#! /usr/bin/env escript
%%
%% Synchronized publisher
%%
%% We wait for 10 subscribers
-define(SUBSCRIBERS_EXPECTED, 10).
main(_) ->
{ok, Context} = erlzmq:context(),
%% Socket to talk to clients
{ok, Publisher} = erlzmq:socket(Context, pub),
ok = erlzmq:bind(Publisher, "tcp://*:5561"),
%% Socket to receive signals
{ok, Syncservice} = erlzmq:socket(Context, rep),
ok = erlzmq:bind(Syncservice, "tcp://*:5562"),
%% Get synchronization from subscribers
io:format("Waiting for subscribers~n"),
sync_subscribers(Syncservice, ?SUBSCRIBERS_EXPECTED),
%% Now broadcast exactly 1M updates followed by END
io:format("Broadcasting messages~n"),
broadcast(Publisher, 1000000),
ok = erlzmq:send(Publisher, @<@@[[/span]][[span style="color:#BA2121"]]"END"[[/span]][[span style="color:#666666"]]@@>@),
ok = erlzmq:close(Publisher),
ok = erlzmq:close(Syncservice),
ok = erlzmq:term(Context).
sync_subscribers(_Syncservice, 0) -> ok;
sync_subscribers(Syncservice, N) when N > 0 ->
%% Wait for synchornization request
{ok, _} = erlzmq:recv(Syncservice),
%% Send synchronization reply
ok = erlzmq:send(Syncservice, @<>@),
sync_subscribers(Syncservice, N - 1).
broadcast(_Publisher, 0) -> ok;
broadcast(Publisher, N) when N > 0 ->
ok = erlzmq:send(Publisher, @<@@[[/span]][[span style="color:#BA2121"]]"Rhubarb"[[/span]][[span style="color:#666666"]]@@>@),
broadcast(Publisher, N - 1).