Fix tcore event loop timer writing to closed pipe

A delayed PostTask schedules a GLib timeout that writes to the wakeup
pipe. The timeout was untracked, so one pending at destruction would
fire after the loop closed pipe_fds_[1], writing to a closed or reused
fd. Share a liveness flag with the timeout callback so it skips the
write once the loop is destroyed.

Author: JSUYA

flutter/shell/platform/tizen/tizen_event_loop.cc

@@ -34,6 +34,7 @@ TizenEventLoop::TizenEventLoop(std::thread::id main_thread_id,
 }
 
 TizenEventLoop::~TizenEventLoop() {
+  alive_->store(false);
   if (pipe_watch_id_ > 0) {
     g_source_remove(pipe_watch_id_);
   }
@@ -93,19 +94,23 @@ void TizenEventLoop::PostTask(FlutterTask flutter_task,
   const double flutter_duration =
       static_cast<double>(flutter_target_time_nanos) - get_current_time_();
   if (flutter_duration > 0) {
-    int* pipe_write_fd = new int(pipe_fds_[1]);
+    struct TimeoutContext {
+      std::shared_ptr<std::atomic<bool>> alive;
+      int fd;
+    };
+    auto* context = new TimeoutContext{alive_, pipe_fds_[1]};
     g_timeout_add(
         static_cast<guint>(flutter_duration / 1000000.0),
         [](gpointer data) -> gboolean {
-          int* fd = static_cast<int*>(data);
-          if (*fd >= 0) {
+          auto* context = static_cast<TimeoutContext*>(data);
+          if (context->alive->load() && context->fd >= 0) {
             char c = 1;
-            write(*fd, &c, 1);
+            write(context->fd, &c, 1);
           }
-          delete fd;
+          delete context;
           return G_SOURCE_REMOVE;
         },
-        pipe_write_fd);
+        context);
   } else {
     if (pipe_fds_[1] >= 0) {
       char c = 1;

flutter/shell/platform/tizen/tizen_event_loop.h

@@ -12,6 +12,7 @@
 #include <chrono>
 #include <deque>
 #include <functional>
+#include <memory>
 #include <mutex>
 #include <queue>
 #include <set>
@@ -77,6 +78,10 @@ class TizenEventLoop {
   int pipe_fds_[2] = {-1, -1};
   GIOChannel* pipe_channel_ = nullptr;
   guint pipe_watch_id_ = 0;
+  // Shared with pending timeout callbacks so they can detect that this loop was
+  // destroyed and skip writing to the (now closed) pipe.
+  std::shared_ptr<std::atomic<bool>> alive_ =
+      std::make_shared<std::atomic<bool>>(true);
 
   // Returns a TaskTimePoint computed from the given target time from Flutter.
   TaskTimePoint TimePointFromFlutterTime(uint64_t flutter_target_time_nanos);