check for removed observer (#13)

* check for removed observer

* update Readme

Author: TheLartians

.travis.yml

@@ -64,13 +64,8 @@ after_success:
   - cmake -H. -Bbuild/coverage -DCMAKE_BUILD_TYPE=Debug -DLARS_EVENT_ENABLE_TESTS=On -DENABLE_TEST_COVERAGE=On -DCMAKE_CXX_COMPILER=g++-8
   - cmake --build build/coverage
   - cmake --build build/coverage --target test
-  # collect coverage data
-  - lcov --gcov-tool $(which gcov-8) --directory . --capture --output-file coverage.info
-  # remove lib files
-  - lcov --gcov-tool $(which gcov-8) --remove coverage.info '/usr/*' "${HOME}"'/.cache/*' --output-file coverage.info
-  # remove test files
-  - lcov --gcov-tool $(which gcov-8) --remove coverage.info $(pwd)/tests/*.cpp  --output-file coverage.info
-  # print coverage info
+  # create coverage report
+  - lcov --gcov-tool $(which gcov-8) --directory . --capture --no-external --exclude "*tests*" --exclude "*_deps*" --quiet --output-file coverage.info
+  # output coverage
   - lcov --gcov-tool $(which gcov-8) --list coverage.info
-  # upload coverage data
   - bash <(curl -s https://codecov.io/bash) -f coverage.info || echo "Codecov did not collect coverage reports"

CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
 # ---- Project ----
 
 project(LarsEvent 
-  VERSION 2.0.2
+  VERSION 2.0.3
   LANGUAGES CXX
 )
 

README.md

@@ -36,7 +36,7 @@ With [CPM](https://github.com/TheLartians/CPM), lars::Event can be used in a CMa
 ```cmake
 CPMAddPackage(
   NAME LarsEvent
-  VERSION 2.0.2
+  VERSION 2.0.3
   GIT_REPOSITORY https://github.com/TheLartians/Event.git
 )
 

include/lars/event.h

@@ -5,6 +5,7 @@
 #include <vector>
 #include <utility>
 #include <mutex>
+#include <algorithm>
 
 namespace lars{
 
@@ -45,7 +46,7 @@ namespace lars{
 
     struct StoredHandler {
       HandlerID id;
-      Handler callback;
+      std::shared_ptr<Handler> callback;
     };
 
     using HandlerList = std::vector<StoredHandler>;
@@ -60,7 +61,7 @@ namespace lars{
 
     HandlerID addHandler(Handler h)const{
       std::lock_guard<std::mutex> lock(data->observerMutex);
-      data->observers.emplace_back(StoredHandler{data->IDCounter,h});
+      data->observers.emplace_back(StoredHandler{data->IDCounter,std::make_shared<Handler>(h)});
       return data->IDCounter++;
     }
 
@@ -108,11 +109,17 @@ namespace lars{
     }
 
     void emit(Args ... args) const {
+      std::vector<std::weak_ptr<Handler>> handlers;
+      handlers.resize(data->observers.size());
       data->observerMutex.lock();
-      auto tmpObservers = data->observers;
+      std::transform(data->observers.begin(), data->observers.end(), handlers.begin(), [](auto &h){
+        return h.callback;
+      });
       data->observerMutex.unlock();
-      for(auto &observer: tmpObservers){
-        observer.callback(args...);
+      for(auto &weakCallback: handlers){
+        if(auto callback = weakCallback.lock()){
+          (*callback)(args...);
+        }
       }
     }
 

tests/CMakeLists.txt

@@ -31,6 +31,7 @@ set_target_properties(lars-event-tests PROPERTIES CXX_STANDARD 17 COMPILE_FLAGS
 
 ENABLE_TESTING() 
 ADD_TEST(lars-event-tests lars-event-tests)
+
 # ---- code coverage ----
 
 if (${ENABLE_TEST_COVERAGE})

tests/event.cpp

@@ -59,11 +59,21 @@ TEST_CASE("Event"){
     lars::Event<> event;
     lars::Event<>::Observer observer;
     unsigned count = 0;
-    observer = event.createObserver([&](){ observer.reset(); count++; });
-    event.emit();
-    REQUIRE(count == 1);
-    event.emit();
-    REQUIRE(count == 1);
+    SECTION("self removing"){
+      observer = event.createObserver([&](){ observer.reset(); count++; });
+      event.emit();
+      REQUIRE(count == 1);
+      event.emit();
+      REQUIRE(count == 1);
+    }
+    SECTION("other removing"){
+      event.connect([&](){ observer.reset(); });
+      observer = event.createObserver([&](){ count++; });
+      event.emit();
+      REQUIRE(count == 0);
+      event.emit();
+      REQUIRE(count == 0);
+    }
   }
 
   SECTION("adding observers during emit"){