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• How to acquire still webcam image

  - by Silv3rSurf

  I need some help deciding what to use to acquire an image from a webcam. I want to acquire a single image. I know you can typically acquire a still image at a higher resolution than a single video frame. Currently, I am using MATLAB's image acquisition toolbox.. which apparently only supports obtaining frames in video mode(so lower resolution). Which other libraries do you recommend? Has anyone else encountered this problem?

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• ACE_Mutex::acquire problem

  - by O. Askari

  Hi, I have a mutex in my class with the following definition: ACE_Mutex m_specsMutex; When i use the acquire() method that takes no parameters everything works just fine. But when i use it with a time value (as follows) it just immediately returns with -1 value. I'm sure that this mutex hasn't been acquired anywhere else so it shouldn't return -1. m_specsMutex.acquire(ACE_OS::gettimeofday() + ACE_Time_Value(30)) Am i doing anything wrong?

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• How do most small businesses acquire Office licenses?

  - by LuckyLindy

  A company I sometimes consult for is relatively small (40 employees), and they have a royal mess of Office licenses. OEM, Retail, Upgrades, O2K/XP/2K3/2K7, etc. They basically buy whatever retail license they can find cheapest online, and have someone track it all in a spreadsheet for compliance purposes. They also use a Microsoft Action pack license for getting another 10 copies of Office/Vista for free. While it all seems to follow Microsoft's licensing rules, it also seems horribly inefficient. I've talked to them about Microsoft's Open license, but they don't see any advantage to it. What do other relatively small businesses do? Are Open licenses popular, or do most of them just buy retail like my client?

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• Java ReentrantReadWriteLocks - how to safely acquire write lock?

  - by Andrzej Doyle

  I am using in my code at the moment a ReentrantReadWriteLock to synchronize access over a tree-like structure. This structure is large, and read by many threads at once with occasional modifications to small parts of it - so it seems to fit the read-write idiom well. I understand that with this particular class, one cannot elevate a read lock to a write lock, so as per the Javadocs one must release the read lock before obtaining the write lock. I've used this pattern successfully in non-reentrant contexts before. What I'm finding however is that I cannot reliably acquire the write lock without blocking forever. Since the read lock is reentrant and I am actually using it as such, the simple code lock.getReadLock().unlock(); lock.getWriteLock().lock() can block if I have acquired the readlock reentrantly. Each call to unlock just reduces the hold count, and the lock is only actually released when the hold count hits zero. EDIT to clarify this, as I don't think I explained it too well initially - I am aware that there is no built-in lock escalation in this class, and that I have to simply release the read lock and obtain the write lock. My problem is/was that regardless of what other threads are doing, calling getReadLock().unlock() may not actually release this thread's hold on the lock if it acquired it reentrantly, in which case the call to getWriteLock().lock() will block forever as this thread still has a hold on the read lock and thus blocks itself. For example, this code snippet will never reach the println statement, even when run singlethreaded with no other threads accessing the lock: final ReadWriteLock lock = new ReentrantReadWriteLock(); lock.getReadLock().lock(); // In real code we would go call other methods that end up calling back and // thus locking again lock.getReadLock().lock(); // Now we do some stuff and realise we need to write so try to escalate the // lock as per the Javadocs and the above description lock.getReadLock().unlock(); // Does not actually release the lock lock.getWriteLock().lock(); // Blocks as some thread (this one!) holds read lock System.out.println("Will never get here"); So I ask, is there a nice idiom to handle this situation? Specifically, when a thread that holds a read lock (possibly reentrantly) discovers that it needs to do some writing, and thus wants to "suspend" its own read lock in order to pick up the write lock (blocking as required on other threads to release their holds on the read lock), and then "pick up" its hold on the read lock in the same state afterwards? Since this ReadWriteLock implementation was specifically designed to be reentrant, surely there is some sensible way to elevate a read lock to a write lock when the locks may be acquired reentrantly? This is the critical part that means the naive approach does not work.

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• How to quickly acquire and process real time screen output

  - by Akusete

  I am trying to write a program to play a full screen PC game for fun (as an experiment in Computer Vision and Artificial Intelligence). For this experiment I am assuming the game has no underlying API for AI players (nor is the source available) so I intend to process the visual information rendered by the game on the screen. The game runs in full screen mode on a win32 system (direct-X I assume). Currently I am using the win32 functions #include <windows.h> #include <cvaux.h> class Screen { public: HWND windowHandle; HDC windowContext; HBITMAP buffer; HDC bufferContext; CvSize size; uchar* bytes; int channels; Screen () { windowHandle = GetDesktopWindow(); windowContext = GetWindowDC (windowHandle); size = cvSize (GetDeviceCaps (windowContext, HORZRES), GetDeviceCaps (windowContext, VERTRES)); buffer = CreateCompatibleBitmap (windowContext, size.width, size.height); bufferContext = CreateCompatibleDC (windowContext); SelectObject (bufferContext, buffer); channels = 4; bytes = new uchar[size.width * size.height * channels]; } ~Screen () { ReleaseDC(windowHandle, windowContext); DeleteDC(bufferContext); DeleteObject(buffer); delete[] bytes; } void CaptureScreen (IplImage* img) { BitBlt(bufferContext, 0, 0, size.width, size.height, windowContext, 0, 0, SRCCOPY); int n = size.width * size.height; int imgChannels = img->nChannels; GetBitmapBits (buffer, n * channels, bytes); uchar* src = bytes; uchar* dest = (uchar*) img->imageData; uchar* end = dest + n * imgChannels; while (dest < end) { dest[0] = src[0]; dest[1] = src[1]; dest[2] = src[2]; dest += imgChannels; src += channels; } } The rate at which I can process frames using this approach is much to slow. Is there a better way to acquire screen frames?

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• Exception: attempt to acquire a reference on a close SQLiteClosable

  - by CommonsWare

  I posted this back in May on the [android-developers] Google Group. I never heard back and was not able to reproduce the problem until one of my students did last week. I figured I'd post it here and see if it rang any bells for anyone. In one of my code samples, I have the following method: static Cursor getAll(SQLiteDatabase db, String orderBy) { return(db.rawQuery("SELECT * FROM restaurants "+orderBy, null)); } When I run it, sporadically, I get this: 05-01 14:45:05.849: ERROR/AndroidRuntime(1145): java.lang.IllegalStateException: attempt to acquire a reference on a close SQLiteClosable 05-01 14:45:05.849: ERROR/AndroidRuntime(1145): at android.database.sqlite.SQLiteClosable.acquireReference(SQLiteClosable.java:31) 05-01 14:45:05.849: ERROR/AndroidRuntime(1145): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:56) 05-01 14:45:05.849: ERROR/AndroidRuntime(1145): at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:49) 05-01 14:45:05.849: ERROR/AndroidRuntime(1145): at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:49) 05-01 14:45:05.849: ERROR/AndroidRuntime(1145): at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1118) 05-01 14:45:05.849: ERROR/AndroidRuntime(1145): at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1092) 05-01 14:45:05.849: ERROR/AndroidRuntime(1145): at apt.tutorial.Restaurant.getAll(Restaurant.java:14) This makes no sense to me. The database is definitely open. The SQLiteClosable is the SQLiteQuery created by SQLiteQueryDriver, and I see no evidence that there is an object pool or something going on here that might explain how a "new" SQLiteClosable is already closed. The fact that it is sporadic (meaning the same UI operations sometimes trigger the exception, but not always) suggests some sort of pool, race condition, or something...but I'm not sure where. Thoughts? Thanks! UPDATE: The code in question is from the LunchList tutorials out of my Android Programming Tutorials book. It's a bit spread out and not terribly suitable for posting directly in SO. You can download the code for that book from the above link if you want to take a look at it. I do not recall exactly which edition of the tutorial the student was working on at the time, though it was in the Tutorial 12-Tutorial 16 range. I was mostly hoping to run across somebody who had tripped over this problem before and had a likely culprit. I'm fairly certain my database is open. Thanks again!

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• Acquire Internet Explorer window position

  - by Ilya

  How do I get in Internet Explorer values equivalent to: window.outerWidth and window.outerHeight in Firefox ? I've seen some "solution": window.screenLeft and window.screenTop but it is not correct. These properties give inner dimensions. I resize a window and I need values to use with window.resizeTo() later, to restore original size after.

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• SQL SERVER – LCK_M_XXX – Wait Type – Day 15 of 28

  - by pinaldave

  Locking is a mechanism used by the SQL Server Database Engine to synchronize access by multiple users to the same piece of data, at the same time. In simpler words, it maintains the integrity of data by protecting (or preventing) access to the database object. From Book On-Line: LCK_M_BU Occurs when a task is waiting to acquire a Bulk Update (BU) lock. LCK_M_IS Occurs when a task is waiting to acquire an Intent Shared (IS) lock. LCK_M_IU Occurs when a task is waiting to acquire an Intent Update (IU) lock. LCK_M_IX Occurs when a task is waiting to acquire an Intent Exclusive (IX) lock. LCK_M_S Occurs when a task is waiting to acquire a Shared lock. LCK_M_SCH_M Occurs when a task is waiting to acquire a Schema Modify lock. LCK_M_SCH_S Occurs when a task is waiting to acquire a Schema Share lock. LCK_M_SIU Occurs when a task is waiting to acquire a Shared With Intent Update lock. LCK_M_SIX Occurs when a task is waiting to acquire a Shared With Intent Exclusive lock. LCK_M_U Occurs when a task is waiting to acquire an Update lock. LCK_M_UIX Occurs when a task is waiting to acquire an Update With Intent Exclusive lock. LCK_M_X Occurs when a task is waiting to acquire an Exclusive lock. LCK_M_XXX Explanation: I think the explanation of this wait type is the simplest. When any task is waiting to acquire lock on any resource, this particular wait type occurs. The common reason for the task to be waiting to put lock on the resource is that the resource is already locked and some other operations may be going on within it. This wait also indicates that resources are not available or are occupied at the moment due to some reasons. There is a good chance that the waiting queries start to time out if this wait type is very high. Client application may degrade the performance as well. You can use various methods to find blocking queries: EXEC sp_who2 SQL SERVER – Quickest Way to Identify Blocking Query and Resolution – Dirty Solution DMV – sys.dm_tran_locks DMV – sys.dm_os_waiting_tasks Reducing LCK_M_XXX wait: Check the Explicit Transactions. If transactions are very long, this wait type can start building up because of other waiting transactions. Keep the transactions small. Serialization Isolation can build up this wait type. If that is an acceptable isolation for your business, this wait type may be natural. The default isolation of SQL Server is ‘Read Committed’. One of my clients has changed their isolation to “Read Uncommitted”. I strongly discourage the use of this because this will probably lead to having lots of dirty data in the database. Identify blocking queries mentioned using various methods described above, and then optimize them. Partition can be one of the options to consider because this will allow transactions to execute concurrently on different partitions. If there are runaway queries, use timeout. (Please discuss this solution with your database architect first as timeout can work against you). Check if there is no memory and IO-related issue using the following counters: Checking Memory Related Perfmon Counters SQLServer: Memory Manager\Memory Grants Pending (Consistent higher value than 0-2) SQLServer: Memory Manager\Memory Grants Outstanding (Consistent higher value, Benchmark) SQLServer: Buffer Manager\Buffer Hit Cache Ratio (Higher is better, greater than 90% for usually smooth running system) SQLServer: Buffer Manager\Page Life Expectancy (Consistent lower value than 300 seconds) Memory: Available Mbytes (Information only) Memory: Page Faults/sec (Benchmark only) Memory: Pages/sec (Benchmark only) Checking Disk Related Perfmon Counters Average Disk sec/Read (Consistent higher value than 4-8 millisecond is not good) Average Disk sec/Write (Consistent higher value than 4-8 millisecond is not good) Average Disk Read/Write Queue Length (Consistent higher value than benchmark is not good) Read all the post in the Wait Types and Queue series. Note: The information presented here is from my experience and there is no way that I claim it to be accurate. I suggest reading Book OnLine for further clarification. All the discussion of Wait Stats in this blog is generic and varies from system to system. It is recommended that you test this on a development server before implementing it to a production server. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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• makecert gives "Fail to acquire a security provider from the issuer's certificate" - why?

  - by mark

  Dear ladies and sirs. Observe this simple batch file: makecert -n "CN=MyCA" -sr localmachine -ss root -a sha1 -cy authority -r -sv MyCA.pvk MyCA.cer del MyCA.pvk del MyCA.cer makecert -n "CN=il-mark-lt" -sr localmachine -ss my -cy end -pe -sky exchange -a sha1 -is root -ir localmachine -in MyCA However, the last makecert fails with the following error message: Error: Fail to acquire a security provider from the issuer's certificate How do I troubleshoot it? Any ideas? BTW, the first makecert succeeds. Of course, I delete it again, before running the commands again. Thanks. EDIT1 I understood the reasons for the failure. The second command expects the file MyCA.pvk to exist, but I do not want to keep it around. So, what can I do?

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• Emacs / Wanderlust / OSX -- Any ideas what could cause Emacs to acquire focus when using Wanderlust?

  - by lawlist

  I'm using Wanderlust with Emacs on OSX 10.6.8 (Snow Leopard) and frequently switch to a different application while Wanderlust is prefetching e-mails and organizing the summary buffers. At several stages during this process, Emacs acquires focus and steels me away from whatever I was doing in another application. I don't think Wanderlust has any built-in applescripts and I haven't added any, so I have no idea what could be causing Emacs to demand focus. Any ideas how to leave Emacs in the background while updating Wanderlust?

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• In WMI, can I use a join (or something similar) to acquire the IisWebServer object for a site, given

  - by Precipitous

  Given a server name and a physical path, I'd like to be able to hunt down the IISWebServer object and ApplicationPool. Website url is also an acceptable input. Our technologies are IIS 6, WMI, and access via C# or Powershell 2. I'm certain this would be easier with IIS 7 its managed API. We don't have that yet. Here's what I can do: Get a list of IIS virtual directories from IISWebVirtualDirSetting and filter (offline) for the matching physical path. $theVirtualDir = gwmi -Namespace "root/MicrosoftIISv2" ` -ComputerName $servername -authentication PacketPrivacy ` -class "IISWebVirtualDirSetting" ` | where-object {$_.Path -like $deployLocation} From the virtual directory object, I can get a name (like W3SVC/40565456/root). Given this name, I can get to other goodies, such as the IIS web server object. gwmi -Namespace "root/MicrosoftIISv2" ` -ComputerName $servername ` -authentication PacketPrivacy ` -Query "SELECT * FROM IisWebServer WHERE Name='W3SVC/40589473'" The questions, restated: 1) This is a query language. Can I join or subquery so that 1 WMI query statement gets web servers based on IISWebVirtualDir.Path? How? 2) In solving 1, you'll have to explain how to query on the Path property. Why is this an invalid query? "SELECT * FROM IISWebVirtualDirSetting WHERE Path='D:\sites\globaldominator'"

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• C#, Can I check on a lock without trying to acquire it?

  - by Biff MaGriff

  Hello, I have a lock in my c# web app that prevents users from running the update script once it has started. I was thinking I would put a notification in my master page to let the user know that the data isn't all there yet. Currently I do my locking like so. protected void butRefreshData_Click(object sender, EventArgs e) { Thread t = new Thread(new ParameterizedThreadStart(UpdateDatabase)); t.Start(this); //sleep for a bit to ensure that javascript has a chance to get rendered Thread.Sleep(100); } public static void UpdateDatabase(object con) { if (Monitor.TryEnter(myLock)) { Updater.RepopulateDatabase(); Monitor.Exit(myLock); } else { Common.RegisterStartupScript(con, AlreadyLockedJavaScript); } } And I do not want to do if(Monitor.TryEnter(myLock)) Monitor.Exit(myLock); else //show processing labal As I imagine there is a slight possibility that it might display the notification when it isn't actually running. Is there an alternative I can use? Edit: Hi Everyone, thanks a lot for your suggestions! Unfortunately I couldn't quite get them to work... However I combined the ideas on 2 answers and came up with my own solution.

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• How to acquire the Context in an Adobe AIR Native Extension?

  - by rotaercz

  In the following line of code... ProgressDialog progressDialog = ProgressDialog.show(getBaseContext(), "LOADING_TITLE", "LOADING_MESSAGE"); In place of getBaseContext() I've tried... getApplicationContext() this NativeActivity.this (NativeActivity)getApplicationContext() Among others. I'm not sure why it's not working. In the NativeExtensionContext which extends FREContext I am passing the activity using getActivity() to NativeActivity. Everything works well but I get a "Nullpointerexception" or “android.view.WindowManager$BadTokenException: Unable to add window — token null is not for an application” when I try I try to get a reference to the Context. Anyone with experience using Adobe AIR Native Extensions and/or Android Java would be great.

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• How can I acquire an aggregated list of known proxy IP addresses?

  - by Howard3

  I'd like to use this to help maintain a good defence against people trying to skirt the rules of my system. I've found TOR endpoints, nothing that's readily available to be shot into a script (needs to be parsed) but they work. However I need a list which goes beyond TOR yet I cannot find anything conclusive just yet. Any suggestions would be greatly appreciated.

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• How to reset the language of the package descriptions

  - by xubuntix

  I have had German as my main language about a year ago. Later I changed it to English. Most parts of the system accepted the change. The notable exceptions are the package descriptions, which remain in German for some packages. You can see in the image (apt-cache and software-center), that while some descriptions are in English, some have remained in German. So the question is: how do I reset this? I guess that there is somewhere a description cache that needs to be told that it should update all descriptions? EDIT: As asked: the output of some language related commands: $ cat /etc/default/locale LANG="en_US.UTF-8" $ apt-config dump | grep Lang Acquire::Languages ""; Acquire::Languages:: "de_DE"; Acquire::Languages:: "de"; Acquire::Languages:: "en"; Acquire::Languages:: "none"; $ locale LANG=de_DE.UTF-8 LANGUAGE=en LC_CTYPE="de_DE.UTF-8" LC_NUMERIC="de_DE.UTF-8" LC_TIME="de_DE.UTF-8" LC_COLLATE="de_DE.UTF-8" LC_MONETARY="de_DE.UTF-8" LC_MESSAGES="de_DE.UTF-8" LC_PAPER="de_DE.UTF-8" LC_NAME="de_DE.UTF-8" LC_ADDRESS="de_DE.UTF-8" LC_TELEPHONE="de_DE.UTF-8" LC_MEASUREMENT="de_DE.UTF-8" LC_IDENTIFICATION="de_DE.UTF-8" LC_ALL= As a note: I'm not sure what each entry means, but some of the de_DE.UTF-8 are probably ok, since I do want paper-sizes, monetary, time, etc. in standard German formats.

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• In the Field: "How to Learn"

  Choosing the best way to acquire knowledge

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• System wide Proxy settings when on a windows network with a password

  - by sav

  I'm using Ubuntu on a windows network. I want to connect to the world wide web. I have followed the steps here which I have found very useful. However when I try to ping a website (eg: ping www.wikipedia.org) I get no reply. I can ping local computers on my network, but I need to go through our proxy to get to the world wide web. I can even browse wikipedia using firefox, I just needed to enter the proxy configuration script location and my username and password. I'm quite sure the reason I'm having this trouble is because I havn't entered a username and password. I'm not sure how to do this on a system wide level. ultimately I would like to be able to use package managers like synaptic but first I need them to be able to connect to the internet. EDIT As sugested I created a /etc/apt/apt.conf file like Acquire::http::Proxy "http://chrisav:[email protected]:8080"; Acquire::https::Proxy "https://chrisav:[email protected]:8080"; Acquire::ftp::Proxy "ftp://chrisav:[email protected]:8080"; Acquire::socks::Proxy "socks://chrisav:[email protected]:8080"; However I still cant ping wikipedia when I try installing stuff I get chris@chris-Ubuntu:~$ sudo apt-get install kate Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package kate

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• Package Manager cannot access repositories but internet is working

  - by kazman

  I am currently at a conference in another country and my package manager cannot access repositories. My internet is working fine and I can ping the repositories or go to them in a browser, but package manager fails to access them. If I sudo apt-get update it throws Something wicked happened resolving 'wwwproxy:3128' (-5 - No address associated with hostname) (or Ign's). This proxy corresponds to my proxy at my office back at home, but I have disabled proxy in the package manager. Scanning for best repository doesn't work either, it doesn't manage to connect to any. I have searched for this online and have checked things about my apt.conf file. My apt.conf contains: Acquire::http::proxy "http://wwwproxy:3128/"; Acquire::https::proxy "https://wwwproxy:3128/"; Acquire::ftp::proxy "ftp://wwwproxy:3128/"; Acquire::socks::proxy "socks://wwwproxy:3128/"; If I remove apt.conf (or replace with blank), it makes no difference. I don't see that it should since I am connecting directly (and have set it so in my network options in Package manager network settings) I have also tried some things with resolv.conf (changing name address to primary and secondary dns) to no avail. (im not sure if this would help, following other advice) I am running 12.04. (I wrote this very quickly and wrote down everything I have tried to possibly shorten the troubleshooting process, have very limited time between lectures and need this sorted asap, my apologies)

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• How to still webcam image

  - by Silv3rSurf

  I need some help deciding what to use to acquire an image from a webcam. I want to acquire a single image. I know you can typically acquire a still image at a higher resolution than a single video frame. Currently, I am using MATLAB's image acquisition toolbox.. which apparently only supports obtaining frames in video mode(so lower resolution). Which other libraries do you recommend? Has anyone else encountered this problem?

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• Changing default Home application in android without user interaction

  - by Acquire

  Is there any way to make it so my app can set itself as the default Home app without any user interaction?

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• PTLQueue : a scalable bounded-capacity MPMC queue

  - by Dave

  Title: Fast concurrent MPMC queue -- I've used the following concurrent queue algorithm enough that it warrants a blog entry. I'll sketch out the design of a fast and scalable multiple-producer multiple-consumer (MPSC) concurrent queue called PTLQueue. The queue has bounded capacity and is implemented via a circular array. Bounded capacity can be a useful property if there's a mismatch between producer rates and consumer rates where an unbounded queue might otherwise result in excessive memory consumption by virtue of the container nodes that -- in some queue implementations -- are used to hold values. A bounded-capacity queue can provide flow control between components. Beware, however, that bounded collections can also result in resource deadlock if abused. The put() and take() operators are partial and wait for the collection to become non-full or non-empty, respectively. Put() and take() do not allocate memory, and are not vulnerable to the ABA pathologies. The PTLQueue algorithm can be implemented equally well in C/C++ and Java. Partial operators are often more convenient than total methods. In many use cases if the preconditions aren't met, there's nothing else useful the thread can do, so it may as well wait via a partial method. An exception is in the case of work-stealing queues where a thief might scan a set of queues from which it could potentially steal. Total methods return ASAP with a success-failure indication. (It's tempting to describe a queue or API as blocking or non-blocking instead of partial or total, but non-blocking is already an overloaded concurrency term. Perhaps waiting/non-waiting or patient/impatient might be better terms). It's also trivial to construct partial operators by busy-waiting via total operators, but such constructs may be less efficient than an operator explicitly and intentionally designed to wait. A PTLQueue instance contains an array of slots, where each slot has volatile Turn and MailBox fields. The array has power-of-two length allowing mod/div operations to be replaced by masking. We assume sensible padding and alignment to reduce the impact of false sharing. (On x86 I recommend 128-byte alignment and padding because of the adjacent-sector prefetch facility). Each queue also has PutCursor and TakeCursor cursor variables, each of which should be sequestered as the sole occupant of a cache line or sector. You can opt to use 64-bit integers if concerned about wrap-around aliasing in the cursor variables. Put(null) is considered illegal, but the caller or implementation can easily check for and convert null to a distinguished non-null proxy value if null happens to be a value you'd like to pass. Take() will accordingly convert the proxy value back to null. An advantage of PTLQueue is that you can use atomic fetch-and-increment for the partial methods. We initialize each slot at index I with (Turn=I, MailBox=null). Both cursors are initially 0. All shared variables are considered "volatile" and atomics such as CAS and AtomicFetchAndIncrement are presumed to have bidirectional fence semantics. Finally T is the templated type. I've sketched out a total tryTake() method below that allows the caller to poll the queue. tryPut() has an analogous construction. Zebra stripping : alternating row colors for nice-looking code listings. See also google code "prettify" : https://code.google.com/p/google-code-prettify/ Prettify is a javascript module that yields the HTML/CSS/JS equivalent of pretty-print. -- pre:nth-child(odd) { background-color:#ff0000; } pre:nth-child(even) { background-color:#0000ff; } border-left: 11px solid #ccc; margin: 1.7em 0 1.7em 0.3em; background-color:#BFB; font-size:12px; line-height:65%; " // PTLQueue : Put(v) : // producer : partial method - waits as necessary assert v != null assert Mask = 1 && (Mask & (Mask+1)) == 0 // Document invariants // doorway step // Obtain a sequence number -- ticket // As a practical concern the ticket value is temporally unique // The ticket also identifies and selects a slot auto tkt = AtomicFetchIncrement (&PutCursor, 1) slot * s = &Slots[tkt & Mask] // waiting phase : // wait for slot's generation to match the tkt value assigned to this put() invocation. // The "generation" is implicitly encoded as the upper bits in the cursor // above those used to specify the index : tkt div (Mask+1) // The generation serves as an epoch number to identify a cohort of threads // accessing disjoint slots while s-Turn != tkt : Pause assert s-MailBox == null s-MailBox = v // deposit and pass message Take() : // consumer : partial method - waits as necessary auto tkt = AtomicFetchIncrement (&TakeCursor,1) slot * s = &Slots[tkt & Mask] // 2-stage waiting : // First wait for turn for our generation // Acquire exclusive "take" access to slot's MailBox field // Then wait for the slot to become occupied while s-Turn != tkt : Pause // Concurrency in this section of code is now reduced to just 1 producer thread // vs 1 consumer thread. // For a given queue and slot, there will be most one Take() operation running // in this section. // Consumer waits for producer to arrive and make slot non-empty // Extract message; clear mailbox; advance Turn indicator // We have an obvious happens-before relation : // Put(m) happens-before corresponding Take() that returns that same "m" for T v = s-MailBox if v != null : s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 // unlock slot to admit next producer and consumer return v Pause tryTake() : // total method - returns ASAP with failure indication for auto tkt = TakeCursor slot * s = &Slots[tkt & Mask] if s-Turn != tkt : return null T v = s-MailBox // presumptive return value if v == null : return null // ratify tkt and v values and commit by advancing cursor if CAS (&TakeCursor, tkt, tkt+1) != tkt : continue s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 return v The basic idea derives from the Partitioned Ticket Lock "PTL" (US20120240126-A1) and the MultiLane Concurrent Bag (US8689237). The latter is essentially a circular ring-buffer where the elements themselves are queues or concurrent collections. You can think of the PTLQueue as a partitioned ticket lock "PTL" augmented to pass values from lock to unlock via the slots. Alternatively, you could conceptualize of PTLQueue as a degenerate MultiLane bag where each slot or "lane" consists of a simple single-word MailBox instead of a general queue. Each lane in PTLQueue also has a private Turn field which acts like the Turn (Grant) variables found in PTL. Turn enforces strict FIFO ordering and restricts concurrency on the slot mailbox field to at most one simultaneous put() and take() operation. PTL uses a single "ticket" variable and per-slot Turn (grant) fields while MultiLane has distinct PutCursor and TakeCursor cursors and abstract per-slot sub-queues. Both PTL and MultiLane advance their cursor and ticket variables with atomic fetch-and-increment. PTLQueue borrows from both PTL and MultiLane and has distinct put and take cursors and per-slot Turn fields. Instead of a per-slot queues, PTLQueue uses a simple single-word MailBox field. PutCursor and TakeCursor act like a pair of ticket locks, conferring "put" and "take" access to a given slot. PutCursor, for instance, assigns an incoming put() request to a slot and serves as a PTL "Ticket" to acquire "put" permission to that slot's MailBox field. To better explain the operation of PTLQueue we deconstruct the operation of put() and take() as follows. Put() first increments PutCursor obtaining a new unique ticket. That ticket value also identifies a slot. Put() next waits for that slot's Turn field to match that ticket value. This is tantamount to using a PTL to acquire "put" permission on the slot's MailBox field. Finally, having obtained exclusive "put" permission on the slot, put() stores the message value into the slot's MailBox. Take() similarly advances TakeCursor, identifying a slot, and then acquires and secures "take" permission on a slot by waiting for Turn. Take() then waits for the slot's MailBox to become non-empty, extracts the message, and clears MailBox. Finally, take() advances the slot's Turn field, which releases both "put" and "take" access to the slot's MailBox. Note the asymmetry : put() acquires "put" access to the slot, but take() releases that lock. At any given time, for a given slot in a PTLQueue, at most one thread has "put" access and at most one thread has "take" access. This restricts concurrency from general MPMC to 1-vs-1. We have 2 ticket locks -- one for put() and one for take() -- each with its own "ticket" variable in the form of the corresponding cursor, but they share a single "Grant" egress variable in the form of the slot's Turn variable. Advancing the PutCursor, for instance, serves two purposes. First, we obtain a unique ticket which identifies a slot. Second, incrementing the cursor is the doorway protocol step to acquire the per-slot mutual exclusion "put" lock. The cursors and operations to increment those cursors serve double-duty : slot-selection and ticket assignment for locking the slot's MailBox field. At any given time a slot MailBox field can be in one of the following states: empty with no pending operations -- neutral state; empty with one or more waiting take() operations pending -- deficit; occupied with no pending operations; occupied with one or more waiting put() operations -- surplus; empty with a pending put() or pending put() and take() operations -- transitional; or occupied with a pending take() or pending put() and take() operations -- transitional. The partial put() and take() operators can be implemented with an atomic fetch-and-increment operation, which may confer a performance advantage over a CAS-based loop. In addition we have independent PutCursor and TakeCursor cursors. Critically, a put() operation modifies PutCursor but does not access the TakeCursor and a take() operation modifies the TakeCursor cursor but does not access the PutCursor. This acts to reduce coherence traffic relative to some other queue designs. It's worth noting that slow threads or obstruction in one slot (or "lane") does not impede or obstruct operations in other slots -- this gives us some degree of obstruction isolation. PTLQueue is not lock-free, however. The implementation above is expressed with polite busy-waiting (Pause) but it's trivial to implement per-slot parking and unparking to deschedule waiting threads. It's also easy to convert the queue to a more general deque by replacing the PutCursor and TakeCursor cursors with Left/Front and Right/Back cursors that can move either direction. Specifically, to push and pop from the "left" side of the deque we would decrement and increment the Left cursor, respectively, and to push and pop from the "right" side of the deque we would increment and decrement the Right cursor, respectively. We used a variation of PTLQueue for message passing in our recent OPODIS 2013 paper. ul { list-style:none; padding-left:0; padding:0; margin:0; margin-left:0; } ul#myTagID { padding: 0px; margin: 0px; list-style:none; margin-left:0;} -- -- There's quite a bit of related literature in this area. I'll call out a few relevant references: Wilson's NYU Courant Institute UltraComputer dissertation from 1988 is classic and the canonical starting point : Operating System Data Structures for Shared-Memory MIMD Machines with Fetch-and-Add. Regarding provenance and priority, I think PTLQueue or queues effectively equivalent to PTLQueue have been independently rediscovered a number of times. See CB-Queue and BNPBV, below, for instance. But Wilson's dissertation anticipates the basic idea and seems to predate all the others. Gottlieb et al : Basic Techniques for the Efficient Coordination of Very Large Numbers of Cooperating Sequential Processors Orozco et al : CB-Queue in Toward high-throughput algorithms on many-core architectures which appeared in TACO 2012. Meneghin et al : BNPVB family in Performance evaluation of inter-thread communication mechanisms on multicore/multithreaded architecture Dmitry Vyukov : bounded MPMC queue (highly recommended) Alex Otenko : US8607249 (highly related). John Mellor-Crummey : Concurrent queues: Practical fetch-and-phi algorithms. Technical Report 229, Department of Computer Science, University of Rochester Thomasson : FIFO Distributed Bakery Algorithm (very similar to PTLQueue). Scott and Scherer : Dual Data Structures I'll propose an optimization left as an exercise for the reader. Say we wanted to reduce memory usage by eliminating inter-slot padding. Such padding is usually "dark" memory and otherwise unused and wasted. But eliminating the padding leaves us at risk of increased false sharing. Furthermore lets say it was usually the case that the PutCursor and TakeCursor were numerically close to each other. (That's true in some use cases). We might still reduce false sharing by incrementing the cursors by some value other than 1 that is not trivially small and is coprime with the number of slots. Alternatively, we might increment the cursor by one and mask as usual, resulting in a logical index. We then use that logical index value to index into a permutation table, yielding an effective index for use in the slot array. The permutation table would be constructed so that nearby logical indices would map to more distant effective indices. (Open question: what should that permutation look like? Possibly some perversion of a Gray code or De Bruijn sequence might be suitable). As an aside, say we need to busy-wait for some condition as follows : "while C == 0 : Pause". Lets say that C is usually non-zero, so we typically don't wait. But when C happens to be 0 we'll have to spin for some period, possibly brief. We can arrange for the code to be more machine-friendly with respect to the branch predictors by transforming the loop into : "if C == 0 : for { Pause; if C != 0 : break; }". Critically, we want to restructure the loop so there's one branch that controls entry and another that controls loop exit. A concern is that your compiler or JIT might be clever enough to transform this back to "while C == 0 : Pause". You can sometimes avoid this by inserting a call to a some type of very cheap "opaque" method that the compiler can't elide or reorder. On Solaris, for instance, you could use :"if C == 0 : { gethrtime(); for { Pause; if C != 0 : break; }}". It's worth noting the obvious duality between locks and queues. If you have strict FIFO lock implementation with local spinning and succession by direct handoff such as MCS or CLH,then you can usually transform that lock into a queue. Hidden commentary and annotations - invisible : * And of course there's a well-known duality between queues and locks, but I'll leave that topic for another blog post. * Compare and contrast : PTLQ vs PTL and MultiLane * Equivalent : Turn; seq; sequence; pos; position; ticket * Put = Lock; Deposit Take = identify and reserve slot; wait; extract & clear; unlock * conceptualize : Distinct PutLock and TakeLock implemented as ticket lock or PTL Distinct arrival cursors but share per-slot "Turn" variable provides exclusive role-based access to slot's mailbox field put() acquires exclusive access to a slot for purposes of "deposit" assigns slot round-robin and then acquires deposit access rights/perms to that slot take() acquires exclusive access to slot for purposes of "withdrawal" assigns slot round-robin and then acquires withdrawal access rights/perms to that slot At any given time, only one thread can have withdrawal access to a slot at any given time, only one thread can have deposit access to a slot Permissible for T1 to have deposit access and T2 to simultaneously have withdrawal access * round-robin for the purposes of; role-based; access mode; access role mailslot; mailbox; allocate/assign/identify slot rights; permission; license; access permission; * PTL/Ticket hybrid Asymmetric usage ; owner oblivious lock-unlock pairing K-exclusion add Grant cursor pass message m from lock to unlock via Slots[] array Cursor performs 2 functions : + PTL ticket + Assigns request to slot in round-robin fashion Deconstruct protocol : explication put() : allocate slot in round-robin fashion acquire PTL for "put" access store message into slot associated with PTL index take() : Acquire PTL for "take" access // doorway step seq = fetchAdd (&Grant, 1) s = &Slots[seq & Mask] // waiting phase while s-Turn != seq : pause Extract : wait for s-mailbox to be full v = s-mailbox s-mailbox = null Release PTL for both "put" and "take" access s-Turn = seq + Mask + 1 * Slot round-robin assignment and lock "doorway" protocol leverage the same cursor and FetchAdd operation on that cursor FetchAdd (&Cursor,1) + round-robin slot assignment and dispersal + PTL/ticket lock "doorway" step waiting phase is via "Turn" field in slot * PTLQueue uses 2 cursors -- put and take. Acquire "put" access to slot via PTL-like lock Acquire "take" access to slot via PTL-like lock 2 locks : put and take -- at most one thread can access slot's mailbox Both locks use same "turn" field Like multilane : 2 cursors : put and take slot is simple 1-capacity mailbox instead of queue Borrow per-slot turn/grant from PTL Provides strict FIFO Lock slot : put-vs-put take-vs-take at most one put accesses slot at any one time at most one put accesses take at any one time reduction to 1-vs-1 instead of N-vs-M concurrency Per slot locks for put/take Release put/take by advancing turn * is instrumental in ... * P-V Semaphore vs lock vs K-exclusion * See also : FastQueues-excerpt.java dice-etc/queue-mpmc-bounded-blocking-circular-xadd/ * PTLQueue is the same as PTLQB - identical * Expedient return; ASAP; prompt; immediately * Lamport's Bakery algorithm : doorway step then waiting phase Threads arriving at doorway obtain a unique ticket number Threads enter in ticket order * In the terminology of Reed and Kanodia a ticket lock corresponds to the busy-wait implementation of a semaphore using an eventcount and a sequencer It can also be thought of as an optimization of Lamport's bakery lock was designed for fault-tolerance rather than performance Instead of spinning on the release counter, processors using a bakery lock repeatedly examine the tickets of their peers --

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• The best way to snatch an expiring domain?

  - by SilvrSun

  There's a domain that I've been looking to acquire that is expiring on the 30th of this month. I don't think it is very popular, and the guy hasn't seemed to update the website in two years now. So, I was doing some research and came across this site that seems to review some "snatching" services, but the article is quite outdated. So, I'm wondering if anyone can offer any newer information on the topic, or whether the recommend any services for helping me acquire the site in question?

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• Know More About Oracle Row Lock

  - by Liu Maclean(???)

  ??????Oracle??????????row lock,??ORACLE????????????????????,row lock???????????????????????????????,??Server Process?pin????block buffer????????? ????????,?process A ??update???????? Z?????????, ???????rollback???commit;??Process B??????DML??, ???????rowid???? Z???, ???????????process A????????ITL???,????????cleanout??,????????row???????????commit, ???????Process B????”enq: TX – row lock contention”??????? ????Process B????????????? ?????????Process A???????row,??Process B???????”enq: TX – row lock contention”???? ????????  ????????: SESSION A: SQL> select * from v$version; BANNER ---------------------------------------------------------------- Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi PL/SQL Release 10.2.0.5.0 - Production CORE    10.2.0.5.0      Production TNS for Linux: Version 10.2.0.5.0 - Production NLSRTL Version 10.2.0.5.0 - Production SQL> select * from global_name; GLOBAL_NAME -------------------------------------------------------------------------------- www.oracledatabase12g.com SQL> create table maclean_lock(t1 int); Table created. SQL> insert into maclean_lock values (1); 1 row created. SQL> commit; Commit complete. SQL> select dbms_rowid.rowid_block_number(rowid),dbms_rowid.rowid_relative_fno(rowid) from maclean_lock; DBMS_ROWID.ROWID_BLOCK_NUMBER(ROWID) DBMS_ROWID.ROWID_RELATIVE_FNO(ROWID) ------------------------------------ ------------------------------------                                67642                                    1 SQL>  select distinct sid from v$mystat;        SID ----------        142 SQL> select pid,spid from v$process where addr = ( select paddr from v$session where sid=(select distinct sid from v$mystat));        PID SPID ---------- ------------         17 15636 ??SESSION A ????savepoint ,?update ?????????         SQL>  savepoint NONLOCK; Savepoint created. SQL> select * From v$Lock where sid=142; no rows selected SQL> set linesize 140 pagesize 1400 SQL>  update maclean_lock set t1=t1+2; 1 row updated. SQL> select * From v$Lock where sid=142; ADDR             KADDR                   SID TY        ID1        ID2      LMODE    REQUEST      CTIME      BLOCK ---------------- ---------------- ---------- -- ---------- ---------- ---------- ---------- ---------- ---------- 0000000091FC69F0 0000000091FC6A18        142 TM      55829          0          3          0          6          0 00000000914B4008 00000000914B4040        142 TX     393232        609          6          0          6          0         SQL> select dump(3,16) from dual; DUMP(3,16) -------------------------------------------------------------------------------- Typ=2 Len=2: c1,4 ALTER SYSTEM DUMP DATAFILE 1 BLOCK 67642;  Object id on Block? Y  seg/obj: 0xda16  csc: 0x00.234718  itc: 2  flg: O  typ: 1 - DATA      fsl: 0  fnx: 0x0 ver: 0x01  Itl           Xid                  Uba         Flag  Lck        Scn/Fsc 0x01   0x000a.00f.000001e0  0x00800075.02a6.29  C---    0  scn 0x0000.00234711 0x02   0x0007.018.000001fe  0x0080065c.017a.02  ----    1  fsc 0x0000.00000000 data_block_dump,data header at 0x81d185c =============== tsiz: 0x1fa0 hsiz: 0x14 pbl: 0x081d185c bdba: 0x0041083a      76543210 flag=-------- ntab=1 nrow=1 frre=-1 fsbo=0x14 fseo=0x1f9a avsp=0x1f83 tosp=0x1f83 0xe:pti[0]      nrow=1  offs=0 0x12:pri[0]     offs=0x1f9a block_row_dump: tab 0, row 0, @0x1f9a tl: 6 fb: --H-FL-- lb: 0x2  cc: 1 col  0: [ 2]  c1 04 end_of_block_dump ?? BLOCK DUMP ???? ??????XID=0x0007.018.000001fe ?transaction?? lb:0x1 ??SESSION B ,?????UPDATE?? ???enq: TX - row lock contention ?? SQL> select distinct sid from v$mystat;        SID ----------        140 SQL> select pid,spid from v$process where addr = ( select paddr from v$session where sid=(select distinct sid from v$mystat));        PID SPID ---------- ------------         24 15652 SQL> alter system set "_trace_events"='10000-10999:255:24'; System altered.         SQL> update maclean_lock set t1=t1+2; select * From v$Lock where sid=142 or sid=140 order by sid; SESSION C: SQL> select * From v$Lock where sid=142 or sid=140 order by sid; ADDR             KADDR                   SID TY        ID1        ID2      LMODE    REQUEST      CTIME      BLOCK ---------------- ---------------- ---------- -- ---------- ---------- ---------- ---------- ---------- ---------- 0000000091FC6B10 0000000091FC6B38        140 TM      55829          0          3          0         84          0 00000000924F4A58 00000000924F4A78        140 TX     458776        510          0          6         84          0 00000000914B51E8 00000000914B5220        142 TX     458776        510          6          0        312          1 0000000091FC69F0 0000000091FC6A18        142 TM      55829          0          3          0        312          0 ???? SESSION B SID=140 ?SESSION A ?TX ENQUEUE ?X mode?REQUEST SQL> oradebug dump systemstate 266; Statement processed. SESSION B waiter's enqueue lock       SO: 0x924f4a58, type: 5, owner: 0x92bb8dc8, flag: INIT/-/-/0x00       (enqueue) TX-00070018-000001FE    DID: 0001-0018-00000022       lv: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  res_flag: 0x6       req: X, lock_flag: 0x0, lock: 0x924f4a78, res: 0x925617c0       own: 0x92b76be0, sess: 0x92b76be0, proc: 0x92a737a0, prv: 0x925617e0 TX-00070018-000001FE=> TX 458776 510 SESSION A owner's enqueue lock       SO: 0x914b51e8, type: 40, owner: 0x92b796d0, flag: INIT/-/-/0x00       (trans) flg = 0x1e03, flg2 = 0xc0000, prx = 0x0, ros = 2147483647 bsn = 0xed5 bndsn = 0xee7 spn = 0xef7       efd = 3       file:xct.c lineno:1179       DID: 0001-0011-000000C2       parent xid: 0x0000.000.00000000       env: (scn: 0x0000.00234718  xid: 0x0007.018.000001fe  uba: 0x0080065c.017a.02  statement num=0  parent xid: xid: 0x0000.000.00000000  scn: 0x00 00.00234718 0sch: scn: 0x0000.00000000)       cev: (spc = 7818  arsp = 914e8310  ubk tsn: 1 rdba: 0x0080065c  useg tsn: 1 rdba: 0x00800069             hwm uba: 0x0080065c.017a.02  col uba: 0x00000000.0000.00             num bl: 1 bk list: 0x91435070)             cr opc: 0x0 spc: 7818 uba: 0x0080065c.017a.02       (enqueue) TX-00070018-000001FE    DID: 0001-0011-000000C2       lv: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  res_flag: 0x6       mode: X, lock_flag: 0x0, lock: 0x914b5220, res: 0x925617c0       own: 0x92b796d0, sess: 0x92b796d0, proc: 0x92a6ffd8, prv: 0x925617d0        xga: 0x8b7c6d40, heap: UGA       Trans IMU st: 2 Pool index 65535, Redo pool 0x914b58d0, Undo pool 0x914b59b8       Redo pool range [0x86de640 0x86de640 0x86e0e40]       Undo pool range [0x86dbe40 0x86dbe40 0x86de640]         ----------------------------------------         SO: 0x91435070, type: 39, owner: 0x914b51e8, flag: -/-/-/0x00         (List of Blocks) next index = 1         index   itli   buffer hint   rdba       savepoint         -----------------------------------------------------------             0      2   0x647f1fc8    0x41083a     0xee7 ?SESSION A? ROLLBACK ?savepoint: SQL> rollback to NONLOCK; Rollback complete. ????savepoint ??update??????? ??UPDATE???????? ROLLBACK: SQL> select * From v$Lock where sid=142 or sid=140; ADDR             KADDR                   SID TY        ID1        ID2      LMODE    REQUEST      CTIME      BLOCK ---------------- ---------------- ---------- -- ---------- ---------- ---------- ---------- ---------- ---------- 00000000924F4A58 00000000924F4A78        140 TX     458776        510          0          6        822          0 0000000091FC6B10 0000000091FC6B38        140 TM      55829          0          3          0        822          0 00000000914B51E8 00000000914B5220        142 TX     458776        510          6          0       1050          1 ???? SESSION A 142 ???SAVEPOINT ???????TM LOCK ????? ROLLBACK TO SAVEPOINT?????SESSION???TX LOCK!!!! ??????SESSION 142???TX ID1=458776 ID2=510, ????ROLLBACK TO SAVEPOINT?????????ABORT TRANSACTION ?? SESSION B  SID=140??  SESSION A ?? , ?????????SESSION B? update???HANG?? ?????????CACHE?????:  Object id on Block? Y  seg/obj: 0xda16  csc: 0x00.2347b7  itc: 2  flg: O  typ: 1 - DATA      fsl: 0  fnx: 0x0 ver: 0x01  Itl           Xid                  Uba         Flag  Lck        Scn/Fsc 0x01   0x000a.00f.000001e0  0x00800075.02a6.29  C---    0  scn 0x0000.00234711 0x02   0x0000.000.00000000  0x00000000.0000.00  ----    0  fsc 0x0000.00000000 data_block_dump,data header at 0x745d85c =============== tsiz: 0x1fa0 hsiz: 0x14 pbl: 0x0745d85c bdba: 0x0041083a      76543210 flag=-------- ntab=1 nrow=1 frre=-1 fsbo=0x14 fseo=0x1f9a avsp=0x1f83 tosp=0x1f83 0xe:pti[0]      nrow=1  offs=0 0x12:pri[0]     offs=0x1f9a block_row_dump: tab 0, row 0, @0x1f9a tl: 6 fb: --H-FL-- lb: 0x0  cc: 1 col  0: [ 2]  c1 02 end_of_block_dump ???? ITL=0x02? ?????????,col  0: [ 2]  c1 02 ????????? ?????????SESSION D ,??????row lock?? ?UPDATE???????? SESSION D: SQL> update maclean_lock set t1=t1+2; 1 row updated. SQL> rollback; Rollback complete. ??SESSION B ??????????? ?????ORACLE????????, ??????????? TX lock?? row lock , ????????2??? row lock?????????, ?TX lock????????ENQUEUE LOCK???? ?????????PROCESS K?DML???????????????????????,??????????TX LOCK, ????PROCESS Z?????????????????????????ROW LOCK????????, ???????OLTP?????????????????????? ??ROW LOCK?Release ??????TX?ENQUEUE LOCK,?????????Process J ????????????, Process K??????????? ,Process K?????????,???row piece?lb??0x0 ,?????ITL, Process Z???ITL???????Process J????XID,?????Process J?????TX lock, PROCESS K ???TX resource?Enqueue Waiter Linked List?????X mode(exclusive)?enqueue lock? ???Process J??TX lock?,Process J?????TX resource?Enqueue Waiter Linked List ???Process K??????,??POST?????Process K? TX lock??????, ???????row lock???????,????????? ?????????? ?????: SESSION A ???PID =17 ?????????????????? SESSION B ???PID =24 ??????? "_trace_events"='10000-10999:255:24';  KST trace ??????? Server Process??? SESSION A PID=17  ?? acqure?SX mode???TM Lock ,?? ????Transaction?????UNDO SEGMENT 7,???XID 7.24.510, ?acquire ?X mode? TX-00070018-000001fe ? ?????? 00070018-000001fe ???? 7- 24 - 510? XID ? 781F4B8A:007A569C    17   142 10704  83 ksqgtl: acquire TM-0000da15-00000000 mode=SX flags=GLOBAL|XACT why="contention" 781F4B92:007A569D    17   142 10704  19 ksqgtl: SUCCESS 781F4BB3:007A569E    17   142 10812   2 0x000000000041083A 0x0000000000000000 0x0000000000234717 781F4BBA:007A569F    17   142 10812   3 0x0000000000000000 0x0000000000000000 0x0000000000000000 781F4BC0:007A56A0    17   142 10812   4 0x0000000000000000 0x0000000000000000 0x0000000000000000 781F4BD3:007A56A1    17   142 10812   5 0x000000000041083A 0x0000000000000000 0x0000000000000000 781F4BFE:007A56A2    17   142 10811   1 0x000000000041083A 0x0000000000000000 0x0000000000234711 0x0000000000000002 781F4C06:007A56A3    17   142 10811   2 0x000000000041083A 0x0000000000000000 0x0000000000234718 0x00007FA074EDA560 781F4C26:007A56A4    17   142 10813   1 ktubnd: Bind usn 7 nax 1 nbx 0 lng 0 par 0 781F4C43:007A56A5    17   142 10813   2 ktubnd: Txn Bound xid: 7.24.510 781F4C4A:007A56A6    17   142 10704  83 ksqgtl: acquire TX-00070018-000001fe mode=X flags=GLOBAL|XACT why="contention" 781F4C51:007A56A7    17   142 10704  19 ksqgtl: SUCCESS ?????????? ???????? 781F4CBF:007A56A8    17   142 10005   1 KSL WAIT BEG [SQL*Net message to client] 1650815232/0x62657100 1/0x1 0/0x0 781F4CCC:007A56A9    17   142 10005   2 KSL WAIT END [SQL*Net message to client] 1650815232/0x62657100 1/0x1 0/0x0 time=13 781F4CDE:007A56AA    17   142 10005   1 KSL WAIT BEG [SQL*Net message from client] 1650815232/0x62657100 1/0x1 0/0x0 786BD85D:007A57E0    17   142 10005   2 KSL WAIT END [SQL*Net message from client] 1650815232/0x62657100 1/0x1 0/0x0 time=5016447 786BD966:007A57E1    17   142 10005   1 KSL WAIT BEG [SQL*Net message to client] 1650815232/0x62657100 1/0x1 0/0x0 786BD96E:007A57E2    17   142 10005   2 KSL WAIT END [SQL*Net message to client] 1650815232/0x62657100 1/0x1 0/0x0 time=8 SESSION B ???PID =24  ,??????? SX mode? TM lock,??row lock? acquire X mode?TX-00070018-000001fe ksqgtl: acquire TM-0000da15-00000000 mode=SX flags=GLOBAL|XACT why="contention" ksqgtl: SUCCESS 0x000000000041083A 0x0000000000000000 0x00000000002354F8 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x000000000041083A 0x0000000000000000 0x00000000002354F8 0x0000000000000001 0x000000000041083A 0x0000000000000000 0x00000000002354F8 0x0000000008A63780 0x0000000000000001 0x0000000000800861 0x0000000000000241 0x0000000000000001 0x000000000041083A 0x0000000000000001 0x0000000000000001 0x000000000041083A 0x0000000000000000 0x00000000002354F9 0x0000000000000002 ksqgtl: acquire TX-00070018-000001fe mode=X flags=GLOBAL|LONG why="row lock contention" C4048EBD:007F52B6    24   140 10005   2 KSL WAIT END [enq: TX - row lock contention] 1415053318/0x54580006 458776/0x70018 510/0x1fe time=2929879 C4048ED4:007F52B7    24   140 10005   1 KSL WAIT BEG [enq: TX - row lock contention] 1415053318/0x54580006 458776/0x70018 510/0x1fe C43146CA:007F535E    24   140 10005   2 KSL WAIT END [enq: TX - row lock contention] 1415053318/0x54580006 458776/0x70018 510/0x1fe time=2930676 ????????? ,PID=24 ??????ksqcmi???????? deadlock C43146D9:007F535F    24   140 10704 134 ksqcmi: performing local deadlock detection on TX-00070018-000001fe C43146F8:007F5360    24   140 10704 150 ksqcmi: deadlock not detected on TX-00070018-000001fe ?? ??? PID 17 ??ROLLBACK ???? ,????????: PID 17 ROLLBACK; D7A495BB:007F9D3E    17   142 10005   4 KSL POST SENT postee=24 loc='ksqrcl' id1=0 id2=0 name=   type=0 D7A495D8:007F9D3F    17   142 10444  12 ABORT TRANSACTION - xid: 0x0007.018.000001fe ??  PID 17 ??? TX resource?Enqueue Waiter linked List ???PID 24???,????KSL POST SENT ?? PID 24, ???ksqrcl???ENQUEUE LOCK ?PID 24??????KSL POST (KSL POST RCVD poster=17), ?ksqgtl???? TX-00070018-000001fe ?? ksqrcl??, ??PID 24???????? TX lock?USN ,??????? USN 3 XID 3.11.582 ,???acquire TX-0003000b-00000246 D7A49616:007F9D41    24   140 10005   3 KSL POST RCVD poster=17 loc='ksqrcl' id1=0 id2=0 name=   type=0 fac#=0 facpost=1 D7A4961C:007F9D42    24   140 10704  19 ksqgtl: SUCCESS D7A4967D:007F9D43    24   140 10704 117 ksqrcl: release TX-00070018-000001fe mode=X D7A496A5:007F9D44    24   140 10813   1 ktubnd: Bind usn 3 nax 1 nbx 0 lng 0 par 0 D7A496C2:007F9D45    24   140 10813   2 ktubnd: Txn Bound xid: 3.11.582 D7A496C7:007F9D46    24   140 10704  83 ksqgtl: acquire TX-0003000b-00000246 mode=X flags=GLOBAL|XACT why="contention" D7A496E4:007F9D47    24   140 10704  19 ksqgtl: SUCCESS ROW LOCK?Release ??????TX?ENQUEUE LOCK,?????????Process J ????????????, Process K??????????? ,Process K?????????,???row piece?lb??0×0 ,?????ITL,Process Z???ITL???????Process J????XID,?????Process J?????TX lock,PROCESS K ???TX resource?Enqueue Waiter Linked List?????X mode(exclusive)?enqueue lock? ???Process J??TX lock?,Process J?????TX resource?Enqueue Waiter Linked List ???Process K??????,??POST?????Process K? TX lock??????,???????row lock???????,?????????

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• VAMT 3.0 Proxy Activate - No ‘Apply Confirmation ID’ option at all

  - by lez

  I tried to activate my windows box in isolated network zone, so I followed the process of 'Scenario 2: Proxy Activation' in http://technet.microsoft.com/en-us/library/hh825202.aspx using two VAMT 3.0 hosts. Everything went fine (actually I'm not sure what option to choose when exporting VAMT data to .cilx file, I tried 'Export products and product keys' and 'Export proxy activation data only' anyway, is this a cause of this problem, I have no idea), until I wanted to apply the CID and activate the isolated pc. In 'Activate', there is no 'Apply Confirmation ID' option!, its only options are 'Acquire and save confirmation ID only' and 'Acquire confirmation ID, apply to selected machine(s) and activate'. The error message is 'cannot resolve remote name 'go.microsoft.com'' when I chose any of them, looks like acquire confirmation id always need to go to this url. But I just want to apply cid... Has anyone run into this, please? I searched internet, seems no answer... Any suggestion would be appreciated, thank you!

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• What are the benefits of running chef-server instead of chef-solo?

  - by strife25

  I am looking at automated deployment solutions for my team and have been playing with Chef for the past few days. I've been able to get a simple web app up an running from a base Red Hat VM using chef-solo. Our end goal is to use Chef (or another system) to automatically deploy application topologies to the cloud as we run builds. Our process would basically run like so: Our web app code, dependencies, and chef cookbooks are stored in SCM A build is executed and greats a single package for images to acquire and test against The build engine then deploys new cloud images that run a chef client to get packages installed. The images acquire the cookbooks from SCM or the Chef server and install everything to get up and running What are the benefits and/or use cases for getting a Chef Server running? Are there any major benefits to have a Chef Server hold and acquire the cookbooks from SCM vs. using chef-solo and having a script that will pull the cookbooks from SCM?

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