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• "Interview"

  Thomas Kurian, senior vice president, Oracle Fusion Middleware, talks about Oracle’s acquisition of BEA.

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• Last chance to register to the Oracle FY14 Global Partner Kickoff (June 25, 2013)

  - by Julien Haye

  This is your last chance to register to the Oracle FY14 Global Partner Kickoff and to join us live/online tomorrow June 25, 2013 at 9:00am PDT / 5:00 pm GMT / 6:00pm CET! What to Expect: Watch Oracle Executives, including Oracle President, Mark Hurd, John Fowler, Thomas Kurian, and more outline the product strategy and direction for the company Learn about the different ways to accelerate sales and make money with Oracle through our full stack offering Participate in the conversation during the webcast via twitter using either @oraclepartners or #opn. Oracle Partner Kickoff Agenda Welcome & Executive Address Oracle Executives on Engineered Systems Selling to the C-Level Executive Innovation in Industries Partner Sales Call to Action Partner Pulse: Post Show Partner Discussion Watch it live at: OPN homepage OPN Facebook page For more information, email [email protected]. We look forward to you participation. Oracle EMEA PartnerNetwork Oracle FY14 Partner Kickoff Watch it live at: OPN homepage OPN Facebook page Tuesday, 25th June, 2013 9:00 am PT FY14 Partner Kickoff Speakers Mark Hurd President, Oracle Thomas Kurian EVP, Product Development, Oracle John Fowler EVP, Systems, Oracle

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• Oracle OpenWorld 2013 Summary

  - by JuergenKress

  Did you miss the Oracle OpenWorld 2013 – here are the key information from Thomas Kurian’s middleware presentation, our partners presentations and the first impressions on SOA Suite 12c. Thanks to all partners for the excellent presentations and the product management team for the superb demo ground! Oracle OpenWorld General Session 2013: Middleware Watch Full-Length Keynote JavaOne keynote At our WebLogic Community Workspace (WebLogic Community membership required): you can download the presentation slides from Thomas Kurian’s presentation FMWGeneralSessionTKv22.pptx. Download all session slides here. WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: OOW,ORacle OpenWorld,WebLogic 12c training,education,WebLogic,WebLogic Community,Oracle,OPN,Jürgen Kress

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• Data Warehouse Workshop

  - by Davide Mauri

  I’m really really pleased to announce that it’s possible to register to the Data Warehouse Workshop that I and Thomas Kejser developed togheter.  Several months ago we decided to join forces in order to create a workshop that would contain not only the theoretical stuff, but also the experience we both have and all the best practices and lesson learned that can make the difference between a success and a failure when building a Data Warehouse. The first sheduled date is 7 February in Kista (Sweden): http://www.eventzilla.net/web/event?eventid=2138965081 and until 30th November there is the Super Early Bird to save more the 100€ (150$). The workshop will be very similar to the one I delivered at PASS Summit summit, with some extra technical stuff since it’s one hour longer. In addition to that for this first version both me and Thomas will be present, so it’s a great change  to make sure you super-charge your DW/BI project with insights that aren’t available anywhere else! If you’re into the BI field and you live in Europe, don’t miss this opportunity!

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• 12c - Invisible Columns...

  - by noreply(at)blogger.com (Thomas Kyte)

  Remember when 11g first came out and we had "invisible indexes"?  It seemed like a confusing feature - indexes that would be maintained by modifications (hence slowing them down), but would not be used by queries (hence never speeding them up).  But - after you looked at them a while, you could see how they can be useful.  For example - to add an index in a running production system, an index used by the next version of the code to be introduced later that week - but not tested against the queries in version one of the application in place now.  We all know that when you add an index - one of three things can happen - a given query will go much faster, it won't affect a given query at all, or... It will make some untested query go much much slower than it used to.  So - invisible indexes allowed us to modify the schema in a 'safe' manner - hiding the change until we were ready for it.Invisible columns accomplish the same thing - the ability to introduce a change while minimizing any negative side effects of that change.  Normally when you add a column to a table - any program with a SELECT * would start seeing that column, and programs with an INSERT INTO T VALUES (...) would pretty much immediately break (an INSERT without a list of columns in it).  Now we can add a column to a table in an invisible fashion, the column will not show up in a DESCRIBE command in SQL*Plus, it will not be returned with a SELECT *, it will not be considered in an INSERT INTO T VALUES statement.  It can be accessed by any query that asks for it, it can be populated by an INSERT statement that references it, but you won't see it otherwise.For example, let's start with a simple two column table:ops$tkyte%ORA12CR1> create table t  2  ( x int,  3    y int  4  )  5  /Table created.ops$tkyte%ORA12CR1> insert into t values ( 1, 2 );1 row created.Now, we will add an invisible column to it:ops$tkyte%ORA12CR1> alter table t add                     ( z int INVISIBLE );Table altered.Notice that a DESCRIBE will not show us this column:ops$tkyte%ORA12CR1> desc t Name              Null?    Type ----------------- -------- ------------ X                          NUMBER(38) Y                          NUMBER(38)and existing inserts are unaffected by it:ops$tkyte%ORA12CR1> insert into t values ( 3, 4 );1 row created.A SELECT * won't see it either:ops$tkyte%ORA12CR1> select * from t;         X          Y---------- ----------         1          2         3          4But we have full access to it (in well written programs! The ones that use a column list in the insert and select - never relying on "defaults":ops$tkyte%ORA12CR1> insert into t (x,y,z)                         values ( 5,6,7 );1 row created.ops$tkyte%ORA12CR1> select x, y, z from t;         X          Y          Z---------- ---------- ----------         1          2         3          4         5          6          7and when we are sure that we are ready to go with this column, we can just modify it:ops$tkyte%ORA12CR1> alter table t modify z visible;Table altered.ops$tkyte%ORA12CR1> select * from t;         X          Y          Z---------- ---------- ----------         1          2         3          4         5          6          7I will say that a better approach to this - one that is available in 11gR2 and above - would be to use editioning views (part of Edition Based Redefinition - EBR ).  I would rather use EBR over this approach, but in an environment where EBR is not being used, or the editioning views are not in place, this will achieve much the same.Read these for information on EBR:http://www.oracle.com/technetwork/issue-archive/2010/10-jan/o10asktom-172777.htmlhttp://www.oracle.com/technetwork/issue-archive/2010/10-mar/o20asktom-098897.htmlhttp://www.oracle.com/technetwork/issue-archive/2010/10-may/o30asktom-082672.html

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• Apache/Django subdomains problem

  - by Thomas

  Now I have apache configuration which works only with localhost domain (http://localhost/). Alias /media/ "/sciezka/do/instalacji/django/contrib/admin/media/" Alias /site_media/ "/sciezka/do/plikow/site_media/" <Location "/"> SetHandler python-program PythonHandler django.core.handlers.modpython SetEnv DJANGO_SETTINGS_MODULE settings PythonPath "['/thomas/django_projects/project'] + sys.path" PythonDebug On </Location> <Location "/site_media"> SetHandler none </Location> How can I make it working for some subdomains like pl.localhost or uk.localhost? This subdomains should display the same page what domain (localhost). Second question: It is possible change default localhost address (http://localhost/) to (http://localhost.com/) or (http://www.localhost.com/) or something else?

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• Apache/Django subdomains problem

  - by Thomas

  Now I have apache configuration which works only with localhost domain (http://localhost/). Alias /media/ "/sciezka/do/instalacji/django/contrib/admin/media/" Alias /site_media/ "/sciezka/do/plikow/site_media/" <Location "/"> SetHandler python-program PythonHandler django.core.handlers.modpython SetEnv DJANGO_SETTINGS_MODULE settings PythonPath "['/thomas/django_projects/project'] + sys.path" PythonDebug On </Location> <Location "/site_media"> SetHandler none </Location> How can I make it working for some subdomains like pl.localhost or uk.localhost? This subdomains should display the same page what domain (localhost). Second question: It is possible change default localhost address (http://localhost/) to (http://localhost.com/) or (http://www.localhost.com/) or something else?

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• Detecting rotation to landscape manually

  - by Thomas Joos

  hi all, I am working on an iPhone application based on UITabBarController and UIViewControllers for each page. The app needs to run in portrait mode only, so every view controller + app delegate goes with this line of code: (BOOL)shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation)interfaceOrientation { return (interfaceOrientation == UIInterfaceOrientationPortrait); } There is one view controller where I would like to pop up a UIImageView when the iPhone is rotaed to landscapeleft. The design of the image looks landscape, although the width and height are 320x460 ( so its portrait ). How can/should I detect this type of rotation manually, just in this specific view controller, withouth having an auto rotation on the entire view? Thomas UPDATE: Thanks! I added this listener in the viewDidLoad: [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didRotate:)name:UIDeviceOrientationDidChangeNotification object:nil]; the didRotate looks like this: (void) didRotate:(NSNotification *)notification { UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation]; if (orientation == UIDeviceOrientationLandscapeLeft) { //your code here } }

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• How do I display a local html file in a UIWebView?

  - by Thomas

  I have a relatively simple question that I cannot seem to find the answer for. While doing the Google Maps Java API Tutorials, I ran into a problem. I can load an HTML file from the web, but when I try it locally, it just displays the contents of the file instead of running the script. Here's what works: NSString *url = @"http://code.google.com/apis/maps/documentation/v3/examples/geocoding-simple.html"; NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:url]]; [webView loadRequest:request]; I want to store the HTML file locally and run it from the device itself, so I tried: [webView loadRequest:[NSURLRequest requestWithURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"geocoding-simple" ofType:@"html"]isDirectory:NO]]]; and it just displayed the contents of the file. What am I doing wrong here? Thomas

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• Mobile iPhone - Multiple buttons in a row

  - by Thomas

  Hello all: I'm an iPhone developer, but new to web development. I've done some basic HTML websites and made one in iWeb as well. I'm trying to branch out to actual mobile development now, so I checked out Dashcode. Anyway, I'm trying to put a Call Button, Mail Button, and Map Button in horizontal alignment. I realize that I can add a Column Layout and have two buttons in a row, but that's the most I've gotten. Any ideas? Thanks! Thomas

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• Reading UDP Packets

  - by Thomas Mathiesen

  I am having some trouble dissecting a UDP packet. I am receiving the packets and storing the data and sender-address in variables 'data' and 'addr' with: data,addr = UDPSock.recvfrom(buf) This parses the data as a string, that I am now unable to turn into bytes. I know the structure of the datagram packet which is a total of 28 bytes, and that the data I am trying to get out is in bytes 17:28. I have tried doing this: mybytes = data[16:19] print struct.unpack('>I', mybytes) --> struct.error: unpack str size does not match format And this: response = (0, 0, data[16], data[17], 6) bytes = array('B', response[:-1]) print struct.unpack('>I', bytes) --> TypeError: Type not compatible with array type And this: print "\nData byte 17:", str.encode(data[17]) --> UnicodeEncodeError: 'ascii' codec can't encode character u'\xff' in position 0: ordinal not in range(128) And I am not sure what to try next. I am completely new to sockets and byte-conversions in Python, so any advice would be helpful :) Thanks, Thomas

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• Problem with javascript in firefox when moving google ads

  - by thomas woelfer

  hi. i have a website with google ads on it. i would like to make it load faster. thus i moved all the google scripts to the bottom of the page. i also have a placeholder at the location where the ad(s) should be displayed and other divs that (initially) get the ads. finally (in window.onload) i'm moving the ads that have just be fetched from google to their target locations. (a simple example page is here: http://www.nickles.de/temp/ads.html ) this works in ie, but it doesn't work in ff. (that is, in firefox, non-text ads show up fine, while text-ads don't. [or at least, not in a reliable way.]) any ideas what would be causing this? Thanks! -thomas woelfer

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• Mobile Safari iPhone Development - Multiple buttons in a row

  - by Thomas

  Hello all: I'm an iPhone developer, but new to web development. I've done some basic HTML websites and made one in iWeb as well. I'm trying to branch out to actual mobile development now, so I checked out Dashcode. Anyway, I'm trying to put a Call Button, Mail Button, and Map Button in horizontal alignment. I realize that I can add a Column Layout and have two buttons in a row, but that's the most I've gotten. Any ideas? Thanks! Thomas

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• How to check a local wifi connection

  - by Thomas Joos

  hi all, I'm writing an app which connects to a static ip adress in a local network. How can I check if I have a local network connection? I want to connect to http://192.168.2.5 and i tried using the Rechability class but it returns FALSE, while the device is definately connected ( when i don't do the check, the app works fine so there is a connection ): Reachability *r = [Reachability reachabilityWithHostName:@"http://192.168.2.5"]; NetworkStatus internetStatus = [r currentReachabilityStatus]; How should work this out? Thomas

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• Latex change color of intext citing with hyperref package and natbib

  - by Thomas

  I am using the natbib and hyperref package in conjunction with my latex document. I would like to change to the color of my hyppereferenced citations (the box around the citation) from the ugly baseline green to a more muted (violet or navy blue). However, in using the suggested code to do this, I can not get the citation link colors to change. My code is as follows \usepackage[usenames,dvipsnames]{color} \usepackage[round]{natbib} \usepackage[hyperfootnotes=false]{hyperref} \usepackage[hyperfootnotes=false]{hyperref} \hypersetup{ colorlinks=false, citecolor=Violet, linkcolor=Red, urlcolor=Blue} \begin{document} \bibliographystyle{apsr} \bibliography{exp_final} \end{document} However, when I compile (I compiled multiple times to make sure) this my pdf file looks the same as if I had excluded the formatting in the hypersetup (still the same ugly green). I would also like to box the footnote citations as well. Any ideas or help would be much appreciated. Thanks, Thomas

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• Problem with eastern european characters when scraping data from the European Parliaments Website

  - by Thomas Jensen

  Dear Experts I am trying to scrape a lot of data from the European Parliament website for a research project. Ther first step is the create a list if all parliamentarians, however due to the many Eastern European names and the accents they use i get a lot of missing entries. Here is an example of what is giving me troubles (notice the accents at the end of the family name): ANDRIKIENE, Laima Liucija Group of the European People's Party (Christian Democrats) So far I have been using PyParser and the following code: parser_names name = Word(alphanums + alphas8bit) begin, end = map(Suppress, "<") names = begin + ZeroOrMore(name) + "," + ZeroOrMore(name) + end for name in names.searchString(page): print(name) However this does not catch the name from the html above. Any advice in how to proceed? Best, Thomas

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• How to always run a service in the background

  - by Thomas H

  Hi I am in the process of creating an app that is similar to the build-in SMS app. What I need: - a service that is always running in the background - every 5 min. the service checks the current location of the device and calls a web service - if certain criteria are meet, the service should generate a notification (just like the SMS app) - when the notification is clicked, the user is taken to the app (just like the SMS app) - when the app is installed the service should be started - when the device is rebooted, the service should be started What I have tried: - running a regular service which worked just fine until android kills the service - using the AlarmManager the make the 5 min. interval call to a service. But I was not able to make this work. Any help would be greatly appreciated... -Thomas

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• Why does Spring Security's BindAuthenticator require read permissions for users?

  - by Thomas

  Hi all, I'm currently implementing/configuring the LDAP authentication of a Java web application using Spring Security 3.0. I'm using Microsoft AD LDS as LDAP server and chose the Spring's BindAuthenticator. I found out that the authentication only works if the authenticated user is a member of the partition's Readers role. The BindAuthenticator tries to read the user's attributes after the authentication, which seems reasonable in scenarios where authorities are retrieved from the directory service. Being new to LDAP and AD, is this an acceptable practise when the application is integrated in an existing AD structure? Can fine-tune an give the user dns only read permissions for their own attributes rather than adding them to the Reader group? Thanks Thomas

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• What is a good DBMS for archiving?

  - by Thomas.Winsnes

  I've been stuck in a MsSql/MySql world now for a few years, and I've decided to spread my wings a little further. At the moment I'm researching which DBMS is good at things needed when archiving data. Eg. lots of writes and low reads. I've seen the NoSQL crusade, but I have a very RDBMS mindset, so I'm a bit skeptical. Anyone have any suggestions? Or even any pointers to where there are some benchmarks etc for this kind of stuff. Thank you :) Thomas

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• logrotate compress files after the postrotate script

  - by Thomas

  I have an application generating a really heavy big log file every days (~800MB a day), thus I need to compress them but since the compression takes time, I want that logrotate compress the file after reloading/sending HUP signal to the application. /var/log/myapp.log { rotate 7 size 500M compress weekly postrotate /bin/kill -HUP `cat /var/run/myapp.pid 2>/dev/null` 2>/dev/null || true endscript } Is it already the case that the compression takes place after the postrotate (which would be counter-intuitive)? If not Can anyone tell me if it's possible to do that without an extra command script (an option or some trick)? Thanks Thomas

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• Does anyone has the experience of using the new p4 replicate command in their Perforce back-up /rest

  - by Thomas Corriol

  Hi all, we recently performed an upgrade of our whole perforce system to 2009.02 During this exercise, we noticed that the back-up /restore process that was installed here by the Perforce consultant a year ago was not completely working. Basically, the verify command has never worked (scary !). As we are obliged to revisit our Back-Up/Restore scripts, I was toying with the idea of using the new p4 replicate command. The idea is to use it alongside an rsync of the data files, so that in case of crash we will lose at worst an hour of work (if we execute them every hour). Does anyone has the experience or an example of back-up/restore scripts using the p4 replicate command of the 2009.02 version ? Thanks, Thomas

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• Problems after adding Control dynamically on Panel

  - by Thomas

  Hello, I have added an View List onto a Panel like that: panelComponent.Controls.Add(viewListComponent); Everthing works just fine. Mouse Events are handled, Repaint works. But one: I cant dynamically move it around. If i change the control.Top Variablen it just sit there and nothing. Its clued to the top left corner. Resizing the right and bottom line works just fine! I did it without dynamically adding and than no Problem. Hope you can help. Thomas

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• Right div pushing center div further down

  - by Chase

  I cannot get this last div to go up properly in my layout and have tried countless things. I'm not sure what's going on with my css? Here is a screenshot: http://img291.imageshack.us/img291/5377/screenshot20100528at123.png #events { float: left; width: 420px; margin:0 0 5px 0; font-family:Helvetica, Arial, sans-serif; font-size: 16px; background-image: url(images/lastfmhead.jpg); background-repeat: no-repeat; height:360px; overflow:hidden; display: inline; } #events table { width:419px; } #events th, td { padding: 3px 3px; } #whatsup ul, #citywhatsup ul { margin:0 5px 0 5px; text-align:left; font-family:Helvetica, Arial, sans-serif; } #whatsup ul li, #citywhatsup ul li{ list-style-type:none; list-style: none; } #whatsup hr, #citywhatsup hr{ border: none 0; border-top: 1px dashed #990000;/*the border*/ width: 100%; height: 1px; margin: 1px auto 5px auto;/*whatever the total width of the border-top and border-bottom equal*/ } #events ul { margin:5px 5px 0 5px; } #events ul li{ list-style-type:none; list-style: none; } #attending ul { display: inline-block; margin: 0; width:200px; } #attending ul li { display: inline-block; list-style-image:none; margin:0; padding:2px 5px 2px 5px; } #attending { width: 230px; margin:0 13px 5px 12px; float: left; display: inline; background-image: url(images/otherhead.jpg); background-repeat: no-repeat; text-align:center; height:360px; overflow:hidden; } #whatsup { width: 230px; margin:0 0 5px 0; float: left; display:inline; background-image: url(images/otherhead.jpg); background-repeat: no-repeat; text-align:center; } #eventtitle{ margin: 3px 0 -3px 0; } #eventtitle { color: #900; margin-left: 5px; font-size:16px; } #tweetit { color: #487B96 !important; font-size:16px; margin: 3px 0 -4px 0; } #photos { background-image: url(images/flickrheader.jpg); background-repeat: no-repeat; width: 665px; clear:both; } <div id="cityevents"> <h2> Events </h2> <table> <th>Date </th><th> Who's Playing </th><th> Venue </th><th> City </th><th> Tickets </th> <tr><td>May 28</td><td><a href='http://www.songkick.com/concerts/5384486?utm_source=1121&utm_medium=partner' target='_blank'>Jill King</a></td><td>Open Eye Cafe</td><td>Carrboro</td><td style='text-align:center;'><span style='color: #999'> Find </span></td></tr><tr><td>May 28</td><td><a href='http://www.songkick.com/concerts/5281141?utm_source=1121&utm_medium=partner' target='_blank'>Ahleuchatistas</a></td><td>Nightlight</td><td>Chapel Hill</td><td style='text-align:center;'><span style='color: #999'> Find </span></td></tr><tr><td>May 28</td><td><a href='http://www.songkick.com/concerts/4970896?utm_source=1121&utm_medium=partner' target='_blank'>Sam Quinn</a></td><td>Local 506</td><td>Chapel Hill</td><td style='text-align:center;'><span style='color: #999'> Find </span></td></tr><tr><td>May 29</td><td><a href='http://www.songkick.com/concerts/5303661?utm_source=1121&utm_medium=partner' target='_blank'>Cagematch Mayhem, Champion Vs Au Jus, Heartbreaker Vs Au Jus</a></td><td>DSI Comedy Theater</td><td>Carrboro</td><td style='text-align:center;'><a href='http://www.songkick.com/concerts/5303661/tickets?utm_source=1121&utm_medium=partner' target='_blank'> Find </a></td></tr><tr><td>May 29</td><td><a href='http://www.songkick.com/concerts/4722066?utm_source=1121&utm_medium=partner' target='_blank'>Lewd Acts, Converge, Gaza, Black Breath</a></td><td>Cat's Cradle</td><td>Carrboro</td><td style='text-align:center;'><a href='http://www.songkick.com/concerts/4722066/tickets?utm_source=1121&utm_medium=partner' target='_blank'> Find </a></td></tr><tr><td>May 29</td><td><a href='http://www.songkick.com/concerts/4647076?utm_source=1121&utm_medium=partner' target='_blank'>Nate Currin</a></td><td>Broad Street Cafe</td><td>Durham</td><td style='text-align:center;'><span style='color: #999'> Find </span></td></tr><tr><td>May 29</td><td><a href='http://www.songkick.com/concerts/5580211?utm_source=1121&utm_medium=partner' target='_blank'>International Night</a></td><td>Serena Rtp</td><td>Durham</td><td style='text-align:center;'><a href='http://www.songkick.com/concerts/5580211/tickets?utm_source=1121&utm_medium=partner' target='_blank'> Find </a></td></tr><tr><td>May 29</td><td><a href='http://www.songkick.com/concerts/4770241?utm_source=1121&utm_medium=partner' target='_blank'>Jill King</a></td><td>Caffe Driade</td><td>Chapel Hill</td><td style='text-align:center;'><span style='color: #999'> Find </span></td></tr><tr><td>May 29</td><td><a href='http://www.songkick.com/concerts/5406411?utm_source=1121&utm_medium=partner' target='_blank'>Sunbears!</a></td><td>Local 506</td><td>Chapel Hill</td><td style='text-align:center;'><span style='color: #999'> Find </span></td></tr><tr><td>May 29</td><td><a href='http://www.songkick.com/concerts/4924136?utm_source=1121&utm_medium=partner' target='_blank'>Studio Gangsters</a></td><td>The Reservoir</td><td>Carrboro</td><td style='text-align:center;'><span style='color: #999'> Find </span></td></tr><tr><td>May 30</td><td><a href='http://www.songkick.com/concerts/5252161?utm_source=1121&utm_medium=partner' target='_blank'>She Wants Revenge</a></td><td>Cat's Cradle</td><td>Carrboro</td><td style='text-align:center;'><span style='color: #999'> Find </span></td></tr><tr><td>May 30</td><td><a href='http://www.songkick.com/concerts/4436326?utm_source=1121&utm_medium=partner' target='_blank'>Unheard Radio Battle of the Bands</a></td><td>Mansion 462</td><td>Chapel Hill</td><td style='text-align:center;'><a href='http://www.songkick.com/concerts/4436326/tickets?utm_source=1121&utm_medium=partner' target='_blank'> Find </a></td></tr><tr><td>May 30</td><td><a href='http://www.songkick.com/concerts/4924141?utm_source=1121&utm_medium=partner' target='_blank'>Studio Gangsters</a></td><td>The Cave</td><td>Chapel Hill</td><td style='text-align:center;'><span style='color: #999'> Find </span></td></tr><tr><td>Jun 2</td><td><a href='http://www.songkick.com/concerts/5252881?utm_source=1121&utm_medium=partner' target='_blank'>Jeanne Jolly</a></td><td>Caffe Driade</td><td>Chapel Hill</td><td style='text-align:center;'><span style='color: #999'> Find </span></td></tr><tr><td>Jun 2</td><td><a href='http://www.songkick.com/concerts/4628026?utm_source=1121&utm_medium=partner' target='_blank'>James Husband, Of Montreal</a></td><td>Cat's Cradle</td><td>Carrboro</td><td style='text-align:center;'><a href='http://www.songkick.com/concerts/4628026/tickets?utm_source=1121&utm_medium=partner' target='_blank'> Find </a></td></tr><tr><td>Jun 2</td><td><a href='http://www.songkick.com/concerts/5019466?utm_source=1121&utm_medium=partner' target='_blank'>Camera Obscura</a></td><td>Duke Gardens</td><td>Durham</td><td style='text-align:center;'><a href='http://www.songkick.com/concerts/5019466/tickets?utm_source=1121&utm_medium=partner' target='_blank'> Find </a></td></tr><tr><td>Jun 3</td><td><a href='http://www.songkick.com/concerts/4226511?utm_source=1121&utm_medium=partner' target='_blank'>Reverend Horton Heat, Cracker, Legendary Shack Shakers</a></td><td>Cat's Cradle</td><td>Carrboro</td><td style='text-align:center;'><a href='http://www.songkick.com/concerts/4226511/tickets?utm_source=1121&utm_medium=partner' target='_blank'> Find </a></td></tr><tr><td>Jun 3</td><td><a href='http://www.songkick.com/concerts/5253371?utm_source=1121&utm_medium=partner' target='_blank'>American Aquarium</a></td><td>Local 506</td><td>Chapel Hill</td><td style='text-align:center;'><span style='color: #999'> Find </span></td></tr><tr><td>Jun 4</td><td><a href='http://www.songkick.com/concerts/4285251?utm_source=1121&utm_medium=partner' target='_blank'>Laurence Juber</a></td><td>The ArtsCenter</td><td>Carrboro</td><td style='text-align:center;'><span style='color: #999'> Find </span></td></tr><tr><td>Jun 4</td><td><a href='http://www.songkick.com/concerts/5642566?utm_source=1121&utm_medium=partner' target='_blank'>Community Jam, Pt Scarborough Is a Movie, Armageddon'it</a></td><td>DSI Comedy Theater</td><td>Carrboro</td><td style='text-align:center;'><a href='http://www.songkick.com/concerts/5642566/tickets?utm_source=1121&utm_medium=partner' target='_blank'> Find </a></td></tr><tr><td>Jun 4</td><td><a href='http://www.songkick.com/concerts/4676216?utm_source=1121&utm_medium=partner' target='_blank'>Big Bill Morganfield</a></td><td>Papa Mojos Roadhouse</td><td>Durham</td><td style='text-align:center;'><span style='color: #999'> Find </span></td></tr> </table> </div> <!-- Events --> <div id="citywhatsup"> <h2> What's Up? <div id="tweetit"><a class="btn-slide">Tell em'</a> </div></h2> <div id="twitpanel"></div> <script type="text/javascript"> twttr.anywhere(function (T) { T("#twitpanel").tweetBox({ height: 100, width: 215, label: '', defaultContent: "" }); }); </script> <script type="text/javascript"> twttr.anywhere(function (T) { T("#whatsup").linkifyUsers(); }); </script> <ul> <li><img src='http://a1.twimg.com/profile_images/898693876/4604414396_0464180430_b_normal.jpg' 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  Read the article

• help with fixing fwts errors log

  - by jasmines

  Here is an extract of results.log: MTRR validation. Test 1 of 3: Validate the kernel MTRR IOMEM setup. FAILED [MEDIUM] MTRRIncorrectAttr: Test 1, Memory range 0xc0000000 to 0xdfffffff (PCI Bus 0000:00) has incorrect attribute Write-Combining. FAILED [MEDIUM] MTRRIncorrectAttr: Test 1, Memory range 0xfee01000 to 0xffffffff (PCI Bus 0000:00) has incorrect attribute Write-Protect. ==================================================================================================== Test 1 of 1: Kernel log error check. Kernel message: [ 0.208079] [Firmware Bug]: ACPI: BIOS _OSI(Linux) query ignored ADVICE: This is not exactly a failure mode but a warning from the kernel. The _OSI() method has implemented a match to the 'Linux' query in the DSDT and this is redundant because the ACPI driver matches onto the Windows _OSI strings by default. FAILED [HIGH] KlogACPIErrorMethodExecutionParse: Test 1, HIGH Kernel message: [ 3.512783] ACPI Error : Method parse/execution failed [\_SB_.PCI0.GFX0._DOD] (Node f7425858), AE_AML_PACKAGE_LIMIT (20110623/psparse-536) ADVICE: This is a bug picked up by the kernel, but as yet, the firmware test suite has no diagnostic advice for this particular problem. Found 1 unique errors in kernel log. ==================================================================================================== Check if system is using latest microcode. ---------------------------------------------------------------------------------------------------- Cannot read microcode file /usr/share/misc/intel-microcode.dat. Aborted test, initialisation failed. ==================================================================================================== MSR register tests. FAILED [MEDIUM] MSRCPUsInconsistent: Test 1, MSR SYSENTER_ESP (0x175) has 1 inconsistent values across 2 CPUs for (shift: 0 mask: 0xffffffffffffffff). MSR CPU 0 -> 0xf7bb9c40 vs CPU 1 -> 0xf7bc7c40 FAILED [MEDIUM] MSRCPUsInconsistent: Test 1, MSR MISC_ENABLE (0x1a0) has 1 inconsistent values across 2 CPUs for (shift: 0 mask: 0x400c51889). MSR CPU 0 -> 0x850088 vs CPU 1 -> 0x850089 ==================================================================================================== Checks firmware has set PCI Express MaxReadReq to a higher value on non-motherboard devices. ---------------------------------------------------------------------------------------------------- Test 1 of 1: Check firmware settings MaxReadReq for PCI Express devices. MaxReadReq for pci://00:00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 03) is low (128) [Audio device]. MaxReadReq for pci://00:02:00.0 Network controller: Intel Corporation PRO/Wireless 5100 AGN [Shiloh] Network Connection is low (128) [Network controller]. FAILED [LOW] LowMaxReadReq: Test 1, 2 devices have low MaxReadReq settings. Firmware may have configured these too low. ADVICE: The MaxReadRequest size is set too low and will affect performance. It will provide excellent bus sharing at the cost of bus data transfer rates. Although not a critical issue, it may be worth considering setting the MaxReadRequest size to 256 or 512 to increase throughput on the PCI Express bus. Some drivers (for example the Brocade Fibre Channel driver) allow one to override the firmware settings. Where possible, this BIOS configuration setting is worth increasing it a little more for better performance at a small reduction of bus sharing. ==================================================================================================== PCIe ASPM check. ---------------------------------------------------------------------------------------------------- Test 1 of 2: PCIe ASPM ACPI test. PCIE ASPM is not controlled by Linux kernel. ADVICE: BIOS reports that Linux kernel should not modify ASPM settings that BIOS configured. It can be intentional because hardware vendors identified some capability bugs between the motherboard and the add-on cards. Test 2 of 2: PCIe ASPM registers test. WARNING: Test 2, RP 00h:1Ch.01h L0s not enabled. WARNING: Test 2, RP 00h:1Ch.01h L1 not enabled. WARNING: Test 2, Device 02h:00h.00h L0s not enabled. WARNING: Test 2, Device 02h:00h.00h L1 not enabled. PASSED: Test 2, PCIE aspm setting matched was matched. WARNING: Test 2, RP 00h:1Ch.05h L0s not enabled. WARNING: Test 2, RP 00h:1Ch.05h L1 not enabled. WARNING: Test 2, Device 85h:00h.00h L0s not enabled. WARNING: Test 2, Device 85h:00h.00h L1 not enabled. PASSED: Test 2, PCIE aspm setting matched was matched. ==================================================================================================== Extract and analyse Windows Management Instrumentation (WMI). Test 1 of 2: Check Windows Management Instrumentation in DSDT Found WMI Method WMAA with GUID: 5FB7F034-2C63-45E9-BE91-3D44E2C707E4, Instance 0x01 Found WMI Event, Notifier ID: 0x80, GUID: 95F24279-4D7B-4334-9387-ACCDC67EF61C, Instance 0x01 PASSED: Test 1, GUID 95F24279-4D7B-4334-9387-ACCDC67EF61C is handled by driver hp-wmi (Vendor: HP). Found WMI Event, Notifier ID: 0xa0, GUID: 2B814318-4BE8-4707-9D84-A190A859B5D0, Instance 0x01 FAILED [MEDIUM] WMIUnknownGUID: Test 1, GUID 2B814318-4BE8-4707-9D84-A190A859B5D0 is unknown to the kernel, a driver may need to be implemented for this GUID. ADVICE: A WMI driver probably needs to be written for this event. It can checked for using: wmi_has_guid("2B814318-4BE8-4707-9D84-A190A859B5D0"). One can install a notify handler using wmi_install_notify_handler("2B814318-4BE8-4707-9D84-A190A859B5D0", handler, NULL). http://lwn.net/Articles/391230 describes how to write an appropriate driver. Found WMI Object, Object ID AB, GUID: 05901221-D566-11D1-B2F0-00A0C9062910, Instance 0x01, Flags: 00 Found WMI Method WMBA with GUID: 1F4C91EB-DC5C-460B-951D-C7CB9B4B8D5E, Instance 0x01 Found WMI Object, Object ID BC, GUID: 2D114B49-2DFB-4130-B8FE-4A3C09E75133, Instance 0x7f, Flags: 00 Found WMI Object, Object ID BD, GUID: 988D08E3-68F4-4C35-AF3E-6A1B8106F83C, Instance 0x19, Flags: 00 Found WMI Object, Object ID BE, GUID: 14EA9746-CE1F-4098-A0E0-7045CB4DA745, Instance 0x01, Flags: 00 Found WMI Object, Object ID BF, GUID: 322F2028-0F84-4901-988E-015176049E2D, Instance 0x01, Flags: 00 Found WMI Object, Object ID BG, GUID: 8232DE3D-663D-4327-A8F4-E293ADB9BF05, Instance 0x01, Flags: 00 Found WMI Object, Object ID BH, GUID: 8F1F6436-9F42-42C8-BADC-0E9424F20C9A, Instance 0x00, Flags: 00 Found WMI Object, Object ID BI, GUID: 8F1F6435-9F42-42C8-BADC-0E9424F20C9A, Instance 0x00, Flags: 00 Found WMI Method WMAC with GUID: 7391A661-223A-47DB-A77A-7BE84C60822D, Instance 0x01 Found WMI Object, Object ID BJ, GUID: DF4E63B6-3BBC-4858-9737-C74F82F821F3, Instance 0x05, Flags: 00 ==================================================================================================== Disassemble DSDT to check for _OSI("Linux"). ---------------------------------------------------------------------------------------------------- Test 1 of 1: Disassemble DSDT to check for _OSI("Linux"). This is not strictly a failure mode, it just alerts one that this has been defined in the DSDT and probably should be avoided since the Linux ACPI driver matches onto the Windows _OSI strings { If (_OSI ("Linux")) { Store (0x03E8, OSYS) } If (_OSI ("Windows 2001")) { Store (0x07D1, OSYS) } If (_OSI ("Windows 2001 SP1")) { Store (0x07D1, OSYS) } If (_OSI ("Windows 2001 SP2")) { Store (0x07D2, OSYS) } If (_OSI ("Windows 2006")) { Store (0x07D6, OSYS) } If (LAnd (MPEN, LEqual (OSYS, 0x07D1))) { TRAP (0x01, 0x48) } TRAP (0x03, 0x35) } WARNING: Test 1, DSDT implements a deprecated _OSI("Linux") test. ==================================================================================================== 0 passed, 0 failed, 1 warnings, 0 aborted, 0 skipped, 0 info only. ==================================================================================================== ACPI DSDT Method Semantic Tests. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP Failed to install global event handler. Test 22 of 93: Check _PSR (Power Source). ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 22, Detected an infinite loop when evaluating method '\_SB_.AC__._PSR'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. PASSED: Test 22, \_SB_.AC__._PSR correctly acquired and released locks 16 times. Test 35 of 93: Check _TMP (Thermal Zone Current Temp). ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 35, Detected an infinite loop when evaluating method '\_TZ_.DTSZ._TMP'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. PASSED: Test 35, \_TZ_.DTSZ._TMP correctly acquired and released locks 14 times. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 35, Detected an infinite loop when evaluating method '\_TZ_.CPUZ._TMP'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. PASSED: Test 35, \_TZ_.CPUZ._TMP correctly acquired and released locks 10 times. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 35, Detected an infinite loop when evaluating method '\_TZ_.SKNZ._TMP'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. PASSED: Test 35, \_TZ_.SKNZ._TMP correctly acquired and released locks 10 times. PASSED: Test 35, _TMP correctly returned sane looking value 0x00000b4c (289.2 degrees K) PASSED: Test 35, \_TZ_.BATZ._TMP correctly acquired and released locks 9 times. PASSED: Test 35, _TMP correctly returned sane looking value 0x00000aac (273.2 degrees K) PASSED: Test 35, \_TZ_.FDTZ._TMP correctly acquired and released locks 7 times. Test 46 of 93: Check _DIS (Disable). FAILED [MEDIUM] MethodShouldReturnNothing: Test 46, \_SB_.PCI0.LPCB.SIO_.COM1._DIS returned values, but was expected to return nothing. Object returned: INTEGER: 0x00000000 ADVICE: This probably won't cause any errors, but it should be fixed as the AML code is not conforming to the expected behaviour as described in the ACPI specification. FAILED [MEDIUM] MethodShouldReturnNothing: Test 46, \_SB_.PCI0.LPCB.SIO_.LPT0._DIS returned values, but was expected to return nothing. Object returned: INTEGER: 0x00000000 ADVICE: This probably won't cause any errors, but it should be fixed as the AML code is not conforming to the expected behaviour as described in the ACPI specification. Test 61 of 93: Check _WAK (System Wake). Test _WAK(1) System Wake, State S1. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 61, Detected an infinite loop when evaluating method '\_WAK'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. Test _WAK(2) System Wake, State S2. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 61, Detected an infinite loop when evaluating method '\_WAK'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. Test _WAK(3) System Wake, State S3. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 61, Detected an infinite loop when evaluating method '\_WAK'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. Test _WAK(4) System Wake, State S4. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 61, Detected an infinite loop when evaluating method '\_WAK'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. Test _WAK(5) System Wake, State S5. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 61, Detected an infinite loop when evaluating method '\_WAK'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. Test 87 of 93: Check _BCL (Query List of Brightness Control Levels Supported). Package has 2 elements: 00: INTEGER: 0x00000000 01: INTEGER: 0x00000000 FAILED [MEDIUM] Method_BCLElementCount: Test 87, Method _BCL should return a package of more than 2 integers, got just 2. Test 88 of 93: Check _BCM (Set Brightness Level). ACPICA Exception AE_AML_PACKAGE_LIMIT during execution of method _BCM FAILED [CRITICAL] AEAMLPackgeLimit: Test 88, Detected error 'Package limit' when evaluating '\_SB_.PCI0.GFX0.DD02._BCM'. ==================================================================================================== ACPI table settings sanity checks. ---------------------------------------------------------------------------------------------------- Test 1 of 1: Check ACPI tables. PASSED: Test 1, Table APIC passed. Table ECDT not present to check. FAILED [MEDIUM] FADT32And64BothDefined: Test 1, FADT 32 bit FIRMWARE_CONTROL is non-zero, and X_FIRMWARE_CONTROL is also non-zero. Section 5.2.9 of the ACPI specification states that if the FIRMWARE_CONTROL is non-zero then X_FIRMWARE_CONTROL must be set to zero. ADVICE: The FADT FIRMWARE_CTRL is a 32 bit pointer that points to the physical memory address of the Firmware ACPI Control Structure (FACS). There is also an extended 64 bit version of this, the X_FIRMWARE_CTRL pointer that also can point to the FACS. Section 5.2.9 of the ACPI specification states that if the X_FIRMWARE_CTRL field contains a non zero value then the FIRMWARE_CTRL field *must* be zero. This error is also detected by the Linux kernel. If FIRMWARE_CTRL and X_FIRMWARE_CTRL are defined, then the kernel just uses the 64 bit version of the pointer. PASSED: Test 1, Table HPET passed. PASSED: Test 1, Table MCFG passed. PASSED: Test 1, Table RSDT passed. PASSED: Test 1, Table RSDP passed. Table SBST not present to check. PASSED: Test 1, Table XSDT passed. ==================================================================================================== Re-assemble DSDT and find syntax errors and warnings. ---------------------------------------------------------------------------------------------------- Test 1 of 2: Disassemble and reassemble DSDT FAILED [HIGH] AMLAssemblerError4043: Test 1, Assembler error in line 2261 Line | AML source ---------------------------------------------------------------------------------------------------- 02258| 0x00000000, // Range Minimum 02259| 0xFEDFFFFF, // Range Maximum 02260| 0x00000000, // Translation Offset 02261| 0x00000000, // Length | ^ | error 4043: Invalid combination of Length and Min/Max fixed flags 02262| ,, _Y0E, AddressRangeMemory, TypeStatic) 02263| DWordMemory (ResourceProducer, PosDecode, MinFixed, MaxFixed, Cacheable, ReadWrite, 02264| 0x00000000, // Granularity ==================================================================================================== ADVICE: (for error #4043): This occurs if the length is zero and just one of the resource MIF/MAF flags are set, or the length is non-zero and resource MIF/MAF flags are both set. These are illegal combinations and need to be fixed. See section 6.4.3.5 Address Space Resource Descriptors of version 4.0a of the ACPI specification for more details. FAILED [HIGH] AMLAssemblerError4050: Test 1, Assembler error in line 2268 Line | AML source ---------------------------------------------------------------------------------------------------- 02265| 0xFEE01000, // Range Minimum 02266| 0xFFFFFFFF, // Range Maximum 02267| 0x00000000, // Translation Offset 02268| 0x011FEFFF, // Length | ^ | error 4050: Length is not equal to fixed Min/Max window 02269| ,, , AddressRangeMemory, TypeStatic) 02270| }) 02271| Method (_CRS, 0, Serialized) ==================================================================================================== ADVICE: (for error #4050): The minimum address is greater than the maximum address. This is illegal. FAILED [HIGH] AMLAssemblerError1104: Test 1, Assembler error in line 8885 Line | AML source ---------------------------------------------------------------------------------------------------- 08882| Method (_DIS, 0, NotSerialized) 08883| { 08884| DSOD (0x02) 08885| Return (0x00) | ^ | warning level 0 1104: Reserved method should not return a value (_DIS) 08886| } 08887| 08888| Method (_SRS, 1, NotSerialized) ==================================================================================================== FAILED [HIGH] AMLAssemblerError1104: Test 1, Assembler error in line 9195 Line | AML source ---------------------------------------------------------------------------------------------------- 09192| Method (_DIS, 0, NotSerialized) 09193| { 09194| DSOD (0x01) 09195| Return (0x00) | ^ | warning level 0 1104: Reserved method should not return a value (_DIS) 09196| } 09197| 09198| Method (_SRS, 1, NotSerialized) ==================================================================================================== FAILED [HIGH] AMLAssemblerError1127: Test 1, Assembler error in line 9242 Line | AML source ---------------------------------------------------------------------------------------------------- 09239| CreateWordField (CRES, \_SB.PCI0.LPCB.SIO.LPT0._CRS._Y21._MAX, MAX2) 09240| CreateByteField (CRES, \_SB.PCI0.LPCB.SIO.LPT0._CRS._Y21._LEN, LEN2) 09241| CreateWordField (CRES, \_SB.PCI0.LPCB.SIO.LPT0._CRS._Y22._INT, IRQ0) 09242| CreateWordField (CRES, \_SB.PCI0.LPCB.SIO.LPT0._CRS._Y23._DMA, DMA0) | ^ | warning level 0 1127: ResourceTag smaller than Field (Tag: 8 bits, Field: 16 bits) 09243| If (RLPD) 09244| { 09245| Store (0x00, Local0) ==================================================================================================== FAILED [HIGH] AMLAssemblerError1128: Test 1, Assembler error in line 18682 Line | AML source ---------------------------------------------------------------------------------------------------- 18679| Store (0x01, Index (DerefOf (Index (Local0, 0x02)), 0x01)) 18680| If (And (WDPE, 0x40)) 18681| { 18682| Wait (\_SB.BEVT, 0x10) | ^ | warning level 0 1128: Result is not used, possible operator timeout will be missed 18683| } 18684| 18685| Store (BRID, Index (DerefOf (Index (Local0, 0x02)), 0x02)) ==================================================================================================== ADVICE: (for warning level 0 #1128): The operation can possibly timeout, and hence the return value indicates an timeout error. However, because the return value is not checked this very probably indicates that the code is buggy. A possible scenario is that a mutex times out and the code attempts to access data in a critical region when it should not. This will lead to undefined behaviour. This should be fixed. Table DSDT (0) reassembly: Found 2 errors, 4 warnings. Test 2 of 2: Disassemble and reassemble SSDT PASSED: Test 2, SSDT (0) reassembly, Found 0 errors, 0 warnings. FAILED [HIGH] AMLAssemblerError1104: Test 2, Assembler error in line 60 Line | AML source ---------------------------------------------------------------------------------------------------- 00057| { 00058| Store (CPDC (Arg0), Local0) 00059| GCAP (Local0) 00060| Return (Local0) | ^ | warning level 0 1104: Reserved method should not return a value (_PDC) 00061| } 00062| 00063| Method (_OSC, 4, NotSerialized) ==================================================================================================== FAILED [HIGH] AMLAssemblerError1104: Test 2, Assembler error in line 174 Line | AML source ---------------------------------------------------------------------------------------------------- 00171| { 00172| Store (\_PR.CPU0.CPDC (Arg0), Local0) 00173| GCAP (Local0) 00174| Return (Local0) | ^ | warning level 0 1104: Reserved method should not return a value (_PDC) 00175| } 00176| 00177| Method (_OSC, 4, NotSerialized) ==================================================================================================== FAILED [HIGH] AMLAssemblerError1104: Test 2, Assembler error in line 244 Line | AML source ---------------------------------------------------------------------------------------------------- 00241| { 00242| Store (\_PR.CPU0.CPDC (Arg0), Local0) 00243| GCAP (Local0) 00244| Return (Local0) | ^ | warning level 0 1104: Reserved method should not return a value (_PDC) 00245| } 00246| 00247| Method (_OSC, 4, NotSerialized) ==================================================================================================== FAILED [HIGH] AMLAssemblerError1104: Test 2, Assembler error in line 290 Line | AML source ---------------------------------------------------------------------------------------------------- 00287| { 00288| Store (\_PR.CPU0.CPDC (Arg0), Local0) 00289| GCAP (Local0) 00290| Return (Local0) | ^ | warning level 0 1104: Reserved method should not return a value (_PDC) 00291| } 00292| 00293| Method (_OSC, 4, NotSerialized) ==================================================================================================== Table SSDT (1) reassembly: Found 0 errors, 4 warnings. PASSED: Test 2, SSDT (2) reassembly, Found 0 errors, 0 warnings. PASSED: Test 2, SSDT (3) reassembly, Found 0 errors, 0 warnings. ==================================================================================================== 3 passed, 10 failed, 0 warnings, 0 aborted, 0 skipped, 0 info only. ==================================================================================================== Critical failures: 1 method test, at 1 log line: 1449: Detected error 'Package limit' when evaluating '\_SB_.PCI0.GFX0.DD02._BCM'. High failures: 11 klog test, at 1 log line: 121: HIGH Kernel message: [ 3.512783] ACPI Error: Method parse/execution failed [\_SB_.PCI0.GFX0._DOD] (Node f7425858), AE_AML_PACKAGE_LIMIT (20110623/psparse-536) syntaxcheck test, at 1 log line: 1668: Assembler error in line 2261 syntaxcheck test, at 1 log line: 1687: Assembler error in line 2268 syntaxcheck test, at 1 log line: 1703: Assembler error in line 8885 syntaxcheck test, at 1 log line: 1716: Assembler error in line 9195 syntaxcheck test, at 1 log line: 1729: Assembler error in line 9242 syntaxcheck test, at 1 log line: 1742: Assembler error in line 18682 syntaxcheck test, at 1 log line: 1766: Assembler error in line 60 syntaxcheck test, at 1 log line: 1779: Assembler error in line 174 syntaxcheck test, at 1 log line: 1792: Assembler error in line 244 syntaxcheck test, at 1 log line: 1805: Assembler error in line 290 Medium failures: 9 mtrr test, at 1 log line: 76: Memory range 0xc0000000 to 0xdfffffff (PCI Bus 0000:00) has incorrect attribute Write-Combining. mtrr test, at 1 log line: 78: Memory range 0xfee01000 to 0xffffffff (PCI Bus 0000:00) has incorrect attribute Write-Protect. msr test, at 1 log line: 165: MSR SYSENTER_ESP (0x175) has 1 inconsistent values across 2 CPUs for (shift: 0 mask: 0xffffffffffffffff). msr test, at 1 log line: 173: MSR MISC_ENABLE (0x1a0) has 1 inconsistent values across 2 CPUs for (shift: 0 mask: 0x400c51889). wmi test, at 1 log line: 528: GUID 2B814318-4BE8-4707-9D84-A190A859B5D0 is unknown to the kernel, a driver may need to be implemented for this GUID. method test, at 1 log line: 1002: \_SB_.PCI0.LPCB.SIO_.COM1._DIS returned values, but was expected to return nothing. method test, at 1 log line: 1011: \_SB_.PCI0.LPCB.SIO_.LPT0._DIS returned values, but was expected to return nothing. method test, at 1 log line: 1443: Method _BCL should return a package of more than 2 integers, got just 2. acpitables test, at 1 log line: 1643: FADT 32 bit FIRMWARE_CONTROL is non-zero, and X_FIRMWARE_CONTROL is also non-zero. Se

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• value types in the vm

  - by john.rose

  value types in the vm p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} p.p2 {margin: 0.0px 0.0px 14.0px 0.0px; font: 14.0px Times} p.p3 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times} p.p4 {margin: 0.0px 0.0px 15.0px 0.0px; font: 14.0px Times} p.p5 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier} p.p6 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier; min-height: 17.0px} p.p7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p8 {margin: 0.0px 0.0px 0.0px 36.0px; text-indent: -36.0px; font: 14.0px Times; min-height: 18.0px} p.p9 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p10 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; color: #000000} li.li1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} li.li7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} span.s1 {font: 14.0px Courier} span.s2 {color: #000000} span.s3 {font: 14.0px Courier; color: #000000} ol.ol1 {list-style-type: decimal} Or, enduring values for a changing world. Introduction A value type is a data type which, generally speaking, is designed for being passed by value in and out of methods, and stored by value in data structures. The only value types which the Java language directly supports are the eight primitive types. Java indirectly and approximately supports value types, if they are implemented in terms of classes. For example, both Integer and String may be viewed as value types, especially if their usage is restricted to avoid operations appropriate to Object. In this note, we propose a definition of value types in terms of a design pattern for Java classes, accompanied by a set of usage restrictions. We also sketch the relation of such value types to tuple types (which are a JVM-level notion), and point out JVM optimizations that can apply to value types. This note is a thought experiment to extend the JVM’s performance model in support of value types. The demonstration has two phases.  Initially the extension can simply use design patterns, within the current bytecode architecture, and in today’s Java language. But if the performance model is to be realized in practice, it will probably require new JVM bytecode features, changes to the Java language, or both.  We will look at a few possibilities for these new features. An Axiom of Value In the context of the JVM, a value type is a data type equipped with construction, assignment, and equality operations, and a set of typed components, such that, whenever two variables of the value type produce equal corresponding values for their components, the values of the two variables cannot be distinguished by any JVM operation. Here are some corollaries: A value type is immutable, since otherwise a copy could be constructed and the original could be modified in one of its components, allowing the copies to be distinguished. Changing the component of a value type requires construction of a new value. The equals and hashCode operations are strictly component-wise. If a value type is represented by a JVM reference, that reference cannot be successfully synchronized on, and cannot be usefully compared for reference equality. A value type can be viewed in terms of what it doesn’t do. We can say that a value type omits all value-unsafe operations, which could violate the constraints on value types.  These operations, which are ordinarily allowed for Java object types, are pointer equality comparison (the acmp instruction), synchronization (the monitor instructions), all the wait and notify methods of class Object, and non-trivial finalize methods. The clone method is also value-unsafe, although for value types it could be treated as the identity function. Finally, and most importantly, any side effect on an object (however visible) also counts as an value-unsafe operation. A value type may have methods, but such methods must not change the components of the value. It is reasonable and useful to define methods like toString, equals, and hashCode on value types, and also methods which are specifically valuable to users of the value type. Representations of Value Value types have two natural representations in the JVM, unboxed and boxed. An unboxed value consists of the components, as simple variables. For example, the complex number x=(1+2i), in rectangular coordinate form, may be represented in unboxed form by the following pair of variables: /*Complex x = Complex.valueOf(1.0, 2.0):*/ double x_re = 1.0, x_im = 2.0; These variables might be locals, parameters, or fields. Their association as components of a single value is not defined to the JVM. Here is a sample computation which computes the norm of the difference between two complex numbers: double distance(/*Complex x:*/ double x_re, double x_im,         /*Complex y:*/ double y_re, double y_im) {     /*Complex z = x.minus(y):*/     double z_re = x_re - y_re, z_im = x_im - y_im;     /*return z.abs():*/     return Math.sqrt(z_re*z_re + z_im*z_im); } A boxed representation groups component values under a single object reference. The reference is to a ‘wrapper class’ that carries the component values in its fields. (A primitive type can naturally be equated with a trivial value type with just one component of that type. In that view, the wrapper class Integer can serve as a boxed representation of value type int.) The unboxed representation of complex numbers is practical for many uses, but it fails to cover several major use cases: return values, array elements, and generic APIs. The two components of a complex number cannot be directly returned from a Java function, since Java does not support multiple return values. The same story applies to array elements: Java has no ’array of structs’ feature. (Double-length arrays are a possible workaround for complex numbers, but not for value types with heterogeneous components.) By generic APIs I mean both those which use generic types, like Arrays.asList and those which have special case support for primitive types, like String.valueOf and PrintStream.println. Those APIs do not support unboxed values, and offer some problems to boxed values. Any ’real’ JVM type should have a story for returns, arrays, and API interoperability. The basic problem here is that value types fall between primitive types and object types. Value types are clearly more complex than primitive types, and object types are slightly too complicated. Objects are a little bit dangerous to use as value carriers, since object references can be compared for pointer equality, and can be synchronized on. Also, as many Java programmers have observed, there is often a performance cost to using wrapper objects, even on modern JVMs. Even so, wrapper classes are a good starting point for talking about value types. If there were a set of structural rules and restrictions which would prevent value-unsafe operations on value types, wrapper classes would provide a good notation for defining value types. This note attempts to define such rules and restrictions. Let’s Start Coding Now it is time to look at some real code. Here is a definition, written in Java, of a complex number value type. @ValueSafe public final class Complex implements java.io.Serializable {     // immutable component structure:     public final double re, im;     private Complex(double re, double im) {         this.re = re; this.im = im;     }     // interoperability methods:     public String toString() { return "Complex("+re+","+im+")"; }     public List<Double> asList() { return Arrays.asList(re, im); }     public boolean equals(Complex c) {         return re == c.re && im == c.im;     }     public boolean equals(@ValueSafe Object x) {         return x instanceof Complex && equals((Complex) x);     }     public int hashCode() {         return 31*Double.valueOf(re).hashCode()                 + Double.valueOf(im).hashCode();     }     // factory methods:     public static Complex valueOf(double re, double im) {         return new Complex(re, im);     }     public Complex changeRe(double re2) { return valueOf(re2, im); }     public Complex changeIm(double im2) { return valueOf(re, im2); }     public static Complex cast(@ValueSafe Object x) {         return x == null ? ZERO : (Complex) x;     }     // utility methods and constants:     public Complex plus(Complex c)  { return new Complex(re+c.re, im+c.im); }     public Complex minus(Complex c) { return new Complex(re-c.re, im-c.im); }     public double abs() { return Math.sqrt(re*re + im*im); }     public static final Complex PI = valueOf(Math.PI, 0.0);     public static final Complex ZERO = valueOf(0.0, 0.0); } This is not a minimal definition, because it includes some utility methods and other optional parts.  The essential elements are as follows: The class is marked as a value type with an annotation. The class is final, because it does not make sense to create subclasses of value types. The fields of the class are all non-private and final.  (I.e., the type is immutable and structurally transparent.) From the supertype Object, all public non-final methods are overridden. The constructor is private. Beyond these bare essentials, we can observe the following features in this example, which are likely to be typical of all value types: One or more factory methods are responsible for value creation, including a component-wise valueOf method. There are utility methods for complex arithmetic and instance creation, such as plus and changeIm. There are static utility constants, such as PI. The type is serializable, using the default mechanisms. There are methods for converting to and from dynamically typed references, such as asList and cast. The Rules In order to use value types properly, the programmer must avoid value-unsafe operations.  A helpful Java compiler should issue errors (or at least warnings) for code which provably applies value-unsafe operations, and should issue warnings for code which might be correct but does not provably avoid value-unsafe operations.  No such compilers exist today, but to simplify our account here, we will pretend that they do exist. A value-safe type is any class, interface, or type parameter marked with the @ValueSafe annotation, or any subtype of a value-safe type.  If a value-safe class is marked final, it is in fact a value type.  All other value-safe classes must be abstract.  The non-static fields of a value class must be non-public and final, and all its constructors must be private. Under the above rules, a standard interface could be helpful to define value types like Complex.  Here is an example: @ValueSafe public interface ValueType extends java.io.Serializable {     // All methods listed here must get redefined.     // Definitions must be value-safe, which means     // they may depend on component values only.     List<? extends Object> asList();     int hashCode();     boolean equals(@ValueSafe Object c);     String toString(); } //@ValueSafe inherited from supertype: public final class Complex implements ValueType { … The main advantage of such a conventional interface is that (unlike an annotation) it is reified in the runtime type system.  It could appear as an element type or parameter bound, for facilities which are designed to work on value types only.  More broadly, it might assist the JVM to perform dynamic enforcement of the rules for value types. Besides types, the annotation @ValueSafe can mark fields, parameters, local variables, and methods.  (This is redundant when the type is also value-safe, but may be useful when the type is Object or another supertype of a value type.)  Working forward from these annotations, an expression E is defined as value-safe if it satisfies one or more of the following: The type of E is a value-safe type. E names a field, parameter, or local variable whose declaration is marked @ValueSafe. E is a call to a method whose declaration is marked @ValueSafe. E is an assignment to a value-safe variable, field reference, or array reference. E is a cast to a value-safe type from a value-safe expression. E is a conditional expression E0 ? E1 : E2, and both E1 and E2 are value-safe. Assignments to value-safe expressions and initializations of value-safe names must take their values from value-safe expressions. A value-safe expression may not be the subject of a value-unsafe operation.  In particular, it cannot be synchronized on, nor can it be compared with the “==” operator, not even with a null or with another value-safe type. In a program where all of these rules are followed, no value-type value will be subject to a value-unsafe operation.  Thus, the prime axiom of value types will be satisfied, that no two value type will be distinguishable as long as their component values are equal. More Code To illustrate these rules, here are some usage examples for Complex: Complex pi = Complex.valueOf(Math.PI, 0); Complex zero = pi.changeRe(0);  //zero = pi; zero.re = 0; ValueType vtype = pi; @SuppressWarnings("value-unsafe")   Object obj = pi; @ValueSafe Object obj2 = pi; obj2 = new Object();  // ok List<Complex> clist = new ArrayList<Complex>(); clist.add(pi);  // (ok assuming List.add param is @ValueSafe) List<ValueType> vlist = new ArrayList<ValueType>(); vlist.add(pi);  // (ok) List<Object> olist = new ArrayList<Object>(); olist.add(pi);  // warning: "value-unsafe" boolean z = pi.equals(zero); boolean z1 = (pi == zero);  // error: reference comparison on value type boolean z2 = (pi == null);  // error: reference comparison on value type boolean z3 = (pi == obj2);  // error: reference comparison on value type synchronized (pi) { }  // error: synch of value, unpredictable result synchronized (obj2) { }  // unpredictable result Complex qq = pi; qq = null;  // possible NPE; warning: “null-unsafe" qq = (Complex) obj;  // warning: “null-unsafe" qq = Complex.cast(obj);  // OK @SuppressWarnings("null-unsafe")   Complex empty = null;  // possible NPE qq = empty;  // possible NPE (null pollution) The Payoffs It follows from this that either the JVM or the java compiler can replace boxed value-type values with unboxed ones, without affecting normal computations.  Fields and variables of value types can be split into their unboxed components.  Non-static methods on value types can be transformed into static methods which take the components as value parameters. Some common questions arise around this point in any discussion of value types. Why burden the programmer with all these extra rules?  Why not detect programs automagically and perform unboxing transparently?  The answer is that it is easy to break the rules accidently unless they are agreed to by the programmer and enforced.  Automatic unboxing optimizations are tantalizing but (so far) unreachable ideal.  In the current state of the art, it is possible exhibit benchmarks in which automatic unboxing provides the desired effects, but it is not possible to provide a JVM with a performance model that assures the programmer when unboxing will occur.  This is why I’m writing this note, to enlist help from, and provide assurances to, the programmer.  Basically, I’m shooting for a good set of user-supplied “pragmas” to frame the desired optimization. Again, the important thing is that the unboxing must be done reliably, or else programmers will have no reason to work with the extra complexity of the value-safety rules.  There must be a reasonably stable performance model, wherein using a value type has approximately the same performance characteristics as writing the unboxed components as separate Java variables. There are some rough corners to the present scheme.  Since Java fields and array elements are initialized to null, value-type computations which incorporate uninitialized variables can produce null pointer exceptions.  One workaround for this is to require such variables to be null-tested, and the result replaced with a suitable all-zero value of the value type.  That is what the “cast” method does above. Generically typed APIs like List<T> will continue to manipulate boxed values always, at least until we figure out how to do reification of generic type instances.  Use of such APIs will elicit warnings until their type parameters (and/or relevant members) are annotated or typed as value-safe.  Retrofitting List<T> is likely to expose flaws in the present scheme, which we will need to engineer around.  Here are a couple of first approaches: public interface java.util.List<@ValueSafe T> extends Collection<T> { … public interface java.util.List<T extends Object|ValueType> extends Collection<T> { … (The second approach would require disjunctive types, in which value-safety is “contagious” from the constituent types.) With more transformations, the return value types of methods can also be unboxed.  This may require significant bytecode-level transformations, and would work best in the presence of a bytecode representation for multiple value groups, which I have proposed elsewhere under the title “Tuples in the VM”. But for starters, the JVM can apply this transformation under the covers, to internally compiled methods.  This would give a way to express multiple return values and structured return values, which is a significant pain-point for Java programmers, especially those who work with low-level structure types favored by modern vector and graphics processors.  The lack of multiple return values has a strong distorting effect on many Java APIs. Even if the JVM fails to unbox a value, there is still potential benefit to the value type.  Clustered computing systems something have copy operations (serialization or something similar) which apply implicitly to command operands.  When copying JVM objects, it is extremely helpful to know when an object’s identity is important or not.  If an object reference is a copied operand, the system may have to create a proxy handle which points back to the original object, so that side effects are visible.  Proxies must be managed carefully, and this can be expensive.  On the other hand, value types are exactly those types which a JVM can “copy and forget” with no downside. Array types are crucial to bulk data interfaces.  (As data sizes and rates increase, bulk data becomes more important than scalar data, so arrays are definitely accompanying us into the future of computing.)  Value types are very helpful for adding structure to bulk data, so a successful value type mechanism will make it easier for us to express richer forms of bulk data. Unboxing arrays (i.e., arrays containing unboxed values) will provide better cache and memory density, and more direct data movement within clustered or heterogeneous computing systems.  They require the deepest transformations, relative to today’s JVM.  There is an impedance mismatch between value-type arrays and Java’s covariant array typing, so compromises will need to be struck with existing Java semantics.  It is probably worth the effort, since arrays of unboxed value types are inherently more memory-efficient than standard Java arrays, which rely on dependent pointer chains. It may be sufficient to extend the “value-safe” concept to array declarations, and allow low-level transformations to change value-safe array declarations from the standard boxed form into an unboxed tuple-based form.  Such value-safe arrays would not be convertible to Object[] arrays.  Certain connection points, such as Arrays.copyOf and System.arraycopy might need additional input/output combinations, to allow smooth conversion between arrays with boxed and unboxed elements. Alternatively, the correct solution may have to wait until we have enough reification of generic types, and enough operator overloading, to enable an overhaul of Java arrays. Implicit Method Definitions The example of class Complex above may be unattractively complex.  I believe most or all of the elements of the example class are required by the logic of value types. If this is true, a programmer who writes a value type will have to write lots of error-prone boilerplate code.  On the other hand, I think nearly all of the code (except for the domain-specific parts like plus and minus) can be implicitly generated. Java has a rule for implicitly defining a class’s constructor, if no it defines no constructors explicitly.  Likewise, there are rules for providing default access modifiers for interface members.  Because of the highly regular structure of value types, it might be reasonable to perform similar implicit transformations on value types.  Here’s an example of a “highly implicit” definition of a complex number type: public class Complex implements ValueType {  // implicitly final     public double re, im;  // implicitly public final     //implicit methods are defined elementwise from te fields:     //  toString, asList, equals(2), hashCode, valueOf, cast     //optionally, explicit methods (plus, abs, etc.) would go here } In other words, with the right defaults, a simple value type definition can be a one-liner.  The observant reader will have noticed the similarities (and suitable differences) between the explicit methods above and the corresponding methods for List<T>. Another way to abbreviate such a class would be to make an annotation the primary trigger of the functionality, and to add the interface(s) implicitly: public @ValueType class Complex { … // implicitly final, implements ValueType (But to me it seems better to communicate the “magic” via an interface, even if it is rooted in an annotation.) Implicitly Defined Value Types So far we have been working with nominal value types, which is to say that the sequence of typed components is associated with a name and additional methods that convey the intention of the programmer.  A simple ordered pair of floating point numbers can be variously interpreted as (to name a few possibilities) a rectangular or polar complex number or Cartesian point.  The name and the methods convey the intended meaning. But what if we need a truly simple ordered pair of floating point numbers, without any further conceptual baggage?  Perhaps we are writing a method (like “divideAndRemainder”) which naturally returns a pair of numbers instead of a single number.  Wrapping the pair of numbers in a nominal type (like “QuotientAndRemainder”) makes as little sense as wrapping a single return value in a nominal type (like “Quotient”).  What we need here are structural value types commonly known as tuples. For the present discussion, let us assign a conventional, JVM-friendly name to tuples, roughly as follows: public class java.lang.tuple.$DD extends java.lang.tuple.Tuple {      double $1, $2; } Here the component names are fixed and all the required methods are defined implicitly.  The supertype is an abstract class which has suitable shared declarations.  The name itself mentions a JVM-style method parameter descriptor, which may be “cracked” to determine the number and types of the component fields. The odd thing about such a tuple type (and structural types in general) is it must be instantiated lazily, in response to linkage requests from one or more classes that need it.  The JVM and/or its class loaders must be prepared to spin a tuple type on demand, given a simple name reference, $xyz, where the xyz is cracked into a series of component types.  (Specifics of naming and name mangling need some tasteful engineering.) Tuples also seem to demand, even more than nominal types, some support from the language.  (This is probably because notations for non-nominal types work best as combinations of punctuation and type names, rather than named constructors like Function3 or Tuple2.)  At a minimum, languages with tuples usually (I think) have some sort of simple bracket notation for creating tuples, and a corresponding pattern-matching syntax (or “destructuring bind”) for taking tuples apart, at least when they are parameter lists.  Designing such a syntax is no simple thing, because it ought to play well with nominal value types, and also with pre-existing Java features, such as method parameter lists, implicit conversions, generic types, and reflection.  That is a task for another day. Other Use Cases Besides complex numbers and simple tuples there are many use cases for value types.  Many tuple-like types have natural value-type representations. These include rational numbers, point locations and pixel colors, and various kinds of dates and addresses. Other types have a variable-length ‘tail’ of internal values. The most common example of this is String, which is (mathematically) a sequence of UTF-16 character values. Similarly, bit vectors, multiple-precision numbers, and polynomials are composed of sequences of values. Such types include, in their representation, a reference to a variable-sized data structure (often an array) which (somehow) represents the sequence of values. The value type may also include ’header’ information. Variable-sized values often have a length distribution which favors short lengths. In that case, the design of the value type can make the first few values in the sequence be direct ’header’ fields of the value type. In the common case where the header is enough to represent the whole value, the tail can be a shared null value, or even just a null reference. Note that the tail need not be an immutable object, as long as the header type encapsulates it well enough. This is the case with String, where the tail is a mutable (but never mutated) character array. Field types and their order must be a globally visible part of the API.  The structure of the value type must be transparent enough to have a globally consistent unboxed representation, so that all callers and callees agree about the type and order of components  that appear as parameters, return types, and array elements.  This is a trade-off between efficiency and encapsulation, which is forced on us when we remove an indirection enjoyed by boxed representations.  A JVM-only transformation would not care about such visibility, but a bytecode transformation would need to take care that (say) the components of complex numbers would not get swapped after a redefinition of Complex and a partial recompile.  Perhaps constant pool references to value types need to declare the field order as assumed by each API user. This brings up the delicate status of private fields in a value type.  It must always be possible to load, store, and copy value types as coordinated groups, and the JVM performs those movements by moving individual scalar values between locals and stack.  If a component field is not public, what is to prevent hostile code from plucking it out of the tuple using a rogue aload or astore instruction?  Nothing but the verifier, so we may need to give it more smarts, so that it treats value types as inseparable groups of stack slots or locals (something like long or double). My initial thought was to make the fields always public, which would make the security problem moot.  But public is not always the right answer; consider the case of String, where the underlying mutable character array must be encapsulated to prevent security holes.  I believe we can win back both sides of the tradeoff, by training the verifier never to split up the components in an unboxed value.  Just as the verifier encapsulates the two halves of a 64-bit primitive, it can encapsulate the the header and body of an unboxed String, so that no code other than that of class String itself can take apart the values. Similar to String, we could build an efficient multi-precision decimal type along these lines: public final class DecimalValue extends ValueType {     protected final long header;     protected private final BigInteger digits;     public DecimalValue valueOf(int value, int scale) {         assert(scale >= 0);         return new DecimalValue(((long)value << 32) + scale, null);     }     public DecimalValue valueOf(long value, int scale) {         if (value == (int) value)             return valueOf((int)value, scale);         return new DecimalValue(-scale, new BigInteger(value));     } } Values of this type would be passed between methods as two machine words. Small values (those with a significand which fits into 32 bits) would be represented without any heap data at all, unless the DecimalValue itself were boxed. (Note the tension between encapsulation and unboxing in this case.  It would be better if the header and digits fields were private, but depending on where the unboxing information must “leak”, it is probably safer to make a public revelation of the internal structure.) Note that, although an array of Complex can be faked with a double-length array of double, there is no easy way to fake an array of unboxed DecimalValues.  (Either an array of boxed values or a transposed pair of homogeneous arrays would be reasonable fallbacks, in a current JVM.)  Getting the full benefit of unboxing and arrays will require some new JVM magic. Although the JVM emphasizes portability, system dependent code will benefit from using machine-level types larger than 64 bits.  For example, the back end of a linear algebra package might benefit from value types like Float4 which map to stock vector types.  This is probably only worthwhile if the unboxing arrays can be packed with such values. More Daydreams A more finely-divided design for dynamic enforcement of value safety could feature separate marker interfaces for each invariant.  An empty marker interface Unsynchronizable could cause suitable exceptions for monitor instructions on objects in marked classes.  More radically, a Interchangeable marker interface could cause JVM primitives that are sensitive to object identity to raise exceptions; the strangest result would be that the acmp instruction would have to be specified as raising an exception. @ValueSafe public interface ValueType extends java.io.Serializable,         Unsynchronizable, Interchangeable { … public class Complex implements ValueType {     // inherits Serializable, Unsynchronizable, Interchangeable, @ValueSafe     … It seems possible that Integer and the other wrapper types could be retro-fitted as value-safe types.  This is a major change, since wrapper objects would be unsynchronizable and their references interchangeable.  It is likely that code which violates value-safety for wrapper types exists but is uncommon.  It is less plausible to retro-fit String, since the prominent operation String.intern is often used with value-unsafe code. We should also reconsider the distinction between boxed and unboxed values in code.  The design presented above obscures that distinction.  As another thought experiment, we could imagine making a first class distinction in the type system between boxed and unboxed representations.  Since only primitive types are named with a lower-case initial letter, we could define that the capitalized version of a value type name always refers to the boxed representation, while the initial lower-case variant always refers to boxed.  For example: complex pi = complex.valueOf(Math.PI, 0); Complex boxPi = pi;  // convert to boxed myList.add(boxPi); complex z = myList.get(0);  // unbox Such a convention could perhaps absorb the current difference between int and Integer, double and Double. It might also allow the programmer to express a helpful distinction among array types. As said above, array types are crucial to bulk data interfaces, but are limited in the JVM.  Extending arrays beyond the present limitations is worth thinking about; for example, the Maxine JVM implementation has a hybrid object/array type.  Something like this which can also accommodate value type components seems worthwhile.  On the other hand, does it make sense for value types to contain short arrays?  And why should random-access arrays be the end of our design process, when bulk data is often sequentially accessed, and it might make sense to have heterogeneous streams of data as the natural “jumbo” data structure.  These considerations must wait for another day and another note. More Work It seems to me that a good sequence for introducing such value types would be as follows: Add the value-safety restrictions to an experimental version of javac. Code some sample applications with value types, including Complex and DecimalValue. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. A staggered roll-out like this would decouple language changes from bytecode changes, which is always a convenient thing. A similar investigation should be applied (concurrently) to array types.  In this case, it seems to me that the starting point is in the JVM: Add an experimental unboxing array data structure to a production JVM, perhaps along the lines of Maxine hybrids.  No bytecode or language support is required at first; everything can be done with encapsulated unsafe operations and/or method handles. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. That’s enough musing me for now.  Back to work!

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