multithreading

问题 The following code block, preforms loading of an object in C#. public bool IsModelLoaded { get; set; } public override MyObject Load() { if (!IsModelLoaded) { Model = MyService.LoadMyObject(Model); IsModelLoaded = true; } return Model; } My intention is to run this block only once, and hence loading the Model only once. Nevertheless, this code block runs twice from 2 different threads.. How can I make sure that this block runs only once? (on multiplethreads). Thank You. 回答1: Simplest would be

问题 The following code block, preforms loading of an object in C#. public bool IsModelLoaded { get; set; } public override MyObject Load() { if (!IsModelLoaded) { Model = MyService.LoadMyObject(Model); IsModelLoaded = true; } return Model; } My intention is to run this block only once, and hence loading the Model only once. Nevertheless, this code block runs twice from 2 different threads.. How can I make sure that this block runs only once? (on multiplethreads). Thank You. 回答1: Simplest would be

问题 The following code block, preforms loading of an object in C#. public bool IsModelLoaded { get; set; } public override MyObject Load() { if (!IsModelLoaded) { Model = MyService.LoadMyObject(Model); IsModelLoaded = true; } return Model; } My intention is to run this block only once, and hence loading the Model only once. Nevertheless, this code block runs twice from 2 different threads.. How can I make sure that this block runs only once? (on multiplethreads). Thank You. 回答1: Simplest would be

问题 I have been seeing in the literature for some of the newer CPU's such as the Intel Xeon "Nehalem-EX" as having 8 cores and 16 threads. What are they talking about here? I saw mention of this in reference so SPARCS too, surely this isn't the kind of logical threads spawned by code ? Is this hyperthreading re-named? 回答1: Yes, Nehalem-based processors implement Hyper-threading. The new Nehalem-EX which you refer to has 8 physical cores where each core can be seen as 2 logical cores for a total

问题 I have been seeing in the literature for some of the newer CPU's such as the Intel Xeon "Nehalem-EX" as having 8 cores and 16 threads. What are they talking about here? I saw mention of this in reference so SPARCS too, surely this isn't the kind of logical threads spawned by code ? Is this hyperthreading re-named? 回答1: Yes, Nehalem-based processors implement Hyper-threading. The new Nehalem-EX which you refer to has 8 physical cores where each core can be seen as 2 logical cores for a total

问题 I do not understand why Java throw exception from subject in this code. Could somebody explain me it? class Wait implements Runnable { public void run() { synchronized (Object.class) { try { while(true) { System.out.println("Before wait()"); wait(); System.out.println("After wait()"); } } catch (InterruptedException e) { e.printStackTrace(); } } } } public class ObjectMethodInConcurency { public static void main(String[] args) { Wait w = new Wait(); (new Thread(w)).start(); } } 回答1: Use

问题 I thought the whole purpose of a channel was to share data between threads. I have this code, based on this example: let tx_thread = tx.clone(); let ctx = self; thread::spawn(|| { ... let result = ctx.method() tx_thread.send((String::from(result), someOtherString)).unwrap(); }) Where tx is a mpsc::Sender<(String, String)> error[E0277]: the trait bound `std::sync::mpsc::Sender<(std::string::String, std::string::String)>: std::marker::Sync` is not satisfied --> src/my_module/my_file.rs:137:9 |

问题 I thought the whole purpose of a channel was to share data between threads. I have this code, based on this example: let tx_thread = tx.clone(); let ctx = self; thread::spawn(|| { ... let result = ctx.method() tx_thread.send((String::from(result), someOtherString)).unwrap(); }) Where tx is a mpsc::Sender<(String, String)> error[E0277]: the trait bound `std::sync::mpsc::Sender<(std::string::String, std::string::String)>: std::marker::Sync` is not satisfied --> src/my_module/my_file.rs:137:9 |

问题 This question already has answers here : File.Move Does Not Work - File Already Exists (9 answers) Closed 9 days ago . I'm developing a multi threaded application. I have somewhere in my code : File.Delete(sidetapedata); File.Move(sidetapedata2, sidetapedata); //sidetapedata and sidetapedata2 are two file paths that correspond to sidetapedata.txt and sidetaptdata2.txt in some directory. The second line sometimes runs fine and other times, it throws an IOException : Cannot create a file when

问题 This question already has answers here : File.Move Does Not Work - File Already Exists (9 answers) Closed 9 days ago . I'm developing a multi threaded application. I have somewhere in my code : File.Delete(sidetapedata); File.Move(sidetapedata2, sidetapedata); //sidetapedata and sidetapedata2 are two file paths that correspond to sidetapedata.txt and sidetaptdata2.txt in some directory. The second line sometimes runs fine and other times, it throws an IOException : Cannot create a file when