On Sat, 19 Feb 2011 21:55:53 -0500, Jonathan M Davis <[email protected]>
wrote:
On Saturday 19 February 2011 18:26:25 Steven Schveighoffer wrote:
I was working on an I/O library that I plan to use in development, and
possibly submit to phobos, and I thought of this case.
A standard file can be shared or unshared. In C, since there is no
notion
of shared/unshared, everything is shared. So any writes/reads from a
FILE
* lock the object.
But in D, we can avoid those locks when the file is unshared. However,
this means I have to write two pretty much identical functions for each
call.
Is there an expected way to do this? I've really avoided doing anything
with shared or threads since the new concurrency model came out, but
with
I/O, I'll have to deal with it.
I think a logical thing to do would be to have the shared version of the
function call the unshared version after locking the object. Is that a
good idea? Is the correct way to do this to mark the shared function
synchronized, and then cast 'this' to unshared to call the other
function? Does this automatically happen with shared functions?
I would point out that per TDPL, either an entire class is synchronized
or none
of it is. You don't synchronize individual functions. Now, I don' think
that
that's the way that it's implemented at the moment, but that's the
eventual
situation as I understand it. So, your class shouldn't have a mixture of
synchronized or unsynchronized. According to TDPL, it's illegal.
OK, I kind of remember that now. So that means, I need to create two
identical hierarchies, a synchronized one and a non-synchronized one?
I think what I'll do for now is write the non-synchronized versions, and
then see about maybe automating the synchronized parts.
-Steve
