From 493cf5648faff9a27c1604ecf422986fb7d93fcc Mon Sep 17 00:00:00 2001
From: Mingbo <1418561105@qq.com>
Date: Tue, 25 Jun 2024 13:42:54 +0800
Subject: [PATCH] Repair crash when event comes between default listener set
 and enable() called. (#493)

---
 .../cyclonedds/core/EntityDelegate.hpp        |  1 +
 .../cyclonedds/core/EntityDelegate.cpp        | 25 ++++++++++++++++---
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/src/ddscxx/include/org/eclipse/cyclonedds/core/EntityDelegate.hpp b/src/ddscxx/include/org/eclipse/cyclonedds/core/EntityDelegate.hpp
index 000f917a..dfff0684 100644
--- a/src/ddscxx/include/org/eclipse/cyclonedds/core/EntityDelegate.hpp
+++ b/src/ddscxx/include/org/eclipse/cyclonedds/core/EntityDelegate.hpp
@@ -131,6 +131,7 @@ class OMG_DDS_API EntityDelegate :
     dds::core::status::StatusMask listener_mask;
     long callback_count;
     dds_listener_t *listener_callbacks;
+    dds_listener_t *temp_listener_callbacks;
 
 private:
     void *listener;
diff --git a/src/ddscxx/src/org/eclipse/cyclonedds/core/EntityDelegate.cpp b/src/ddscxx/src/org/eclipse/cyclonedds/core/EntityDelegate.cpp
index 284d4f5f..cabb6db8 100644
--- a/src/ddscxx/src/org/eclipse/cyclonedds/core/EntityDelegate.cpp
+++ b/src/ddscxx/src/org/eclipse/cyclonedds/core/EntityDelegate.cpp
@@ -36,6 +36,7 @@ org::eclipse::cyclonedds::core::EntityDelegate::EntityDelegate() :
   enabled_(false),
   listener_mask(0),
   listener_callbacks(NULL),
+  temp_listener_callbacks(NULL),
   listener(NULL)
 {
   this->callback_mutex = dds_alloc (sizeof (ddsrt_mutex_t));
@@ -58,6 +59,15 @@ org::eclipse::cyclonedds::core::EntityDelegate::~EntityDelegate()
   }
   this->listener_callbacks = NULL;
 
+  if (this->temp_listener_callbacks != NULL)
+  {
+      void *arg;
+      dds_lget_data_available_arg(this->temp_listener_callbacks, nullptr, &arg, nullptr);
+      dds_delete_listener(this->temp_listener_callbacks);
+      delete reinterpret_cast<org::eclipse::cyclonedds::core::ListenerArg *>(arg);
+  }
+    this->temp_listener_callbacks = NULL;
+
   ddsrt_cond_destroy (static_cast<ddsrt_cond_t*>(this->callback_cond));
   ddsrt_mutex_destroy (static_cast<ddsrt_mutex_t*>(this->callback_mutex));
   dds_free (this->callback_cond);
@@ -228,16 +238,23 @@ org::eclipse::cyclonedds::core::EntityDelegate::listener_set(
     }
 
     // Delete previous ddsc listener callbacks object
-    if (this->listener_callbacks != NULL)
-    {
+    if (this->enabled_ && this->listener_callbacks != nullptr) {
         void *prev_arg;
         dds_lget_data_available_arg(this->listener_callbacks, nullptr, &prev_arg, nullptr);
         dds_delete_listener(this->listener_callbacks);
         delete reinterpret_cast<org::eclipse::cyclonedds::core::ListenerArg *>(prev_arg);
+    } else if (this->temp_listener_callbacks != nullptr) {
+        void *prev_arg;
+        dds_lget_data_available_arg(this->temp_listener_callbacks, nullptr, &prev_arg, nullptr);
+        dds_delete_listener(this->temp_listener_callbacks);
+        delete reinterpret_cast<org::eclipse::cyclonedds::core::ListenerArg *>(prev_arg);
     }
 
-    // Store new listener
-    this->listener_callbacks = callbacks;
+    if (this->listener_callbacks == nullptr || this->enabled_) {
+        this->listener_callbacks = callbacks;
+    } else {
+        this->temp_listener_callbacks = callbacks;
+    }
 }
 
 void * org::eclipse::cyclonedds::core::EntityDelegate::listener_get () const