c++ - Is pointer dereferencing atomic? -


lets have pointer integer. 

volatile int* commonpointer = new int();

and have multiple threads dereference pointer.

int blah = *commonpointer;

but, 1 thread needs change pointer's address:

int* temp = new int(); int* old = commonpointer; interlockedexchange(&commonpointer,temp); delete old;

now, lets ignore fact threads may reading "old" value, , may reading "new" value, that's not issue in case.

can there scenario 1 thread starts dereference pointer, address deleted, , gets exception ?
or dereferencing atomic enough won't happen ?

nothing in c++ standard guarantees atomicity in case.

you must protect relevant code areas mutex: std::atomic not enough since provide atomic access pointer not include dereference operation.


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