Hi All, Concurrency is one of the hot topics on quite a few technology podcasts. Yet I couldn't find a podcast dedicated to concurrency programming fundamentals, techniques etc. If there's no podcast that specializes on concurrency which of technology podcasts highlights this topic best? ...
Once upon a time, to write x86 assembler, for example, you would have instructions stating "load the EDX register with the value 5", "increment the EDX" register, etc. With modern CPUs that have 4 cores (or even more), at the machine code level does it just look like there are 4 separate CPUs (i.e. are there just 4 distinct "EDX" regist...
So I just finished watching this talk on the Python Global Interpreter Lock (GIL) http://blip.tv/file/2232410. The gist of it is that the GIL is a pretty good design for single core systems (Python essentially leaves the thread handling/scheduling up to the operating system). But that this can seriously backfire on multi-core systems an...
( I ask because it was before serious SMP and multicore that I studied OS. I like to have some vision of how code is being executed. ) If I have a multicore x86 CPU booting directly into my program. Can someone recommend a website which describes what assembler commands do I have to control affinity? ...
I have written a little python application and here you can see how Task Manager looks during a typical run. While the application is perfectly multithreaded, unsurprisingly it uses only one CPU core. Regardless of the fact that most modern scripting languages support multithreading, scripts can run on one CPU core only. Ruby, Python,...
A comment to http://stackoverflow.com/questions/945232/whats-wrong-with-this-fix-for-double-checked-locking says: The issue is that the variable may be assigned before the constructor is run (or completes), not before the object is allocated. Let us consider code: A *a; void Test() { a = new A; } To allow for more for...
I have a large set of scalar values distributed over a 3D mesh (one value per vertex.) My goal is to show: all points in the mesh where the value is greater than a threshold. AND group the points that are connected (to simplify the display.) So my basic solution was: Find the points that pass the threshold test For each point th...
I have created a concurrent, recursive directory traversal and file processing program, which sometimes hangs after all parallel computations have finished but the 'primary' thread never continues with other tasks. The code is basically a fork-join style concurrent aggregator, and after the parallel aggregation completes, it should dis...
I've been tasked to write a high performance, high availability service that will run on a multicore box. Do I need to make use of Task Parellel Library to really leverage a multicore server or will the service automagically run faster if I throw more hardware (cores) at it? Does the .NET framework provide the magic for me under the co...
I realize this is more of a hardware question, but this is also very relevant to software, especially when programming for mult-threaded multi-core/cpu environments. Which is better, and why? Whether it be regarding efficiency, speed, productivity, usability, etc. 1.) A computer/server with 4 quad-core CPUs? or 2.) A computer/server...
Possible Duplicate: Programmatically find the number of cores on a machine I have a 3d game, and I am rebuilding its engine from scratch. The new incarnation uses multi-threading to take advantage of multiple cores. Does anyone know of a cross-platform(linux/win/mac) solution for querying the number of available cores? ...
Hi All, This is a somewhat generic question. Suppose that I am creating a simple application in Java or VC++ which creates two threads and I run the application in a multicore system. Without any specific directive for which core to run, will the application itself will distribute the threads across various cores? Thanks. ...
Straightforward C#/Java code is extremely difficult to parallelize, multi-thread, etc. As a result, straightforward C#/Java code will use less and less of the total processing power on a box (because everything is now going to be multi-core). Solving this problem in C# and Java is not simple. Mutability and side effects are key to get...
I'm working on a multithreaded application, and I want to debug it using GDB. Problem is, one of my threads keeps dying with the message: pure virtual method called terminate called without an active exception Abort I know the cause of that message, but I have no idea where in my thread it occurs. A backtrace would really be helpful....
Before I start, I want to point out that I'm pretty sure this actually happened. All my logs suggest that it did. I'd like to know whether I'm wrong and this is impossible, whether it's just incredibly unlikely (which I suspect), or if it's not that unlikely and I'm doing something fundamentally wrong. I have 4 instances of the same c...
In order to do quality assurance in a critical multicore (8) workstation, I want to run the same code in different processors but not in parallel or concurrently. I need to run it 8 times, one run for each processor. What I don't know is how to select the processor I want. How can this be accomplished in Python? ...
I've been reading about Python's multiprocessing module. I still don't think I have a very good understanding of what it can do. Let's say I have a quadcore processor and I have a list with 1,000,000 integers and I want the sum of all the integers. I could simply do: list_sum = sum(my_list) But this only sends it to one core. Is i...
If you spawn a child process in ruby (using Kernel.system for example), can it use a different CPU to the parent process? If so, can you use multiple threads (within the same CPU) in a parent process, and have each thread spawning a child process that can use a different CPU, even in ruby 1.8? (Background -- it's superscript.rb from t...
I'm writing a Java program which uses a lot of CPU because of the nature of what it does. However, lots of it can run in parallel. When I run it, it only seems to use one CPU until it needs more then it uses another CPU - is there anything I can do in Java to force different threads to run on different cores/CPUs? ...
In general the operating system takes care of allocating threads to cores. I wonder whether there is a way for the program to be invloved in this allocation. In other words: Is there an API (for either the Linux or Win32 platforms) enabling to create a thread that is associated with a specific core? ...