From 2ac9b2088a933b3f67135c1eb5e2bf1f42e8801b Mon Sep 17 00:00:00 2001
From: Karl Seguin <k@openmymind.io>
Date: Tue, 2 Sep 2025 19:45:49 +0800
Subject: [PATCH] Always monitor the CDP client socket, even on page.wait

---
 src/browser/ScriptManager.zig |  2 +-
 src/browser/page.zig          | 10 +++++++--
 src/cdp/cdp.zig               |  2 +-
 src/http/Client.zig           | 41 ++++++++++++++++++++++++-----------
 src/http/Http.zig             | 17 ++++++++++-----
 src/server.zig                |  6 ++++-
 6 files changed, 54 insertions(+), 24 deletions(-)

diff --git a/src/browser/ScriptManager.zig b/src/browser/ScriptManager.zig
index 7a17cdc3..190d8f13 100644
--- a/src/browser/ScriptManager.zig
+++ b/src/browser/ScriptManager.zig
@@ -285,7 +285,7 @@ pub fn blockingGet(self: *ScriptManager, url: [:0]const u8) !BlockingResult {
 
     // rely on http's timeout settings to avoid an endless/long loop.
     while (true) {
-        _ = try client.tick(.{ .timeout_ms = 200 });
+        _ = try client.tick(200);
         switch (blocking.state) {
             .running => {},
             .done => |result| return result,
diff --git a/src/browser/page.zig b/src/browser/page.zig
index 211ed598..05430281 100644
--- a/src/browser/page.zig
+++ b/src/browser/page.zig
@@ -313,7 +313,10 @@ pub const Page = struct {
                     }
 
                     // There should only be 1 active http transfer, the main page
-                    _ = try http_client.tick(.{ .timeout_ms = ms_remaining });
+                    if (try http_client.tick(ms_remaining) == .extra_socket) {
+                        // data on a socket we aren't handling, return to caller
+                        return;
+                    }
                 },
                 .html, .parsed => {
                     // The HTML page was parsed. We now either have JS scripts to
@@ -374,7 +377,10 @@ pub const Page = struct {
                         // inflight requests
                         else @min(ms_remaining, ms_to_next_task orelse 1000);
 
-                    _ = try http_client.tick(.{ .timeout_ms = ms_to_wait });
+                    if (try http_client.tick(ms_to_wait) == .extra_socket) {
+                        // data on a socket we aren't handling, return to caller
+                        return;
+                    }
 
                     if (request_intercepted) {
                         // Again, proritizing intercepted requests. Exit this
diff --git a/src/cdp/cdp.zig b/src/cdp/cdp.zig
index a9d932f0..a6b645d1 100644
--- a/src/cdp/cdp.zig
+++ b/src/cdp/cdp.zig
@@ -103,7 +103,7 @@ pub fn CDPT(comptime TypeProvider: type) type {
         pub fn handleMessage(self: *Self, msg: []const u8) bool {
             // if there's an error, it's already been logged
             self.processMessage(msg) catch return false;
-            self.pageWait();
+            // self.pageWait();
             return true;
         }
 
diff --git a/src/http/Client.zig b/src/http/Client.zig
index 0b42ff80..cec046ff 100644
--- a/src/http/Client.zig
+++ b/src/http/Client.zig
@@ -87,6 +87,11 @@ notification: ?*Notification = null,
 // restoring, this originally-configured value is what it goes to.
 http_proxy: ?[:0]const u8 = null,
 
+// libcurl can monitor arbitrary sockets. Currently, we ever [maybe] want to
+// monitor the CDP client socket, so we've done the simplest thing possible
+// by having this single optional field
+extra_socket: ?posix.socket_t = null,
+
 const TransferQueue = std.DoublyLinkedList;
 
 pub fn init(allocator: Allocator, ca_blob: ?c.curl_blob, opts: Http.Opts) !*Client {
@@ -162,11 +167,7 @@ pub fn abort(self: *Client) void {
     }
 }
 
-const TickOpts = struct {
-    timeout_ms: i32 = 0,
-    poll_socket: ?posix.socket_t = null,
-};
-pub fn tick(self: *Client, opts: TickOpts) !bool {
+pub fn tick(self: *Client, timeout_ms: i32) !PerformStatus {
     while (true) {
         if (self.handles.hasAvailable() == false) {
             break;
@@ -178,7 +179,7 @@ pub fn tick(self: *Client, opts: TickOpts) !bool {
         const handle = self.handles.getFreeHandle().?;
         try self.makeRequest(handle, transfer);
     }
-    return self.perform(opts.timeout_ms, opts.poll_socket);
+    return self.perform(timeout_ms);
 }
 
 pub fn request(self: *Client, req: Request) !void {
@@ -342,15 +343,25 @@ fn makeRequest(self: *Client, handle: *Handle, transfer: *Transfer) !void {
     }
 
     self.active += 1;
-    _ = try self.perform(0, null);
+    _ = try self.perform(0);
 }
 
-fn perform(self: *Client, timeout_ms: c_int, socket: ?posix.socket_t) !bool {
+pub const PerformStatus = enum{
+    extra_socket,
+    normal,
+};
+
+fn perform(self: *Client, timeout_ms: c_int) !PerformStatus {
     const multi = self.multi;
     var running: c_int = undefined;
     try errorMCheck(c.curl_multi_perform(multi, &running));
 
-    if (socket) |s| {
+    // We're potentially going to block for a while until we get data. Process
+    // whatever messages we have waiting ahead of time.
+    try self.processMessages();
+
+    var status = PerformStatus.normal;
+    if (self.extra_socket) |s| {
         var wait_fd = c.curl_waitfd{
             .fd = s,
             .events = c.CURL_WAIT_POLLIN,
@@ -359,12 +370,18 @@ fn perform(self: *Client, timeout_ms: c_int, socket: ?posix.socket_t) !bool {
         try errorMCheck(c.curl_multi_poll(multi, &wait_fd, 1, timeout_ms, null));
         if (wait_fd.revents != 0) {
             // the extra socket we passed in is ready, let's signal our caller
-            return true;
+            status = .extra_socket;
         }
-    } else if (running > 0 and timeout_ms > 0) {
+    } else if (running > 0) {
         try errorMCheck(c.curl_multi_poll(multi, null, 0, timeout_ms, null));
     }
 
+    try self.processMessages();
+    return status;
+}
+
+fn processMessages(self: *Client) !void {
+    const multi = self.multi;
     var messages_count: c_int = 0;
     while (c.curl_multi_info_read(multi, &messages_count)) |msg_| {
         const msg: *c.CURLMsg = @ptrCast(msg_);
@@ -422,8 +439,6 @@ fn perform(self: *Client, timeout_ms: c_int, socket: ?posix.socket_t) !bool {
             self.requestFailed(transfer, err);
         }
     }
-
-    return false;
 }
 
 fn endTransfer(self: *Client, transfer: *Transfer) void {
diff --git a/src/http/Http.zig b/src/http/Http.zig
index ebd1e476..6f1f1fdc 100644
--- a/src/http/Http.zig
+++ b/src/http/Http.zig
@@ -83,16 +83,21 @@ pub fn deinit(self: *Http) void {
     self.arena.deinit();
 }
 
-pub fn poll(self: *Http, timeout_ms: i32, socket: posix.socket_t) bool {
-    return self.client.tick(.{
-        .timeout_ms = timeout_ms,
-        .poll_socket = socket,
-    }) catch |err| {
+pub fn poll(self: *Http, timeout_ms: i32) Client.PerformStatus {
+    return self.client.tick(timeout_ms) catch |err| {
         log.err(.app, "http poll", .{ .err = err });
-        return false;
+        return .normal;
     };
 }
 
+pub fn monitorSocket(self: *Http, socket: posix.socket_t) void {
+    self.client.extra_socket = socket;
+}
+
+pub fn unmonitorSocket(self: *Http) void {
+    self.client.extra_socket = null;
+}
+
 pub fn newConnection(self: *Http) !Connection {
     return Connection.init(self.ca_blob, &self.opts);
 }
diff --git a/src/server.zig b/src/server.zig
index 2a16bd8d..0bb48f65 100644
--- a/src/server.zig
+++ b/src/server.zig
@@ -126,8 +126,12 @@ pub const Server = struct {
 
         var last_message = timestamp();
         var http = &self.app.http;
+
+        http.monitorSocket(socket);
+        defer http.unmonitorSocket();
+
         while (true) {
-            if (http.poll(20, socket)) {
+            if (http.poll(10) == .extra_socket) {
                 const n = posix.read(socket, client.readBuf()) catch |err| {
                     log.warn(.app, "CDP read", .{ .err = err });
                     return;