From 974a6e30273c675dd267d632976977c1b1362a3b Mon Sep 17 00:00:00 2001
From: Antonio Filipovic <61245998+antoniofilipovic@users.noreply.github.com>
Date: Thu, 7 Sep 2023 17:42:27 +0200
Subject: [PATCH] Fix bug on mgp dispatcher guard (#1225)

---
 include/mgp.hpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/include/mgp.hpp b/include/mgp.hpp
index 2b1f0318d..8ffeeee46 100644
--- a/include/mgp.hpp
+++ b/include/mgp.hpp
@@ -126,6 +126,12 @@ class MemoryDispatcher final {
     map_.erase(this_id);
   }
 
+  bool IsThisThreadRegistered() noexcept {
+    const auto this_id = std::this_thread::get_id();
+    std::shared_lock lock(mut_);
+    return map_.contains(this_id);
+  }
+
  private:
   std::unordered_map<std::thread::id, mgp_memory *> map_;
   std::shared_mutex mut_;
@@ -136,7 +142,7 @@ class MemoryDispatcher final {
 // header. The use of the 'mgp_memory *memory' pointer is deprecated
 // and will be removed in upcoming releases.
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-inline extern MemoryDispatcher mrd{};
+inline MemoryDispatcher mrd{};
 
 // TODO - Once we deprecate this we should remove this
 // and make sure nothing relies on it anymore. This alone
@@ -164,7 +170,7 @@ class MemoryDispatcherGuard final {
 // the mapping instead.
 template <typename Func, typename... Args>
 inline decltype(auto) MemHandlerCallback(Func &&func, Args &&...args) {
-  if (memory) {
+  if (!mrd.IsThisThreadRegistered()) {
     return std::forward<Func>(func)(std::forward<Args>(args)..., memory);
   }
   return std::forward<Func>(func)(std::forward<Args>(args)..., mrd.GetMemoryResource());