Reworked code to use way less shared ptr locks

Signed-off-by: Janosch Machowinski <j.machowinski@nospam.org>

rclcpp/include/rclcpp/executors/cbg_executor.hpp

@@ -21,6 +21,7 @@
 #include <deque>
 #include <unordered_map>
 
+#include "rclcpp/executors/detail/any_executable_weak_ref.hpp"
 #include "rclcpp/executor.hpp"
 #include "rclcpp/executors/callback_group_state.hpp"
 #include "rclcpp/macros.hpp"
@@ -48,19 +49,20 @@ class ExecutionGroup
     next_unprocessed_ready_executable = 0;
   }
 
-  void add_ready_executable(const Executable & e)
+  void add_ready_executable(AnyExecutableWeakRef & e)
   {
-    ready_executables.push_back(e);
+    ready_executables.push_back(&e);
+//     ready_executables.push_back(std::get<const Executable>(e.executable));
   }
 
   bool has_unprocessed_executables()
   {
     for (; next_unprocessed_ready_executable < ready_executables.size();
       next_unprocessed_ready_executable++)
     {
-      const auto & ready_executable = ready_executables[next_unprocessed_ready_executable];
+      auto & ready_executable = ready_executables[next_unprocessed_ready_executable];
 
-      if (ready_executable.lock()) {
+      if (ready_executable->executable_alive()) {
         return true;
       }
     }
@@ -74,7 +76,7 @@ class ExecutionGroup
     {
       const auto & ready_executable = ready_executables[next_unprocessed_ready_executable];
 
-      if (fill_any_executable(any_executable, ready_executable)) {
+      if (fill_any_executable(any_executable, std::get<const Executable>(ready_executable->executable))) {
         // mark the current element as processed
         next_unprocessed_ready_executable++;
 
@@ -108,7 +110,7 @@ class ExecutionGroup
           return false;
         }
 
-        any_executable.data = *data;
+//         any_executable.data = *data;
 
         return true;
       //RCUTILS_LOG_INFO("Executing timer");
@@ -142,7 +144,7 @@ class ExecutionGroup
     return false;
   }
 
-  std::vector<Executable> ready_executables;
+  std::vector<AnyExecutableWeakRef *> ready_executables;
   size_t next_unprocessed_ready_executable = 0;
 
 };
@@ -166,11 +168,11 @@ class CallbackGroupScheduler
 
   void clear_and_prepare(const CallbackGroupState & cb_elements);
 
-  void add_ready_executable(const rclcpp::SubscriptionBase::WeakPtr & executable);
-  void add_ready_executable(const rclcpp::ServiceBase::WeakPtr & executable);
-  void add_ready_executable(const rclcpp::TimerBase::WeakPtr & executable);
-  void add_ready_executable(const rclcpp::ClientBase::WeakPtr & executable);
-  void add_ready_executable(const rclcpp::Waitable::WeakPtr & executable);
+  void add_ready_timer(AnyExecutableWeakRef & executable);
+  void add_ready_subscription(AnyExecutableWeakRef & executable);
+  void add_ready_service(AnyExecutableWeakRef & executable);
+  void add_ready_client(AnyExecutableWeakRef & executable);
+  void add_ready_waitable(AnyExecutableWeakRef & executable);
 
   enum Priorities
   {

rclcpp/include/rclcpp/executors/detail/any_executable_weak_ref.hpp

@@ -5,6 +5,7 @@
 #include "rclcpp/client.hpp"
 #include "rclcpp/waitable.hpp"
 #include "rclcpp/guard_condition.hpp"
+#include "rclcpp/executors/callback_group_state.hpp"
 
 namespace rclcpp::executors
 {
@@ -17,27 +18,72 @@ struct AnyExecutableWeakRef
   AnyExecutableWeakRef(const rclcpp::SubscriptionBase::WeakPtr & p, int16_t callback_group_index)
   : executable(p),
     callback_group_index(callback_group_index)
-  {}
+  {
+    if(auto shr = p.lock())
+    {
+      rcl_handle_shr_ptr = shr->get_subscription_handle();
+    }
+    else
+    {
+      rcl_handle_shr_ptr = std::monostate();
+    }
+  }
 
   AnyExecutableWeakRef(const rclcpp::TimerBase::WeakPtr & p, int16_t callback_group_index)
   : executable(p),
     callback_group_index(callback_group_index)
-  {}
+  {
+    if(auto shr = p.lock())
+    {
+      rcl_handle_shr_ptr = shr->get_timer_handle();
+    }
+    else
+    {
+      rcl_handle_shr_ptr = std::monostate();
+    }
+  }
 
   AnyExecutableWeakRef(const rclcpp::ServiceBase::WeakPtr & p, int16_t callback_group_index)
   : executable(p),
     callback_group_index(callback_group_index)
-  {}
+  {
+    if(auto shr = p.lock())
+    {
+      rcl_handle_shr_ptr = shr->get_service_handle();
+    }
+    else
+    {
+      rcl_handle_shr_ptr = std::monostate();
+    }
+  }
 
   AnyExecutableWeakRef(const rclcpp::ClientBase::WeakPtr & p, int16_t callback_group_index)
   : executable(p),
     callback_group_index(callback_group_index)
-  {}
+  {
+    if(auto shr = p.lock())
+    {
+      rcl_handle_shr_ptr = shr->get_client_handle();
+    }
+    else
+    {
+      rcl_handle_shr_ptr = std::monostate();
+    }
+  }
 
   AnyExecutableWeakRef(const rclcpp::Waitable::WeakPtr & p, int16_t callback_group_index)
   : executable(p),
     callback_group_index(callback_group_index)
-  {}
+  {
+    if(auto shr = p.lock())
+    {
+      rcl_handle_shr_ptr = shr;
+    }
+    else
+    {
+      rcl_handle_shr_ptr = std::monostate();
+    }
+  }
 
   AnyExecutableWeakRef(
     const rclcpp::GuardCondition::WeakPtr & p,
@@ -49,6 +95,76 @@ struct AnyExecutableWeakRef
   {
     //special case, guard conditions are auto processed by waking up the wait set
     // therefore they shall never create a real executable
+
+    {
+    if(auto shr = p.lock())
+    {
+      rcl_handle_shr_ptr = shr;
+    }
+    else
+    {
+      rcl_handle_shr_ptr = std::monostate();
+    }
+  }
+
+
+  }
+
+  /**
+   * Checks, if the executable still exists, or if was deleted
+   */
+  bool executable_alive()
+  {
+    auto check_valid = [this] (const auto &shr_ptr)
+    {
+      auto use_cnt = shr_ptr.use_count();
+       if(use_cnt <= 1)
+       {
+         rcl_handle_shr_ptr = std::monostate();
+         return false;
+       }
+
+       return true;
+    };
+
+    switch(rcl_handle_shr_ptr.index()) {
+      case AnyExecutableWeakRef::ExecutableIndex::Subscription:
+          {
+            return check_valid(std::get<std::shared_ptr<rcl_subscription_t>>(rcl_handle_shr_ptr));
+          }
+          break;
+        case AnyExecutableWeakRef::ExecutableIndex::Timer:
+          {
+            return check_valid(std::get<std::shared_ptr<const rcl_timer_t>>(rcl_handle_shr_ptr));
+          }
+          break;
+        case AnyExecutableWeakRef::ExecutableIndex::Service:
+          {
+            return check_valid(std::get<std::shared_ptr<rcl_service_t>>(rcl_handle_shr_ptr));
+          }
+          break;
+        case AnyExecutableWeakRef::ExecutableIndex::Client:
+          {
+            return check_valid(std::get<std::shared_ptr<rcl_client_t>>(rcl_handle_shr_ptr));
+          }
+          break;
+        case AnyExecutableWeakRef::ExecutableIndex::Waitable:
+          {
+            return check_valid(std::get<std::shared_ptr<rclcpp::Waitable>>(rcl_handle_shr_ptr));
+          }
+          break;
+        case AnyExecutableWeakRef::ExecutableIndex::GuardCondition:
+          {
+            return check_valid(std::get<std::shared_ptr<rclcpp::GuardCondition>>(rcl_handle_shr_ptr));
+          }
+        case AnyExecutableWeakRef::ExecutableIndex::Deleted:
+          {
+            return false;
+          }
+          break;
+
+      }
+      return false;
   }
 
  AnyExecutableWeakRef(const AnyExecutableWeakRef &) = delete;
@@ -69,10 +185,16 @@ struct AnyExecutableWeakRef
     Client,
     Waitable,
     GuardCondition,
+    Deleted,
   };
 
   // shared_ptr holding the rcl handle during wait
-  std::shared_ptr<const void> rcl_handle_shr_ptr;
+
+  using RclHandleVariant = std::variant<std::shared_ptr<rcl_subscription_t>, std::shared_ptr<const rcl_timer_t>,
+    std::shared_ptr<rcl_service_t>, std::shared_ptr<rcl_client_t>,
+    rclcpp::Waitable::SharedPtr, rclcpp::GuardCondition::SharedPtr, std::monostate>;
+
+  RclHandleVariant rcl_handle_shr_ptr;
 
   // A function that should be executed if the executable is a guard condition and ready
   std::function<void(void)> handle_guard_condition_fun;