Parallel task ventilator in Objective-C

/* Task ventilator - sends task batch to workers via PUSH socket. */
#import <Foundation/Foundation.h>
#import "ZMQObjC.h"
#import "ZMQHelper.h"

int
main(void)
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
ZMQContext *ctx = [[[ZMQContext alloc] initWithIOThreads:1U] autorelease];
ZMQSocket *sender = [ctx socketWithType:ZMQ_PUSH];
[sender bindToEndpoint:@"tcp://*:5557"];

NSLog(@"Press Enter when the workers are ready: ");
(void)getchar();
NSLog(@"Sending tasks to workers…");

/* Signal batch start with message of "0". */
NSData *signalData = [@"0" dataUsingEncoding:NSUTF8StringEncoding];
[sender sendData:signalData withFlags:0];

/* Initialize random number generator. */
(void)srandom((unsigned)time(NULL));

/* Send kTaskCount tasks. */
unsigned long totalMsec = 0UL;
static const int kTaskCount = 100;
for (int task = 0; task < kTaskCount; ++task) {
/* Random workload from 1 to 100 msec. */
int workload = within(100) + 1;
totalMsec += workload;
NSString *text = [NSString stringWithFormat:@"%d", workload];
NSData *textData = [text dataUsingEncoding:NSUTF8StringEncoding];
[sender sendData:textData withFlags:0];
}
NSLog(@"Total expected cost: %lu ms", totalMsec);

/* Let IOThreads finish sending. */
sleep(1);

[sender close];
[pool drain];
return EXIT_SUCCESS;
}