ios多核心 處理代碼

// 多核心加速處理函數// 在阻塞期間，建立和處理器核心數相同數量的線程來執行回呼函數// 例如 雙核 會執行下面的方法// pfun(0, 2)// pfun(1, 2)inlinevoid MultiCoreProcessing(void (^pfun)(int i_thread, int num_thread)){    NSUInteger processorCount = [[NSProcessInfo processInfo] processorCount];        //單核CPU直接執行    if (!OPT_MULTICORE || processorCount == 1)    {        pfun(0, 1);        return;    }        unsigned short int count = processorCount;        //訊號量    dispatch_semaphore_t *semPart = (dispatch_semaphore_t*)malloc(sizeof(dispatch_semaphore_t)*count);        //啟動    for (int i=0; i<count; i++)    {        //建立一個等待的訊號量        semPart[i] = dispatch_semaphore_create(0);                dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^(void){                        //執行回調方法            pfun(i, count);                        dispatch_semaphore_signal(semPart[i]);        });    }        //等待任務結束    for (int i=0; i<count; i++)    {        dispatch_semaphore_wait(semPart[i], DISPATCH_TIME_FOREVER);        dispatch_release(semPart[i]);    }        free(semPart);}用法：void (^pfun)(int, int)  = ^void (int i_thread, int num_thread)    {        //將圖片資料分割成 num_thread 次執行，每個線程處理一部分資料        TiBitmapData *bitmapPart = SplitBitmap(bitmap, i_thread, num_thread);                AdjustVibrance(*bitmapPart, saturation, vibrance);                delete bitmapPart;    };        MultiCoreProcessing(pfun);