What does "atomic" mean in programming? - Stack Overflow
May 8, 2015 · In the Effective Java book, it states: The language specification guarantees that reading or writing a variable is atomic unless the variable is of type long or double [JLS, 17.4.7]. What do...
c++ - What exactly is std::atomic? - Stack Overflow
Aug 13, 2015 · Objects of atomic types are the only C++ objects that are free from data races; that is, if one thread writes to an atomic object while another thread reads from it, the behavior is well-defined. …
c++ - Cross-platform Support for 128-bit Atomic Operations in Clang ...
Jun 19, 2025 · We are currently evaluating 128-bit atomic operation support across platforms and compilers, and I wanted to confirm the level of support available in Clang specifically. Our reference …
Which types on a 64-bit computer are naturally atomic in gnu C and …
Apr 14, 2022 · I had a 25-hr debugging marathon in < 2 days and then wrote this answer here. See also the bottom of this question for more info. and documentation on 8-bit variables having naturally …
When should std::atomic_compare_exchange_strong be used?
Jul 29, 2013 · There are two atomic CAS operations in C++11: atomic_compare_exchange_weak and atomic_compare_exchange_strong. According to cppreference: The weak forms of the functions are …
When do I really need to use atomic<bool> instead of bool?
May 1, 2013 · You need atomic<bool> to avoid race-conditions. A race-condition occurs if two threads access the same memory location, and at least one of them is a write operation. If your program …
c++ - What is the difference between load/store relaxed atomic and ...
Sep 9, 2020 · 11 The difference is that a normal load/store is not guaranteed to be tear-free, whereas a relaxed atomic read/write is. Also, the atomic guarantees that the compiler doesn't rearrange or …
c++ - the gist behind atomic shared pointer - Stack Overflow
Jan 23, 2025 · At least atomic<shared_ptr<T>> gives you per-object locking, instead of a single lock for the whole stack. So multiple threads can be waiting for different locks if multiple pops start in parallel.
How to guarantee 64-bit writes are atomic? - Stack Overflow
Apr 6, 2015 · When can 64-bit writes be guaranteed to be atomic, when programming in C on an Intel x86-based platform (in particular, an Intel-based Mac running MacOSX 10.4 using the Intel …
Are C/C++ fundamental types atomic? - Stack Overflow
Feb 6, 2016 · Are C/C++ fundamental types, like int, double, etc., atomic, e.g. threadsafe? Are they free from data races; that is, if one thread writes to an object of such a type while another thread reads fr...