Return thread handles for gossip service

Allocating a pointer to hold the thread handles & limited shared state
in order to properly deallocate the associated resources and join
the threads correctly is more appropriate than spawning a whole thread
for that purpose.

src/cmd/cmd.zig

@@ -376,7 +376,9 @@ fn gossip() !void {
         &.{},
     );
     defer gossip_service.deinit();
-    try runGossipWithConfigValues(&gossip_service);
+
+    const gossip_run_state = try runGossipWithConfigValues(&gossip_service);
+    defer gossip_run_state.deinit(&gossip_service);
 }
 
 /// entrypoint to run a full solana validator
@@ -406,7 +408,9 @@ fn validator() !void {
         &.{.{ .tag = socket_tag.REPAIR, .port = repair_port }},
     );
     defer gossip_service.deinit();
-    const gossip_handle = try std.Thread.spawn(.{}, runGossipWithConfigValues, .{&gossip_service});
+
+    const gossip_run_state = try runGossipWithConfigValues(&gossip_service);
+    defer gossip_run_state.deinit(&gossip_service);
 
     // repair
     var repair_socket = try Socket.create(network.AddressFamily.ipv4, network.Protocol.udp);
@@ -503,7 +507,6 @@ fn validator() !void {
 
     logger.infof("accounts-db setup done...", .{});
 
-    gossip_handle.join();
     repair_handle.join();
     shred_receive_handle.join();
 }
@@ -570,7 +573,7 @@ fn initRepair(
     };
 }
 
-fn runGossipWithConfigValues(gossip_service: *GossipService) !void {
+fn runGossipWithConfigValues(gossip_service: *GossipService) !*GossipService.RunState {
     const gossip_config = config.current.gossip;
     return gossip_service.run(gossip_config.spy_node, gossip_config.dump);
 }
@@ -736,8 +739,10 @@ fn downloadSnapshot() !void {
         &.{},
     );
     defer gossip_service.deinit();
-    const handle = try std.Thread.spawn(.{}, runGossipWithConfigValues, .{&gossip_service});
-    handle.detach();
+
+    const gossip_run_state = try runGossipWithConfigValues(&gossip_service);
+    _ = &gossip_run_state;
+    // defer gossip_run_state.deinit(&gossip_service);
 
     const trusted_validators = try getTrustedValidators(gpa_allocator);
     defer if (trusted_validators) |*tvs| tvs.deinit();

src/gossip/fuzz.zig

@@ -307,8 +307,13 @@ pub fn run() !void {
         &fuzz_exit,
         .noop,
     );
+    defer {
+        fuzz_exit.store(true, .unordered);
+        gossip_service_fuzzer.deinit();
+    }
 
-    var fuzz_handle = try std.Thread.spawn(.{}, GossipService.run, .{ &gossip_service_fuzzer, true, false });
+    const gossip_run_state = try gossip_service_fuzzer.run(true, false);
+    defer gossip_run_state.deinit(&gossip_service_fuzzer);
 
     const SLEEP_TIME = 0;
     // const SLEEP_TIME = std.time.ns_per_ms * 10;
@@ -403,9 +408,6 @@ pub fn run() !void {
 
     // cleanup
     std.debug.print("\t=> shutting down...\n", .{});
-    fuzz_exit.store(true, .unordered);
-    fuzz_handle.join();
-    gossip_service_fuzzer.deinit();
     std.debug.print("\t=>fuzzy gossip service shutdown\n", .{});
 
     exit_handle.join();