atomicity in C++

Question

Data synchronization

Good day!

There was a problem: it is necessary to synchronize flows through testAndSet: But here with atomic a problem, and without it in any way. Can you tell me a library for atomically changing a variable in C++?
int atomic testAndSet ( char *lock ) {
char var;
var = *lock;
*lock = 1;
return var;
}


Answer 1

Without cross-platform requirements, you can use WInAPI and its Interlocked* functions.

Answer 2

I won't answer your specific question. But I myself write in the U ++ framework, where all these things are present in a cross-platform form:
Atomic t;
AtomicWrite(t, 1);

Answer 3

GCC has built-in functions like _sync_val_compare_and_swap().
Under Solaris, you can #include <atomic.h> where there are functions like atomic_cas().
Under Windows - API from the InterlockedCompareExchange () category.
I don't know of a universal solution. Several times I met inline assembler for this case under #ifdefs for different platforms.