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### Multiple socket reader as in the ZeroMQ guide.
# SHELL> Rscript wuserver.r &
# SHELL> Rscript taskvent.r &
# SHELL> Rscript mspoller.r
# SHELL> rm weather.ipc
library(pbdZMQ, quietly = TRUE)
### Initial.
context <- zmq.ctx.new()
receiver <- zmq.socket(context, .pbd_env$ZMQ.ST$PULL)
zmq.connect(receiver, "tcp://localhost:5557")
subscriber <- zmq.socket(context, .pbd_env$ZMQ.ST$SUB)
zmq.connect(subscriber, "tcp://localhost:5556")
zmq.setsockopt(subscriber, .pbd_env$ZMQ.SO$SUBSCRIBE, "20993")
### Process messages from both sockets.
cat("Press Ctrl+C or Esc to stop mspoller.\n")
i.rec <- 0
i.sub <- 0
while(TRUE){
### Set poller.
poller <- zmq.poll(c(receiver, subscriber),
c(.pbd_env$ZMQ.PO$POLLIN, .pbd_env$ZMQ.PO$POLLIN))
### Check receiver.
if(bitwAnd(zmq.poll.get.revents(1), .pbd_env$ZMQ.PO$POLLIN)){
ret <- zmq.recv(receiver)
if(ret$len != -1){
cat("task ventilator:", ret$buf, "at", i.rec, "\n")
i.rec <- i.rec + 1
}
}
### Check subscriber.
if(bitwAnd(zmq.poll.get.revents(2), .pbd_env$ZMQ.PO$POLLIN)){
ret <- zmq.recv(subscriber)
if(ret$len != -1){
cat("weather update:", ret$buf, "at", i.sub, "\n")
i.sub <- i.sub + 1
}
}
if(i.rec >= 5 & i.sub >= 5){
break
}
Sys.sleep(runif(1, 0.5, 1))
}
### Finish.
zmq.poll.free()
zmq.close(receiver)
zmq.close(subscriber)
zmq.ctx.destroy(context)
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