On Saturday, 16 February 2013 at 11:30:00 UTC, Jos van Uden wrote:
On 16-2-2013 8:58, qznc wrote:
On Saturday, 16 February 2013 at 06:58:01 UTC, qznc wrote:
On Saturday, 16 February 2013 at 02:23:42 UTC, Jos van Uden
wrote:
On 5-2-2013 20:45, Jos van Uden wrote:
By the way, I think 'Qznc' may want to have a look at 'The
dining
philosophers':
http://rosettacode.org/wiki/Dining_philosophers
I should find the time to solve it this weekend.
Wow, my kid let me do some hacking right now and it was
simpler than expected.
Posted a solution already.
Wow, that was quick. Thanks!
The current D code for Dining philosophers does not compile with
dmd v2.063.2, the error message being
dining.d(34): Error: cannot uniquely infer foreach argument types
The code looks OK to me (but I'm a D newbie) so I wonder if
someone could explain the inference issue. Where should an
annotation be added to allow this to compile?
1 import std.stdio, std.algorithm, std.string,
std.parallelism,
2 core.sync.mutex;
3
4 void eat(in uint i, in string name, Mutex[] forks) {
5 writeln(name, " is hungry.");
6
7 immutable j = (i + 1) % forks.length;
8
9 // Take forks i and j. The lower one first to prevent
deadlock.
10 auto fork1 = forks[min(i, j)];
11 auto fork2 = forks[max(i, j)];
12
13 fork1.lock();
14 scope(exit) fork1.unlock();
15
16 fork2.lock();
17 scope(exit) fork2.unlock();
18
19 writeln(name, " is eating.");
20 writeln(name, " is full.");
21 }
22
23 void think(in string name) {
24 writeln(name, " is thinking.");
25 }
26
27 void main() {
28 const philosophers = "Aristotle Kant Spinoza Marx
Russell".split();
29 Mutex[philosophers.length] forks;
30 foreach (ref fork; forks)
31 fork = new Mutex();
32
33 defaultPoolThreads = forks.length;
34 foreach (uint i, philo; taskPool.parallel(philosophers))
{
35 foreach (_; 0 .. 100) {
36 eat(i, philo, forks);
37 think(philo);
38 }
39 }
40 }
BTW, I like the coding style being used in the rosetta examples
and TDPL much better than the library style.
-- Brian
