Hot-restart guard comes from fox_utils 0.1.8 (shared with other media_kit apps)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/desktop/linux/runner/CMakeLists.txt

@@ -9,7 +9,6 @@ project(runner LANGUAGES CXX)
 add_executable(${BINARY_NAME}
   "main.cc"
   "my_application.cc"
-  "hot_restart_guard.cc"
   "${FLUTTER_MANAGED_DIR}/generated_plugin_registrant.cc"
 )
 
@@ -23,6 +22,5 @@ add_definitions(-DAPPLICATION_ID="${APPLICATION_ID}")
 # Add dependency libraries. Add any application-specific dependencies here.
 target_link_libraries(${BINARY_NAME} PRIVATE flutter)
 target_link_libraries(${BINARY_NAME} PRIVATE PkgConfig::GTK)
-target_link_libraries(${BINARY_NAME} PRIVATE ${CMAKE_DL_LIBS})
 
 target_include_directories(${BINARY_NAME} PRIVATE "${CMAKE_SOURCE_DIR}")

apps/desktop/linux/runner/hot_restart_guard.cc

@@ -1,69 +0,0 @@
-#include "hot_restart_guard.h"
-
-#ifdef NDEBUG
-
-void hot_restart_guard_attach(FlView* view) {}
-
-#else
-
-#include <dlfcn.h>
-#include <stdint.h>
-#include <unistd.h>
-
-namespace {
-
-// Mirrors media_kit's NativeReferenceHolder (debug only): a calloc'd buffer
-// of kReferenceBufferSize intptr slots holding live mpv_handle addresses,
-// its address written in decimal to <tmp>/<kFilePrefix><pid>.
-constexpr int kReferenceBufferSize = 512;
-constexpr char kFilePrefix[] = "com.alexmercerind.media_kit.NativeReferenceHolder.";
-
-using SetWakeupCallback = void (*)(void* ctx, void (*cb)(void*), void* d);
-
-SetWakeupCallback find_set_wakeup_callback() {
-  static const char* const kNames[] = {"libmpv.so.2", "libmpv.so", "libmpv.so.1"};
-  for (const char* name : kNames) {
-    void* lib = dlopen(name, RTLD_NOW | RTLD_NOLOAD);
-    if (lib == nullptr) continue;
-    auto fn = reinterpret_cast<SetWakeupCallback>(
-        dlsym(lib, "mpv_set_wakeup_callback"));
-    dlclose(lib);  // Drops only the reference NOLOAD added.
-    if (fn != nullptr) return fn;
-  }
-  return nullptr;
-}
-
-// Runs on the engine's UI thread before the old isolate shuts down, so the
-// buffer is not being written concurrently. Clearing the callback takes the
-// same lock mpv calls it under: once this returns, mpv never calls it again.
-// The handles stay in the buffer: media_kit's startup in the new isolate
-// still sends them "quit".
-void on_pre_engine_restart(FlEngine* engine, gpointer user_data) {
-  g_autofree gchar* name = g_strdup_printf("%s%d", kFilePrefix, getpid());
-  g_autofree gchar* path = g_build_filename(g_get_tmp_dir(), name, nullptr);
-  g_autofree gchar* contents = nullptr;
-  if (!g_file_get_contents(path, &contents, nullptr, nullptr)) return;
-  const guint64 address = g_ascii_strtoull(contents, nullptr, 10);
-  if (address == 0) return;
-  const SetWakeupCallback set_wakeup = find_set_wakeup_callback();
-  if (set_wakeup == nullptr) return;
-  const auto* slots = reinterpret_cast<const intptr_t*>(address);
-  int cleared = 0;
-  for (int i = 0; i < kReferenceBufferSize; i++) {
-    if (slots[i] == 0) continue;
-    set_wakeup(reinterpret_cast<void*>(slots[i]), nullptr, nullptr);
-    cleared++;
-  }
-  if (cleared > 0) {
-    g_message("hot restart: unhooked %d mpv wakeup callback(s)", cleared);
-  }
-}
-
-}  // namespace
-
-void hot_restart_guard_attach(FlView* view) {
-  g_signal_connect(fl_view_get_engine(view), "on-pre-engine-restart",
-                   G_CALLBACK(on_pre_engine_restart), nullptr);
-}
-
-#endif

apps/desktop/linux/runner/hot_restart_guard.h

@@ -1,13 +0,0 @@
-#ifndef RUNNER_HOT_RESTART_GUARD_H_
-#define RUNNER_HOT_RESTART_GUARD_H_
-
-#include <flutter_linux/flutter_linux.h>
-
-// Debug builds: before a hot restart tears the Dart isolate down, unhooks
-// the libmpv wakeup callbacks that media_kit's players point at that
-// isolate's NativeCallables. Without this, the next mpv event on a leftover
-// player calls into freed code and the process dies (SIGSEGV on mpv's
-// "core" thread). No-op in profile/release.
-void hot_restart_guard_attach(FlView* view);
-
-#endif  // RUNNER_HOT_RESTART_GUARD_H_

apps/desktop/linux/runner/my_application.cc

@@ -6,7 +6,6 @@
 #endif
 
 #include "flutter/generated_plugin_registrant.h"
-#include "hot_restart_guard.h"
 
 struct _MyApplication {
   GtkApplication parent_instance;
@@ -88,7 +87,6 @@ static void my_application_activate(GApplication* application) {
   gtk_widget_realize(GTK_WIDGET(view));
 
   fl_register_plugins(FL_PLUGIN_REGISTRY(view));
-  hot_restart_guard_attach(view);
 
   gtk_widget_grab_focus(GTK_WIDGET(view));
 }

apps/desktop/pubspec.lock

@@ -228,11 +228,11 @@ packages:
     dependency: "direct main"
     description:
       path: "."
-      ref: "v0.1.7"
+      ref: "v0.1.8"
-      resolved-ref: dc16bba05491f54daf528ed83484ea9b6eab8825
+      resolved-ref: d2435a06b26d4f94c3c3777e6ef006ac84f4eef4
       url: "https://git.senkochan.moe/Foxyz/fox_utils.git"
     source: git
-    version: "0.1.7"
+    version: "0.1.8"
   hive_ce:
     dependency: "direct main"
     description:

apps/desktop/pubspec.yaml

@@ -29,7 +29,7 @@ dependencies:
   fox_utils:
     git:
       url: https://git.senkochan.moe/Foxyz/fox_utils.git
-      ref: v0.1.7
+      ref: v0.1.8
 dev_dependencies:
   flutter_test:
     sdk: flutter

docs/DEVELOPMENT.md

@@ -131,11 +131,11 @@ unexpectedly` line just before it is expected. Without the app:
 - Hot restart with any media_kit `Player` alive (session, thumbnails, sfx)
   used to SIGSEGV on mpv's `core` thread: each mpv handle's wakeup callback
   is a `NativeCallable` of the old isolate, freed by the restart, and media_kit
-  then sends the leftover handles `quit`, which fires it. The Linux runner
+  then sends the leftover handles `quit`, which fires it. `fox_utils`' Linux
-  (`linux/runner/hot_restart_guard.cc`, debug builds only) clears those
+  plugin (from 0.1.8, debug builds only) clears those callbacks on the
-  callbacks on the engine's `on-pre-engine-restart` signal, reading the
+  engine's `on-pre-engine-restart` signal, reading the handles from
-  handles from media_kit's debug-only `NativeReferenceHolder` buffer (address
+  media_kit's debug-only `NativeReferenceHolder` buffer (address in
-  in `$TMPDIR/com.alexmercerind.media_kit.NativeReferenceHolder.<pid>`). Old
+  `$TMPDIR/com.alexmercerind.media_kit.NativeReferenceHolder.<pid>`). Old
   players are leaked, not destroyed, until the process exits. Re-check this
   after a media_kit upgrade.
 - mpv reconnect flags: comma form works, colon form is rejected. Re-verify