On 2012-11-14 10:30:46 +0000, Timon Gehr <timon.g...@gmx.ch> said:
On 11/14/2012 04:12 AM, Michel Fortin wrote:
On 2012-11-13 19:54:32 +0000, Timon Gehr <timon.g...@gmx.ch> said:
On 11/12/2012 02:48 AM, Michel Fortin wrote:
I feel like the concurrency aspect of D2 was rushed in the haste of
having it ready for TDPL. Shared, deadlock-prone synchronized classes[1]
as well as destructors running in any thread (thanks GC!) plus a couple
of other irritants makes the whole concurrency scheme completely flawed
if you ask me. D2 needs a near complete overhaul on the concurrency
front.
I'm currently working on a big code base in C++. While I do miss D when
it comes to working with templates as well as for its compilation speed
and a few other things, I can't say I miss D much when it comes to
anything touching concurrency.
[1]: http://michelf.ca/blog/2012/mutex-synchonization-in-d/
I am always irritated by shared-by-default static variables.
I tend to have very little global state in my code,
So do I. A thread-local static variable does not imply global state.
(The execution stack is static.) Eg. in a few cases it is sensible to
use static variables as implicit arguments to avoid having to pass them
around by copying them all over the execution stack.
private int x = 0;
int foo(){
int xold = x;
scope(exit) x = xold;
x = new_value;
bar(); // reads x
return baz(); // reads x
}
I'd consider that poor style. Use a struct to encapsulate the state,
then make bar, and baz member functions of that struct. The resulting
code is cleaner and easier to read:
pure int foo() {
auto state = State(new_value);
state.bar();
return state.baz();
}
You could achieve something similar with nested functions too.
Unfortunately, this destroys 'pure' even though it actually does not.
Using a local-scoped struct would work with pure, be more efficient
(accessing thread-local variables takes more cycles), and be less
error-prone while refactoring.
--
Michel Fortin
michel.for...@michelf.ca
http://michelf.ca/
