coretext shaper owns CFReleaseThread, works on both Metal and OpenGL now

src/font/shaper/coretext.zig

@@ -5,6 +5,8 @@ const Allocator = std.mem.Allocator;
 const macos = @import("macos");
 const trace = @import("tracy").trace;
 const font = @import("../main.zig");
+const os = @import("../../os/main.zig");
+const terminal = @import("../../terminal/main.zig");
 const Face = font.Face;
 const Collection = font.Collection;
 const DeferredFace = font.DeferredFace;
@@ -14,7 +16,7 @@ const Library = font.Library;
 const SharedGrid = font.SharedGrid;
 const Style = font.Style;
 const Presentation = font.Presentation;
-const terminal = @import("../../terminal/main.zig");
+const CFReleaseThread = os.CFReleaseThread;
 
 const log = std.log.scoped(.font_shaper);
 
@@ -62,6 +64,12 @@ pub const Shaper = struct {
     /// sent to the release thread when endFrame is called.
     cf_release_pool: std.ArrayListUnmanaged(*anyopaque),
 
+    /// Dedicated thread for releasing CoreFoundation objects. Some objects,
+    /// such as those produced by CoreText, have excessively slow release
+    /// callback logic.
+    cf_release_thread: *CFReleaseThread,
+    cf_release_thr: std.Thread,
+
     const CellBuf = std.ArrayListUnmanaged(font.shape.Cell);
     const CodepointList = std.ArrayListUnmanaged(Codepoint);
     const Codepoint = struct {
@@ -215,6 +223,20 @@ pub const Shaper = struct {
         const cached_fonts = std.ArrayList(?*macos.foundation.Dictionary).init(alloc);
         errdefer cached_fonts.deinit();
 
+        // Create the CF release thread.
+        var cf_release_thread = try alloc.create(CFReleaseThread);
+        errdefer alloc.destroy(cf_release_thread);
+        cf_release_thread.* = try CFReleaseThread.init(alloc);
+        errdefer cf_release_thread.deinit();
+
+        // Start the CF release thread.
+        var cf_release_thr = try std.Thread.spawn(
+            .{},
+            CFReleaseThread.threadMain,
+            .{cf_release_thread},
+        );
+        cf_release_thr.setName("cf_release") catch {};
+
         return .{
             .alloc = alloc,
             .cell_buf = .{},
@@ -223,6 +245,8 @@ pub const Shaper = struct {
             .writing_direction = writing_direction,
             .cached_fonts = cached_fonts,
             .cf_release_pool = .{},
+            .cf_release_thread = cf_release_thread,
+            .cf_release_thr = cf_release_thr,
         };
     }
 
@@ -247,6 +271,15 @@ pub const Shaper = struct {
             );
         }
         self.cf_release_pool.deinit(self.alloc);
+
+        // Stop the CF release thread
+        {
+            self.cf_release_thread.stop.notify() catch |err|
+                log.err("error notifying cf release thread to stop, may stall err={}", .{err});
+            self.cf_release_thr.join();
+        }
+        self.cf_release_thread.deinit();
+        self.alloc.destroy(self.cf_release_thread);
     }
 
     /// Release all cached fonts.
@@ -258,6 +291,38 @@ pub const Shaper = struct {
         }
     }
 
+    pub fn endFrame(self: *Shaper) void {
+        if (self.cf_release_pool.items.len == 0) return;
+
+        // Get all the items in the pool as an owned slice so we can
+        // send it to the dedicated release thread.
+        const items = self.cf_release_pool.toOwnedSlice(self.alloc) catch |err| {
+            log.warn("error converting release pool to owned slice, slow release err={}", .{err});
+            for (self.cf_release_pool.items) |ref| macos.foundation.CFRelease(ref);
+            self.cf_release_pool.clearRetainingCapacity();
+            return;
+        };
+
+        // Send the items. If the send succeeds then we wake up the
+        // thread to process the items. If the send fails then do a manual
+        // cleanup.
+        if (self.cf_release_thread.mailbox.push(.{ .release = .{
+            .refs = items,
+            .alloc = self.alloc,
+        } }, .{ .forever = {} }) != 0) {
+            self.cf_release_thread.wakeup.notify() catch |err| {
+                log.warn(
+                    "error notifying cf release thread to wake up, may stall err={}",
+                    .{err},
+                );
+            };
+            return;
+        }
+
+        for (items) |ref| macos.foundation.CFRelease(ref);
+        self.alloc.free(items);
+    }
+
     pub fn runIterator(
         self: *Shaper,
         grid: *SharedGrid,

src/renderer/Metal.zig

@@ -136,12 +136,6 @@ layer: objc.Object, // CAMetalLayer
 /// a display link.
 display_link: ?DisplayLink = null,
 
-/// Dedicated thread for releasing CoreFoundation objects some objects,
-/// such as those produced by CoreText, have excessively slow release
-/// callback logic.
-cf_release_thread: CFReleaseThread,
-cf_release_thr: std.Thread,
-
 /// Custom shader state. This is only set if we have custom shaders.
 custom_shader_state: ?CustomShaderState = null,
 
@@ -598,9 +592,6 @@ pub fn init(alloc: Allocator, options: renderer.Options) !Metal {
         .cursor_color = options.config.cursor_color,
         .current_background_color = options.config.background,
 
-        .cf_release_thread = undefined,
-        .cf_release_thr = undefined,
-
         // Render state
         .cells = .{},
         .uniforms = .{
@@ -698,18 +689,6 @@ pub fn loopEnter(self: *Metal, thr: *renderer.Thread) !void {
         &thr.draw_now,
     );
     display_link.start() catch {};
-
-    // Create the CF release thread.
-    self.cf_release_thread = try CFReleaseThread.init(self.alloc);
-    errdefer self.cf_release_thread.deinit();
-
-    // Start the CF release thread.
-    self.cf_release_thr = try std.Thread.spawn(
-        .{},
-        CFReleaseThread.threadMain,
-        .{&self.cf_release_thread},
-    );
-    self.cf_release_thr.setName("cf_release") catch {};
 }
 
 /// Called by renderer.Thread when it exits the main loop.
@@ -722,15 +701,6 @@ pub fn loopExit(self: *Metal) void {
     // is gone which is fine.
     const display_link = self.display_link orelse return;
     display_link.stop() catch {};
-
-    // Stop the CF release thread
-    {
-        self.cf_release_thread.stop.notify() catch |err|
-            log.err("error notifying cf release thread to stop, may stall err={}", .{err});
-        self.cf_release_thr.join();
-    }
-
-    self.cf_release_thread.deinit();
 }
 
 fn displayLinkCallback(
@@ -1028,22 +998,9 @@ pub fn updateFrame(
         &critical.color_palette,
     );
 
-    if (self.font_shaper.cf_release_pool.items.len > 0) {
-        const alloc = self.font_shaper.alloc;
-        const items = try self.font_shaper.cf_release_pool.toOwnedSlice(alloc);
-        if (self.cf_release_thread.mailbox.push(
-            .{ .release = .{
-                .refs = items,
-                .alloc = alloc,
-            } },
-            .{ .forever = {} },
-        ) != 0) {
-            try self.cf_release_thread.wakeup.notify();
-        } else {
-            for (items) |ref| macos.foundation.CFRelease(ref);
-            alloc.free(items);
-        }
-    }
+    // Notify our shaper we're done for the frame. For some shapers like
+    // CoreText this triggers off-thread cleanup logic.
+    self.font_shaper.endFrame();
 
     // Update our viewport pin
     self.cells_viewport = critical.viewport_pin;

src/renderer/OpenGL.zig

@@ -732,6 +732,10 @@ pub fn updateFrame(
             critical.cursor_style,
             &critical.color_palette,
         );
+
+        // Notify our shaper we're done for the frame. For some shapers like
+        // CoreText this triggers off-thread cleanup logic.
+        self.font_shaper.endFrame();
     }
 }