Are incrementers / decrementers (var++, var–) etc thread safe?

by

No, incrementing is not thread-safe. Neither are the INC and DEC instructions. They all require a load and a store, and a thread running on another CPU could do its own load or store on the same memory location interleaved between those operations.

Some languages have built-in support for thread synchronization, but it’s usually something you have to ask for, not something you get automatically on every variable. Those that don’t have built-in support usually have access to a library that provides similar functionality.

More Related Contents:

  1. What is the meaning of the term “thread-safe”?
  2. Asynchronous vs Multithreading – Is there a difference?
  3. What is thread contention?
  4. How to detect and debug multi-threading problems?
  5. Are “data races” and “race condition” actually the same thing in context of concurrent programming
  6. Simple Deadlock Examples
  7. What is the difference between a process and a thread?
  8. What is the difference between concurrency, parallelism and asynchronous methods?
  9. Multi-threading in VBA
  10. What is a mutex?
  11. Recursive Lock (Mutex) vs Non-Recursive Lock (Mutex)
  12. What will be used for data exchange between threads are executing on one Core with HT?
  13. Atomic UPDATE .. SELECT in Postgres
  14. Can Selenium use multi threading in one browser?
  15. Thread context switch Vs. process context switch
  16. Is NodeJS really Single-Threaded?
  17. How to make Qt work when main thread is busy?
  18. Difference between the TPL & async/await (Thread handling)
  19. Doxygen is Slow
  20. Running two threads at the same time
  21. Workaround for ncurses multi-thread read and write
  22. Multithreading: What is the point of more threads than cores?
  23. Does multithreading make sense for IO-bound operations?
  24. How efficient is locking and unlocked mutex? What is the cost of a mutex?
  25. Multithreaded & SIMD vectorized Mandelbrot in R using Rcpp & OpenMP
  26. How does x86 pause instruction work in spinlock *and* can it be used in other scenarios?
  27. Canonical way to generate random numbers in Cython
  28. Can a hyper-threaded processor core execute two threads at the exact same time?
  29. “Collection was mutated while being enumerated” on executeFetchRequest
  30. Prolog find all paths Implementation

Leave a Comment