👀 Views: 50 💬 Answers: 1 📅 Created: 2025-06-02

C++17 std::shared_ptr multi-threading cpp

I'm a bit lost with I'm sure I'm missing something obvious here, but I’m encountering a segmentation fault when trying to manage a resource using `std::shared_ptr` with a custom deleter in a C++17 multi-threaded application. The shared pointer is initialized with a custom deleter that logs the deletion, but during concurrent access from multiple threads, the application crashes with the message: `Segmentation fault (core dumped)`. Here is a simplified version of the code: ```cpp #include <iostream> #include <memory> #include <thread> #include <vector> struct Resource { int id; Resource(int id) : id(id) { std::cout << "Resource " << id << " created\n"; } ~Resource() { std::cout << "Resource " << id << " destroyed\n"; } }; void customDeleter(Resource* res) { std::cout << "Custom deleter called for Resource " << res->id << "\n"; delete res; } void threadFunction(std::shared_ptr<Resource> res) { std::this_thread::sleep_for(std::chrono::milliseconds(100)); std::cout << "Thread accessing Resource " << res->id << "\n"; } int main() { std::vector<std::shared_ptr<Resource>> resources; for (int i = 0; i < 5; ++i) { resources.emplace_back(std::shared_ptr<Resource>(new Resource(i), customDeleter)); } std::vector<std::thread> threads; for (auto& res : resources) { threads.emplace_back(threadFunction, res); } for (auto& t : threads) { t.join(); } return 0; } ``` In this example, I create multiple threads that access the same `std::shared_ptr<Resource>`. I believe the segmentation fault occurs when the `shared_ptr` is going out of scope while another thread is accessing it. I tried ensuring that the `shared_ptr` instances remain valid for the lifetime of the threads, but the issue persists. Could there be an issue with the way I'm initializing the `shared_ptr` with the custom deleter, or is it related to the multi-threaded access? Any suggestions or insights would be greatly appreciated! This is part of a larger API I'm building. Thanks in advance! For reference, this is a production mobile app. Cheers for any assistance!