reusability

问题 I have a queue of jobs and I want to make a pool of four threads where I can throw my jobs at. What I am stuck at is in how to make the threads and keep them suspended while there is no work. JOB QUEUE | job1 | job2 | job3 | job4 | .. THREAD POOL | thread1 | thread2 | thread3 | thread4 | To create the threads I have currently at the initialisation point: for (t=0; t<num_of_threads; t++){ pthread_create(&(threads[t]), NULL, doSth2, NULL); } Where num_of_threads=4 and doSth2 is a function with

问题 Can someone explain why this works with the pointer: char * str1; str1 = "Hello1"; str1 = "new string"; // but not this char str2 [] = "hello"; str2 = "four"; // or this char str3 []; str3 = "hello"; str3 = "hello"; 回答1: Why it works with pointers: When you say char * str1 in C, you are allocating a pointer in the memory. When you write str1 = "Hello"; , you are creating a string literal in memory and making the pointer point to it. When you create another string literal "new string" and

问题 I am having trouble with reuse cells and UICollectionView on iOS 7. My code works fine on iOS 6 but in iOS 7 it does not reuse the cell after calling dequeueReusableCellWithReuseIdentifier (do not call prepareForReuse ). Even this code https://developer.apple.com/library/ios/samplecode/CollectionView-Simple/Introduction/Intro.html#//apple_ref/doc/uid/DTS40012860 does not reuse cell on iOS7 (but works well on iOS6), on every dequeueReusableCellWithReuseIdentifier it creates a new cell and

问题 Apple's iOS TableView and cell reuse is killing me. I searched and searched and studied, but can't find good docs or good answers. The problem is that when the TableView reuses cells things like Checkmarks (cell accessory) set on a selected Cell are repeated in the cells further down in the table view. I understand that cell reuse is by design, due to memory constraints, but if you have a list with say 50 items, and it starts setting extra checkmarks where they're not wanted, this makes whole

问题 My first question so hope it is suitable: Shared interface assembly - I have a 'shared' assembly which has an interface, let's call it IDocRepository . It's marked with [ServiceContract] and there are several [OperationContract] -marked methods. WCF implementation assemblies - I have two WCF service projects, each referencing the shared assembly, each implementing that interface as a WCF service. Consumer assembly - Finally, I have a 'client' project, also referencing the shared assembly,

问题 I have a test solution which only has one area called Admin. I would like to reuse Admin across a number of other web applications. I have a web application setup in IIS, I have then added a virtual application, /Admin coming from Areas\Admin . When I navigate to /Admin, I see a directory listing. When I try to hit a controller, /Admin/News. I get a 404 error. It could be that the areas are not registering, even though the code is there in the global.asax. However, I am sure I am going about