iOS 多線程GCD的基本使用，ios多線程gcd

iOS 多線程GCD的基本使用，ios多線程gcd

《iOS多線程簡介》中提到：GCD中有2個核心概念：1、任務（執行什麼操作）2、隊列（用來存放任務）

那麼多線程GCD的基本使用有哪些呢？

可以分以下多種情況：

1、非同步函數 + 並發隊列

/** * 非同步函數 + 並發隊列：可以同時開啟多條線程 */- (void)asyncConcurrent{    // 1.建立一個並發隊列    // dispatch_queue_create(const char *label, dispatch_queue_attr_t attr);    // label : 相當於隊列的名字    // dispatch_queue_t queue = dispatch_queue_create("com.kyle.queue", DISPATCH_QUEUE_CONCURRENT);        // 1.獲得全域的並發隊列    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);        // 2.將任務排入佇列    dispatch_async(queue, ^{        for (NSInteger i = 0; i<3; i++) {            NSLog(@"this is first %@",[NSThread currentThread]);        }    });    dispatch_async(queue, ^{        for (NSInteger i = 0; i<3; i++) {            NSLog(@"this is second %@",[NSThread currentThread]);        }    });        dispatch_async(queue, ^{        for (NSInteger i = 0; i<3; i++) {            NSLog(@"this is third %@",[NSThread currentThread]);        }    });    }

2、同步函數 + 並發隊列

/** * 同步函數 + 並發隊列：不會開啟新的線程 */- (void)syncConcurrent{    // 1.獲得全域的並發隊列    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);        // 2.將任務排入佇列    dispatch_sync(queue, ^{        NSLog(@"this is first %@",[NSThread currentThread]);    });    dispatch_sync(queue, ^{        NSLog(@"this is second %@",[NSThread currentThread]);    });    dispatch_sync(queue, ^{        NSLog(@"this is third %@",[NSThread currentThread]);    });    }

3、非同步函數 + 串列隊列

/** * 非同步函數 + 串列隊列：會開啟新的線程，但是任務是串列的，執行完一個任務，再執行下一個任務 */- (void)asyncSerial{    // 1.建立串列隊列    dispatch_queue_t queue = dispatch_queue_create("com.kyle.queue", DISPATCH_QUEUE_SERIAL);    //    dispatch_queue_t queue = dispatch_queue_create("com.kyle.queue", NULL);        // 2.將任務排入佇列    dispatch_async(queue, ^{        NSLog(@"this is first %@",[NSThread currentThread]);    });    dispatch_async(queue, ^{        NSLog(@"this is second %@",[NSThread currentThread]);    });    dispatch_async(queue, ^{        NSLog(@"this is third %@",[NSThread currentThread]);    });}

4、同步函數 + 串列隊列

/** * 同步函數 + 串列隊列：不會開啟新的線程，在當前線程執行任務。任務是串列的，執行完一個任務，再執行下一個任務 */- (void)syncSerial{    // 1.建立串列隊列    dispatch_queue_t queue = dispatch_queue_create("com.kyle.queue", DISPATCH_QUEUE_SERIAL);        // 2.將任務排入佇列    dispatch_sync(queue, ^{        NSLog(@"this is first %@",[NSThread currentThread]);    });    dispatch_sync(queue, ^{        NSLog(@"this is second %@",[NSThread currentThread]);    });    dispatch_sync(queue, ^{        NSLog(@"this is third %@",[NSThread currentThread]);    });}

5、非同步函數 + 主隊列

// * 非同步函數 + 主隊列：只在主線程中執行任務- (void)asyncMain{    // 1.獲得主隊列    dispatch_queue_t  queue =  dispatch_get_main_queue();    // 2.將任務排入佇列    dispatch_async(queue, ^{        NSLog(@"this is first %@",[NSThread currentThread]);        NSLog(@"this is second %@",[NSThread currentThread]);        NSLog(@"this is third %@",[NSThread currentThread]);    });}

6、同步函數 + 主隊列

// * 同步函數 + 主隊列：- (void)syncMain{    NSLog(@"begin");        // 1.獲得主隊列    dispatch_queue_t queue =  dispatch_get_main_queue();    // 2.將任務排入佇列    dispatch_sync(queue, ^{        NSLog(@"this is %@",[NSThread currentThread]);            });    NSLog(@"end");}

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