Featured post

c# - Usage of Server Side Controls in MVC Frame work -

-
i using asp.net 4.0 , mvc 2.0 web application. project requiremrnt have use server side control in application not possibl in noraml case. ideally want use adrotator control , datalist control. i saw few samples , references in codepleax mvc controllib howwver found less useful. can tell how utilize theese controls in asp.net application along mvc. note: please provide functionalities related adrotator , datalist controls not equivalent functionalities thanks in advace. mvc pages not use normal .net solution makes use of normal .net components impossible. a normal .net page use event driven solution call different methods service side mvc use actions , view completly different way handle things. also, mvc not use viewstate normal .net controlls require. found article discussing mixing of normal .net , mvc.
3 comments

java - if multiple threads are updating the same variable, what should be done so each thread updates the variable correctly? -

-

if multiple threads updating same variable, should each thread updates variable correctly?

any appreciated

there several options:

1) using no synchronization @ all

this can work if data of primitive type (not long/double), , don't care reading stale values (which unlikely)

2) declaring field volatile

this guarantee stale values never read. works fine objects (assuming objects aren't changed after creation), because of happens-before guarantees of volatile variables (see "java memory model").

3) using java.util.concurrent.atomiclong, atomicinteger etc

they thread safe, , support special operations atomic incrementation , atomic compare-and-set operations.

4) protecting reads , writes same lock

this approach provides mutual exclusion, allows defining large atomic operation, multiple data members manipulated single operation.


Comments

Post a Comment

Popular posts from this blog

c# - Usage of Server Side Controls in MVC Frame work -

-
i using asp.net 4.0 , mvc 2.0 web application. project requiremrnt have use server side control in application not possibl in noraml case. ideally want use adrotator control , datalist control. i saw few samples , references in codepleax mvc controllib howwver found less useful. can tell how utilize theese controls in asp.net application along mvc. note: please provide functionalities related adrotator , datalist controls not equivalent functionalities thanks in advace. mvc pages not use normal .net solution makes use of normal .net components impossible. a normal .net page use event driven solution call different methods service side mvc use actions , view completly different way handle things. also, mvc not use viewstate normal .net controlls require. found article discussing mixing of normal .net , mvc.
Read more

cocoa - Nesting arrays into NSDictionary object (Objective-C) -

-
i define tasks using nsdictionary, i'd save in plist file (i didn't have luck core data far), got stuck @ 2 points: -- when using initwithobjectsandkeys: can change data type number or boolean, using nsdate's numberwithint: , numberwithbool: methods, respectively. can't seem find method change type date though. couldn't find in documentation. -- second problem ran nested arrays. how can add them dictionary? i have uploaded picture here of trying achieve. thank in advance! do mean nsnumber 's +numberwithint: , +numberwithbool: methods, not nsdate ? it's nsnumber defines methods. to convert number date, depends on number is. if it's unix timestamp, [nsdate datewithtimeintervalsince1970:thetimestampinseconds] . as adding nsarray objects dictionary: [yourdictionary setobject:yourarray forkey:@"somekey"]; you'll have post code if need more question isn't clear.
Read more

ios - Very simple iPhone App crashes on UILabel settext -

-
i have simple application. have button , label in ib. have ibaction onclick calls settext on label. there's outlet label. connected in ib. crashes app first time in simulator. when launch again, sets text. crashes again next time. crashes on actual device. should simple, i'm not sure i'm doing wrong. thanks. in .h file : #import <uikit/uikit.h> @interface untitledviewcontroller : uiviewcontroller { iboutlet uilabel *label; iboutlet uibutton *button; } @property (nonatomic, retain) uilabel *label; -(ibaction) onclick1: (id) sender; @end and in .m: - (ibaction) onclick1: (id) sender { //[label settext:@"hello world!"]; label.text = @"hello world!"; //[button settitle:@"clicked" forstate:uicontrolstatenormal]; } sorry, i'm new site. how crash log , stack? thanks. edit : while answer technically correct, doesn't answer question @ :( sorry < warning - guess > if you're
Read more