C++11 Implementation of Spinlock using header “

by

The problem is that compare_exchange_weak updates the unlatched variable once it fails. From the documentation of compare_exchange_weak:

Compares the contents of the atomic object’s contained value with
expected:
– if true, it replaces the contained value with val (like store).
– if false, it replaces expected with the contained value .

I.e., after the first failing compare_exchange_weak, unlatched will be updated to true, so the next loop iteration will try to compare_exchange_weak true with true. This succeeds and you just took a lock that was held by another thread.

Solution:
Make sure to set unlatched back to false before each compare_exchange_weak, e.g.:

while(!latch.compare_exchange_weak(unlatched, true, std::memory_order_acquire)) {
    unlatched = false;
}

More Related Contents:

  1. C++11 introduced a standardized memory model. What does it mean? And how is it going to affect C++ programming?
  2. How do I terminate a thread in C++11?
  3. Concurrency: Atomic and volatile in C++11 memory model
  4. Passing object by reference to std::thread in C++11
  5. Why don’t compilers merge redundant std::atomic writes?
  6. What are the correct link options to use std::thread in GCC under linux?
  7. std::thread pass by reference calls copy constructor
  8. C++11 thread-safe queue
  9. Difference between pointer and reference as thread parameter
  10. How to use std::async on a member function?
  11. How to give priority to privileged thread in mutex locking?
  12. Which std::async implementations use thread pools?
  13. C++0x thread interruption
  14. What causes runtime error message: std::system_error – operation not permitted, including mult-threading? [duplicate]
  15. What is the difference between packaged_task and async
  16. Get the status of a std::future
  17. std::thread is not a member of namespace std using Eclipse Kepler MinGW
  18. Is it smart to replace boost::thread and boost::mutex with c++11 equivalents?
  19. C++11 STL containers and thread safety
  20. Can I use std::async without waiting for the future limitation?
  21. Waiting for multiple futures?
  22. C++ terminate called without an active exception
  23. What is different between join() and detach() for multi threading in C++?
  24. std::thread error (thread not member of std)
  25. MinGW error: ‘thread’ is not a member of ‘std’
  26. Double-Checked Lock Singleton in C++11
  27. I want to kill a std::thread using its thread object? [duplicate]
  28. thread safety of MPI send using threads created with std::async
  29. GCC std::thread not found in namespace std
  30. Why does this simple std::thread example not work?

Leave a Comment