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- What does atomic mean in programming? - Stack Overflow
"An operation acting on shared memory is atomic if it completes in a single step relative to other threads When an atomic store is performed on a shared memory, no other thread can observe the modification half-complete When an atomic load is performed on a shared variable, it reads the entire value as it appeared at a single moment in time "
- What are atomic operations for newbies? - Stack Overflow
Here, each upsert is atomic: the first one left count at 2, the second one left it at 3 Everything works Note that "atomic" is contextual: in this case, the upsert operation only needs to be atomic with respect to operations on the answers table in the database; the computer can be free to do other things as long as they don't affect (or are
- sql - What is atomicity in dbms - Stack Overflow
The definition of atomic is hazy; a value that is atomic in one application could be non-atomic in another For a general guideline, a value is non-atomic if the application deals with only a part of the value Eg: The current Wikipedia article on First NF (Normal Form) section Atomicity actually quotes from the introductory parts above
- What are atomic types in the C language? - Stack Overflow
The type sig_atomic_t is always an integer data type, but which one it is, and how many bits it contains, may vary from machine to machine Data Type: sig_atomic_t This is an integer data type Objects of this type are always accessed atomically In practice, you can assume that int is atomic You can also assume that pointer types are atomic
- When do I really need to use atomic lt;bool gt; instead of bool?
Using std::atomic::compare_exchange we can do the entire if swap logic atomically such that the other thread could not set a to false in between the if and the swap (without locking) In such a circumstance if the swap was made than b must be false on exit This is just one example of an atomic operation that applies to a two value type such as
- In C#, what does atomic mean? - Stack Overflow
If a processor word is 16 bits wide, a 16-bit MOV instruction will be atomic However, a 32-bit MOV operation would not be atomic Such a non-atomic MOV instruction is normally not provided by the instruction set but by some higher-level language as with C's long long or C#'s long Operations on these data types are not guaranteed to be atomic!
- What is the difference between atomic and critical in OpenMP?
Atomic Operations If, as in the example above, our critical section is a single assignment, OpenMP provides a potentially more efficient way of protecting this OpenMP provides an atomic directive which, like critical, specifies the next statement must be done by one thread at a time: #pragma omp atomic global_data++; Unlike a critical directive:
- difference between standards atomic bool and atomic flag
std::atomic<bool> std::atomic_flag The std::atomic_flag contains the following explanation: std::atomic_flag is an atomic boolean type Unlike all specializations of std::atomic, it is guaranteed to be lock-free Unlike std::atomic<bool>, std::atomic_flag does not provide load or store operations which I fail to understand
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