Logtalk 2.29.4 files.

git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@1800 b08c6af1-5177-4d33-ba66-4b1c6b8b522a

Logtalk/examples/threads/buffer/buffer.lgt

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+
+:- object(buffer).
+
+	:- threaded.
+
+	:- public([put/1, get/1]).
+
+	:- private(item/1).
+	:- dynamic(item/1).
+
+	put(N) :-
+		(	N > 0										% wait until the previous item is consumed
+		->	NP is N - 1, threaded_wait(consumed(NP))	% (except for the first item!) 
+		;	true
+		),
+		assertz(item(N)),
+		sender(Sender),
+		writeq(Sender), write(' wrote item '), write(N), nl,
+		threaded_notify(produced(N)).					% notify consumer that a new item is available
+
+	get(N) :-
+		threaded_wait(produced(N)),						% wait until an item is available
+		retract(item(N)),
+		sender(Sender),
+		writeq(Sender), write(' read item '), write(N), nl,
+		threaded_notify(consumed(N)).					% notify producer that the item was consumed
+
+:- end_object.
+
+
+:- object(producer).
+
+	:- public(run/1).
+
+	run(N) :-
+		run(0, N).
+
+	run(N, N) :- !.
+	run(M, N) :-
+		M < N,
+		random::random(1, 5, Random),	% simulate a variable time to 
+		thread_sleep(Random),			% produce a new item
+		buffer::put(M),
+		M2 is M + 1,
+		run(M2, N).
+
+:- end_object.
+
+
+:- object(consumer).
+
+	:- public(run/1).
+
+	run(N) :-
+		run(0, N).
+
+	run(N, N) :- !.
+	run(M, N) :-
+		M < N,
+		random::random(1, 5, Random),	% simulate a variable time
+		thread_sleep(Random),			% to consume an item
+		buffer::get(M),
+		M2 is M + 1,
+		run(M2, N).
+
+:- end_object.