chore: update vendored libghostty-vt

refs #276

1 files changed, 18 insertions, 4 deletions

diff --git a/vendor/libghostty-vt/src/renderer/generic.zig b/vendor/libghostty-vt/src/renderer/generic.zig
index 0f4a294b..14b79036 100644
--- a/vendor/libghostty-vt/src/renderer/generic.zig
+++ b/vendor/libghostty-vt/src/renderer/generic.zig
@@ -1170,8 +1170,10 @@ pub fn Renderer(comptime GraphicsAPI: type) type {
                 //     std.log.err("[updateFrame critical time] start={}\tduration={} us", .{ start_micro, end.since(start) / std.time.ns_per_us });
                 // }
 
-                state.mutex.lock();
-                defer state.mutex.unlock();
+                // Lock while signaling demand so the IO parse thread
+                // can't starve us. See renderer.State.lockDemand.
+                state.lockDemand();
+                defer state.unlockDemand();
 
                 // If we're in a synchronized output state, we pause all rendering.
                 if (state.terminal.modes.get(.synchronized_output)) {
@@ -1199,8 +1201,15 @@ pub fn Renderer(comptime GraphicsAPI: type) type {
                     state.terminal.scrollViewport(.bottom);
                 }
 
-                // Update our terminal state
-                try self.terminal_state.update(self.alloc, state.terminal);
+                // Begin the update of our terminal state. Work that
+                // doesn't require terminal access (e.g. style
+                // denormalization) is deferred to the endUpdate call
+                // outside of this critical section, keeping our lock
+                // hold time as short as possible.
+                try self.terminal_state.beginUpdate(
+                    self.alloc,
+                    state.terminal,
+                );
 
                 // If our terminal state is dirty at all we need to redo
                 // the viewport search.
@@ -1279,6 +1288,11 @@ pub fn Renderer(comptime GraphicsAPI: type) type {
                 };
             };
 
+            // Outside the critical area, complete the update we began
+            // within it. This must be done before anything reads the
+            // render state (e.g. rebuildCells).
+            self.terminal_state.endUpdate();
+
             // Outside the critical area we can update our links to contain
             // our regex results.
             self.config.links.renderCellMap(