debug: properly set thread names on macOS

src/crash/sentry.zig

@@ -81,6 +81,13 @@ pub fn init(gpa: Allocator) !void {
 fn initThread(gpa: Allocator) !void {
     if (comptime !build_options.sentry) return;
 
+    // Right now, on Darwin, `std.Thread.setName` can only name the current
+    // thread, and we have no way to get the current thread from within it,
+    // so instead we use this code to name the thread instead.
+    if (builtin.os.tag.isDarwin()) {
+        internal_os.macos.pthread_setname_np(&"sentry-init".*);
+    }
+
     var arena = std.heap.ArenaAllocator.init(gpa);
     defer arena.deinit();
     const alloc = arena.allocator();

src/os/cf_release_thread.zig

@@ -8,6 +8,7 @@ const std = @import("std");
 const builtin = @import("builtin");
 const macos = @import("macos");
 
+const internal_os = @import("../os/main.zig");
 const xev = @import("../global.zig").xev;
 const BlockingQueue = @import("../datastruct/main.zig").BlockingQueue;
 
@@ -119,6 +120,13 @@ pub fn threadMain(self: *Thread) void {
 fn threadMain_(self: *Thread) !void {
     defer log.debug("cf release thread exited", .{});
 
+    // Right now, on Darwin, `std.Thread.setName` can only name the current
+    // thread, and we have no way to get the current thread from within it,
+    // so instead we use this code to name the thread instead.
+    if (builtin.os.tag.isDarwin()) {
+        internal_os.macos.pthread_setname_np(&"cf_release".*);
+    }
+
     // Start the async handlers. We start these first so that they're
     // registered even if anything below fails so we can drain the mailbox.
     self.wakeup.wait(&self.loop, &self.wakeup_c, Thread, self, wakeupCallback);

src/os/macos.zig

@@ -88,6 +88,10 @@ extern "c" fn pthread_set_qos_class_self_np(
     relative_priority: c_int,
 ) c_int;
 
+pub extern "c" fn pthread_setname_np(
+    name: [*:0]const u8,
+) void;
+
 pub const NSOperatingSystemVersion = extern struct {
     major: i64,
     minor: i64,

src/renderer/Thread.zig

@@ -198,6 +198,13 @@ pub fn threadMain(self: *Thread) void {
 fn threadMain_(self: *Thread) !void {
     defer log.debug("renderer thread exited", .{});
 
+    // Right now, on Darwin, `std.Thread.setName` can only name the current
+    // thread, and we have no way to get the current thread from within it,
+    // so instead we use this code to name the thread instead.
+    if (builtin.os.tag.isDarwin()) {
+        internal_os.macos.pthread_setname_np(&"renderer".*);
+    }
+
     // Setup our crash metadata
     crash.sentry.thread_state = .{
         .type = .renderer,

src/termio/Exec.zig

@@ -1364,6 +1364,13 @@ pub const ReadThread = struct {
         // Always close our end of the pipe when we exit.
         defer posix.close(quit);
 
+        // Right now, on Darwin, `std.Thread.setName` can only name the current
+        // thread, and we have no way to get the current thread from within it,
+        // so instead we use this code to name the thread instead.
+        if (builtin.os.tag.isDarwin()) {
+            internal_os.macos.pthread_setname_np(&"io-reader".*);
+        }
+
         // Setup our crash metadata
         crash.sentry.thread_state = .{
             .type = .io,

src/termio/Thread.zig

@@ -16,6 +16,7 @@ const ArenaAllocator = std.heap.ArenaAllocator;
 const builtin = @import("builtin");
 const xev = @import("../global.zig").xev;
 const crash = @import("../crash/main.zig");
+const internal_os = @import("../os/main.zig");
 const termio = @import("../termio.zig");
 const renderer = @import("../renderer.zig");
 const BlockingQueue = @import("../datastruct/main.zig").BlockingQueue;
@@ -202,6 +203,13 @@ pub fn threadMain(self: *Thread, io: *termio.Termio) void {
 fn threadMain_(self: *Thread, io: *termio.Termio) !void {
     defer log.debug("IO thread exited", .{});
 
+    // Right now, on Darwin, `std.Thread.setName` can only name the current
+    // thread, and we have no way to get the current thread from within it,
+    // so instead we use this code to name the thread instead.
+    if (builtin.os.tag.isDarwin()) {
+        internal_os.macos.pthread_setname_np(&"io".*);
+    }
+
     // Setup our crash metadata
     crash.sentry.thread_state = .{
         .type = .io,