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  • CSS overflow character not pushing down <div>

    - by Uncle Toby
    I have a <div> called bigbox which contain a <div>called wrapper . The wrapper contain 2 <div> called textbox and checkbox. If the characters inside textbox overflow , it doesn't push the other wrapper below . How can I make the below wrapper go down ? here is the jsfiddle : http://jsfiddle.net/WA63P/ <html> <head> <title>Page</title> <script type="text/javascript" src="jquery-1.9.1.min.js"></script> <style type="text/css"> .bigbox { background-color: #F5E49C; color: #000; padding: 0 5px; width:280px; height:500px; position: absolute; text-align: center;content: "";display: block;clear: both; } .box { background-color: #272822; color: #9C5A3C; height:100px; width:260px; margin-bottom: 10px; position: relative; top:10px; } .textbox { background-color: #FFFFFF; color: #272822; height:100px; width:160px;float:left;text-align: left } .checkbox { background-color: #FFFFFF; height:50px; width:50px; float:right; d } </style> <div class="bigbox"> <div class="box"> <div class="textbox">background background background background background background background background background background background background background background background background background background background background background background </div> <div class="checkbox"> </div> </div> <div class="box"> <div class="textbox"> </div> <div class="checkbox"> </div> </div> </body> </html>

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  • Drill down rss reader iphone

    - by bing
    Hi everyone, I have made a simple rss reader. The app loads an xml atom file in an array. Now I have added categories to my atom feed, which are first loaded in the array What is the best way to add drill down functionality programmatically. Now only the categories are loaded into the array and displayed. This is the implementation code ..... loading xml file <snip> ..... - (void)parserDidStartDocument:(NSXMLParser *)parser { NSLog(@"found file and started parsing"); } - (void)parser:(NSXMLParser *)parser parseErrorOccurred:(NSError *)parseError { NSString * errorString = [NSString stringWithFormat:@"Unable to download story feed from web site (Error code %i )", [parseError code]]; NSLog(@"error parsing XML: %@", errorString); UIAlertView * errorAlert = [[UIAlertView alloc] initWithTitle:@"Error loading content" message:errorString delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil]; [errorAlert show]; } - (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict{ //NSLog(@"found this element: %@", elementName); currentElement = [elementName copy]; if ([elementName isEqualToString:@"entry"]) { // clear out our story item caches... Categoryentry = [[NSMutableDictionary alloc] init]; currentID = [[NSMutableString alloc] init]; currentTitle = [[NSMutableString alloc] init]; currentSummary = [[NSMutableString alloc] init]; currentContent = [[NSMutableString alloc] init]; } } - (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName{ //NSLog(@"ended element: %@", elementName); if ([elementName isEqualToString:@"entry"]) { // save values to an entry, then store that item into the array... [Categoryentry setObject:currentTitle forKey:@"title"]; [Categoryentry setObject:currentID forKey:@"id"]; [Categoryentry setObject:currentSummary forKey:@"summary"]; [Categoryentry setObject:currentContent forKey:@"content"]; [categories addObject:[Categoryentry copy]]; NSLog(@"adding category: %@", currentTitle); } } - (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{ //NSLog(@"found characters: %@", string); // save the characters for the current item... if ([currentElement isEqualToString:@"title"]) { [currentTitle appendString:string]; } else if ([currentElement isEqualToString:@"id"]) { [currentID appendString:string]; } else if ([currentElement isEqualToString:@"summary"]) { [currentSummary appendString:string]; } else if ([currentElement isEqualToString:@"content"]) { [currentContent appendString:string]; } } - (void)parserDidEndDocument:(NSXMLParser *)parser { [activityIndicator stopAnimating]; [activityIndicator removeFromSuperview]; NSLog(@"all done!"); NSLog(@"categories array has %d entries", [categories count]); [newsTable reloadData]; }

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  • ASP.NET Drop Down list , the button function not firing after the first click

    - by Pinu
    ASP.Net Dropdownlist , on changing the value of drop down list and clicking the button it is not sending an upadted value to the New.aspx <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Test_DropDown.aspx.cs" Inherits="Test_DropDown" % <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> <title>Untitled Page</title> </head> <body> <form id="form1" runat="server"> <div> <asp:DropDownList ID="ddl_test" runat="server" OnSelectedIndexChanged="ddl_test_SelectedIndexChanged" AutoPostBack="true"> <asp:ListItem>First Item</asp:ListItem> <asp:ListItem>Second Item</asp:ListItem> <asp:ListItem>Third Item</asp:ListItem> </asp:DropDownList> <asp:HiddenField ID="hdf_ddl" runat="server" /> <asp:Button ID="btn_test" runat="server" Text="Button" OnClick="Button1_Click" /> </div> </form> </body> </html> using System; using System.Data; using System.Configuration; using System.Collections; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; public partial class Test_DropDown : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { } protected void Button1_Click(object sender, EventArgs e) { string passValue = ddl_test.SelectedValue.ToString(); string val = hdf_ddl.Value.ToString(); btn_test.Attributes.Add("onclick", "window.open('New.aspx?ddlValue=" + val + "', 'OpenPopWindow','left=250,top=100,width=500,height=500,toolbar=1,resizable=0,status=0,menubar=0,scrollbars=1');return false;"); //btn_test.OnClientClick = "window.open('New.aspx?ddlValue=" + val + "', 'OpenPopWindow','left=250,top=100,width=500,height=500,toolbar=1,resizable=0,status=0,menubar=0,scrollbars=1');return false;"; } protected void ddl_test_SelectedIndexChanged(object sender, EventArgs e) { hdf_ddl.Value = ddl_test.SelectedValue.ToString(); } }

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  • Implementing hoverIntent for Drop Down Menu (coming from click_event)

    - by stormeTrooper
    I've just recently started programming, I was hoping for some help. I have a drop down menu that was originally activated by click_event, however I want to now implement hoverIntent in order to make the menu drop. The issue I am having now is being able to use the menu, because whenever I invoke the menu now, once I leave the area that activates the menu, the menu closes. If you could explain to me like I'm five, I'd appreciate it, thanks :) The code I am using as follows: JavaScript: function setupUserConfigMenu() { $('.user_profile_btn').hoverIntent( function (event) { $('#user_settings_dropdown').animate({height:['toggle', 'swing'] }, 225); }, function (event) { $('#user_settings_dropdown').animate({height:['toggle', 'swing'] }, 225); }) } HTML: <li> <a href="<%= "#" %>" class="user_profile_btn" title="Your profile page"><%= truncate(current_user.full_name || current_user.name, :length => 28) %> <div class="arrow_down"></div></a> <ul id="user_settings_dropdown"> <li> <a href="<%= current_user.get_url(true) %>"> <%= image_tag current_user.get_thumb_url, :size => "30x30" %> <div> <%= truncate(current_user.full_name || current_user.name, :length => 40) %> <br> View profile </div> </a> </li> <div class="grey_line"></div> <li class="settings_list_item"> <%= link_to "Settings", edit_user_registration_path %> </li> <li class="settings_list_item"> <%= link_to "About", "/about" %> </li> <li class="settings_list_item"> <%= link_to "Logout", destroy_user_session_path, :method => :delete %> </li> </ul> </li>

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  • Graphics/Vision Interesting Topics

    - by Myx
    Hello: I would like to do an interesting project for a computer graphics course. I know that there is a lot of literature out there (i.e. SIGGRAPH conference papers). I have a very large range of interest with regard to computer graphics (i.e. image processing, 3D modeling, rendering, animation). However, I've only taken computer vision/graphics for 2 semesters and thus don't have too much background experience, except for the class projects that I had to do. I've been looking through SIGGRAPH papers trying to see if there is anything that will be of interest to me but the literature is extremely vast. I was wondering if anyone has any topic suggestions, anything interesting that you ran across that you could recommend. I would prefer to do something fun yet slightly challenging (not really interested in making a shooter game). If this question does not belong here, I apologize and please let me know where I should move it. Thanks!

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  • How to prevent samba from holding a file lock after a client disconnects?

    - by Jean-Francois Chevrette
    Here I have a Samba server (Debian 5.0) thats is configured to host Windows XP profiles. Clients connects to this server and work on their profiles directly on the samba share (the profile is not copied locally). Every now and then, a client may not shutdown properly and thus Windows does not free the file locks. When looking at the samba locking table, we can see that many files are still locked even though the client is not connected anymore. In our case, this seems to occur with lockfiles created by Mozilla Thunderbird and Firefox. Here's an example of the samba locking table: # smbstatus -L | grep DENY_ALL | head -n5 Pid Uid DenyMode Access R/W Oplock SharePath Name Time -------------------------------------------------------------------------------------------------- 15494 10345 DENY_ALL 0x3019f RDWR EXCLUSIVE+BATCH /home/CORP/user1 app.profile/user1.thunderbird/parent.lock Mon Nov 22 07:12:45 2010 18040 10454 DENY_ALL 0x3019f RDWR EXCLUSIVE+BATCH /home/CORP/user2 app.profile/user2.thunderbird/parent.lock Mon Nov 22 11:20:45 2010 26466 10056 DENY_ALL 0x3019f RDWR EXCLUSIVE+BATCH /home/CORP/user3 app.profile/user3.firefox/parent.lock Mon Nov 22 08:48:23 2010 We can see that the files were opened by Windows and imposed a DENY_ALL lock. Now when a client reconnects to this share and tries to open those files, samba says that they are locked and denies access. Is there any way to work around this situation or am I missing something? Edit: We would like to avoid disabling file locks on the samba server because there are good reasons to have those enabled.

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  • How to drill down with jQuery?

    - by Timothy Reed
    I'm new to jQuery so sorry if this sounds stupid but I'm having truble drilling down to other elemnts. Paticularly I want to fade in the .menu li a:hover class with jquery. .menu { padding:0; margin:0; list-style:none; } .menu li { float:left; margin-left:1px; } .menu li a { display:block; height:44px; line-height:40px; padding:0 5px; float:right; color:#fff; text-decoration:none; font-family:"Palatino Linotype", "Book Antiqua", Palatino, serif; font-size:12px; font-weight:bold; } .menu li a b { text-transform:uppercase; } .menu li a:hover { color:#E4FFC5; background: url(../images/arrow.png) no-repeat center bottom; } .current { background: url(../images/arrow.png) no-repeat center bottom; font-size:16px; font-weight:bold; } .spacer p { display:block; height:44px; line-height:40px; padding:0 5px; float:right; color:#fff; text-decoration:none; font-family:"Palatino Linotype", "Book Antiqua", Palatino, serif; font-size:12px; font-weight:bold; } <ul class="menu"> <li class="current"><a href="index.html">Home</a></li> <li class="spacer"> <p>|</p> </li> <li><a href="#">Mission &amp; Values </a></li> <li class="spacer"> <p>|</p> </li> <li><a href="#">Caregivers</a></li> <li class="spacer"> <p>|</p> </li> <li><a href="#">Special Programs </a></li> <li class="spacer"> <p>|</p> </li> <li><a href="#">Enployment</a></li> <li class="spacer"> <p>|</p> </li> <li><a href="#">Contact</a></li> </ul> <script type="text/javascript"> $(function() { $('a').mouseover(function() { $('.logo').animate ({opacity:'0.6'}, 'normal'); }); $('a').mouseout (function() { $('.logo').animate ({opacity:'1'}, 'normal'); $('.menu li a:hover').fadeIn ('slow'); }); </script>

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  • Build a Drill Down TableView with arrays

    - by skiria
    I'm trying to build a Drill down tableview to show the information that I have in a hierachy of arrays and classes. I have 3 classes: class Video { nameVideo, id, description, user... } class Topic {nameTopic, topicID, NSMutableArray videos; } class Category {nameCategory, categoryID, NSMUtableArray topics} And then in my app delegate I defined //AppDelegate.h NSMutableArray categories; The app display the tableView with nameCategory, but then, when I select a row it shows a tableview with 0 rows. If I check, for the second view the NumberOfRowsInSection, it returns me 0. I supose that the error is that I don't build correctly the provisional array called tableDataSource, I don't know the reason why it doesn't copy the new information on this array. ` - (void)viewDidLoad { [super viewDidLoad]; appDelegate = (TSCAppDelegate *)[[UIApplication sharedApplication] delegate]; //self.title = @"Categoria"; if(CurrentLevel == 0) { //Initialize our table data source NSArray *tempArray = [[NSArray alloc] init]; self.tableDataSource = tempArray; [tempArray release]; self.tableDataSource = appDelegate.categories; self.navigationItem.title = @"Categoria"; CurrentTitle = @"Categoria"; } else { self.navigationItem.title = CurrentTitle; } } - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return 1; } // Customize the number of rows in the table view. - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { NSLog (@"contador_ %i,", [self.tableDataSource count]); //--> On the second view it is 0! return [self.tableDataSource count]; } // Customize the appearance of table view cells. - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier]autorelease]; } // Configure the cell. if (CurrentLevel == 0) { Category *aCategory = [self.tableDataSource objectAtIndex:indexPath.row]; cell.text = aCategory.nameCategory; } if (CurrentLevel == 1) { Topic *aTopic = [self.tableDataSource objectAtIndex:indexPath.row]; cell.text = aTopic.nameTopic; } else if ([CurrentLevel == 0]){ Topic *aTopic = [self.tableDataSource objectAtIndex:indexPath.row]; cell.text = aTopic.nameTopic; //NSLog(@"inside!!"); } cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator; return cell; } - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { //Get the actual Category Category *aCategory = [self.tableDataSource objectAtIndex:indexPath.row]; //NSLog (@" CATEGORY: %@", aCategory.nameCategory); //NSLog (@" CATEGORY: %i", aCategory.categoryID); //NSLog (@" TOPICS OF CATEGORY: %i", [aCategory.topics count]); //Prepare to tableview. navegaTableViewController *nvController = [[navegaTableViewController alloc] initWithNibName:@"navegaTableView" bundle:[NSBundle mainBundle]]; //Increment the Current View nvController.CurrentLevel += 1; //Set the title; nvController.CurrentTitle = @"Topic"; nvController.tableDataSource = aCategory.topics; //Push the new table view on the stack [self.navigationController pushViewController:nvController animated:YES]; [nvController release]; } `

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  • Drop down list in menu disappears before able to click

    - by user1834770
    I've had quite a search through forums looking for a solution for this, but since I don't know coding I'm not sure what applies to me and what doesn't. So, apologies if this is an often solved problem, but I'll greatly appreciate your help! After much trial and error, I've managed to get a drop down list of pages on my navigation bar; however, when I go to click on a sub-page, the entire menu disappears. I've read through other similar problems where there has been an issue with a margin that's too big, but I think my margins are set to '0'. The blog is at: http://swirlstwirlsblog.blogspot.com.au/ I haven't got content in the sub pages but there are there and linked in the html/javascript widget. I've also looked at it in Chrome, Mozilla, and Safari and it's the same issue. I'm also not sure if this is a javascript, css, or html problem, so please be kind in your responses--I'm only new! Thanks so much to anyone able to help me on this. Here's the script I used in the Widget: <ul id="jsddm"> <li><a href="http://swirlstwirlsblog.blogspot.com.au/">Home</a> <li><a href="http://swirlstwirlsblog.blogspot.com.au/search/label/sparkles">Sparkles</a> </li> <li><a href="http://swirlstwirlsblog.blogspot.com.au/search/label/friendship">Friendship</a> </li> <li><a href="http://swirlstwirlsblog.blogspot.com.au/search/label/humour">Humour</a> </li> <li><a href="">About</a> <ul> <li><a href="http://swirlstwirlsblog.blogspot.com.au/p/about_16.html">Us</a></li> <li><a href="http://swirlstwirlsblog.blogspot.com.au/p/contributers.html">Contributors</a> </li> <li><a href="http://swirlstwirlsblog.blogspot.com.au/p/advertising.html">Advertising</a> </li> <li><a href="http://swirlstwirlsblog.blogspot.com.au/p/privacy-policies.html">Privacy</a></li> <li><a href="http://swirlstwirlsblog.blogspot.com.au/p/contact.html">Contact</a></li> </ul> </li> </li></ul> And here's the html code I put in the template: <pre>#jsddm { margin: 0; padding: 15px; z-index:1000000000; position:relative; } #jsddm li { float: left; list-style: none; font: 12px Tahoma, Arial; } #jsddm li a { display: block; white-space: nowrap; margin:1px 3px; padding: 5px 10px; border-right: 1px color: eeeeee; text-shadow: #ffffff 0 1px 0; color: #363636; font-size: 15px; font-family: crushed; text-decoration: none; vertical-align: middle; } #jsddm li a:hover { background: #C8C8C8; } #jsddm li ul { margin: 0; padding: 0; position: absolute; visibility: hidden; border-top: 1px solid white; } #jsddm li ul li { float: none; display: inline; } #jsddm li ul li a { width: auto; background: #ffffff; } #jsddm li ul li a:hover { background: #eeeeee; }</pre>

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  • Know more about Enqueue Deadlock Detection

    - by Liu Maclean(???)
    ??? ORACLE ALLSTAR???????????????????,??????? ???????enqueue lock?????????3 ??????,????????????????????????????ora-00060 dead lock??process???3s: SQL> select * from v$version; BANNER ---------------------------------------------------------------- Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi PL/SQL Release 10.2.0.5.0 - Production CORE 10.2.0.5.0 Production TNS for Linux: Version 10.2.0.5.0 - Production NLSRTL Version 10.2.0.5.0 - Production SQL> select * from global_name; GLOBAL_NAME -------------------------------------------------------------------------------- www.oracledatabase12g.com PROCESS A: set timing on; update maclean1 set t1=t1+1; PROCESS B: update maclean2 set t1=t1+1; PROCESS A: update maclean2 set t1=t1+1; PROCESS B: update maclean1 set t1=t1+1; ??3s? PROCESS A ?? ERROR at line 1: ORA-00060: deadlock detected while waiting for resource Elapsed: 00:00:03.02 ????Process A????????????? 3s,?????????????,??????? ?????????? ???????: SQL> col name for a30 SQL> col value for a5 SQL> col DESCRIB for a50 SQL> set linesize 140 pagesize 1400 SQL> SELECT x.ksppinm NAME, y.ksppstvl VALUE, x.ksppdesc describ 2 FROM SYS.x$ksppi x, SYS.x$ksppcv y 3 WHERE x.inst_id = USERENV ('Instance') 4 AND y.inst_id = USERENV ('Instance') 5 AND x.indx = y.indx 6 AND x.ksppinm='_enqueue_deadlock_scan_secs'; NAME VALUE DESCRIB ------------------------------ ----- -------------------------------------------------- _enqueue_deadlock_scan_secs 0 deadlock scan interval SQL> alter system set "_enqueue_deadlock_scan_secs"=18 scope=spfile; System altered. Elapsed: 00:00:00.01 SQL> startup force; ORACLE instance started. Total System Global Area 851443712 bytes Fixed Size 2100040 bytes Variable Size 738198712 bytes Database Buffers 104857600 bytes Redo Buffers 6287360 bytes Database mounted. Database opened. PROCESS A: SQL> set timing on; SQL> update maclean1 set t1=t1+1; 1 row updated. Elapsed: 00:00:00.06 Process B SQL> update maclean2 set t1=t1+1; 1 row updated. SQL> update maclean1 set t1=t1+1; Process A: SQL> SQL> alter session set events '10704 trace name context forever,level 10:10046 trace name context forever,level 8'; Session altered. SQL> update maclean2 set t1=t1+1; update maclean2 set t1=t1+1 * ERROR at line 1: ORA-00060: deadlock detected while waiting for resource  Elapsed: 00:00:18.05 ksqcmi: TX,90011,4a9 mode=6 timeout=21474836 WAIT #12: nam='enq: TX - row lock contention' ela= 2930070 name|mode=1415053318 usn<<16 | slot=589841 sequence=1193 obj#=56810 tim=1308114759849120 WAIT #12: nam='enq: TX - row lock contention' ela= 2930636 name|mode=1415053318 usn<<16 | slot=589841 sequence=1193 obj#=56810 tim=1308114762779801 WAIT #12: nam='enq: TX - row lock contention' ela= 2930439 name|mode=1415053318 usn<<16 | slot=589841 sequence=1193 obj#=56810 tim=1308114765710430 *** 2012-06-12 09:58:43.089 WAIT #12: nam='enq: TX - row lock contention' ela= 2931698 name|mode=1415053318 usn<<16 | slot=589841 sequence=1193 obj#=56810 tim=1308114768642192 WAIT #12: nam='enq: TX - row lock contention' ela= 2930428 name|mode=1415053318 usn<<16 | slot=589841 sequence=1193 obj#=56810 tim=1308114771572755 WAIT #12: nam='enq: TX - row lock contention' ela= 2931408 name|mode=1415053318 usn<<16 | slot=589841 sequence=1193 obj#=56810 tim=1308114774504207 DEADLOCK DETECTED ( ORA-00060 ) [Transaction Deadlock] The following deadlock is not an ORACLE error. It is a deadlock due to user error in the design of an application or from issuing incorrect ad-hoc SQL. The following information may aid in determining the deadlock: ??????Process A?’enq: TX – row lock contention’ ?????ORA-00060 deadlock detected????3s ??? 18s , ???hidden parameter “_enqueue_deadlock_scan_secs”?????,????????0? ??????????: SQL> alter system set "_enqueue_deadlock_scan_secs"=4 scope=spfile; System altered. Elapsed: 00:00:00.01 SQL> alter system set "_enqueue_deadlock_time_sec"=9 scope=spfile; System altered. Elapsed: 00:00:00.00 SQL> startup force; ORACLE instance started. Total System Global Area 851443712 bytes Fixed Size 2100040 bytes Variable Size 738198712 bytes Database Buffers 104857600 bytes Redo Buffers 6287360 bytes Database mounted. Database opened. SQL> set linesize 140 pagesize 1400 SQL> show parameter dead NAME TYPE VALUE ------------------------------------ -------------------------------- ------------------------------ _enqueue_deadlock_scan_secs integer 4 _enqueue_deadlock_time_sec integer 9 SQL> set timing on SQL> select * from maclean1 for update wait 8; T1 ---------- 11 Elapsed: 00:00:00.01 PROCESS B SQL> select * from maclean2 for update wait 8; T1 ---------- 3 SQL> select * from maclean1 for update wait 8; select * from maclean1 for update wait 8 PROCESS A SQL> select * from maclean2 for update wait 8; select * from maclean2 for update wait 8 * ERROR at line 1: ORA-30006: resource busy; acquire with WAIT timeout expired Elapsed: 00:00:08.00 ???????? ??? select for update wait?enqueue request timeout ?????8s? ,???????”_enqueue_deadlock_scan_secs”=4(deadlock scan interval),?4s???deadlock detected,????Process A????deadlock ???, ??????? ??Process A?????8s?raised??”ORA-30006: resource busy; acquire with WAIT timeout expired”??,??ORA-00060,?????process A???????? ????????”_enqueue_deadlock_time_sec”(requests with timeout <= this will not have deadlock detection)???,?enqueue request time < “_enqueue_deadlock_time_sec”?Server process?????dead lock detection,?????????enqueue request ??????timeout??????(_enqueue_deadlock_time_sec????5,?timeout<5s),???????????????;??????timeout>”_enqueue_deadlock_time_sec”???,Oracle????????????????????? ??????????: SQL> show parameter dead NAME TYPE VALUE ------------------------------------ -------------------------------- ------------------------------ _enqueue_deadlock_scan_secs integer 4 _enqueue_deadlock_time_sec integer 9 Process A: SQL> set timing on; SQL> select * from maclean1 for update wait 10; T1 ---------- 11 Process B: SQL> select * from maclean2 for update wait 10; T1 ---------- 3 SQL> select * from maclean1 for update wait 10; PROCESS A: SQL> select * from maclean2 for update wait 10; select * from maclean2 for update wait 10 * ERROR at line 1: ORA-00060: deadlock detected while waiting for resource Elapsed: 00:00:06.02 ??????? select for update wait 10?10s??, ?? 10s?????_enqueue_deadlock_time_sec???(9s),??Process A???????? ???????????????6s ???????_enqueue_deadlock_scan_secs?4s ? ???????????,???????????_enqueue_deadlock_scan_secs?????????3???? ??: enqueue lock?????????????? 1. ?????????deadlock detection??3s????, ????????_enqueue_deadlock_scan_secs(deadlock scan interval)???,??????0,????????_enqueue_deadlock_scan_secs?????????3???, ?_enqueue_deadlock_scan_secs=0 ??3s??, ?_enqueue_deadlock_scan_secs=4??6s??,????? 2. ???????_enqueue_deadlock_time_sec(requests with timeout <= this will not have deadlock detection)???,?enqueue request timeout< _enqueue_deadlock_time_sec(????5),?Server process?????????enqueue request timeout>_enqueue_deadlock_time_sec ????_enqueue_deadlock_scan_secs???????, ??request timeout??????select for update wait [TIMEOUT]??? ??: ???10.2.0.1?????????2?hidden parameter , ???patchset 10.2.0.3????? _enqueue_deadlock_time_sec, ?patchset 10.2.0.5??????_enqueue_deadlock_scan_secs? ?????RAC???????????10s, ???????_lm_dd_interval(dd time interval in seconds) ,????????8.0.6???? ???????????????,??????,  ?10g???????60s,?11g???????10s?  ???????11g??_lm_dd_interval?????????????,?????11g??LMD????????????,??????????RAC?LMD?Deadlock Detection???????CPU,???11g?Oracle????Team???LMD????????CPU????: ????????11g?LMD???????,???????11g??? UTS TRACE ????? DD???: SQL> select * from v$version; BANNER -------------------------------------------------------------------------------- Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production PL/SQL Release 11.2.0.3.0 - Production CORE 11.2.0.3.0 Production TNS for Linux: Version 11.2.0.3.0 - Production NLSRTL Version 11.2.0.3.0 - Production SQL> SQL> select * from global_name 2 ; GLOBAL_NAME -------------------------------------------------------------------------------- www.oracledatabase12g.com SQL> alter system set "_lm_dd_interval"=20 scope=spfile; System altered. SQL> startup force; ORACLE instance started. Total System Global Area 1570009088 bytes Fixed Size 2228704 bytes Variable Size 1325403680 bytes Database Buffers 234881024 bytes Redo Buffers 7495680 bytes Database mounted. Database opened. SQL> set linesize 140 pagesize 1400 SQL> show parameter lm_dd NAME TYPE VALUE ------------------------------------ -------------------------------- ------------------------------ _lm_dd_interval integer 20 SQL> select count(*) from gv$instance; COUNT(*) ---------- 2 instance 1: SQL> oradebug setorapid 12 Oracle pid: 12, Unix process pid: 8608, image: [email protected] (LMD0) ? LMD0??? UTS TRACE??RAC???????????? SQL> oradebug event 10046 trace name context forever,level 8:10708 trace name context forever,level 103: trace[rac.*] disk high; Statement processed. Elapsed: 00:00:00.00 SQL> update maclean1 set t1=t1+1; 1 row updated. instance 2: SQL> update maclean2 set t1=t1+1; 1 row updated. SQL> update maclean1 set t1=t1+1; Instance 1: SQL> update maclean2 set t1=t1+1; update maclean2 set t1=t1+1 * ERROR at line 1: ORA-00060: deadlock detected while waiting for resource Elapsed: 00:00:20.51 LMD0???UTS TRACE 2012-06-12 22:27:00.929284 : [kjmpbmsg:process][type 22][msg 0x7fa620ac85a8][from 1][seq 8148.0][len 192] 2012-06-12 22:27:00.929346 : [kjmxmpm][type 22][seq 0.0][msg 0x7fa620ac85a8][from 1] *** 2012-06-12 22:27:00.929 * kjddind: received DDIND msg with subtype x6 * reqp->dd_master_inst_kjxmddi == 1 * kjddind: dump sgh: 2012-06-12 22:27:00.929346*: kjddind: req->timestamp [0.15], kjddt [0.13] 2012-06-12 22:27:00.929346*: >> DDmsg:KJX_DD_REMOTE,TS[0.15],Inst 1->2,ddxid[id1,id2,inst:2097153,31,1],ddlock[0x95023930,829],ddMasterInst 1 2012-06-12 22:27:00.929346*: lock [0x95023930,829], op = [mast] 2012-06-12 22:27:00.929346*: reqp->timestamp [0.15], kjddt [0.13] 2012-06-12 22:27:00.929346*: kjddind: updated local timestamp [0.15] * kjddind: case KJX_DD_REMOTE 2012-06-12 22:27:00.929346*: ADD IO NODE WFG: 0 frame pointer 2012-06-12 22:27:00.929346*: PUSH: type=res, enqueue(0xffffffff.0xffffffff)=0xbbb9af40, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: PROCESS: type=res, enqueue(0xffffffff.0xffffffff)=0xbbb9af40, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: POP: type=res, enqueue(0xffffffff.0xffffffff)=0xbbb9af40, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: kjddopr[TX 0xe000c.0x32][ext 0x5,0x0]: blocking lock 0xbbb9a800, owner 2097154 of inst 2 2012-06-12 22:27:00.929346*: PUSH: type=txn, enqueue(0xffffffff.0xffffffff)=0xbbb9a800, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: PROCESS: type=txn, enqueue(0xffffffff.0xffffffff)=0xbbb9a800, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: ADD NODE TO WFG: type=txn, enqueue(0xffffffff.0xffffffff)=0xbbb9a800, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: POP: type=txn, enqueue(0xffffffff.0xffffffff)=0xbbb9a800, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: kjddopt: converting lock 0xbbce92f8 on 'TX' 0x80016.0x5d4,txid [2097154,34]of inst 2 2012-06-12 22:27:00.929346*: PUSH: type=res, enqueue(0xffffffff.0xffffffff)=0xbbce92f8, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: PROCESS: type=res, enqueue(0xffffffff.0xffffffff)=0xbbce92f8, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: ADD NODE TO WFG: type=res, enqueue(0xffffffff.0xffffffff)=0xbbce92f8, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929855 : GSIPC:AMBUF: rcv buff 0x7fa620aa8cd8, pool rcvbuf, rqlen 1102 2012-06-12 22:27:00.929878 : GSIPC:GPBMSG: new bmsg 0x7fa620aa8d48 mb 0x7fa620aa8cd8 msg 0x7fa620aa8d68 mlen 192 dest x100 flushsz -1 2012-06-12 22:27:00.929878*: << DDmsg:KJX_DD_REMOTE,TS[0.15],Inst 2->1,ddxid[id1,id2,inst:2097153,31,1],ddlock[0x95023930,829],ddMasterInst 1 2012-06-12 22:27:00.929878*: lock [0xbbce92f8,287], op = [mast] 2012-06-12 22:27:00.929878*: ADD IO NODE WFG: 0 frame pointer 2012-06-12 22:27:00.929923 : [kjmpbmsg:compl][msg 0x7fa620ac8588][typ p][nmsgs 1][qtime 0][ptime 0] 2012-06-12 22:27:00.929947 : GSIPC:PBAT: flush start. flag 0x79 end 0 inc 4.4 2012-06-12 22:27:00.929963 : GSIPC:PBAT: send bmsg 0x7fa620aa8d48 blen 224 dest 1.0 2012-06-12 22:27:00.929979 : GSIPC:SNDQ: enq msg 0x7fa620aa8d48, type 65521 seq 8325, inst 1, receiver 0, queued 1 012-06-12 22:27:00.929979 : GSIPC:SNDQ: enq msg 0x7fa620aa8d48, type 65521 seq 8325, inst 1, receiver 0, queued 1 2012-06-12 22:27:00.929996 : GSIPC:BSEND: flushing sndq 0xb491dd28, id 0, dcx 0xbc517770, inst 1, rcvr 0 qlen 0 1 2012-06-12 22:27:00.930014 : GSIPC:BSEND: no batch1 msg 0x7fa620aa8d48 type 65521 len 224 dest (1:0) 2012-06-12 22:27:00.930088 : kjbsentscn[0x0.3f72dc][to 1] 2012-06-12 22:27:00.930144 : GSIPC:SENDM: send msg 0x7fa620aa8d48 dest x10000 seq 8325 type 65521 tkts x1 mlen xe00110 2012-06-12 22:27:00.930531 : GSIPC:KSXPCB: msg 0x7fa620aa8d48 status 30, type 65521, dest 1, rcvr 0 WAIT #0: nam='ges remote message' ela= 1372 waittime=80 loop=0 p3=74 obj#=-1 tim=1339554420931640 2012-06-12 22:27:00.931728 : GSIPC:RCVD: ksxp msg 0x7fa620af6490 sndr 1 seq 0.8149 type 65521 tkts 1 2012-06-12 22:27:00.931746 : GSIPC:RCVD: watq msg 0x7fa620af6490 sndr 1, seq 8149, type 65521, tkts 1 2012-06-12 22:27:00.931763 : GSIPC:RCVD: seq update (0.8148)->(0.8149) tp -15 fg 0x4 from 1 pbattr 0x0 2012-06-12 22:27:00.931779 : GSIPC:TKT: collect msg 0x7fa620af6490 from 1 for rcvr 0, tickets 1 2012-06-12 22:27:00.931794 : kjbrcvdscn[0x0.3f72dc][from 1][idx 2012-06-12 22:27:00.931810 : kjbrcvdscn[no bscn dd_master_inst_kjxmddi == 1 * kjddind: dump sgh: NXTIN (nil) 0 wq 0 cvtops x0 0x0.0x0(ext 0x0,0x0)[0000-0000-00000000] inst 1 BLOCKER 0xbbb9a800 5 wq 1 cvtops x28 TX 0xe000c.0x32(ext 0x5,0x0)[20000-0002-00000022] inst 2 BLOCKED 0xbbce92f8 5 wq 2 cvtops x1 TX 0x80016.0x5d4(ext 0x2,0x0)[20000-0002-00000022] inst 2 NXTOUT (nil) 0 wq 0 cvtops x0 0x0.0x0(ext 0x0,0x0)[0000-0000-00000000] inst 1 2012-06-12 22:27:00.932058*: kjddind: req->timestamp [0.15], kjddt [0.15] 2012-06-12 22:27:00.932058*: >> DDmsg:KJX_DD_VALIDATE,TS[0.15],Inst 1->2,ddxid[id1,id2,inst:2097153,31,1],ddlock[0x95023930,829],ddMasterInst 1 2012-06-12 22:27:00.932058*: lock [(nil),0], op = [vald_dd] 2012-06-12 22:27:00.932058*: kjddind: updated local timestamp [0.15] * kjddind: case KJX_DD_VALIDATE *** 2012-06-12 22:27:00.932 * kjddvald called: kjxmddi stuff: * cont_lockp (nil) * dd_lockp 0x95023930 * dd_inst 1 * dd_master_inst 1 * sgh graph: NXTIN (nil) 0 wq 0 cvtops x0 0x0.0x0(ext 0x0,0x0)[0000-0000-00000000] inst 1 BLOCKER 0xbbb9a800 5 wq 1 cvtops x28 TX 0xe000c.0x32(ext 0x5,0x0)[20000-0002-00000022] inst 2 BLOCKED 0xbbce92f8 5 wq 2 cvtops x1 TX 0x80016.0x5d4(ext 0x2,0x0)[20000-0002-00000022] inst 2 NXTOUT (nil) 0 wq 0 cvtops x0 0x0.0x0(ext 0x0,0x0)[0000-0000-00000000] inst 1 POP WFG NODE: lock=(nil) * kjddvald: dump the PRQ: BLOCKER 0xbbb9a800 5 wq 1 cvtops x28 TX 0xe000c.0x32(ext 0x5,0x0)[20000-0002-00000022] inst 2 BLOCKED 0xbbce92f8 5 wq 2 cvtops x1 TX 0x80016.0x5d4(ext 0x2,0x0)[20000-0002-00000022] inst 2 * kjddvald: KJDD_NXTONOD ->node_kjddsg.dinst_kjddnd =1 * kjddvald: ... which is not my node, my subgraph is validated but the cycle is not complete Global blockers dump start:--------------------------------- DUMP LOCAL BLOCKER/HOLDER: block level 5 res [0x80016][0x5d4],[TX][ext 0x2,0x0] ??dead lock!!! ???????11.2.0.3???? RAC LMD???????????”_lm_dd_interval”????????????20s?  ???????10g?_lm_dd_interval???60s,??????Processes?????????????????,????????????Server Process????????60s??????11g?????(??????LMD???????)???????,???????????10s??? Enqueue Deadlock Detection? ?11g??? RAC?LMD???????hidden parameter ????”_lm_dd_interval”???,RAC????????????????,???????????: SQL> col name for a50 SQL> col describ for a60 SQL> col value for a20 SQL> set linesize 140 pagesize 1400 SQL> SELECT x.ksppinm NAME, y.ksppstvl VALUE, x.ksppdesc describ 2 FROM SYS.x$ksppi x, SYS.x$ksppcv y 3 WHERE x.inst_id = USERENV ('Instance') 4 AND y.inst_id = USERENV ('Instance') 5 AND x.indx = y.indx 6 AND x.ksppinm like '_lm_dd%'; NAME VALUE DESCRIB -------------------------------------------------- -------------------- ------------------------------------------------------------ _lm_dd_interval 20 dd time interval in seconds _lm_dd_scan_interval 5 dd scan interval in seconds _lm_dd_search_cnt 3 number of dd search per token get _lm_dd_max_search_time 180 max dd search time per token _lm_dd_maxdump 50 max number of locks to be dumped during dd validation _lm_dd_ignore_nodd FALSE if TRUE nodeadlockwait/nodeadlockblock options are ignored 6 rows selected.

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  • .NET Code Evolution

    - by Alois Kraus
    Originally posted on: http://geekswithblogs.net/akraus1/archive/2013/07/24/153504.aspxAt my day job I do look at a lot of code written by other people. Most of the code is quite good and some is even a masterpiece. And there is also code which makes you think WTF… oh it was written by me. Hm not so bad after all. There are many excuses reasons for bad code. Most often it is time pressure followed by not enough ambition (who cares) or insufficient training. Normally I do care about code quality quite a lot which makes me a (perceived) slow worker who does write many tests and refines the code quite a lot because of the design deficiencies. Most of the deficiencies I do find by putting my design under stress while checking for invariants. It does also help a lot to step into the code with a debugger (sometimes also Windbg). I do this much more often when my tests are red. That way I do get a much better understanding what my code really does and not what I think it should be doing. This time I do want to show you how code can evolve over the years with different .NET Framework versions. Once there was  time where .NET 1.1 was new and many C++ programmers did switch over to get rid of not initialized pointers and memory leaks. There were also nice new data structures available such as the Hashtable which is fast lookup table with O(1) time complexity. All was good and much code was written since then. At 2005 a new version of the .NET Framework did arrive which did bring many new things like generics and new data structures. The “old” fashioned way of Hashtable were coming to an end and everyone used the new Dictionary<xx,xx> type instead which was type safe and faster because the object to type conversion (aka boxing) was no longer necessary. I think 95% of all Hashtables and dictionaries use string as key. Often it is convenient to ignore casing to make it easy to look up values which the user did enter. An often followed route is to convert the string to upper case before putting it into the Hashtable. Hashtable Table = new Hashtable(); void Add(string key, string value) { Table.Add(key.ToUpper(), value); } This is valid and working code but it has problems. First we can pass to the Hashtable a custom IEqualityComparer to do the string matching case insensitive. Second we can switch over to the now also old Dictionary type to become a little faster and we can keep the the original keys (not upper cased) in the dictionary. Dictionary<string, string> DictTable = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase); void AddDict(string key, string value) { DictTable.Add(key, value); } Many people do not user the other ctors of Dictionary because they do shy away from the overhead of writing their own comparer. They do not know that .NET has for strings already predefined comparers at hand which you can directly use. Today in the many core area we do use threads all over the place. Sometimes things break in subtle ways but most of the time it is sufficient to place a lock around the offender. Threading has become so mainstream that it may sound weird that in the year 2000 some guy got a huge incentive for the idea to reduce the time to process calibration data from 12 hours to 6 hours by using two threads on a dual core machine. Threading does make it easy to become faster at the expense of correctness. Correct and scalable multithreading can be arbitrarily hard to achieve depending on the problem you are trying to solve. Lets suppose we want to process millions of items with two threads and count the processed items processed by all threads. A typical beginners code might look like this: int Counter; void IJustLearnedToUseThreads() { var t1 = new Thread(ThreadWorkMethod); t1.Start(); var t2 = new Thread(ThreadWorkMethod); t2.Start(); t1.Join(); t2.Join(); if (Counter != 2 * Increments) throw new Exception("Hmm " + Counter + " != " + 2 * Increments); } const int Increments = 10 * 1000 * 1000; void ThreadWorkMethod() { for (int i = 0; i < Increments; i++) { Counter++; } } It does throw an exception with the message e.g. “Hmm 10.222.287 != 20.000.000” and does never finish. The code does fail because the assumption that Counter++ is an atomic operation is wrong. The ++ operator is just a shortcut for Counter = Counter + 1 This does involve reading the counter from a memory location into the CPU, incrementing value on the CPU and writing the new value back to the memory location. When we do look at the generated assembly code we will see only inc dword ptr [ecx+10h] which is only one instruction. Yes it is one instruction but it is not atomic. All modern CPUs have several layers of caches (L1,L2,L3) which try to hide the fact how slow actual main memory accesses are. Since cache is just another word for redundant copy it can happen that one CPU does read a value from main memory into the cache, modifies it and write it back to the main memory. The problem is that at least the L1 cache is not shared between CPUs so it can happen that one CPU does make changes to values which did change in meantime in the main memory. From the exception you can see we did increment the value 20 million times but half of the changes were lost because we did overwrite the already changed value from the other thread. This is a very common case and people do learn to protect their  data with proper locking.   void Intermediate() { var time = Stopwatch.StartNew(); Action acc = ThreadWorkMethod_Intermediate; var ar1 = acc.BeginInvoke(null, null); var ar2 = acc.BeginInvoke(null, null); ar1.AsyncWaitHandle.WaitOne(); ar2.AsyncWaitHandle.WaitOne(); if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Intermediate did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Intermediate() { for (int i = 0; i < Increments; i++) { lock (this) { Counter++; } } } This is better and does use the .NET Threadpool to get rid of manual thread management. It does give the expected result but it can result in deadlocks because you do lock on this. This is in general a bad idea since it can lead to deadlocks when other threads use your class instance as lock object. It is therefore recommended to create a private object as lock object to ensure that nobody else can lock your lock object. When you read more about threading you will read about lock free algorithms. They are nice and can improve performance quite a lot but you need to pay close attention to the CLR memory model. It does make quite weak guarantees in general but it can still work because your CPU architecture does give you more invariants than the CLR memory model. For a simple counter there is an easy lock free alternative present with the Interlocked class in .NET. As a general rule you should not try to write lock free algos since most likely you will fail to get it right on all CPU architectures. void Experienced() { var time = Stopwatch.StartNew(); Task t1 = Task.Factory.StartNew(ThreadWorkMethod_Experienced); Task t2 = Task.Factory.StartNew(ThreadWorkMethod_Experienced); t1.Wait(); t2.Wait(); if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Experienced did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Experienced() { for (int i = 0; i < Increments; i++) { Interlocked.Increment(ref Counter); } } Since time does move forward we do not use threads explicitly anymore but the much nicer Task abstraction which was introduced with .NET 4 at 2010. It is educational to look at the generated assembly code. The Interlocked.Increment method must be called which does wondrous things right? Lets see: lock inc dword ptr [eax] The first thing to note that there is no method call at all. Why? Because the JIT compiler does know very well about CPU intrinsic functions. Atomic operations which do lock the memory bus to prevent other processors to read stale values are such things. Second: This is the same increment call prefixed with a lock instruction. The only reason for the existence of the Interlocked class is that the JIT compiler can compile it to the matching CPU intrinsic functions which can not only increment by one but can also do an add, exchange and a combined compare and exchange operation. But be warned that the correct usage of its methods can be tricky. If you try to be clever and look a the generated IL code and try to reason about its efficiency you will fail. Only the generated machine code counts. Is this the best code we can write? Perhaps. It is nice and clean. But can we make it any faster? Lets see how good we are doing currently. Level Time in s IJustLearnedToUseThreads Flawed Code Intermediate 1,5 (lock) Experienced 0,3 (Interlocked.Increment) Master 0,1 (1,0 for int[2]) That lock free thing is really a nice thing. But if you read more about CPU cache, cache coherency, false sharing you can do even better. int[] Counters = new int[12]; // Cache line size is 64 bytes on my machine with an 8 way associative cache try for yourself e.g. 64 on more modern CPUs void Master() { var time = Stopwatch.StartNew(); Task t1 = Task.Factory.StartNew(ThreadWorkMethod_Master, 0); Task t2 = Task.Factory.StartNew(ThreadWorkMethod_Master, Counters.Length - 1); t1.Wait(); t2.Wait(); Counter = Counters[0] + Counters[Counters.Length - 1]; if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Master did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Master(object number) { int index = (int) number; for (int i = 0; i < Increments; i++) { Counters[index]++; } } The key insight here is to use for each core its own value. But if you simply use simply an integer array of two items, one for each core and add the items at the end you will be much slower than the lock free version (factor 3). Each CPU core has its own cache line size which is something in the range of 16-256 bytes. When you do access a value from one location the CPU does not only fetch one value from main memory but a complete cache line (e.g. 16 bytes). This means that you do not pay for the next 15 bytes when you access them. This can lead to dramatic performance improvements and non obvious code which is faster although it does have many more memory reads than another algorithm. So what have we done here? We have started with correct code but it was lacking knowledge how to use the .NET Base Class Libraries optimally. Then we did try to get fancy and used threads for the first time and failed. Our next try was better but it still had non obvious issues (lock object exposed to the outside). Knowledge has increased further and we have found a lock free version of our counter which is a nice and clean way which is a perfectly valid solution. The last example is only here to show you how you can get most out of threading by paying close attention to your used data structures and CPU cache coherency. Although we are working in a virtual execution environment in a high level language with automatic memory management it does pay off to know the details down to the assembly level. Only if you continue to learn and to dig deeper you can come up with solutions no one else was even considering. I have studied particle physics which does help at the digging deeper part. Have you ever tried to solve Quantum Chromodynamics equations? Compared to that the rest must be easy ;-). Although I am no longer working in the Science field I take pride in discovering non obvious things. This can be a very hard to find bug or a new way to restructure data to make something 10 times faster. Now I need to get some sleep ….

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  • How to populate a drop down list in Spring MVC

    - by GigaPr
    Hi, would like to populate a drop down list on a jsp page i have my page that looks like <form:form method="POST" action="addRss.htm" commandName="addNewRss" cssClass="addUserForm"> <div class="floatL"> <div class="padding5"> <div class="fieldContainer"> <strong>Title:</strong>&nbsp; </div> <form:errors path="title" cssClass="error"/> <form:input path="title" cssClass="textArea" /> </div> <div class="padding5"> <div class="fieldContainer"> <strong>Description:</strong>&nbsp; </div> <form:errors path="description" cssClass="error"/> <form:input path="description" cssClass="textArea" /> </div> <div class="padding5"> <div class="fieldContainer"> <strong>Language:</strong>&nbsp; </div> <form:errors path="language" cssClass="error"/> <form:select path="language" cssClass="textArea" /> </div> </div> <div class="floatR"> <div class="padding5"> <div class="fieldContainer"> <strong>Link:</strong>&nbsp; </div> <form:errors path="link" cssClass="error"/> <form:input path="link" cssClass="textArea" /> </div> <div class="padding5"> <div class="fieldContainer"> <strong>Url:</strong>&nbsp; </div> <form:errors path="url" cssClass="error"/> <form:input path="url" cssClass="textArea" /> </div> <div class="padding5"> <div class="fieldContainer"> <strong>Url</strong>&nbsp; </div> <form:errors path="url" cssClass="error"/> <form:input path="url" cssClass="textArea" /> </div> </div> <input type="submit" class="floatR" value="Add New Rss"> </form:form> and my controller public class AddRssController extends BaseController { private static final String[] LANGUAGES = { "AL", "AK", "AZ", "AR", "CA", "CO", "CT", "DE", "DC", "FL", "GA", "HI", "ID", "IL", "IN", "IA", "KS", "KY", "LA", "ME", "MD", "MA", "MI", "MN", "MS", "MO", "MT", "NE", "NV", "NH", "NJ", "NM", "NY", "NC", "ND", "OH", "OK", "OR", "PA", "RI", "SC", "SD", "TN", "TX", "UT", "VA", "VT", "WA", "WV", "WI", "WY" }; public AddRssController() { setCommandClass(RSS.class); setCommandName("addNewRss"); } @Override protected Object formBackingObject(HttpServletRequest request) throws Exception { RSS rantForm = (RSS) super.formBackingObject(request); // rantForm.setVehicle(new Vehicle()); return rantForm; } @Override protected Map referenceData(HttpServletRequest request) throws Exception { Map referenceData = new HashMap(); referenceData.put("language", LANGUAGES); return referenceData; } @Override protected ModelAndView onSubmit(Object command, BindException bindException) throws Exception { RSS rss = (RSS) command; rssServiceImplementation.add(rss); return new ModelAndView(getSuccessView()); } } and my BaseController public class BaseController extends SimpleFormController implements Controller { public UserServiceImplementation userServiceImplementation; public UserServiceImplementation getUserServiceImplementation() { return userServiceImplementation; } public void setUserServiceImplementation(UserServiceImplementation userServiceImplementation) { this.userServiceImplementation = userServiceImplementation; } public RssServiceImplementation rssServiceImplementation; public RssServiceImplementation getRssServiceImplementation() { return rssServiceImplementation; } public void setRssServiceImplementation(RssServiceImplementation rssServiceImplementation) { this.rssServiceImplementation = rssServiceImplementation; } } But it doesn t work Any suggestion?

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  • Utility that helps in file locking - expert tips wanted

    - by maix
    I've written a subclass of file that a) provides methods to conveniently lock it (using fcntl, so it only supports unix, which is however OK for me atm) and b) when reading or writing asserts that the file is appropriately locked. Now I'm not an expert at such stuff (I've just read one paper [de] about it) and would appreciate some feedback: Is it secure, are there race conditions, are there other things that could be done better … Here is the code: from fcntl import flock, LOCK_EX, LOCK_SH, LOCK_UN, LOCK_NB class LockedFile(file): """ A wrapper around `file` providing locking. Requires a shared lock to read and a exclusive lock to write. Main differences: * Additional methods: lock_ex, lock_sh, unlock * Refuse to read when not locked, refuse to write when not locked exclusivly. * mode cannot be `w` since then the file would be truncated before it could be locked. You have to lock the file yourself, it won't be done for you implicitly. Only you know what lock you need. Example usage:: def get_config(): f = LockedFile(CONFIG_FILENAME, 'r') f.lock_sh() config = parse_ini(f.read()) f.close() def set_config(key, value): f = LockedFile(CONFIG_FILENAME, 'r+') f.lock_ex() config = parse_ini(f.read()) config[key] = value f.truncate() f.write(make_ini(config)) f.close() """ def __init__(self, name, mode='r', *args, **kwargs): if 'w' in mode: raise ValueError('Cannot open file in `w` mode') super(LockedFile, self).__init__(name, mode, *args, **kwargs) self.locked = None def lock_sh(self, **kwargs): """ Acquire a shared lock on the file. If the file is already locked exclusively, do nothing. :returns: Lock status from before the call (one of 'sh', 'ex', None). :param nonblocking: Don't wait for the lock to be available. """ if self.locked == 'ex': return # would implicitly remove the exclusive lock return self._lock(LOCK_SH, **kwargs) def lock_ex(self, **kwargs): """ Acquire an exclusive lock on the file. :returns: Lock status from before the call (one of 'sh', 'ex', None). :param nonblocking: Don't wait for the lock to be available. """ return self._lock(LOCK_EX, **kwargs) def unlock(self): """ Release all locks on the file. Flushes if there was an exclusive lock. :returns: Lock status from before the call (one of 'sh', 'ex', None). """ if self.locked == 'ex': self.flush() return self._lock(LOCK_UN) def _lock(self, mode, nonblocking=False): flock(self, mode | bool(nonblocking) * LOCK_NB) before = self.locked self.locked = {LOCK_SH: 'sh', LOCK_EX: 'ex', LOCK_UN: None}[mode] return before def _assert_read_lock(self): assert self.locked, "File is not locked" def _assert_write_lock(self): assert self.locked == 'ex', "File is not locked exclusively" def read(self, *args): self._assert_read_lock() return super(LockedFile, self).read(*args) def readline(self, *args): self._assert_read_lock() return super(LockedFile, self).readline(*args) def readlines(self, *args): self._assert_read_lock() return super(LockedFile, self).readlines(*args) def xreadlines(self, *args): self._assert_read_lock() return super(LockedFile, self).xreadlines(*args) def __iter__(self): self._assert_read_lock() return super(LockedFile, self).__iter__() def next(self): self._assert_read_lock() return super(LockedFile, self).next() def write(self, *args): self._assert_write_lock() return super(LockedFile, self).write(*args) def writelines(self, *args): self._assert_write_lock() return super(LockedFile, self).writelines(*args) def flush(self): self._assert_write_lock() return super(LockedFile, self).flush() def truncate(self, *args): self._assert_write_lock() return super(LockedFile, self).truncate(*args) def close(self): self.unlock() return super(LockedFile, self).close() (the example in the docstring is also my current use case for this) Thanks for having read until down here, and possibly even answering :)

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  • Drop down menus and pathetic art of styling

    - by fmz
    Sorry folks, I must be brain-dead or something but I can't get the styling on these drop-down menus to cooperate. I have the color and the font right, but I have unwanted spaces between the list elements and the a and the a:hover sizes should be the same. I would appreciate some help getting this to work correctly. Here is the page Here is the html: <ul class="dropdown"> <li><a href="#" id="home">Home</a></li> <li><a href="#" id="about">About Us</a> <ul class="sub-menu"> <li><a href="#">Our History</a></li> <li><a href="#">Our Process</a></li> <li><a href="#">Portfolio</a></li> <li><a href="#">Financing</a></li> <li><a href="#">Testimonials</a></li> <li><a href="#">Subcontractors</a></li> </ul> </li> <li><a href="#" id="personal">Personal Banking</a></li> <li><a href="#" id="commercial">Commercial Banking</a></li> <li><a href="#" id="service">Customer Service</a> <ul class="sub-menu"> <li><a href="#">Our History</a></li> <li><a href="#">Our Process</a></li> <li><a href="#">Portfolio</a></li> <li><a href="#">Financing</a></li> <li><a href="#">Testimonials</a></li> <li><a href="#">Subcontractors</a></li> </ul> </li> <li><a href="#" id="investors">Investor Relations</a></li> <li><a href="#" id="contact">Contact Us</a></li> Here is the CSS: ul.dropdown { position: relative; background: #4e8997; height: 40px; padding-left: 5px; } ul.dropdown li { float: left; zoom: 1; } ul.dropdown li a ul.dropdown li a:visited { display: block; margin-top: 5px; padding: .5em .6em; line-height: 16px; color: #fff; font: bold 14px "Helvetica Neue", Arial, Helvetica, Geneva, sans-serif; text-transform: uppercase; border: none; } ul.dropdown a:hover { background-color: #c29c5d; color: #fff; } ul.dropdown a:active { background-color: #c29c5d; color: #fff; } /* LEVEL TWO */ ul.dropdown ul { padding-left: 0; width: 200px; display: none; top:36px; margin-left: 0; position: absolute; } ul.dropdown ul li { font: 10px "Helvetica Neue", Arial, Helvetica, Geneva, sans-serif; border-bottom: 1px solid #ccc; display: block; margin: 0; padding: 0; float: none; color: #fff; background-color: #c29c5d; } ul.dropdown ul li a:link { display: block; font-size: 10px; width: 188px; height: 16px; } ul.dropdown ul li a:hover { background-color: #a2834d; color: #fff; } Thanks!

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  • php drop down how to control the hide and show

    - by user329394
    Hi all, i want to control the drop down box to control show or hide statement. I do like this but it seems it doesn't work, i have it working if im using radio button. can help me with the code? which part am i wrong? thank you. $dbcnx = mysql_connect('localhost', 'root', ''); mysql_select_db('dbase'); if($_POST['gred'])$gred=$_POST['gred'];else $gred=""; <script language="JavaScript"> function funcHide(elemHide1,elemHide2,elemHide3) { document.getElementById(elemHide1).style.display = 'none'; document.getElementById(elemHide2).style.display = 'none'; document.getElementById(elemHide3).style.display = 'none'; document.getElementById(elemShow).style.visibility = 'visible'; } function funcShow(elemShow1,elemShow2,elemShow3) { document.getElementById(elemShow1).style.display = 'block'; document.getElementById(elemShow2).style.display = 'block'; document.getElementById(elemShow3).style.display = 'block'; document.getElementById(elemShow1).style.visibility = 'visible'; document.getElementById(elemShow2).style.visibility = 'visible'; document.getElementById(elemShow3).style.visibility = 'visible'; } </script> <table> <tr> <td>Gred </td> <td>:</td> <td><select name="gred" id="gred"> <option value="">&nbsp;</option> <option value="A17" <?php if($gred=='A17')echo "selected";?> onClick="funcShow('box1', 'box2', 'box3');">A17</option> <option value="A22" <?php if($gred=='A22')echo "selected";?>>A22</option> <option value="A27" <?php if($gred=='A27')echo "selected";?>>A27</option> </select> </td> </tr> <tr> <td>TK</td> <td>:</td> <td> <select name="tk" id="tk"> <option value="">&nbsp;</option> <option value="01" <?php if($tk=='01')echo "selected";?>>01</option> <option value="02" <?php if($tk=='02')echo "selected";?>>02</option> <option value="03" <?php if($tk=='03')echo "selected";?>>03</option> <option value="04" <?php if($tk=='04')echo "selected";?>>04</option> <option value="05" <?php if($tk=='05')echo "selected";?>>05</option> <option value="06" <?php if($tk=='06')echo "selected";?>>06</option> </select> <?} ?> </td> </tr> <tr> <td colspan="2" valign="top">Status</td> <td valign="top">:</td> <td> <?php $qry = "SELECT * from dtable where userid='".$USER->id."'"; $sql = mysql_query($qry); $row = mysql_num_rows($sql); if($row==0) { ?> <input type=radio name="status" <?php if($status=='retake') {?>checked="checked"<?php } ?> value="retake" onClick="funcShow('box1', 'box2', 'box3');">Retake<br /></tr> <tr> <td colspan='2'> <div id="box1" style="display: none;">Last Date <br> Latest Date<br> </div></td> <td><div id="box2" style="display: none;">: <br> : <br></div></td> <td> <div id="box3" style="display: none;"> <?php $rsu[lastdate] ?> <br> <?php $rsu[latestdate] ?> </div> </td>

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  • What approaches exist to setting up continent/country/city drop down menus?

    - by Dave
    How easy (or difficult) is it to have a Continent/Country/City drop down menu? Where one select from Drop Down Menus (for example): 1 - Europe 2 - UK 3 - London and then writes the Province/Area (for example: Essex). Realistically, how long should it take an experienced web developer to write the code of the above, as well as to link this selection to a Browse function and database storing? I do not have a geographical database yet and I am wondering what the fastest and cheapest way to add it to the drop down menu is. Is there any way to get that geographical database for free? I can see this type of geographical drop down menu in thousands of websites, but I am struggling as to how to implement it ASAP. Follow Up: Tks All x your answers and comments so far. I hear what you are saying. I understand that there are rare occasions of Countries with multiple (same) name Cities and that it might be disputable whether a Country belongs to a certain Continent/Region or not (see Russia x example, Europe or Asia?). Anyway, please take a look, for instance, at this website Sign UP screen http://www.couchsurfing.org/register.html My question then is: Where do I get that list (Country/Cities) and how do I create that _array? Manually copying it somewhere else (which would take me ages) or are there ready made lists that can be downloaded from somewhere for free?

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  • Cheap dvr media server

    - by Tester101
    I would like to build a new computer to be used as a DVR and media server. I am thinking of using mythtv as the DVR software, but short of that decision I am completely open to suggestions. Requirements: Must be cheap. Must have low power consumption (since it will always be on). Should be quiet. Should be small. I'm really not sure where to start with this project, and am open to any hardware/software suggestions. Is it possible to build a small quiet and cheap system? *Keep in mind I am working on this project because I am tired of Cable rate increases, but I can't imagine living without a DVR so cost is very important and I would like the system to be sub $200.00. The system also needs to handle the new digital broadcast system. Thanks for the help,

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  • What is the actual difference between Computer Programmers and Software Engineers? Is this description accurate?

    - by Ari
    According to the Bureau of Labor Statistics, this is the difference: Computer programmers write programs. After computer software engineers and systems analysts design software programs, the programmer converts that design into a logical series of instructions that the computer can follow They predict employment to increase for software engineers by 34% but to decline for programmers. Is there actually any such real distinction between the 2 jobs? How can one get a job designing programs (to be implemented by others)?

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  • Power supply triggered to start by another power supply

    - by steampowered
    I am building a raid array in a separate enclosure. I will be putting an empty tower case next to an existing tower computer, and this second tower case will only hold hard drives. There are many solutions for connecting the drives in the second case to the raid card in the first case (SFF-8088 and SFF-8087 cables). But I prefer not to run power from the first case to the second case. Can I use a power supply in the first tower case and cause it to start the power supply in the second case based on an indication from power in the first tower case's power supply? Maybe run a 12 volt cable from the first case to the power supply on the second case only for the purpose of initiating the second power supply.

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  • Macbook Pro 2.66 GHz vs. 2.8 GHz

    - by nevan
    Is there much advantage in getting the higher end Macbook Pro compared to the mid-range one? The differences between the two are: 2.66 GHz vs. 2.8 GHz 256 MB graphics memory vs. 512 MB 3 MB L2 cache vs. 6 MB 320 GB hard drive vs. 500 GB $2000 vs. $2300 I've looked around, but I can't find any direct comparisons for the two machines. I'd be using the machine for development. I generally use a computer for 3 years. I don't really play games, but do use Photoshop regularly. I've heard that once Snow Leopard arrives, the graphics chip will be used to boost the main processor, so I was wondering if getting the one with more graphics memory would be an advantage?

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  • If I split my harddrive, will a system restore delete it?

    - by AoiHana
    I split my 1TB HD from C drive and called it A. I put some files there to back up. I have now come to a point where I need to run a system restore with the discs that came with my computer. If I do a system restore and wipe C drive clean, will I lose the part of the hard drive that I split or will it remain intact and my files uncorrupted? This is a partition I created with windows myself, and dragged files over to it. Thanks!

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  • Why would Copying a Large Image to the Clipboard Freeze a Computer?

    - by Akemi Iwaya
    Sometimes, something really odd happens when using our computers that makes no sense at all…such as copying a simple image to the clipboard and the computer freezing up because of it. An image is an image, right? Today’s SuperUser post has the answer to a puzzled reader’s dilemna. Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites. Original image courtesy of Wikimedia. The Question SuperUser reader Joban Dhillon wants to know why copying an image to the clipboard on his computer freezes it up: I was messing around with some height map images and found this one: (http://upload.wikimedia.org/wikipedia/commons/1/15/Srtm_ramp2.world.21600×10800.jpg) The image is 21,600*10,800 pixels in size. When I right click and select “Copy Image” in my browser (I am using Google Chrome), it slows down my computer until it freezes. After that I must restart. I am curious about why this happens. I presume it is the size of the image, although it is only about 6 MB when saved to my computer. I am also using Windows 8.1 Why would a simple image freeze Joban’s computer up after copying it to the clipboard? The Answer SuperUser contributor Mokubai has the answer for us: “Copy Image” is copying the raw image data, rather than the image file itself, to your clipboard. The raw image data will be 21,600 x 10,800 x 3 (24 bit image) = 699,840,000 bytes of data. That is approximately 700 MB of data your browser is trying to copy to the clipboard. JPEG compresses the raw data using a lossy algorithm and can get pretty good compression. Hence the compressed file is only 6 MB. The reason it makes your computer slow is that it is probably filling your memory up with at least the 700 MB of image data that your browser is using to show you the image, another 700 MB (along with whatever overhead the clipboard incurs) to store it on the clipboard, and a not insignificant amount of processing power to convert the image into a format that can be stored on the clipboard. Chances are that if you have less than 4 GB of physical RAM, then those copies of the image data are forcing your computer to page memory out to the swap file in an attempt to fulfil both memory demands at the same time. This will cause programs and disk access to be sluggish as they use the disk and try to use the data that may have just been paged out. In short: Do not use the clipboard for huge images unless you have a lot of memory and a bit of time to spare. Like pretty graphs? This is what happens when I load that image in Google Chrome, then copy it to the clipboard on my machine with 12 GB of RAM: It starts off at the lower point using 2.8 GB of RAM, loading the image punches it up to 3.6 GB (approximately the 700 MB), then copying it to the clipboard spikes way up there at 6.3 GB of RAM before settling back down at the 4.5-ish you would expect to see for a program and two copies of a rather large image. That is a whopping 3.7 GB of image data being worked on at the peak, which is probably the initial image, a reserved quantity for the clipboard, and perhaps a couple of conversion buffers. That is enough to bring any machine with less than 8 GB of RAM to its knees. Strangely, doing the same thing in Firefox just copies the image file rather than the image data (without the scary memory surge). Have something to add to the explanation? Sound off in the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.

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  • What programming languages should every computer science student be taught?

    - by Anto
    What languages (or classes (as in paradigms) of programming languages, plus a recommended language of that class) should every computer science student be taught in college according to you? Motivate your answers; why that language? What use will one have from it? What concepts does it teach (better than language X does)? Note/clarification: This question is about computer science with heavy focus on software engineering, not pure computer science. It is still computer science education and not software engineering education which is the focus.

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  • How can I force X to start in a computer without a monitor?

    - by Javier Rivera
    I have I computer that have no monitor attached. When I boot it X fails to start because there is no monitor detected. If I boot it with a monitor attached and after X is started I remove the monitor everything works fine. Details and Background: This computer is a kind of hardware consolidation server. It's only purpose is to run two Virtual Box VM's that run Windows XP and some important but seldom used (once or twice a month) programs. For a couple of time it has been lying in a corner with an old monitor attached to it and working great. But space in the office was getting scarce and I moved the computer to the server room. There is no monitor attached to it there (no space), and sometimes the computer is rebooted. When it boots without monitor X is not started, the vms don't start and I get called to solve the problem.

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