Multiple socket poller in Objective-C

/* msreader.m: Reads from multiple sockets the right way. */
#import "ZMQObjC.h"

static NSString *const kTaskVentEndpoint = @"tcp://localhost:5557";
static NSString *const kWeatherServerEndpoint = @"tcp://localhost:5556";

int
main(void)
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
ZMQContext *ctx = [[[ZMQContext alloc] initWithIOThreads:1U] autorelease];

/* Connect to task ventilator. */
ZMQSocket *receiver = [ctx socketWithType:ZMQ_PULL];
[receiver connectToEndpoint:kTaskVentEndpoint];

/* Connect to weather server. */
ZMQSocket *subscriber = [ctx socketWithType:ZMQ_SUB];
[subscriber connectToEndpoint:kWeatherServerEndpoint];
NSData *subData = [@"10001" dataUsingEncoding:NSUTF8StringEncoding];
[subscriber setData:subData forOption:ZMQ_SUBSCRIBE];

/* Initialize poll set. */
zmq_pollitem_t items[2];
[receiver getPollItem:&items[0] forEvents:ZMQ_POLLIN];
[subscriber getPollItem:&items[1] forEvents:ZMQ_POLLIN];

/* Process messages from both sockets. */
for (;;) {
NSAutoreleasePool *p = [[NSAutoreleasePool alloc] init];
[ZMQContext pollWithItems:items count:2
timeoutAfterUsec:ZMQPollTimeoutNever];
[p drain];
}

/* NOT REACHED */
[ctx closeSockets];
[pool drain]; /* This finally releases the autoreleased context. */
return EXIT_SUCCESS;
}