Search Results

Search found 137626 results on 5506 pages for 'linked lists using c'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 51/5506 | < Previous Page | 47 48 49 50 51 52 53 54 55 56 57 58  | Next Page >

  • How to add linked Oracle server to SQL 2008 Express?

    - by David.Chu.ca
    I have tried to download Oracle Client 11g both 32 & 64 packages to Windows 2008 R2 with SQL server 2008 Express. However, I still cannot see Oracle provider in SQL server by using sa log in. Not sure if is it possible to do it for SQL Server express 2008? Any advice to do it? I followed installations from this article: Making Linked Server Connection Between SQL Server 64 Bit & Oracle 32 Bit | MS SQL World After installation and reboot the Windows, I still cannot see the Oracle provider in linked provider in SQL server.

    Read the article

  • Using ConcurrentQueue for thread-safe Performance Bookkeeping.

    - by Strenium
    Just a small tidbit that's sprung up today. I had to book-keep and emit diagnostics for the average thread performance in a highly-threaded code over a period of last X number of calls and no more. Need of the day: a thread-safe, self-managing stats container. Since .NET 4.0 introduced new thread-safe 'Collections.Concurrent' objects and I've been using them frequently - the one in particular seemed like a good fit for storing each threads' performance data - ConcurrentQueue. But I wanted to store only the most recent X# of calls and since the ConcurrentQueue currently does not support size constraint I had to come up with my own generic version which attempts to restrict usage to numeric types only: unfortunately there is no IArithmetic-like interface which constrains to only numeric types – so the constraints here here aren't as elegant as they could be. (Note the use of the Average() method, of course you can use others as well as make your own).   FIFO FixedSizedConcurrentQueue using System;using System.Collections.Concurrent;using System.Linq; namespace xxxxx.Data.Infrastructure{    [Serializable]    public class FixedSizedConcurrentQueue<T> where T : struct, IConvertible, IComparable<T>    {        private FixedSizedConcurrentQueue() { }         public FixedSizedConcurrentQueue(ConcurrentQueue<T> queue)        {            _queue = queue;        }         ConcurrentQueue<T> _queue = new ConcurrentQueue<T>();         public int Size { get { return _queue.Count; } }        public double Average { get { return _queue.Average(arg => Convert.ToInt32(arg)); } }         public int Limit { get; set; }        public void Enqueue(T obj)        {            _queue.Enqueue(obj);            lock (this)            {                T @out;                while (_queue.Count > Limit) _queue.TryDequeue(out @out);            }        }    } }   The usage case is straight-forward, in this case I’m using a FIFO queue of maximum size of 200 to store doubles to which I simply Enqueue() the calculated rates: Usage var RateQueue = new FixedSizedConcurrentQueue<double>(new ConcurrentQueue<double>()) { Limit = 200 }; /* greater size == longer history */   That’s about it. Happy coding!

    Read the article

  • Can't control connection bit rate using iwconfig with Atheros TL-WN821N (AR7010)

    - by Paul H
    I'm trying to reduce the connection bit rate on my Atheros TP-Link TL-WN821N v3 usb wifi adapter due to frequent instability issues (reported connection speed goes down to 1Mb/s and I have to physically reconnect the adapter to regain a connection). I know this is a common problem with this device, and I have tried everything I can think of to fix it, including using drivers from linux-backports; compiling and installing a custom firmware (following instructions on https://wiki.debian.org/ath9k_htc#fw-free) and (as a last resort) using ndiswrapper. When using ndiswrapper, the wifi adapter is stable and operates in g mode at 54Mb/s (whilst when using the default ath9k_htc module, the adapter connects in n mode and the bit rate fluctuates constantly). Unfortunately, with this setup I have to run my processor using only one core, since using SMP with ndiswrapper causes a kernel oops on my system. So I want to lock my bit rate to 54Mb/s (or less, if need be) for connection stability, using the ath9k_htc module. I've tried 'sudo iwconfig wlan0 rate 54M'; the command runs with no error but when I check the bit rate with 'sudo iwlist wlan0 bitrate' the command returns: wlan0 unknown bit-rate information. Current Bit Rate:78 Mb/s Any ideas? Here's some info (hopefully relevant) on my setup: Xubuntu (12.04.3) 64bit (kernel 3.2.0-55.85-generic) using Network Manager. My Router is from Virgin Media, the VMDG480. lshw -C network : *-network description: Wireless interface physical id: 1 bus info: usb@1:4 logical name: wlan0 serial: 74:ea:3a:8f:16:b6 capabilities: ethernet physical wireless configuration: broadcast=yes driver=ath9k_htc driverversion=3.2.0-55 firmware=1.3 ip=192.168.0.9 link=yes multicast=yes wireless=IEEE 802.11bgn lsusb -v: Bus 001 Device 003: ID 0cf3:7015 Atheros Communications, Inc. TP-Link TL-WN821N v3 802.11n [Atheros AR7010+AR9287] Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.00 bDeviceClass 255 Vendor Specific Class bDeviceSubClass 255 Vendor Specific Subclass bDeviceProtocol 255 Vendor Specific Protocol bMaxPacketSize0 64 idVendor 0x0cf3 Atheros Communications, Inc. idProduct 0x7015 TP-Link TL-WN821N v3 802.11n [Atheros AR7010+AR9287] bcdDevice 2.02 iManufacturer 16 ATHEROS iProduct 32 UB95 iSerial 48 12345 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 60 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 0 bmAttributes 0x80 (Bus Powered) MaxPower 500mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 6 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 0 bInterfaceProtocol 0 iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x01 EP 1 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0200 1x 512 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x82 EP 2 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0200 1x 512 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x83 EP 3 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 1 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x04 EP 4 OUT bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 1 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x05 EP 5 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0200 1x 512 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x06 EP 6 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0200 1x 512 bytes bInterval 0 Device Qualifier (for other device speed): bLength 10 bDescriptorType 6 bcdUSB 2.00 bDeviceClass 255 Vendor Specific Class bDeviceSubClass 255 Vendor Specific Subclass bDeviceProtocol 255 Vendor Specific Protocol bMaxPacketSize0 64 bNumConfigurations 1 Device Status: 0x0000 (Bus Powered) iwlist wlan0 scanning: wlan0 Scan completed : Cell 01 - Address: C4:3D:C7:3A:1F:5D Channel:1 Frequency:2.412 GHz (Channel 1) Quality=37/70 Signal level=-73 dBm Encryption key:on ESSID:"my essid" Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s 24 Mb/s; 36 Mb/s; 54 Mb/s Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 48 Mb/s Mode:Master Extra:tsf=00000070cca77186 Extra: Last beacon: 5588ms ago IE: Unknown: 0007756E69636F726E IE: Unknown: 010882848B962430486C IE: Unknown: 030101 IE: Unknown: 2A0100 IE: Unknown: 2F0100 IE: IEEE 802.11i/WPA2 Version 1 Group Cipher : TKIP Pairwise Ciphers (2) : CCMP TKIP Authentication Suites (1) : PSK IE: Unknown: 32040C121860 IE: Unknown: 2D1AFC181BFFFF000000000000000000000000000000000000000000 IE: Unknown: 3D1601080400000000000000000000000000000000000000 IE: Unknown: DD7E0050F204104A0001101044000102103B00010310470010F99C335D7BAC57FB00137DFA79600220102100074E657467656172102300074E6574676561721024000631323334353610420007303030303030311054000800060050F20400011011000743473331303144100800022008103C0001011049000600372A000120 IE: Unknown: DD090010180203F02C0000 IE: WPA Version 1 Group Cipher : TKIP Pairwise Ciphers (2) : CCMP TKIP Authentication Suites (1) : PSK IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00 iwconfig: lo no wireless extensions. wlan0 IEEE 802.11bgn ESSID:"my essid" Mode:Managed Frequency:2.412 GHz Access Point: C4:3D:C7:3A:1F:5D Bit Rate=78 Mb/s Tx-Power=20 dBm Retry long limit:7 RTS thr:off Fragment thr:off Power Management:off Link Quality=36/70 Signal level=-74 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0,

    Read the article

  • Using a PowerShell Script to delete old files for SQL Server

    Many clients are using custom stored procedures or third party tools to backup databases in production environments instead of using database maintenance plans. One of the things that you need to do is to maintain the number of backup files that exist on disk, so you don't run out of disk space. There are several techniques for deleting old files, but in this tip I show how this can be done using PowerShell.

    Read the article

  • Problem with connect to server using FTP(with login)

    - by Sourav Chattopadhyay
    I am unable connect to my remote account using Ubuntu's "Connect to Server" option after moving on to Ubuntu 12.04 LTS. In Ubuntu 10.10 I used to connect to my FTP server by going to Places-Connect to server-FTP (with login) After giving the userid and password the remote folder would mount immediately but now it is showing a busy icon at top until I close the window after some time. I have also tried to connect using Ctrl + L from a Nautilus window using sftp://user@server but result is the same. Even though I could connect to my FTP server using gFTP, the default one from Nautilus is a better option to me.

    Read the article

  • Ruby Gem LoadError mysql2/mysql2 required

    - by Kalli Dalli
    Im trying to setup my rails server on OSX 10.8 but I can't get my rails server to run. - Currently Im using a Zend Server with mysql 5.1. - I also have istalled brew and brew mysql. - And I used: gem install mysql2 -- --srcdir=/usr/local/mysql/include --with-opt-include=/usr/local/mysql/include the server worked already but now, I always get this loadError below. This is what my Gemfile says: ralphs-macbook-pro:admin-mockup zero$ bundle install Using rake (10.0.2) Using i18n (0.6.1) Using multi_json (1.3.7) Using activesupport (3.2.7) Using builder (3.0.4) Using activemodel (3.2.7) Using erubis (2.7.0) Using journey (1.0.4) Using rack (1.4.1) Using rack-cache (1.2) Using rack-test (0.6.2) Using hike (1.2.1) Using tilt (1.3.3) Using sprockets (2.1.3) Using actionpack (3.2.7) Using mime-types (1.19) Using polyglot (0.3.3) Using treetop (1.4.12) Using mail (2.4.4) Using actionmailer (3.2.7) Using arel (3.0.2) Using tzinfo (0.3.35) Using activerecord (3.2.7) Using activeresource (3.2.7) Using annotate (2.5.0) Using coffee-script-source (1.4.0) Using execjs (1.4.0) Using coffee-script (2.2.0) Using rack-ssl (1.3.2) Using json (1.7.5) Using rdoc (3.12) Using thor (0.16.0) Using railties (3.2.7) Using coffee-rails (3.2.2) Using columnize (0.3.6) Using debugger-ruby_core_source (1.1.5) Using debugger-linecache (1.1.2) Using debugger (1.2.2) Using formtastic (2.2.1) Using haml (3.1.7) Using haml-rails (0.3.5) Using hirb (0.7.0) Using hpricot (0.8.6) Using jquery-rails (2.1.4) Using kgio (2.7.4) Using mysql2 (0.3.11) Using php_serialize (1.2) Using polyamorous (0.5.0) Using rabl (0.7.8) Using railroady (1.1.0) Using bundler (1.2.3) Using rails (3.2.7) Using raindrops (0.10.0) Using randumb (0.3.0) Using sass (3.2.3) Using sass-rails (3.2.5) Using squeel (1.0.13) Using uglifier (1.3.0) Using unicorn (4.4.0) Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem is installed. And after starting rails s /Users/zero/.rvm/gems/ruby-1.9.3-p327/gems/mysql2-0.3.11/lib/mysql2.rb:9:in `require': cannot load such file -- mysql2/mysql2 (LoadError) from /Users/zero/.rvm/gems/ruby-1.9.3-p327/gems/mysql2-0.3.11/lib/mysql2.rb:9:in `<top (required)>' from /Users/zero/.rvm/gems/ruby-1.9.3-p327/gems/bundler-1.2.3/lib/bundler/runtime.rb:68:in `require' from /Users/zero/.rvm/gems/ruby-1.9.3-p327/gems/bundler-1.2.3/lib/bundler/runtime.rb:68:in `block (2 levels) in require' from /Users/zero/.rvm/gems/ruby-1.9.3-p327/gems/bundler-1.2.3/lib/bundler/runtime.rb:66:in `each' from /Users/zero/.rvm/gems/ruby-1.9.3-p327/gems/bundler-1.2.3/lib/bundler/runtime.rb:66:in `block in require' from /Users/zero/.rvm/gems/ruby-1.9.3-p327/gems/bundler-1.2.3/lib/bundler/runtime.rb:55:in `each' from /Users/zero/.rvm/gems/ruby-1.9.3-p327/gems/bundler-1.2.3/lib/bundler/runtime.rb:55:in `require' from /Users/zero/.rvm/gems/ruby-1.9.3-p327/gems/bundler-1.2.3/lib/bundler.rb:128:in `require' from /Users/zero/GitHub/admin-mockup/config/application.rb:7:in `<top (required)>' from /Users/zero/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.7/lib/rails/commands.rb:53:in `require' from /Users/zero/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.7/lib/rails/commands.rb:53:in `block in <top (required)>' from /Users/zero/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.7/lib/rails/commands.rb:50:in `tap' from /Users/zero/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.7/lib/rails/commands.rb:50:in `<top (required)>' from script/rails:6:in `require' from script/rails:6:in `<main>' Thx for any help!

    Read the article

  • Of these 3 methods for reading linked lists from shared memory, why is the 3rd fastest?

    - by Joseph Garvin
    I have a 'server' program that updates many linked lists in shared memory in response to external events. I want client programs to notice an update on any of the lists as quickly as possible (lowest latency). The server marks a linked list's node's state_ as FILLED once its data is filled in and its next pointer has been set to a valid location. Until then, its state_ is NOT_FILLED_YET. I am using memory barriers to make sure that clients don't see the state_ as FILLED before the data within is actually ready (and it seems to work, I never see corrupt data). Also, state_ is volatile to be sure the compiler doesn't lift the client's checking of it out of loops. Keeping the server code exactly the same, I've come up with 3 different methods for the client to scan the linked lists for changes. The question is: Why is the 3rd method fastest? Method 1: Round robin over all the linked lists (called 'channels') continuously, looking to see if any nodes have changed to 'FILLED': void method_one() { std::vector<Data*> channel_cursors; for(ChannelList::iterator i = channel_list.begin(); i != channel_list.end(); ++i) { Data* current_item = static_cast<Data*>(i->get(segment)->tail_.get(segment)); channel_cursors.push_back(current_item); } while(true) { for(std::size_t i = 0; i < channel_list.size(); ++i) { Data* current_item = channel_cursors[i]; ACQUIRE_MEMORY_BARRIER; if(current_item->state_ == NOT_FILLED_YET) { continue; } log_latency(current_item->tv_sec_, current_item->tv_usec_); channel_cursors[i] = static_cast<Data*>(current_item->next_.get(segment)); } } } Method 1 gave very low latency when then number of channels was small. But when the number of channels grew (250K+) it became very slow because of looping over all the channels. So I tried... Method 2: Give each linked list an ID. Keep a separate 'update list' to the side. Every time one of the linked lists is updated, push its ID on to the update list. Now we just need to monitor the single update list, and check the IDs we get from it. void method_two() { std::vector<Data*> channel_cursors; for(ChannelList::iterator i = channel_list.begin(); i != channel_list.end(); ++i) { Data* current_item = static_cast<Data*>(i->get(segment)->tail_.get(segment)); channel_cursors.push_back(current_item); } UpdateID* update_cursor = static_cast<UpdateID*>(update_channel.tail_.get(segment)); while(true) { if(update_cursor->state_ == NOT_FILLED_YET) { continue; } ::uint32_t update_id = update_cursor->list_id_; Data* current_item = channel_cursors[update_id]; if(current_item->state_ == NOT_FILLED_YET) { std::cerr << "This should never print." << std::endl; // it doesn't continue; } log_latency(current_item->tv_sec_, current_item->tv_usec_); channel_cursors[update_id] = static_cast<Data*>(current_item->next_.get(segment)); update_cursor = static_cast<UpdateID*>(update_cursor->next_.get(segment)); } } Method 2 gave TERRIBLE latency. Whereas Method 1 might give under 10us latency, Method 2 would inexplicably often given 8ms latency! Using gettimeofday it appears that the change in update_cursor-state_ was very slow to propogate from the server's view to the client's (I'm on a multicore box, so I assume the delay is due to cache). So I tried a hybrid approach... Method 3: Keep the update list. But loop over all the channels continuously, and within each iteration check if the update list has updated. If it has, go with the number pushed onto it. If it hasn't, check the channel we've currently iterated to. void method_three() { std::vector<Data*> channel_cursors; for(ChannelList::iterator i = channel_list.begin(); i != channel_list.end(); ++i) { Data* current_item = static_cast<Data*>(i->get(segment)->tail_.get(segment)); channel_cursors.push_back(current_item); } UpdateID* update_cursor = static_cast<UpdateID*>(update_channel.tail_.get(segment)); while(true) { for(std::size_t i = 0; i < channel_list.size(); ++i) { std::size_t idx = i; ACQUIRE_MEMORY_BARRIER; if(update_cursor->state_ != NOT_FILLED_YET) { //std::cerr << "Found via update" << std::endl; i--; idx = update_cursor->list_id_; update_cursor = static_cast<UpdateID*>(update_cursor->next_.get(segment)); } Data* current_item = channel_cursors[idx]; ACQUIRE_MEMORY_BARRIER; if(current_item->state_ == NOT_FILLED_YET) { continue; } found_an_update = true; log_latency(current_item->tv_sec_, current_item->tv_usec_); channel_cursors[idx] = static_cast<Data*>(current_item->next_.get(segment)); } } } The latency of this method was as good as Method 1, but scaled to large numbers of channels. The problem is, I have no clue why. Just to throw a wrench in things: if I uncomment the 'found via update' part, it prints between EVERY LATENCY LOG MESSAGE. Which means things are only ever found on the update list! So I don't understand how this method can be faster than method 2. The full, compilable code (requires GCC and boost-1.41) that generates random strings as test data is at: http://pastebin.com/e3HuL0nr

    Read the article

  • What is a practical, real world example of the Linked List?

    - by JStims
    I understand the definition of a Linked List, but how can it be represented and related to a common concept or item? For example, inheritance in OOP can be related to automobiles. All (most) automobiles in real life are the essentially same thing; an automobile has an Engine, you can start() it, you can make the car go(), stop() and so on. An automobile would typically have a maximum passenger capacity but it would differ between a Bus and a SportsCar, which are both automobiles. Is there some real life, intuitive example of the plain ole' singly Linked List like we have with inheritance? The typical textbook Linked List example shows a node with an integer and a pointer to the next, and it just doesn't seem very useful. Your input is appreciated.

    Read the article

  • Why does using cons to create a pair of two lists produce a list and two elements?

    - by fingerprint211b
    I've started learning Scheme, for fun mostly, and because I've never used a functional language before. I chose Scheme because I wanted to read SICP for a long time. Anyway, I'm currently learning about lists, and before that I learned about cons, car and cdr. And there's an example that creates a list of lists with cons, like this : (cons (list 1 2) (list 3 4)) The resulting list is ((1 2) 3 4), which doesn't make sense to me, I would expect ((1 2)(3 4)) to be the result (a list made out of two lists). Why does it behave like that? I realize that if I were to use car, I would get (1 2), and cdr I'd get (3 4) becaue cdr always returns "the rest", but I don't understand why the list isn't made of two lists?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 47 48 49 50 51 52 53 54 55 56 57 58  | Next Page >