<Ramesh@discussions.microsoft.com> wrote:

> Are primitive types like bool threadsafe ? Or do we need to use
> synchronization when multiple threads concurrently access a value type ?

> Are primitive types like bool threadsafe ? Or do we need to use
> synchronization when multiple threads concurrently access a value type ?
>
> Thanks,
> Ramesh

"Peter Duniho" wrote:

> On Fri, 18 Apr 2008 13:20:00 -0700, Ramesh
> <Ramesh@discussions.microsoft.com> wrote:
>
> > Are primitive types like bool threadsafe ? Or do we need to use
> > synchronization when multiple threads concurrently access a value type ?
>
> 32-bit primitives are _sort of_, provided you qualify them with
> "volatile". By "sort of" I mean that you can reliably read the value
> atomically and write the value atomically. Provided only one writer at
> most, you can safely assume that reads will get the entire value, rather
> than a partially updated value.
>
> Other than that, no...they are not thread-safe. For example, incrementing
> an integer or toggling a boolean requires that you read the value first,
> calculate the new value, and then write the new value. Those three
> operations together aren't automatically done atomically, and so you need
> to synchronize access when doing something like that.
>
> Pete