multitasking

问题 is it possible to modify/access the Java call stack ? For instance saving and restoring ? I'm thinking about implementing cooperative multitaskting (especially I/O) just like gevent for python or haskell (which does this natively). The async callback spaghetti mess can't be the best solution. 回答1: The simplest solution is to have multiple threads. You can have up to 10,000 threads running efficiently on a server. If you need much more than this, I would suggest either a) buying a second

问题 I have some test code which i am using to keep my app to stay running in the background state, which works quite well on the iOS 5.1 simulator but is not behaving that way on the actual device. Now i already know the requirements i have to follow, so i have set "background modes" to voip and location. In my delegate's applicationDidEnterBackground method i am calling the following function which i call "doBackgroundActivity( )" to request time for application to complete some long running

问题 I'm building a voip app for iOS and I'm handling working at background. So far, i have iOS listening to the voip socket while app sleeps and wake it uppon incoming data. My question is: When the reachability has changed (Wifi -> 3G, Wifi -> Other Wifi, etc) and the app is suspended, can I get some notification in order to reconnect my voip socket? Thanks. 回答1: Answer was both Yes and No: Register to Reachability network changes notifications. If App goes to background suspended while its voip

问题 I have the following construct: A base-class which does some loading tasks asynchronously and a inherited class which only converts the result of the base-class into a special data-type (it's just a generic version with some extensions, but those are not of importance). I initially call the inherited class' Process-method: public TOut Process(object parameters) { return (TOut) StartProcessor(parameters).Result; } This method calls the following method of the base: protected async Task<object>

问题 I'm constantly seeing this crash when our app (Voip App)is in the background, after device goes to sleep mode. Exception Type: 00000020 Exception Codes: 0xbad22222 Highlighted Thread: 3 Application Specific Information: SBUnsuspendLimit ooVoo[360] exceeded 15 wakes in 300 sec Thread 3 name: com.apple.NSURLConnectionLoader Thread 3: 0 libsystem_kernel.dylib 0x307fc010 mach_msg_trap + 20 1 libsystem_kernel.dylib 0x307fc206 mach_msg + 50 2 CoreFoundation 0x3569b41c __CFRunLoopServiceMachPort +

问题 I am in the situation where I have a collection of objects and every object has to run an expensive method that takes about 5-10 seconds to complete. How can I run all methods in parallel and check the status periodically? I tried to use the @Async annotation with a Future response, but nothing changed. public static void populate(String marketId) { //irrelevant code removed List<Company> companies = mongo().find(new Query(c), Company.class); List<Future> futures = new ArrayList<Future>();

问题 Is it possible to make a call from application with out quitting application in iOS 4? 回答1: You will have to have your application remember its state . That way it can be resumed when launched again. Even with the new multitasking your suspended apps may be forcibly quit if the device needs more memory. Apple has a guide named "Supporting Multitasking In Your Applications" which you should be able to locate. Related SO: Does iOS 4 make “Real Multitasking” available to 3rd party developers?

问题 As the title suggests, is there a way in C to detect when a user-level thread running on top of a kernel-level thread e.g., pthread has blocked (or about to block) for I/O? My use case is as follows: I need to execute tasks in a multithreaded environment (on top of kernel threads e.g., pthreads). The tasks are basically user functions that can be synchronized and may use blocking operations within. I need to hide latency in my implementation. So, I am exploring the idea of implementing the

问题 I was wondering if theres a way to make a batch file that uses a timer script (such as the TIMEOUT command) and while the timer is running, make the batch file do other processes. But when the timer runs out, then exit. (Or carry out another small process) I know this means that te batch file would have to run multiple processes at once, i just want to know if its possible somehow. Any ideas? 回答1: You can use start /b cmd /c myTimeout.bat This starts a new application in the same window

问题 I set the UIApplicationExitsOnSuspend to boolean and checked the checkbox, so I assumed that - (void) applicationDidEnterBackground:(UIApplication *)application is not called - but I always get into that method when I click the home button in my simulator. Am I doing something wrong or can I be sure that the app will behave the "old style" and does not support multitasking? Thanks a lot, Stefan Settings defined at this level Architectures: Standard Base SDK: iPhone Simulator 4.0 Code Signing