Actually fast again???

way faster than before even??

coder@08714a4174bb:~$ nats bench pub foo -s localhost:4223
05:12:23 Starting Core NATS publisher benchmark [clients=1, msg-size=128 B, msgs=100,000, multi-subject=false, multi-subject-max=100,000, sleep=0s, subject=foo]
05:12:23 [1] Starting Core NATS publisher, publishing 100,000 messages
Finished      0s [====================================================================================] 100%

NATS Core NATS publisher stats: 574,666 msgs/sec ~ 70 MiB/sec ~ 1.74us

So cool.

src/server/client.zig JJ: M src/server/main.zig JJ: JJ: Lines starting with "JJ:" (like this one) will be 
removed.

src/main.zig

@@ -1,4 +1,5 @@
 const std = @import("std");
+const builtin = @import("builtin");
 const zits = @import("zits");
 const yazap = @import("yazap");
 
@@ -8,7 +9,7 @@ const Server = zits.Server;
 pub fn main() !void {
     var dba: std.heap.DebugAllocator(.{}) = .init;
     defer _ = dba.deinit();
-    const gpa = dba.allocator();
+    const gpa = if (builtin.mode == .Debug or builtin.mode == .ReleaseSafe) dba.allocator() else std.heap.smp_allocator;
 
     var app = yazap.App.init(gpa, "zits", "High performance NATS compatible client and server.");
     defer app.deinit();

src/server/client.zig

@@ -5,7 +5,8 @@ const Client = @This();
 
 connect: ?Message.Connect,
 
-write_lock: std.Io.Mutex,
+// Messages for this client to receive.
+recv_queue: ?*std.Io.Queue(Message) = null,
 
 from_client: *std.Io.Reader,
 to_client: *std.Io.Writer,
@@ -17,17 +18,18 @@ pub fn init(
 ) Client {
     return .{
         .connect = connect,
-        .write_lock = .init,
         .from_client = in,
         .to_client = out,
     };
 }
 
-/// Return true if the value was put in the clients buffer to process, else false.
+pub fn start(self: *Client, io: std.Io, alloc: std.mem.Allocator, queue: *std.Io.Queue(Message)) !void {
-pub fn send(self: *Client, io: std.Io, msg: Message) !void {
+    self.recv_queue = queue;
-    try self.write_lock.lock(io);
+    var msgs: [16]Message = undefined;
-    defer self.write_lock.unlock(io);
+    while (true) {
-
+        const len = try queue.get(io, &msgs, 1);
+        std.debug.assert(len <= msgs.len);
+        for (msgs[0..len]) |msg| {
             switch (msg) {
                 .@"+ok" => {
                     try writeOk(self.to_client);
@@ -39,12 +41,21 @@ pub fn send(self: *Client, io: std.Io, msg: Message) !void {
                     try writeInfo(self.to_client, info);
                 },
                 .msg => |m| {
+                    defer m.deinit(alloc);
                     try writeMsg(self.to_client, m);
                 },
-        else => {
+                else => |m| {
-            std.debug.panic("unimplemented write", .{});
+                    std.debug.panic("unimplemented write: {any}\n", .{m});
                 },
             }
+        }
+    }
+}
+
+pub fn send(self: *Client, io: std.Io, msg: Message) !void {
+    if (self.recv_queue) |queue| {
+        try queue.putOne(io, msg);
+    } else @panic("Must start() the client before sending it messages.");
 }
 
 pub fn next(self: *Client, allocator: std.mem.Allocator) !Message {

src/server/main.zig

@@ -1,4 +1,5 @@
 const std = @import("std");
+const builtin = @import("builtin");
 const Message = @import("./message_parser.zig").Message;
 pub const ServerInfo = Message.ServerInfo;
 
@@ -120,16 +121,16 @@ fn handleConnection(
     var client_allocator: std.heap.DebugAllocator(.{}) = .init;
     client_allocator.backing_allocator = server_allocator;
     defer _ = client_allocator.deinit();
-    const allocator = client_allocator.allocator();
+    const allocator = if (builtin.mode == .Debug or builtin.mode == .ReleaseSafe) client_allocator.allocator() else server_allocator;
 
     // Set up client writer
-    const w_buffer: []u8 = try allocator.alloc(u8, 1024);
+    const w_buffer: []u8 = try allocator.alloc(u8, 1024 * 10);
     defer allocator.free(w_buffer);
     var writer = stream.writer(io, w_buffer);
     const out = &writer.interface;
 
     // Set up client reader
-    const r_buffer: []u8 = try allocator.alloc(u8, 1024);
+    const r_buffer: []u8 = try allocator.alloc(u8, 1024 * 10);
     defer allocator.free(r_buffer);
     var reader = stream.reader(io, r_buffer);
     const in = &reader.interface;
@@ -139,6 +140,14 @@ fn handleConnection(
     try server.addClient(server_allocator, id, &client);
     defer server.removeClient(io, server_allocator, id);
 
+    var qbuf: [1024]Message = undefined;
+    var queue: std.Io.Queue(Message) = .init(&qbuf);
+
+    var client_task = try io.concurrent(Client.start, .{ &client, io, server_allocator, &queue });
+    defer client_task.cancel(io) catch {};
+
+    try io.sleep(std.Io.Duration.fromMilliseconds(5), .real);
+
     // Do initial handshake with client
     try client.send(io, .{ .info = server.info });
     var connect_arena: std.heap.ArenaAllocator = .init(allocator);
@@ -153,7 +162,7 @@ fn handleConnection(
                 try client.send(io, .pong);
             },
             .@"pub" => |pb| {
-                _ = io.async(publishMessage, .{ server, io, server_allocator, &client, pb });
+                try server.publishMessage(io, server_allocator, &client, pb);
             },
             .sub => |sub| {
                 try server.subscribe(io, server_allocator, id, sub);
@@ -167,7 +176,7 @@ fn handleConnection(
         }
     } else |err| switch (err) {
         error.EndOfStream => {
-            std.debug.print("Client {d} disconnected", .{});
+            std.debug.print("Client {d} disconnected\n", .{id});
         },
         else => {
             return err;
@@ -186,7 +195,7 @@ fn subjectMatches(expected: []const u8, actual: []const u8) bool {
     return std.mem.eql(u8, expected, actual);
 }
 
-fn publishMessage(server: *Server, io: std.Io, gpa: std.mem.Allocator, source_client: *Client, msg: Message.Pub) !void {
+fn publishMessage(server: *Server, io: std.Io, alloc: std.mem.Allocator, source_client: *Client, msg: Message.Pub) !void {
     errdefer {
         if (source_client.connect) |c| {
             if (c.verbose) {
@@ -194,7 +203,7 @@ fn publishMessage(server: *Server, io: std.Io, gpa: std.mem.Allocator, source_cl
             }
         }
     }
-    defer msg.deinit(gpa);
+    defer msg.deinit(alloc);
     for (server.subscriptions.items) |subscription| {
         if (subjectMatches(subscription.subject, msg.subject)) {
             const client = server.clients.get(subscription.client_id) orelse {
@@ -202,10 +211,10 @@ fn publishMessage(server: *Server, io: std.Io, gpa: std.mem.Allocator, source_cl
                 continue;
             };
             client.send(io, .{ .msg = .{
-                .subject = msg.subject,
+                .subject = try alloc.dupe(u8, msg.subject),
-                .sid = subscription.sid,
+                .sid = try alloc.dupe(u8, subscription.sid),
-                .reply_to = msg.reply_to,
+                .reply_to = if (msg.reply_to) |r| try alloc.dupe(u8, r) else null,
-                .payload = msg.payload,
+                .payload = try alloc.dupe(u8, msg.payload),
             } }) catch continue;
         }
     }