refactor(gossip): dump service in own thread

make the gossip dump service work like the other gossip components, where a thread is spawned, and the entire thing exits if it dies.

src/gossip/dump_service.zig

@@ -17,7 +17,7 @@ pub const GossipDumpService = struct {
 
     const Self = @This();
 
-    pub fn run(self: *Self) !void {
+    pub fn run(self: Self) !void {
         const start_time = std.time.timestamp();
         const dir = try std.fmt.allocPrint(self.allocator, "gossip-dumps/{}", .{start_time});
         defer self.allocator.free(dir);
@@ -29,7 +29,7 @@ pub const GossipDumpService = struct {
         }
     }
 
-    fn dumpGossip(self: *Self, dir: []const u8, start_time: i64) !void {
+    fn dumpGossip(self: *const Self, dir: []const u8, start_time: i64) !void {
         const data = blk: {
             var gossip_table_lock = self.gossip_table_rw.read();
             defer gossip_table_lock.unlock();

src/gossip/service.zig

@@ -364,15 +364,13 @@ pub const GossipService = struct {
         });
         defer self.joinAndExit(&responder_handle);
 
-        if (dump) {
-            var dump_svc = GossipDumpService{
-                .allocator = self.allocator,
-                .logger = self.logger,
-                .gossip_table_rw = &self.gossip_table_rw,
-                .exit = self.exit,
-            };
-            try dump_svc.run();
-        }
+        var dump_handle = if (dump) try Thread.spawn(.{}, GossipDumpService.run, .{.{
+            .allocator = self.allocator,
+            .logger = self.logger,
+            .gossip_table_rw = &self.gossip_table_rw,
+            .exit = self.exit,
+        }}) else null;
+        defer if (dump_handle) |*h| self.joinAndExit(h);
     }
 
     fn sortSlices(slices: anytype) void {