fix(windows): wait for Sunshine readiness in service wrapper

src/confighttp.cpp

@@ -33,6 +33,7 @@
 #include "confighttp.h"
 #include "crypto.h"
 #include "display_device.h"
+#include "entry_handler.h"
 #include "file_handler.h"
 #include "globals.h"
 #include "httpcommon.h"
@@ -1833,6 +1834,9 @@ namespace confighttp {
         platf::set_thread_name("confighttp::tcp");
         server->start([&display_addr](const unsigned short port) {
           BOOST_LOG(info) << "Configuration UI available at [https://"sv << display_addr << ":" << port << "]";
+#ifdef _WIN32
+          service_ctrl::signal_ready();
+#endif
         });
       } catch (boost::system::system_error &err) {
         // It's possible the exception gets thrown after calling server->stop() from a different thread

src/entry_handler.cpp

@@ -3,9 +3,13 @@
  * @brief Definitions for entry handling functions.
  */
 // standard includes
+#include <bit>
 #include <csignal>
+#include <cstdint>
+#include <cwchar>
 #include <format>
 #include <iostream>
+#include <string>
 #include <thread>
 
 // local includes
@@ -121,6 +125,37 @@ bool is_gamestream_enabled() {
 }
 
 namespace service_ctrl {
+  /// Environment variable used to pass the inherited service readiness event handle.
+  constexpr auto SERVICE_READY_EVENT_ENV = L"SUNSHINE_SERVICE_READY_EVENT";
+
+  void signal_ready() {
+    std::wstring event_handle_text(32, L'\0');
+    auto length = GetEnvironmentVariableW(SERVICE_READY_EVENT_ENV, event_handle_text.data(), static_cast<DWORD>(event_handle_text.size()));
+    if (length == 0 || length >= event_handle_text.size()) {
+      return;
+    }
+
+    event_handle_text.resize(length);
+    wchar_t *end = nullptr;
+    auto event_handle_value = std::wcstoull(event_handle_text.c_str(), &end, 10);
+    if (event_handle_value == 0 || *end != L'\0') {
+      BOOST_LOG(warning) << "Ignoring invalid service ready event handle";
+      return;
+    }
+
+    auto ready_event_value = static_cast<std::uintptr_t>(event_handle_value);
+    auto ready_event = std::bit_cast<HANDLE>(ready_event_value);
+    if (!SetEvent(ready_event)) {
+      auto winerr = GetLastError();
+      BOOST_LOG(warning) << "Failed to signal service ready event: "sv << winerr;
+      SetEnvironmentVariableW(SERVICE_READY_EVENT_ENV, nullptr);
+      return;
+    }
+
+    CloseHandle(ready_event);
+    SetEnvironmentVariableW(SERVICE_READY_EVENT_ENV, nullptr);
+  }
+
   /**
    * @brief Owns Windows service-manager handles for the Sunshine service.
    */

src/entry_handler.h

@@ -119,6 +119,14 @@ bool is_gamestream_enabled();
  * @brief Namespace for controlling the Sunshine service model on Windows.
  */
 namespace service_ctrl {
+  /**
+   * @brief Signal the Windows service wrapper that Sunshine is ready.
+   * @examples
+   * signal_ready();
+   * @examples_end
+   */
+  void signal_ready();
+
   /**
    * @brief Check if the service is running.
    * @examples