Is the ternary operator (?:) thread safe in C#?

Question

Consider the following two alternatives of getting the higher number between currentPrice and 100...

int price = currentPrice > 100 ? currentPrice : 100

int price = Math.Max(currentPrice, 100)

I raised this question because I was thinking about a context where the currentPrice variable could be edited by other threads.

In the first case... could price obtain a value lower than 100?

I'm thinking about the following:

if (currentPrice > 100) {
    //currentPrice is edited here.
    price = currentPrice;
}

Answer 1

It is not threadsafe.

?: is just shortcut for normal if, so your if sample is equivalent to ? one - you can get price lower than 100 if there is no locking outside this code.

Answer 2

Not a specialist in C#, but even var++ is not thread save, since may translated to from reading into/writing from register in assembly.

Ternary operator is far more complicated. It has 3 parts, while each part can be endlessly big (e.g. call to some function). Therefore, it's pretty easy to conclude that ternary operator is not thread safe.