1. Diego Chohfi Turini
Paralelismo transparente
GCD(Grande Central Dispatcher)
[self SP];
Diego Chohfi - @dchohfi
Monday, March 19, 12

2. “Quando precisamos de paralelismo temos n
problemas, e quando usamos temos n^2
problemas” - @qmx
Diego Chohfi - @dchohfi
Monday, March 19, 12

3. Primeiro:
Blocos ^
Diego Chohfi - @dchohfi
Monday, March 19, 12

4. Véi, na boa.. bloco?
retorno paramêtro nome param
int (^bloco)(int) = ^(int numero){ return numero *10;};
variável corpo do broco
broco
Diego Chohfi - @dchohfi
Monday, March 19, 12

5. Bloco = tipo
typedef double(^Dividir)(double, double);
@property (copy) Dividir dividir;
dividir = ^( double dividendo, double divisor){
return dividendo / divisor;
};
NSLog(@"%f.0", self.dividir(10,2));
Diego Chohfi - @dchohfi
Monday, March 19, 12

6. NSArray *OMG = [[NSArray alloc] initWithObjects:@"MOTHER", @"OF", @"JOBS", nil];
[OMG enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
NSLog(obj);
}];
TWTweetComposeViewController *tweet = [[TWTweetComposeViewController alloc] init];
[tweet setCompletionHandler:^(TWTweetComposeViewControllerResult result){
if(result == TWTweetComposeViewControllerResultDone){
NSLog(@"AI QUE LOUCURA, TWEETEI");
}
}];
int variavelExterna = 10;
void (^block)(int) = ^(int mother){
NSLog(@"OF JOBS %i, guardei escopo!", modern * variavelExterna);
};
block(10);
Diego Chohfi - @dchohfi
Monday, March 19, 12

7. GCD, it’s all about queueing
(based on kqueue)
Diego Chohfi - @dchohfi
Monday, March 19, 12

8. dispatch_queue_t queue = dispatch_get_global_queue(
DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
#define! DISPATCH_QUEUE_PRIORITY_HIGH ! 2
#define! DISPATCH_QUEUE_PRIORITY_DEFAULT 0
#define! DISPATCH_QUEUE_PRIORITY_LOW ! (-2)
#define! DISPATCH_QUEUE_PRIORITY_BACKGROUND! INT16_MIN
dispatch_async(queue, ^{
NSLog(@"Calculando o tamanho do universo, no iPhone 3");
});
Diego Chohfi - @dchohfi
Monday, March 19, 12

9. Criando queue’s
dispatch_queue_t minhaQueue = dispatch_queue_create("br.com.caelum", NULL);
dispatch_async(minhaQueue, ^{
});
Diego Chohfi - @dchohfi
Monday, March 19, 12

10. Alterando views, cuidado!
dispatch_async(queue, ^{
dispatch_async(queue, ^{
[NSThread sleepForTimeInterval:2];
[NSThread sleepForTimeInterval:2];
dispatch_async(dispatch_get_main_queue(), ^{
asyncLabel.text = = @"UNIVERSO CALCULADO";
asynchLabel.text @"UNIVERSO CALCULADO";
});
});
});
syncLabel.text = @"Calculando o universo";
syncLabel.text = @"Calculando o universo";
Diego Chohfi - @dchohfi
Monday, March 19, 12

11. Criando Grupos
dispatch_group_t group = dispatch_group_create();
dispatch_group_async(group,queue,^{
[NSThread sleepForTimeInterval:1];
NSLog(@"Calculando o tamanho do sol");
});
dispatch_group_async(group,queue,^{
NSLog(@"Esperando a mulher fazer compras");
});
dispatch_group_notify(group,queue,^{
NSLog(@"Será executado após os dois blocos");
});
Diego Chohfi - @dchohfi
Monday, March 19, 12

12. Valores fora do escopo
int valorMagico = 0;
__block
dispatch_async(queue,^{
[NSThread sleepForTimeInterval:1];
for (int i=0; i<10; i++) {
valorMagico++;
}
});
Diego Chohfi - @dchohfi
Monday, March 19, 12

13. Batch queueing
dispatch_queue_t queue = dispatch_get_global_queue(0, 0);
dispatch_apply(10, queue, ^(size_t i){
NSLog(@"Numero: %zu", i);//não garante ordem
});
Diego Chohfi - @dchohfi
Monday, March 19, 12