pardes_frame_rows() u16 { const st = &(state orelse return 0); return st.frame_rows; } export fn pardes_cursor_x() i32 { const st = &(state orelse return -1); return if (st.core.surface.cursor) |c| c.x else -1; } export fn pardes_cursor_y() i32 { const st = &(state orelse return -1); return if (st.core.surface.cursor) |c| c.y else -1; } export fn pardes_cursor_bar() bool { const st = &(state orelse return false); return if (st.core.surface.cursor) |c| c.bar else false; } // ---------------------------------------------------------------- effects /// Perform the IO the core queued. `threads_ok` is false for the one drain /// inside pardes_init, which runs before any reader task exists. /// /// ponytail: the lsp, pipe and watch effects do no work here. Each wants real /// machinery — a worker plus a snapshot of the pane's file for lsp /// (src/tty/tty.zig:919), a job copy for pipe, and FSEvents for watch, since /// inotify is Linux-only. Lift tty.zig's implementations when the app is past /// first light. Pipe and watch may simply be dropped; lsp may NOT, see below. fn drainEffects(st: *State, threads_ok: bool) bool { const core = st.core; var did = false; while (core.nextEffect()) |effect| { did = true; switch (effect) { .spawn => |sp| { // The core reuses pane ids and has no close effect, so a // deleted pane's shell lives in its slot until a respawn lands // here. Reap it: cancel joins the reader, and the generation // bump makes its late bytes and eof unreadable. reap(st, sp.pane); st.gens[sp.pane] +%= 1; const gen = st.gens[sp.pane]; const cwd = sp.cwd.slice(); var cwd_buf: [256:0]u8 = undefined; var cwd_z: ?[*:0]const u8 = null; // <= because writing the sentinel slot of a [N:0]u8 is legal, // and Effect's cwd buffer is exactly 256: `<` would silently // drop a maximal path and start the shell wherever the app // bundle was launched from instead. if (cwd.len > 0 and cwd.len <= cwd_buf.len) { @memcpy(cwd_buf[0..cwd.len], cwd); cwd_buf[cwd.len] = 0; cwd_z = @ptrCast(&cwd_buf); } const child = forkShell(core.shellBin(), cwd_z, core.screen_h, core.screen_w); st.ptys[sp.pane] = .{ .file = child.file, .pid = child.pid, .gen = gen, .reader = .{ .any_future = null, .result = {} }, }; // Report the pane's starting directory back to the core (tags). var lbuf: [1024]u8 = undefined; if (look.shellCwd(child.pid, &lbuf)) |wd| core.setCwd(sp.pane, wd); if (threads_ok) if (st.ptys[sp.pane]) |*pt| startReader(st, pt, sp.pane); }, .write => |w| { if (st.ptys[w.pane]) |pt| writeFd(pt.file.handle, w.bytes.slice()); }, .resize_pty => |rs| { if (st.ptys[rs.pane]) |pt| { const ws: posix.winsize = .{ .row = rs.rows, .col = rs.cols, .xpixel = 0, .ypixel = 0 }; _ = posix.system.ioctl(pt.file.handle, TIOCSWINSZ, @intFromPtr(&ws)); } }, .open_link => |url| look.openLink(url.slice()), .save_file => |sf| { const pane = core.panes[sf.pane] orelse continue; const f = pane.file orelse continue; var pathbuf: [4096:0]u8 = undefined; if (f.path.len >= pathbuf.len) continue; @memcpy(pathbuf[0..f.path.len], f.path); pathbuf[f.path.len] = 0; const fd = libc.open(pathbuf[0..f.path.len :0], .{ .ACCMODE = .WRONLY, .CREAT = true, .TRUNC = true }, @as(libc.mode_t, 0o644)); if (fd < 0) continue; writeFd(fd, f.content); _ = libc.close(fd); // After the write, not beside it: every `continue` above is a // save that did not happen and must not be reported as one. var mbuf: [256]u8 = undefined; core.setMessage(sf.pane, message.stamp(&mbuf, "saved", f.path)); }, .new_file => |request| { var path_buf: [4096:0]u8 = undefined; const made = temp_file.create(&path_buf) orelse continue; if (core.openNewFile(request.pane, request.serial, made.path)) made.adopt() else made.discard(); }, .write_dump => { const out = core.dump_out orelse continue; var pbuf: [1024:0]u8 = undefined; const path = pardes.dump.outPath(&pbuf) orelse continue; const fd = libc.open(path, .{ .ACCMODE = .WRONLY, .CREAT = true, .TRUNC = true }, @as(libc.mode_t, 0o644)); if (fd < 0) continue; writeFd(fd, out); _ = libc.close(fd); core.setLastDump(path); }, .set_clipboard => { const cb = st.runtime.set_clipboard orelse continue; const y = core.yank orelse continue; cb(st.runtime.userdata, y.ptr, y.len); }, // An empty answer, immediately: the honest reply from a shell with // no worker, and the only safe one. Tab after a `.` DIVERTS to the // backend instead of indenting and indents late, when the answer // comes back empty (lspResponse); drop the effect and lsp_wait // stays armed, the retroactive indent never fires, and every // dot-Tab for the rest of the session does nothing at all. .lsp => |q| core.update(.{ .lsp_resp = .{ .id = q.id, .rows = "" } }), .pipe, .watch => {}, .quit => {}, } } return did; } // ---------------------------------------------------------------- workers fn startReader(st: *State, pt: *Pty, id: u8) void { pt.reader = st.io.concurrent(readPty, .{ st, st.io, pt.file, id, pt.gen }) catch |err| { // No reader means the shell fills its pty buffer, blocks in write(2) // and the pane silently freezes. Nothing recovers it, so at least say // so — this is what PARDES_LOG exists for. log.err("pane {d} has no reader ({t}); it will not show output", .{ id, err }); return; }; } /// Release one pane's shell: join the reader, close the master, reap the child. /// Order matters — cancel is what unblocks a task parked in read(2), and the fd /// must not be closed under a live reader. Called on eof and again on a spawn /// into the same slot, so it has to tolerate an empty slot. fn reap(st: *State, pane: u8) void { var pt = st.ptys[pane] orelse return; st.ptys[pane] = null; pt.reader.cancel(st.io) catch {}; _ = libc.close(pt.file.handle); // A library inside an app that runs for hours cannot leave these: the tty // shell gets away with never reaping because the process exits seconds // later, but here it would be one zombie per shell ever opened. NOHANG // because the child may still be dying and the UI thread must not wait for // it; the next reap or process exit collects whatever is left. _ = libc.waitpid(pt.pid, null, posix.W.NOHANG); } /// Drain one pty into its inbox and wake the host. The same shape as the tty /// shell's reader, with the vaxis event queue replaced by a mutex and one /// callback: do the blocking thing away from the loop, hand the bytes over, /// leave the core a state machine that never waits. fn readPty(st: *State, io: std.Io, pty: std.Io.File, id: u8, gen: u32) anyerror!void { var read_buf: [0x10000]u8 = undefined; var reader = pty.readerStreaming(io, &read_buf); while (true) { var buf: [0x10000]u8 = undefined; var vec = [_][]u8{&buf}; const n = reader.interface.readVec(&vec) catch break; if (n == 0) break; // Duped outside the lock on purpose — see Inbox. const bytes = st.gpa.dupe(u8, buf[0..n]) catch break; st.inbox.push(st.gpa, .{ .output = .{ .pane = id, .gen = gen, .bytes = bytes } }); wake(st); } st.inbox.push(st.gpa, .{ .eof = .{ .pane = id, .gen = gen } }); wake(st); } /// Ask the host for a tick, at most once per tick. `pardes_tick` clears the /// flag before it drains, so a push that lands mid-drain still wakes and no /// message can be left sitting in the inbox with nobody scheduled to read it. fn wake(st: *State) void { const cb = st.runtime.wakeup orelse return; if (st.inbox.wake_pending.swap(true, .acq_rel)) return; cb(st.runtime.userdata); } // ---------------------------------------------------------------- helpers fn forkShell(bin: []const u8, cwd: ?[*:0]const u8, rows: u16, cols: u16) struct { file: std.Io.File, pid: posix.pid_t } { var master: c_int = undefined; // Resolved BEFORE the fork, into this frame, which the child inherits: // nothing between fork and exec may allocate, so a PATH search cannot // happen there. var path_buf: [std.fs.max_path_bytes]u8 = undefined; const spawn = shell_bin.resolve(bin, &path_buf); const ws = posix.winsize{ .row = rows, .col = cols, .xpixel = 0, .ypixel = 0 }; const pid = forkpty(&master, null, null, &ws); if (pid == 0) { if (cwd) |c| _ = chdir(c); _ = execv(spawn.path, &spawn.argv); _exit(127); } return .{ .file = .{ .handle = master, .flags = .{ .nonblocking = false } }, .pid = pid }; } fn writeFd(fd: c_int, data: []const u8) void { var off: usize = 0; while (off < data.len) { const n = libc.write(fd, data[off..].ptr, data.len - off); if (n < 0) { if (libc.errno(n) == .INTR) continue; return; } // A zero-byte write makes no progress; looping on it would spin the // main thread forever, which here means a beachball rather than the // tty shell's hung terminal. if (n == 0) return; off += @intCast(n); } } fn writeFile(path: [*:0]const u8, contents: []const u8) void { const fd = libc.open(path, .{ .ACCMODE = .WRONLY, .CREAT = true, .TRUNC = true }, @as(libc.mode_t, 0o644)); if (fd < 0) return; defer _ = libc.close(fd); writeFd(fd, contents); } /// Rebuild the process environment as a Map, because a library never sees the /// std.process.Init that main() gets one from. Only the config-path lookup /// reads it, and the arena owns the copies for the life of the process. fn captureEnv(arena: std.mem.Allocator) ?std.process.Environ.Map { var map: std.process.Environ.Map = .init(arena); const environ = std.c.environ; var i: usize = 0; while (environ[i]) |entry| : (i += 1) { const line = std.mem.span(entry); const eq = std.mem.indexOfScalar(u8, line, '=') orelse continue; map.put(line[0..eq], line[eq + 1 ..]) catch return null; } return map; } fn encodeColor(color: pardes.Color) u32 { return switch (color) { .default => color_default, .index => |index| color_indexed | @as(u32, index), .rgb => |rgb| (@as(u32, rgb[0]) << 16) | (@as(u32, rgb[1]) << 8) | rgb[2], }; } fn encodeAttrs(style: pardes.CellStyle) u16 { var attrs: u16 = 0; attrs |= @as(u16, @intFromBool(style.bold)) << 0; attrs |= @as(u16, @intFromBool(style.dim)) << 1; attrs |= @as(u16, @intFromBool(style.italic)) << 2; attrs |= @as(u16, @intFromBool(style.blink)) << 3; attrs |= @as(u16, @intFromBool(style.reverse)) << 4; attrs |= @as(u16, @intFromBool(style.invisible)) << 5; attrs |= @as(u16, @intFromBool(style.strikethrough)) << 6; attrs |= @as(u16, @intFromEnum(style.ul)) << 8; return attrs; } /// Spend accumulated sub-row travel as whole wheel notches, keeping the /// remainder. The core has no fractional scroll — both other shells do this /// same accumulation host-side (stepScroll in gui.zig, the drain loop in /// web/app.mjs) — so it lives here and the Swift side stays a translator. /// /// The lag is clamped to one screen's worth so a nonsense delta (an inertial /// fling reported in points, a NaN) cannot spin the emit loop. fn takeScrollTicks(lag: *f32, delta_rows: f32) i32 { if (!std.math.isFinite(delta_rows)) return 0; const next = std.math.clamp(lag.* + delta_rows, -256, 256); if (!std.math.isFinite(next)) return 0; const whole: i32 = @intFromFloat(@trunc(next)); lag.* = next - @as(f32, @floatFromInt(whole)); return whole; } // ---------------------------------------------------------------- ABI guard // The header is hand-written, so nothing but a test keeps it honest. build.zig // translate-C's src/macos/pardes.h into this test build and every constant and // layout below is asserted against the Zig side — ghostty's trick, and the // cheapest possible insurance against a silent ABI skew. /// Compare one declaration's arity and scalar widths against the header's. /// Not a type equality — translate-C spells pointers `[*c]` and mints its own /// struct types, so nothing here would ever match exactly. Arity and width are /// what actually break: a parameter added on one side only (which is how the /// Swift host first got pardes_scroll wrong), or a u16 that became a u32. fn expectSameAbi(comptime C: type, comptime Z: type) !void { const c_fn = @typeInfo(C).@"fn"; const z_fn = @typeInfo(Z).@"fn"; try std.testing.expectEqual(c_fn.params.len, z_fn.params.len); inline for (c_fn.params, z_fn.params) |cp, zp| try std.testing.expectEqual(@sizeOf(cp.type.?), @sizeOf(zp.type.?)); try std.testing.expectEqual(@sizeOf(c_fn.return_type.?), @sizeOf(z_fn.return_type.?)); } test "pardes.h declares every export the way it is defined" { const c = @import("pardes.h"); try expectSameAbi(@TypeOf(c.pardes_init), @TypeOf(pardes_init)); try expectSameAbi(@TypeOf(c.pardes_deinit), @TypeOf(pardes_deinit)); try expectSameAbi(@TypeOf(c.pardes_tick), @TypeOf(pardes_tick)); try expectSameAbi(@TypeOf(c.pardes_should_quit), @TypeOf(pardes_should_quit)); try expectSameAbi(@TypeOf(c.pardes_animating), @TypeOf(pardes_animating)); try expectSameAbi(@TypeOf(c.pardes_key), @TypeOf(pardes_key)); try expectSameAbi(@TypeOf(c.pardes_paste), @TypeOf(pardes_paste)); try expectSameAbi(@TypeOf(c.pardes_mouse), @TypeOf(pardes_mouse)); try expectSameAbi(@TypeOf(c.pardes_scroll), @TypeOf(pardes_scroll)); try expectSameAbi(@TypeOf(c.pardes_resize), @TypeOf(pardes_resize)); try expectSameAbi(@TypeOf(c.pardes_frame), @TypeOf(pardes_frame)); try expectSameAbi(@TypeOf(c.pardes_frame_cells), @TypeOf(pardes_frame_cells)); try expectSameAbi(@TypeOf(c.pardes_frame_cols), @TypeOf(pardes_frame_cols)); try expectSameAbi(@TypeOf(c.pardes_frame_rows), @TypeOf(pardes_frame_rows)); try expectSameAbi(@TypeOf(c.pardes_cursor_x), @TypeOf(pardes_cursor_x)); try expectSameAbi(@TypeOf(c.pardes_cursor_y), @TypeOf(pardes_cursor_y)); try expectSameAbi(@TypeOf(c.pardes_cursor_bar), @TypeOf(pardes_cursor_bar)); } test "pardes.h matches the Zig boundary" { const c = @import("pardes.h"); const expectEqual = std.testing.expectEqual; try expectEqual(@sizeOf(c.pardes_cell_s), @sizeOf(Cell)); try expectEqual(@offsetOf(c.pardes_cell_s, "text"), @offsetOf(Cell, "text")); try expectEqual(@offsetOf(c.pardes_cell_s, "fg"), @offsetOf(Cell, "fg")); try expectEqual(@offsetOf(c.pardes_cell_s, "bg"), @offsetOf(Cell, "bg")); try expectEqual(@offsetOf(c.pardes_cell_s, "attrs"), @offsetOf(Cell, "attrs")); try expectEqual(@offsetOf(c.pardes_cell_s, "len"), @offsetOf(Cell, "len")); try expectEqual(@offsetOf(c.pardes_cell_s, "flags"), @offsetOf(Cell, "flags")); try expectEqual(@sizeOf(c.pardes_runtime_s), @sizeOf(Runtime)); try expectEqual(@as(u32, c.PARDES_COLOR_DEFAULT), color_default); try expectEqual(@as(u32, c.PARDES_COLOR_INDEXED), color_indexed); try expectEqual(@as(u8, c.PARDES_CELL_DEFAULT), cell_flag_default); // Every key the host has a name for must be the codepoint the core reads. try expectEqual(@as(u21, c.PARDES_KEY_ENTER), pardes.Key.enter); try expectEqual(@as(u21, c.PARDES_KEY_ESCAPE), pardes.Key.escape); try expectEqual(@as(u21, c.PARDES_KEY_TAB), pardes.Key.tab); try expectEqual(@as(u21, c.PARDES_KEY_BACKSPACE), pardes.Key.backspace); try expectEqual(@as(u21, c.PARDES_KEY_UP), pardes.Key.up); try expectEqual(@as(u21, c.PARDES_KEY_DOWN), pardes.Key.down); try expectEqual(@as(u21, c.PARDES_KEY_LEFT), pardes.Key.left); try expectEqual(@as(u21, c.PARDES_KEY_RIGHT), pardes.Key.right); try expectEqual(@as(u21, c.PARDES_KEY_HOME), pardes.Key.home); try expectEqual(@as(u21, c.PARDES_KEY_END), pardes.Key.end); try expectEqual(@as(u21, c.PARDES_KEY_PAGE_UP), pardes.Key.page_up); try expectEqual(@as(u21, c.PARDES_KEY_PAGE_DOWN), pardes.Key.page_down); try expectEqual(@as(u21, c.PARDES_KEY_DELETE), pardes.Key.delete); // The mouse ordinals the switch in pardes_mouse decodes are the enum's own // declaration order; a reorder there is a silent remap of acme's buttons. try expectEqual(c.PARDES_MOUSE_LEFT, @intFromEnum(pardes.Mouse.Button.left)); try expectEqual(c.PARDES_MOUSE_MIDDLE, @intFromEnum(pardes.Mouse.Button.middle)); try expectEqual(c.PARDES_MOUSE_RIGHT, @intFromEnum(pardes.Mouse.Button.right)); try expectEqual(c.PARDES_MOUSE_WHEEL_UP, @intFromEnum(pardes.Mouse.Button.wheel_up)); try expectEqual(c.PARDES_MOUSE_WHEEL_DOWN, @intFromEnum(pardes.Mouse.Button.wheel_down)); try expectEqual(c.PARDES_MOUSE_WHEEL_LEFT, @intFromEnum(pardes.Mouse.Button.wheel_left)); try expectEqual(c.PARDES_MOUSE_WHEEL_RIGHT, @intFromEnum(pardes.Mouse.Button.wheel_right)); try expectEqual(c.PARDES_MOUSE_NONE, @intFromEnum(pardes.Mouse.Button.none)); try expectEqual(c.PARDES_MOUSE_PRESS, @intFromEnum(pardes.Mouse.Kind.press)); try expectEqual(c.PARDES_MOUSE_RELEASE, @intFromEnum(pardes.Mouse.Kind.release)); try expectEqual(c.PARDES_MOUSE_MOTION, @intFromEnum(pardes.Mouse.Kind.motion)); try expectEqual(c.PARDES_MOUSE_DRAG, @intFromEnum(pardes.Mouse.Kind.drag)); // The attribute bits the host decodes, against the encoder that writes them. try expectEqual(@as(u16, c.PARDES_ATTR_BOLD), encodeAttrs(.{ .bold = true })); try expectEqual(@as(u16, c.PARDES_ATTR_DIM), encodeAttrs(.{ .dim = true })); try expectEqual(@as(u16, c.PARDES_ATTR_ITALIC), encodeAttrs(.{ .italic = true })); try expectEqual(@as(u16, c.PARDES_ATTR_BLINK), encodeAttrs(.{ .blink = true })); try expectEqual(@as(u16, c.PARDES_ATTR_REVERSE), encodeAttrs(.{ .reverse = true })); try expectEqual(@as(u16, c.PARDES_ATTR_INVISIBLE), encodeAttrs(.{ .invisible = true })); try expectEqual(@as(u16, c.PARDES_ATTR_STRIKETHROUGH), encodeAttrs(.{ .strikethrough = true })); try expectEqual( @as(u16, c.PARDES_UL_CURLY) << c.PARDES_ATTR_UL_SHIFT, encodeAttrs(.{ .ul = .curly }), ); } test "colors encode to the three tags the host decodes" { const expectEqual = std.testing.expectEqual; try expectEqual(@as(u32, 0x01000000), encodeColor(.default)); try expectEqual(@as(u32, 0x02000021), encodeColor(.{ .index = 33 })); try expectEqual(@as(u32, 0x00112233), encodeColor(.{ .rgb = .{ 0x11, 0x22, 0x33 } })); } test "sub-row scroll spends whole notches and keeps the remainder" { const expectEqual = std.testing.expectEqual; var lag: f32 = 0; // Four quarter-row flicks are one row, and not before the fourth. try expectEqual(@as(i32, 0), takeScrollTicks(&lag, 0.25)); try expectEqual(@as(i32, 0), takeScrollTicks(&lag, 0.25)); try expectEqual(@as(i32, 0), takeScrollTicks(&lag, 0.25)); try expectEqual(@as(i32, 1), takeScrollTicks(&lag, 0.25)); try expectEqual(@as(f32, 0), lag); // Direction reverses without the accumulated travel leaking across it. try expectEqual(@as(i32, -2), takeScrollTicks(&lag, -2.5)); try expectEqual(@as(i32, 0), takeScrollTicks(&lag, 0.25)); // Garbage moves nothing and leaves the accumulator usable; a fling far // past the clamp spends at most one screen and does not spin the caller. lag = 0; try expectEqual(@as(i32, 0), takeScrollTicks(&lag, std.math.nan(f32))); try expectEqual(@as(i32, 0), takeScrollTicks(&lag, std.math.inf(f32))); try expectEqual(@as(f32, 0), lag); try expectEqual(@as(i32, 256), takeScrollTicks(&lag, 1e9)); }