I have my own multithreaded C program which scales in speed smoothly with the number of CPU cores.. I can run it with 1, 2, 3, etc threads and get linear speedup.. up to about 5.5x speed on a 6-core CPU on a Ubuntu Linux box. I had an opportunity to run the program on a very high end Sunfire x4450 with 4 quad-core Xeon processors, runni...
The following program is essentially the same as the one described here. When I run and compile the program using two threads (NTHREADS == 2), I get the following run times: real 0m14.120s user 0m25.570s sys 0m0.050s When it is run with just one thread (NTHREADS == 1), I get run times significantly better even th...
I have a simple UDP server that creates a new thread for processing incoming data. While testing it by sending about 100 packets/second I notice that it's memory usage continues to increase. Is there any leak evident from my code below? Here is the code for the server. public class UDPServer { public static void main(String[] args)...
I have about 4 threads. One thread keeps checking some data that the other thread is updating. The others are doing some processing in the background. All have been started at this point. My question is when the checking thread sees that the data has not been updated yet I currently sleep for a little bit but is there any way for me ...
I am wondering whether watching a file/directory for changes using the FileSystemWatcher class is extremely memory intensive. I am developing a desktop application in C# that will be running behind the scenes continuously on low-performance computers, and I need some way of checking to see if various files have changed. I can think of a ...
I was wondering about the lifespan of a PHP script when called via Ajax. Assume that there is a long-running (i.e. 30 seconds) PHP script on a server and that page is loaded via Ajax. Before the script completes, the user closes the browser. Does the script continue running to completion, is it terminated, or is this a function of the...
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, ...
Hi All Just looking for something ultra simple. I need to spawn a method off to a new thread. I don't care when or how it ends. Can somebody please help me with this? Thank you ...
Let say I have three thread handles HandleList[0] = hThread1; HandleList[1] = hThread2; HandleList[2] = hThread3; /*All the above are of type HANDLE*/ Before closing the application, I want the thread to get its task done. So I want to make app wait till thread completes. So I do, WaitForMultipleObjects(3, HandleList, TRUE, INFINITE...
Hi guys, brand new question. Just implemented multi-threading into my XNA game as it was unable to keep up with using 1 processor. MT is all implemented fine and everything, however the player seems to jitter all over the spot every now and then. I originally thought it was a loss of data between the update and render, but even when i d...
In this code, I have an Entity Framework 4 model with a single "Thing" entity that has an Id and a Name(string) column. I would like to ensure that when I call FindOrCreateThing(name) from multiple threads, only one row in the Things table will ever be created with the given name. Currently, I'm using locks to accomplish this, and it se...
I have found that gc logs without gc activites means that another activity that blocks the system. How can find which thread can cause the stop all the world on the system I have 8 CPU server. Why one thread is in a stuck (or in a loop), other threads cannot work simulteneously. They wait for the stuck Thread. Regards Trustin 49024K...
Hi everyone, I have a class that fetches data in response to button presses in the main activity. Unfortunately, I keep running into problems because this class is not an Activity or a Service. For example, without a Context I cannot translate a resource id into a string: getString(R.string.example_string); // Doesn't work Should I m...
The scenario is as follows: Create an instance of a class (std::map) and sore it as global variable. Spawn threads. Threads read and use the same global instance of the class (call methods, access members etc) All spawned threads quit Global class instance is destroyed No mutex used, no spawn thread modifies the global class instance...
Should my multithreaded application with read only properties require locking? Since nothing is being written I assume there is no need for locks, but I would like to make sure. Would the answer to this question be language agnostic? Without Lock: Private Const m_strFoo as String = "Foo" Public ReadOnly Property Foo() As String Get...
I have a DataGridView control in my Windows Forms Application. I am adding rows to the grid using a background thread. I change the form's cursor to Waitcursor when the process starts and back to Default when it ends. This works well for the form, but not for the grid. When the form's cursor is changed back to default, the grid's cursor ...
I have heard that in Haskell, creating a multi-threaded application is as easy as taking a standard Haskell application and compiling it with the -threaded flag. Other cases, however, have described the use of a par command within the actual source code. What is the state of Haskell multi-threading? How easy is it to introduce into prog...
In C# (console app) I want to hold a collection of objects. All objects are of same type. I want to iterate through the collection calling a method on each object. And then repeat the process continuously. However during iteration objects can be added or removed from the list. (The objects themselves will not be destroyed .. just remo...
hi.. say for example I have this code in my activity: public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Thread cThread = new Thread(new Runner()); cThread.start(); } private NotifyMe(){ //do something here } and this is my Runner class: ...
I had to do heavy I/o bound operation, i.e Parsing large files and converting from one format to other format. Initially I used to do it serially, i.e parsing one after another..! Performance was very poor ( it used take 90+ seconds). So I decided to use threading to improve the performance. I created one thread for each file. ( 4 threa...