synchronization

问题 We need to share very efficiently block of constantly changing information between two processes. Information fits in 64bits block of memory - so inside one process we'd be able to use Interlocked operations (or probably even just ordinary reads/writes) to ensure lock-free access to correct state of information (not just partially written). How can we write and ready block of 64bit data into MMF without locking and synchronization in order to make sure that we don't read partially written

问题 I have a ViewController that is set as delegate of MKMapView and CLLocationManager . This ViewController also receives actions from UI buttons. I have a state machine that needs to be updated whenever some UI action happens or when a new location is available (whether it comes from MKMapView or CLLocationManager ) Obviously, the state machine update must be atomic, but I can't seem to find a good mechanism to do so. Here's a snippet of the code: m_locationSerialQueue = dispatch_queue_create(

问题 I have an object like so: let myObject = { 'db1': [db1_file1Id,db1_file2Id,db_1file3Id], 'db2': [db2_file1Id, db2_file2Id] ... } I iterate through through this object and on each iteration: I connect to the database, retrieve the file, do some stuff and save the file back. Basically asynchronous stuff. for (let prop in myObject) { if (myObject.hasOwnProperty(prop)) { doStuff(prop, myObject[prop]); } } Now the doStuff function makes sure I have a local scope so there is no inconsistencies. But

问题 I am trying to achieve synchronization between different processes. Multiple process calling ProcessLock should be synchronized. I am able to achieve it. But problem here is that Other threads are unable to enter critical section. Lock is always acquired by same application. How can I share the lock between different application. public class ProcessLock : IDisposable { // the name of the global mutex; private const string MutexName = "FAA9569-7DFE-4D6D-874D-19123FB16CBC-8739827-

问题 I'm currently having problems making my audio and video streams stay synced. These are the AVCodecContexts I'm using: For Video: AVCodec* videoCodec = ffmpeg.avcodec_find_encoder(AVCodecID.AV_CODEC_ID_H264) AVCodecContext* videoCodecContext = ffmpeg.avcodec_alloc_context3(videoCodec); videoCodecContext->bit_rate = 400000; videoCodecContext->width = 1280; videoCodecContext->height = 720; videoCodecContext->gop_size = 12; videoCodecContext->max_b_frames = 1; videoCodecContext->pix_fmt =

问题 I'm currently having problems making my audio and video streams stay synced. These are the AVCodecContexts I'm using: For Video: AVCodec* videoCodec = ffmpeg.avcodec_find_encoder(AVCodecID.AV_CODEC_ID_H264) AVCodecContext* videoCodecContext = ffmpeg.avcodec_alloc_context3(videoCodec); videoCodecContext->bit_rate = 400000; videoCodecContext->width = 1280; videoCodecContext->height = 720; videoCodecContext->gop_size = 12; videoCodecContext->max_b_frames = 1; videoCodecContext->pix_fmt =

问题 I have an application on a server which is UK based. Say I needed the application to run at the same time for different countries. For arguments sake say I needed it to send an email to a mailbox whenever the time is 7pm in various countries. How would I be able to achieve this? At the moment I just have it running from the Task Scheduler at the specific time (which is fine for UK based clients). However, I would like to support internationally. Thanks. 回答1: Store date/times as UTC, and then

问题 I need to do writing into the database from different AsyncTask threads but the problem is that we need to be sure that at one time only one thread should be in the process of writing into the db? My question is if i use the singleton pattern in making the single instance of SQLiteDatabase object all over the application,will that single instance manage the synchronization between different threads or not ? Thanks 回答1: My question is if i use the singleton pattern in making the single

问题 This is a question concerning what is the proper way to synchronize a shared object in java. One caveat is that the object that I want to share must be accessed from static methods. My question is, If I synchronize on a static field, does that lock the class the field belongs to similar to the way a synchronized static method would? Or, will this only lock the field itself? In my specific example I am asking: Will calling PayloadService.getPayload() or PayloadService.setPayload() lock

问题 I was thinking of changing system's local time to server's time and then use it but I bet there are other ways to do this. I've been trying to find something like a clock in c#, but couldnt find anything. I'm receiving server's time in a DateTime format. edit: I need my application to use while working same time server does. I just want to get server's time once and after that, make my application work in a while loop using the time I've obtained from the server. There might be a difference