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  • Survive a Software Audit

    - by rosepost1150
    I received a letter from Autodesk asking for a "License Assessment". I understand it as a software audit. They plan to do it remotely. The thing is, I'm a freelancer, I don't use any Software Asset Mangment software, and I just recently swap out my hard drive for a new one, and did a complete clean install, and then I received this request from Autodesk. There is almost nothing on my hard drive now. What do software auditors do when they experience this? Will they (are they allowed) to contact my clients (that info is all over the web..) to get information since they found nothing here?

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  • Driver corruption when deploying Dell Touchpad Drivers (with software) during imaging process

    - by BigHomie
    We're an sccm shop, and use it to deploy Windows. When deploying Dell laptops (multiple models), the touchpad drivers seem install properly, but the software doesn't. The resulting problem is that when the touchpad is pressed on occasion, the mouse pointer will 'jump' to certain points on the screen. A possible symptom of this problem/visible sign is if the touchpad icon isn't in the system tray. The software is in the control panel, but when opened part of the gui is pixelated, indicating botched install maybe? The manual resolution to this, is to go into device manager and uninstall the driver with the option to uninstall all driver software. After a restart, the driver and software is apparently reinstalled, and from there works as expected. Obviously this partially defeats the purpose of a zero touch deployment. If anyone knows why this is and/or a possible workaround, those answers would be valid as well. Barring that, I want to find a way to deploy the driver and touchpad software in an unattended way, so that it can be conditionally installing during the imaging process. To be honest I'm not sure how to troubleshoot this, I suppose I could try drvinst.exe to install the driver, but finding out why this fails initially would keep me from spinning my wheels.

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  • How do games move around objects (in general) (OGL)

    - by user146780
    I'm sure there's not just 1 answer to this but, do game engines actually change the vectors in memory, or use gltransformations? Because pushing and popping the matrix all the time seems inefficient, but if you keep modifying the verticies you cant make use of display lists. So I'm wondering how it's done in general. Thanks

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  • Deploy software with no .msi in AD

    - by Unreason
    I have a small AD in which I am deploying software to domain computers through GPO (using msi installers). What is the best method to deploy software that has no .msi installer, but has switches for silent installs All I can think is to use startup scripts (that will do detect-install/uninstall/upgrade), but I was wondering if there are existing wheel designs in this area... NOTE: I'd like to avoid repackaging to .msi format (unless someone convinces me otherwise). Some examples of software that I would like to deploy picasa 3 VLC

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  • Error while installing emacs23 from Software Center

    - by vrcmr
    Trying to install emacs in Software Center Ubuntu 12.04 got this error. installArchives() failed: Selecting previously unselected package emacs23. (Reading database ... (Reading database ... 5% (Reading database ... 10% (Reading database ... 15% (Reading database ... 20% (Reading database ... 25% (Reading database ... 30% (Reading database ... 35% (Reading database ... 40% (Reading database ... 45% (Reading database ... 50% (Reading database ... 55% (Reading database ... 60% (Reading database ... 65% (Reading database ... 70% (Reading database ... 75% (Reading database ... 80% (Reading database ... 85% (Reading database ... 90% (Reading database ... 95% (Reading database ... 100% (Reading database ... 182385 files and directories currently installed.) Unpacking emacs23 (from .../emacs23_23.3+1-1ubuntu9_i386.deb) ... Processing triggers for desktop-file-utils ... Processing triggers for bamfdaemon ... Rebuilding /usr/share/applications/bamf.index... Processing triggers for gnome-menus ... Processing triggers for man-db ... Setting up emacs23 (23.3+1-1ubuntu9) ... update-alternatives: using /usr/bin/emacs23-x to provide /usr/bin/emacs (emacs) in auto mode. emacs-install emacs23 install/dictionaries-common: Byte-compiling for emacsen flavour emacs23 Warning: Lisp directory `/usr/share/emacs/23.3/site-lisp' does not exist. Warning: Lisp directory `/usr/share/emacs/site-lisp' does not exist. Warning: Lisp directory `/usr/share/emacs/23.3/leim' does not exist. Warning: Lisp directory `/usr/share/emacs/23.3/lisp' does not exist. Warning: Lisp directory `/usr/share/emacs/23.3/leim' does not exist. Error: charsets directory (/usr/share/emacs/23.3/etc/charsets) does not exist. Emacs will not function correctly without the character map files. Please check your installation! Warning: Could not find simple.el nor simple.elc Cannot open load file: bytecomp emacs-install: /usr/lib/emacsen-common/packages/install/dictionaries-common emacs23 failed at /usr/lib/emacsen-common/emacs-install line 28, <TSORT> line 3. dpkg: error processing emacs23 (--configure): subprocess installed post-installation script returned error exit status 255 No apport report written because MaxReports is reached already Errors were encountered while processing: emacs23 Error in function: Setting up emacs23 (23.3+1-1ubuntu9) ... emacs-install emacs23 install/dictionaries-common: Byte-compiling for emacsen flavour emacs23 Warning: Lisp directory `/usr/share/emacs/23.3/site-lisp' does not exist. Warning: Lisp directory `/usr/share/emacs/site-lisp' does not exist. Warning: Lisp directory `/usr/share/emacs/23.3/leim' does not exist. Warning: Lisp directory `/usr/share/emacs/23.3/lisp' does not exist. Warning: Lisp directory `/usr/share/emacs/23.3/leim' does not exist. Error: charsets directory (/usr/share/emacs/23.3/etc/charsets) does not exist. Emacs will not function correctly without the character map files. Please check your installation! Warning: Could not find simple.el nor simple.elc Cannot open load file: bytecomp emacs-install: /usr/lib/emacsen-common/packages/install/dictionaries-common emacs23 failed at /usr/lib/emacsen-common/emacs-install line 28, <TSORT> line 3. dpkg: error processing emacs23 (--configure): subprocess installed post-installation script returned error exit status 255

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  • Oracle Big Data Software Downloads

    - by Mike.Hallett(at)Oracle-BI&EPM
    Companies have been making business decisions for decades based on transactional data stored in relational databases. Beyond that critical data, is a potential treasure trove of less structured data: weblogs, social media, email, sensors, and photographs that can be mined for useful information. Oracle offers a broad integrated portfolio of products to help you acquire and organize these diverse data sources and analyze them alongside your existing data to find new insights and capitalize on hidden relationships. Oracle Big Data Connectors Downloads here, includes: Oracle SQL Connector for Hadoop Distributed File System Release 2.1.0 Oracle Loader for Hadoop Release 2.1.0 Oracle Data Integrator Companion 11g Oracle R Connector for Hadoop v 2.1 Oracle Big Data Documentation The Oracle Big Data solution offers an integrated portfolio of products to help you organize and analyze your diverse data sources alongside your existing data to find new insights and capitalize on hidden relationships. Oracle Big Data, Release 2.2.0 - E41604_01 zip (27.4 MB) Integrated Software and Big Data Connectors User's Guide HTML PDF Oracle Data Integrator (ODI) Application Adapter for Hadoop Apache Hadoop is designed to handle and process data that is typically from data sources that are non-relational and data volumes that are beyond what is handled by relational databases. Typical processing in Hadoop includes data validation and transformations that are programmed as MapReduce jobs. Designing and implementing a MapReduce job usually requires expert programming knowledge. However, when you use Oracle Data Integrator with the Application Adapter for Hadoop, you do not need to write MapReduce jobs. Oracle Data Integrator uses Hive and the Hive Query Language (HiveQL), a SQL-like language for implementing MapReduce jobs. Employing familiar and easy-to-use tools and pre-configured knowledge modules (KMs), the application adapter provides the following capabilities: Loading data into Hadoop from the local file system and HDFS Performing validation and transformation of data within Hadoop Loading processed data from Hadoop to an Oracle database for further processing and generating reports Oracle Database Loader for Hadoop Oracle Loader for Hadoop is an efficient and high-performance loader for fast movement of data from a Hadoop cluster into a table in an Oracle database. It pre-partitions the data if necessary and transforms it into a database-ready format. Oracle Loader for Hadoop is a Java MapReduce application that balances the data across reducers to help maximize performance. Oracle R Connector for Hadoop Oracle R Connector for Hadoop is a collection of R packages that provide: Interfaces to work with Hive tables, the Apache Hadoop compute infrastructure, the local R environment, and Oracle database tables Predictive analytic techniques, written in R or Java as Hadoop MapReduce jobs, that can be applied to data in HDFS files You install and load this package as you would any other R package. Using simple R functions, you can perform tasks such as: Access and transform HDFS data using a Hive-enabled transparency layer Use the R language for writing mappers and reducers Copy data between R memory, the local file system, HDFS, Hive, and Oracle databases Schedule R programs to execute as Hadoop MapReduce jobs and return the results to any of those locations Oracle SQL Connector for Hadoop Distributed File System Using Oracle SQL Connector for HDFS, you can use an Oracle Database to access and analyze data residing in Hadoop in these formats: Data Pump files in HDFS Delimited text files in HDFS Hive tables For other file formats, such as JSON files, you can stage the input in Hive tables before using Oracle SQL Connector for HDFS. Oracle SQL Connector for HDFS uses external tables to provide Oracle Database with read access to Hive tables, and to delimited text files and Data Pump files in HDFS. Related Documentation Cloudera's Distribution Including Apache Hadoop Library HTML Oracle R Enterprise HTML Oracle NoSQL Database HTML Recent Blog Posts Big Data Appliance vs. DIY Price Comparison Big Data: Architecture Overview Big Data: Achieve the Impossible in Real-Time Big Data: Vertical Behavioral Analytics Big Data: In-Memory MapReduce Flume and Hive for Log Analytics Building Workflows in Oozie

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  • Automating custom software installation in a zone

    - by mgerdts
    In Solaris 11, the internals of zone installation are quite different than they were in Solaris 10.  This difference allows the administrator far greater control of what software is installed in a zone.  The rules in Solaris 10 are simple and inflexible: if it is installed in the global zone and is not specifically excluded by package metadata from being installed in a zone, it is installed in the zone.  In Solaris 11, the rules are still simple, but are much more flexible:  the packages you tell it to install and the packages on which they depend will be installed. So, where does the default list of packages come from?  From the AI (auto installer) manifest, of course.  The default AI manifest is /usr/share/auto_install/manifest/zone_default.xml.  Within that file you will find:             <software_data action="install">                 <name>pkg:/group/system/solaris-small-server</name>             </software_data> So, the default installation will install pkg:/group/system/solaris-small-server.  Cool.  What is that?  You can figure out what is in the package by looking for it in the repository with your web browser (click the manifest link), or use pkg(1).  In this case, it is a group package (pkg:/group/), so we know that it just has a bunch of dependencies to name the packages that really wants installed. $ pkg contents -t depend -o fmri -s fmri -r solaris-small-server FMRI compress/bzip2 compress/gzip compress/p7zip ... terminal/luit terminal/resize text/doctools text/doctools/ja text/less text/spelling-utilities web/wget If you would like to see the entire manifest from the command line, use pkg contents -r -m solaris-small-server. Let's suppose that you want to install a zone that also has mercurial and a full-fledged installation of vim rather than just the minimal vim-core that is part of solaris-small-server.  That's pretty easy. First, copy the default AI manifest somewhere where you will edit it and make it writable. # cp /usr/share/auto_install/manifest/zone_default.xml ~/myzone-ai.xml # chmod 644 ~/myzone-ai.xml Next, edit the file, changing the software_data section as follows:             <software_data action="install">                 <name>pkg:/group/system/solaris-small-server</name>                 <name>pkg:/developer/versioning/mercurial</name>                <name>pkg:/editor/vim</name>             </software_data> To figure out  the names of the packages, either search the repository using your browser, or use a command like pkg search hg. Now we are all ready to install the zone.  If it has not yet been configured, that must be done as well. # zonecfg -z myzone 'create; set zonepath=/zones/myzone' # zoneadm -z myzone install -m ~/myzone-ai.xml A ZFS file system has been created for this zone. Progress being logged to /var/log/zones/zoneadm.20111113T004303Z.myzone.install Image: Preparing at /zones/myzone/root. Install Log: /system/volatile/install.15496/install_log AI Manifest: /tmp/manifest.xml.XfaWpE SC Profile: /usr/share/auto_install/sc_profiles/enable_sci.xml Zonename: myzone Installation: Starting ... Creating IPS image Installing packages from: solaris origin: http://localhost:1008/solaris/54453f3545de891d4daa841ddb3c844fe8804f55/ DOWNLOAD PKGS FILES XFER (MB) Completed 169/169 34047/34047 185.6/185.6 PHASE ACTIONS Install Phase 46498/46498 PHASE ITEMS Package State Update Phase 169/169 Image State Update Phase 2/2 Installation: Succeeded Note: Man pages can be obtained by installing pkg:/system/manual done. Done: Installation completed in 531.813 seconds. Next Steps: Boot the zone, then log into the zone console (zlogin -C) to complete the configuration process. Log saved in non-global zone as /zones/myzone/root/var/log/zones/zoneadm.20111113T004303Z.myzone.install Now, for a few things that I've seen people trip over: Ignore that bit about man pages - it's wrong.  Man pages are already installed so long as the right facet is set properly.  And that's a topic for another blog entry. If you boot the zone then just use zlogin myzone, you will see that services you care about haven't started and that svc:/milestone/config:default is starting.  That is because you have not yet logged into the console with zlogin -C myzone. If the zone has been booted for more than a very short while when you first connect to the zone console, it will seem like the console is hung.  That's not really the case - hit ^L (control-L) to refresh the sysconfig(1M) screen that is prompting you for information.

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  • Easy Access a Cornerstone to Fusion Applications HCM User Experience

    - by Jay Richey, HCM Product Marketing
    With Fusion Applications, Oracle fundamentally changes a fragmented, frustrating work situation. Users of Human Capital Management (HCM) software often must bounce around between applications, searching diligently for the right information about employees. They may spend a lot of their time tracking down the data they need to complete a task. Fusion offers a completely different user experience. Read more...

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  • Are there too many qualified software development engineers chasing too few jobs?

    - by T Gregory
    I am trying to write this question in a non-argumentative way, but it is quite emotionally charged for some, so please bear with me. In the U.S., we hear constantly from CEOs that they cannot find enough qualified software engineers. In fact, it is the position of the U.S. government that demand for software engineering talent outpaces supply. This position can be clearly seen in the granting of tens of thousands of H1B visas, but also in the following excerpt from the official 2010-11 Bureau of Labor Statistics Occupational Outlook Handbook: Employment of computer software engineers is expected to increase by 32 percent from 2008-2018, which is much faster than the average for all occupations. In addition, this occupation will see a large number of new jobs, with more than 295,000 created between 2008 and 2018. Demand for computer software engineers will increase as computer networking continues to grow. For example, expanding Internet technologies have spurred demand for computer software engineers who can develop Internet, intranet, and World Wide Web applications. Likewise, electronic data-processing systems in business, telecommunications, healthcare, government, and other settings continue to become more sophisticated and complex. Implementing, safeguarding, and updating computer systems and resolving problems will fuel the demand for growing numbers of systems software engineers. New growth areas will also continue to arise from rapidly evolving technologies. The increasing uses of the Internet, the proliferation of Web sites, and mobile technology such as the wireless Internet have created a demand for a wide variety of new products. As more software is offered over the Internet, and as businesses demand customized software to meet their specific needs, applications and systems software engineers will be needed in greater numbers. In addition, the growing use of handheld computers will create demand for new mobile applications and software systems. As these devices become a larger part of the business environment, it will be necessary to integrate current computer systems with this new, more mobile technology. However, from the the employee side of the equation, we often hear the opposite. Many of the stories of SDEs with graduate degrees and decades of experience on the unemployment line, or the big tech interview war stories, are anecdotal, for sure. But, there is one piece of data that is neither anecdotal nor transitory, and that is the aggregate decisions of millions of undergraduates of what degree to pursue. Here, a different picture emerges from the data, and that picture is not good for the software profession. According the most recent Taulbee Survey from Computer Research Association, undergrad degree production in CS and CE has fallen nearly 60% since 2004. (Undergrad enrollments have ticked up in the past two years, but only modestly). Here we see that a basic disconnect between what corporate CEOs and the US government are saying and what potential employees really think about job prospects in software engineering. So my questions are these. Who are we to believe? Is there an acute talent shortage, or is there a long-term structural oversupply in the SDE labor market? Can anyone provide reliable data on long-term unemployment among SDEs? How many are leaving the profession due to lack of work? Real data is most helpful. Thanks.

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  • General advice from people in the industry - new graduate

    - by confusified
    I'm 20 years old and have just finished a 4 year Information Technology degree in Ireland, The main focus of the course was programming (mainly java) and software engineering. My question (posted in the wrong place as it may be) is : What technologies that I may not have studied should I attempt to teach myself that will be of the most benefit to me in searching for employment? All input appreciated.

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  • SRs @ Oracle: How do I License Thee?

    - by [email protected]
    With the release of the new Sun Ray product last week comes the advent of a different software licensing model. Where Sun had initially taken the approach of '1 desktop device = one license', we later changed things to be '1 concurrent connection to the server software = one license', and while there were ways to tell how many connections there were at a time, it wasn't the easiest thing to do.  And, when should you measure concurrency?  At your busiest time, of course... but when might that be?  9:00 Monday morning this week might yield a different result than 9:00 Monday morning last week.In the acquisition of this desktop virtualization product suite Oracle has changed things to be, in typical Oracle fashion, simpler.  There are now two choices for customers around licensing: Named User licenses and Per Device licenses.Here's how they work, and some examples:The Rules1) A Sun Ray device, and PC running the Desktop Access Client (DAC), are both considered unique devices.OR, 2) Any user running a session on either a Sun Ray or an DAC is still just one user.So, you have a choice of path to go down.Some Examples:Here are 6 use cases I can think of right now that will help you choose the Oracle server software licensing model that is right for your business:Case 1If I have 100 Sun Rays for 100 users, and 20 of them use DAC at home that is 100 user licenses.If I have 100 Sun Rays for 100 users, and 20 of them use DAC at home that is 120 device licenses.Two cases using the same metrics - different licensing models and therefore different results.Case 2If I have 100 Sun Rays for 200 users, and 20 of them use DAC at home that is 200 user licenses.If I have 100 Sun Rays for 200 users, and 20 of them use DAC at home that is 120 device licenses.Same metrics - very different results.Case 3If I have 100 Sun Rays for 50 users, and 20 of them use DAC at home that is 50 user licenses.If I have 100 Sun Rays for 50 users, and 20 of them use DAC at home that is 120 device licenses.Same metrics - but again - very different results.Based on the way your business operates you should be able to see which of the two licensing models is most advantageous to you.Got questions?  I'll try to help.(Thanks to Brad Lackey for the clarifications!)

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  • Difference between $ and # in ADF/JSF/JSP

    - by pavan.pvj
    Found this one interesting. So, picked it from one of the books and posting here.JSP 2.1 and JSF 1.2 - both of them use a unified Expression language. One major and the most obvious difference is between $ and #. JSP 2.1 uses $ and JSF 1.2 uses # in an EL. $ - immediate evaluation# - deferred evaluation$ - $ syntax executes expressions eagerly/immediately, which means that the result is returned immediately when the page renders.# - # syntax defers the expression evaluation to a point defined by the implementing technology. In general, JSF uses deferred EL evaluation because of its multiple lifecycle phases in which events are handled. To ensure the model is prepared before the values are accessed by EL, it must defer EL evaluation until the appropriate point in the life cycle.Note: This is picked up from Oracle Fusion Developer Guide (ISBN: 9780071622547). There is also a very good article here:http://java.sun.com/products/jsp/reference/techart/unifiedEL.html

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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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  • ubuntu 12.10 not updating

    - by gunjan parashar
    i have upgrade to ubuntu 12.10 from ubuntu 12.04 after that it is not updating software updater gives the following error : W:Failed to fetch http://archive.canonical.com/ubuntu/dists/precise/Release.gpg Unable to connect to 10.4.42.15:8080: W:Failed to fetch http://extras.ubuntu.com/ubuntu/dists/quantal/Release.gpg Unable to connect to 10.4.42.15:8080: W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal/Release.gpg Unable to connect to 10.4.42.15:8080: W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal-updates/Release.gpg Unable to connect to 10.4.42.15:8080: W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal-backports/Release.gpg Unable to connect to 10.4.42.15:8080: W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal-security/Release.gpg Unable to connect to 10.4.42.15:8080: W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal-proposed/Release.gpg Unable to connect to 10.4.42.15:8080: W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal/restricted/source/Sources Unable to connect to 10.4.42.15:8080: W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal/main/source/Sources Unable to connect to 10.4.42.15:8080: W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal/multiverse/source/Sources Unable to connect to 10.4.42.15:8080: W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal/universe/source/Sources Unable to connect to 10.4.42.15:8080: : W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal-proposed/universe/i18n/Translation-en Unable to connect to 10.4.42.15:8080: E:Some index files failed to download. They have been ignored, or old ones used instead. along with this i am not able to install any thing from software center , it just asks to use this source and after that it just keeps on quering software sources and nothing happens after that plz help me out , this 12.10 has became a great problem for me and forgive for my poor engish

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  • How Does AutoPatch Handle Shared E-Business Suite Products?

    - by Steven Chan
    Space... is big. Really big. You just won't believe how vastly hugely mindbogglingly big it is.~ Douglas AdamsDouglas Adams could have been talking about the E-Business Suite.  Depending upon whom you ask (and how you count them), there are between 200 to 240 products in Oracle E-Business Suite.  The products that make up Oracle E-Business Suite are tightly integrated. Some of these products are known as shared or dependent products. Installed and registered automatically by Rapid Install, such products depend on components from other products for full functionality.For example:General Ledger (GL) depends on Application Object Library (FND) and Oracle Receivables (AR)Inventory (INV) depends on FND and GLReceivables (AR) depends on FND, INV, and GLIt can sometimes be challenging to craft a patching strategy for these types of product dependencies.  To help you with that, our Applications Database (AD) team has recently published a new document that describes the actions AutoPatch takes with shared Oracle E-Business Suite products:Patching Shared Oracle E-Business Suite Products (Note 1069099.1)

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  • A Method for Reducing Contention and Overhead in Worker Queues for Multithreaded Java Applications

    - by Janice J. Heiss
    A java.net article, rich in practical resources, by IBM India Labs’ Sathiskumar Palaniappan, Kavitha Varadarajan, and Jayashree Viswanathan, explores the challenge of writing code in a way that that effectively makes use of the resources of modern multicore processors and multiprocessor servers.As the article states: “Many server applications, such as Web servers, application servers, database servers, file servers, and mail servers, maintain worker queues and thread pools to handle large numbers of short tasks that arrive from remote sources. In general, a ‘worker queue’ holds all the short tasks that need to be executed, and the threads in the thread pool retrieve the tasks from the worker queue and complete the tasks. Since multiple threads act on the worker queue, adding tasks to and deleting tasks from the worker queue needs to be synchronized, which introduces contention in the worker queue.” The article goes on to explain ways that developers can reduce contention by maintaining one queue per thread. It also demonstrates a work-stealing technique that helps in effectively utilizing the CPU in multicore systems. Read the rest of the article here.

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  • System Wide Performance Sanity Check Procedures

    - by user702295
    Do you need to boost your overall implementation performance? Do you need a direction to pinpoint possible performance opportunities? Are you looking for a general performance guide? Try MOS note 69565.1.  This paper describes a holistic methodology that defines a systematic approach to resolve complex Application performance problems.  It has been successfully used on many critical accounts.  The 'end-to-end' tuning approach encompasses the client, network and database and has proven far more effective than isolated tuning exercises.  It has been used to define and measure targets to ensure success.  Even though it was checked for relevance on 13-Oct-2008, the procedure is still very valuable. Regards!  

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  • Is Java free/open source or not?

    - by user1598390
    On November 13, 2006, Sun released much of Java as free and open source software, (FOSS), under the terms of the GNU General Public License (GPL). On May 8, 2007, Sun finished the process, making all of Java's core code available under free software/open-source distribution terms, aside from a small portion of code to which Sun did not hold the copyright. OpenJDK (Open Java Development Kit) is a free and open source implementation of the Java programming language. It is the result of an effort Sun Microsystems began in 2006. The implementation is licensed under the GNU General Public License (GNU GPL) with a linking exception. Why there are still people that say Java is not open source or free as in free speech ? Am I missing something? Is Java still privative ?

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  • How common is prototyping as the first stage of development?

    - by EpsilonVector
    I've been taking some software design courses in the past few semesters, and while I see the benefit in a lot of the formalism, I still feel like it doesn't tell me anything about the program itself. You can't tell how the program is going to operate from the Use Case spec, even though it discusses what the program can do, and you can't tell anything about the user experience from the requirements document, even though it can include QA requirements. ...sequence diagrams are as good a description of how the software works as the call stack, in other words- very limited, highly partial view of the overall system, and a class diagram is great for describing how the system is built, but is utterly useless in helping you figure out what the software needs to be. Where in all this formalism is the bottom line- how the program looks, operates, and what experience it gives? Doesn't it make more sense to design off of that? Isn't it better to figure out how the program should work via a prototype and strive to implement it for real? I know that I'm probably suffering from being taught engineering by theoreticians, but I got to ask, do they do this in the industry? How do people figure out what the program actually is, not what it should conform to? Do people prototype a lot? ...or do they mostly use the formal tools like UML and I just didn't get the hang of using them yet?

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  • Is Java free/open source or it isn't?

    - by user1598390
    On November 13, 2006, Sun released much of Java as free and open source software, (FOSS), under the terms of the GNU General Public License (GPL). On May 8, 2007, Sun finished the process, making all of Java's core code available under free software/open-source distribution terms, aside from a small portion of code to which Sun did not hold the copyright. OpenJDK (Open Java Development Kit) is a free and open source implementation of the Java programming language. It is the result of an effort Sun Microsystems began in 2006. The implementation is licensed under the GNU General Public License (GNU GPL) with a linking exception. Why there are still people that say Java is not open source or free as in free speech ? Am I missing something? Is Java still privative ?

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  • Effective versus efficient code

    - by Todd Williamson
    TL;DR: Quick and dirty code, or "correct" (insert your definition of this term) code? There is often a tension between "efficient" and "effective" in software development. "Efficient" often means code that is "correct" from the point of view of adhering to standards, using widely-accepted patterns/approaches for structures, regardless of project size, budget, etc. "Effective" is not about being "right", but about getting things done. This often results in code that falls outside the bounds of commonly accepted "correct" standards, usage, etc. Usually the people paying for the development effort have dictated ahead of time what it is that they value more. An organization that lives in a technical space will tend towards the efficient end, others will tend towards the effective. Developers often refuse to compromise their favored approach for the other. In my own experience I have found that people with formal education in software development tend towards the Efficient camp. Those that picked up software development more or less as a tool to get things done tend towards the Effective camp. These camps don't get along very well. When managing a team of developers who are not all in one camp it is challenging. In your own experience, which camp do you land in, and do you find yourself having to justify your approach to others? To management? To other developers?

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  • why not use unmanaged safe code in c#

    - by user613326
    There is an option in c# to execute code unchecked. It's generally not advised to do so, as managed code is much safer and it overcomes a lot of problems. However I am wondering, if you're sure your code won't cause errors, and you know how to handle memory then why (if you like fast code) follow the general advice? I am wondering this since I wrote a program for a video camera, which required some extremely fast bitmap manipulation. I made some fast graphical algorithms myself, and they work excellent on the bitmaps using unmanaged code. Now I wonder in general, if you're sure you don't have memory leaks, or risks of crashes, why not use unmanaged code more often ? PS my background: I kinda rolled into this programming world and I work alone (I do so for a few years) and so I hope this software design question isn't that strange. I don't really have other people out there like a teacher to ask such things.

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  • Performance triage

    - by Dave
    Folks often ask me how to approach a suspected performance issue. My personal strategy is informed by the fact that I work on concurrency issues. (When you have a hammer everything looks like a nail, but I'll try to keep this general). A good starting point is to ask yourself if the observed performance matches your expectations. Expectations might be derived from known system performance limits, prototypes, and other software or environments that are comparable to your particular system-under-test. Some simple comparisons and microbenchmarks can be useful at this stage. It's also useful to write some very simple programs to validate some of the reported or expected system limits. Can that disk controller really tolerate and sustain 500 reads per second? To reduce the number of confounding factors it's better to try to answer that question with a very simple targeted program. And finally, nothing beats having familiarity with the technologies that underlying your particular layer. On the topic of confounding factors, as our technology stacks become deeper and less transparent, we often find our own technology working against us in some unexpected way to choke performance rather than simply running into some fundamental system limit. A good example is the warm-up time needed by just-in-time compilers in Java Virtual Machines. I won't delve too far into that particular hole except to say that it's rare to find good benchmarks and methodology for java code. Another example is power management on x86. Power management is great, but it can take a while for the CPUs to throttle up from low(er) frequencies to full throttle. And while I love "turbo" mode, it makes benchmarking applications with multiple threads a chore as you have to remember to turn it off and then back on otherwise short single-threaded runs may look abnormally fast compared to runs with higher thread counts. In general for performance characterization I disable turbo mode and fix the power governor at "performance" state. Another source of complexity is the scheduler, which I've discussed in prior blog entries. Lets say I have a running application and I want to better understand its behavior and performance. We'll presume it's warmed up, is under load, and is an execution mode representative of what we think the norm would be. It should be in steady-state, if a steady-state mode even exists. On Solaris the very first thing I'll do is take a set of "pstack" samples. Pstack briefly stops the process and walks each of the stacks, reporting symbolic information (if available) for each frame. For Java, pstack has been augmented to understand java frames, and even report inlining. A few pstack samples can provide powerful insight into what's actually going on inside the program. You'll be able to see calling patterns, which threads are blocked on what system calls or synchronization constructs, memory allocation, etc. If your code is CPU-bound then you'll get a good sense where the cycles are being spent. (I should caution that normal C/C++ inlining can diffuse an otherwise "hot" method into other methods. This is a rare instance where pstack sampling might not immediately point to the key problem). At this point you'll need to reconcile what you're seeing with pstack and your mental model of what you think the program should be doing. They're often rather different. And generally if there's a key performance issue, you'll spot it with a moderate number of samples. I'll also use OS-level observability tools to lock for the existence of bottlenecks where threads contend for locks; other situations where threads are blocked; and the distribution of threads over the system. On Solaris some good tools are mpstat and too a lesser degree, vmstat. Try running "mpstat -a 5" in one window while the application program runs concurrently. One key measure is the voluntary context switch rate "vctx" or "csw" which reflects threads descheduling themselves. It's also good to look at the user; system; and idle CPU percentages. This can give a broad but useful understanding if your threads are mostly parked or mostly running. For instance if your program makes heavy use of malloc/free, then it might be the case you're contending on the central malloc lock in the default allocator. In that case you'd see malloc calling lock in the stack traces, observe a high csw/vctx rate as threads block for the malloc lock, and your "usr" time would be less than expected. Solaris dtrace is a wonderful and invaluable performance tool as well, but in a sense you have to frame and articulate a meaningful and specific question to get a useful answer, so I tend not to use it for first-order screening of problems. It's also most effective for OS and software-level performance issues as opposed to HW-level issues. For that reason I recommend mpstat & pstack as my the 1st step in performance triage. If some other OS-level issue is evident then it's good to switch to dtrace to drill more deeply into the problem. Only after I've ruled out OS-level issues do I switch to using hardware performance counters to look for architectural impediments.

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  • How should I describe the process of learning someone else's code? (In an invoicing situation.)

    - by MattyG
    I have a contract to upgrade some in-house software for a large company. The company has requested multiple feature additions and a few bug fixes. This is my first freelance style job. First, I needed to become familiar with how the application worked - I learnt it as if I was a user. Next, I had to learn how the software worked. I started with broad concepts, and then narrowed down into necessary detail before working on each bug fix and feature. At least at the start of the project, it took me a lot longer to learn the existing code than it did to write the additional features. How can I describe the process of learning the existing code on the invoice? (This part of the company usually does things in-house, so doesn't have much experience dealing with software contractors like me, and I fear they may not understand the overhead of learning someone else's code). I don't want to just tack the learning time onto the actual feature upgrade, because in some cases this would make a 'simple task' look like it took me way too long. I want break the invoice into relevant steps, and communicate that I'm charging for the large overhead of learning someone else's code before being able to add my own to it. Is there a standard way of describing this sort of activity when billing for a job?

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