fix lock leak in session_container_impl

project-tsurugi · Apr 18, 2024 · 4d78934 · 4d78934
1 parent d7514a5
commit 4d78934
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Showing 2 changed files with 24 additions and 6 deletions.
diff --git a/src/tateyama/session/resource/container_impl.cpp b/src/tateyama/session/resource/container_impl.cpp
@@ -19,8 +19,18 @@
 namespace tateyama::session::resource {
 
 bool session_container_impl::register_session(std::shared_ptr<session_context_impl> const& session) {
-    foreach([](const std::shared_ptr<session_context>&) {});
+    std::unique_lock lock{mtx_};
 
+    for (auto&& it = session_contexts_.begin(), last = session_contexts_.end(); it != last;) {
+        if (auto sp = (*it).lock(); sp) {
+            ++it;
+        } else {
+            it = session_contexts_.erase(it);
+        }
+    }
+    if (session_contexts_.find(session) != session_contexts_.end()) {
+        return false;
+    }
     session_contexts_.emplace(session);
     return true;
 }

diff --git a/src/tateyama/session/resource/container_impl.h b/src/tateyama/session/resource/container_impl.h
@@ -47,19 +47,27 @@ class session_container_impl : public tateyama::session::session_container {
      */
     virtual ~session_container_impl() = default;
 
-    bool register_session(std::shared_ptr<session_context_impl> const& session);
-
-    void foreach(const std::function<void(const std::shared_ptr<session_context>&)>& func) override;
-
     session_container_impl(session_container_impl const&) = delete;
     session_container_impl(session_container_impl&&) = delete;
     session_container_impl& operator = (session_container_impl const&) = delete;
     session_container_impl& operator = (session_container_impl&&) = delete;
 
+    /**
+     * @brief registers a new session context.
+     * @param session the session context to register
+     * @return true if the target session is successfully registered
+     * @return false if the target session is not registered
+     *    because another session with such the numeric ID already exists in this container
+     * @note Session labels may duplicate in this container
+     */
+    bool register_session(std::shared_ptr<session_context_impl> const& session);
+
+    void foreach(const std::function<void(const std::shared_ptr<session_context>&)>& func) override;
+
 private:
     std::set<std::weak_ptr<session_context_impl>, address_compare> session_contexts_{};
 
-    std::mutex mtx_{};
+    mutable std::mutex mtx_{};
 };
 
 }