Wednesday, July 9, 2008

Partial solution to TCCL problem in OSGi

One of perennial problem that OSGi uses asked from mailing lists is to resolved the problem of TCCL. As I have mentioned in the blog post "OSGi and TCCL dilemma", there is no proper definition is available in OSGi R4.1 specification for TCCL.

On the other hand Eclipse Equinox OSGi implementation has taken steps to prevent this problem with the invent of ContextFinder (CF). When the framework starts, Equinox sets the framework TCCL to CF. Hence, all the bundles spawn from this framework will set its TCCL to CF. CF finds classes and resources from the classloader associate with the current method of the execution stack. (java.lang.SecurityManager#getClassContext). This is not the complete answer to the problem, but it will solve most of the common scenarios. Thus, it's very easy to use this concept and apply to other OSGi implementations as well, such as Apache Felix.

WSO2 is align with producing products that are OSGi enabled. The underline infrastructure of these products uses a product called "Carbon", which is an OSGi wrapper powered with either Eclipse Equinox or Apache Felix and provide a
Web Services infrastructure powered by Apache Axis2. Carbon uses the "servletbridge" design principle to bridge OSGi and Servlet container. Hence, Carbon is one such infrastructure that harness the benefits of server-side OSGi. Though Carbon defaults to Equinox and Felix OSGi implementations, it has give a very powerful API to integrate other OSGi implementations as well.

You will be able to find the source code from "svn co https://svn.wso2.org/repos/wso2/trunk/carbon".

Nice thing about Carbon is that it can switch between Equinox or Felix based on users preference. It can switched to any other OSGi implementations that is registered with too. Carbon uses the prior mentioned ContextFinder principle to solve the TCCL problem and I think it's a very fair assumption until OSGi specification mandate on the TCCL.

One of the very first product that is scheduled to be released on this month on top of the prior mentioned infrastructure is "Data Services Solution", which is a complete solution for data services via web services.

41 comments:

Mirko said...

Well, I am with you, saying that TCCL are a problem in the context of OSGi. However, I don't think it is an issue of the OSGi spec. The spec tries to define a component model and in its nature, it doesn't know anything about the context, each bundle is used. The approach Carbon and actually more Equinox is promoting is a good solution for adopting OSGi as a first step, but I think it is more important to rethink the design of the libraries to get rid of the need for TCCLs or at least have a mechanism to set them in a meaningful way. Neither the component, nor the container should know about it. Only the application, but that's just my opinion of course ;-)

Saminda Abeyruwan said...

You are right. OSGi spec doesn't mandate on TCCL and it's a grey area. When we try to convert the existing jars as bundles to be used in an OSGi environment, we face the problem of not being able to change the code to obtain classes and resources from that classes classloader. Most probably this is due to licences and it's quite error prone to change an production code. So IMHO in order to OSGi to be dominant in server side, it first needs to interoperate with existing stuff. So having notion of a context to a bundle will be handy in a long term scenario.

Rajesh Girish said...

Hi, I'm facing few problems when i followed the OSGI pdf documents for check out the source codes and build using maven,when i build " i'm getting few errors

"The bundle could not be resolved. Reason: Missing Constraint: Import-Package: org.apache.axiom.attachments; version="0.0.0"

how to resolve this.. please inform me ASAP .Advanced thanks for any help.

Ice said...

Hey, really nice post! Wish u a nice day!
best and newest cheap shoes online at a fraction of the cost.

Nargis Satti said...

Cool article, that is interesting that columns have been around us in every day life and we put them in our designs thinking we are creative.
webdevelopment.ae

Unknown said...

Last year's wins at the Turkish Airlines Open and WGC-HSBC Champions have world No 3 Ryder Cup 2018 Live Free Justin Rose in second spot, with Race to Dubai champion Tommy Fleetwood lurking just behind in third thanks to a runner-up finish at Shinnecock Hills.

jishan said...

The World Series 2018 will be the championship series of Major League Baseball's 2018 season.
The 114th edition of the World Series will be played between the American League champion versus the National League champion and will begin on Tuesday,
October 23. A potential Game 7 is scheduled to be played on October 31.[2] The Series will be televised nationally by Fox. For the second year in a row,
the World Series will be sponsored by YouTube TV and officially will be known as the 2018 World Series presented by YouTube TV.[3]

sk shohan said...

ICYMI - free nba 2k18 locker codes Prelude release is live and as a reminder, that means fans can now download the demo on PS4 and Xbox One, but unfortunately, PC and Nintendo Switch users miss out.

The Prelude allows users to download a demo, which is around 11.76 GB in size, which gives players access to the new social space known as the neighbourhood as well as a head start on to the Prelude a full week before NBA 2K18 arrives and get a head start on their MyPLAYER career.

The MyPLAYER career will also carry over for anyone who buys the full game, which is out next week, September 15th for pre-order customers, or September 19, 2017 when it goes on sale at retail

sk shohan said...

Breeders Cup 2018 Live Stream switch' Cup in Louisville will be supplemented continuously yearly Equestricon tradition, celebration and public expo at the Kentucky International Convention Center in downtown Louisville.

Slanting

Private REAL ESTATE

Most costly home deals in Jefferson County in September (PHOTOS)

GOVERNMENT and REGULATIONS

Open paychecks: These are Louisville's most generously compensated authorities

COMING EVENT

Salute to Veterans

Nov. 6

That occasion, which permits horse hustling fans to rub shoulders with significant players in the game, will be featured by a Triple Crown trophy display and signature session for recently resigned Triple Crown victor Justify on Tuesday, Oct. 30. Amid that occasions, visitors will have an opportunity to meet the now-amazing Thoroughbred's proprietors, coach Bob Baffert and move Mike Smith.

nh mhu said...

Wimbledon authorities have chosen the match will Melbourne Cup 2018 Live Stream recommence at 1pm neighborhood time (10pm Saturday night AEST), only a hour prior to the booked beginning of the ladies' last between Serena Williams and Angelique Kerber. That implies, should the rest of Nadal and Djokovic's match last longer than 60 minutes — which, according to what they dished up today, is an undeniable probability — at that point the ladies' last will be postponed.

NFR Live Stream 2018 | Watch CBS Sports Online said...

Hello there, You have done an incredible job. I will certainly digg it and personally recommend to my friends. I am sure they will be benefited from this site.

Sports Videos, Highlights

Sports Videos, Highlights

Unknown said...

Football is a leader among the other kinds of sporting activities, so it’s no wonder it has become one of the most popular searches on the Internet. You don’t have to search a lot to find a website to soccer streams reddit
. Here you will get access to all information in real time, including prognostics, results, statistics of the game, etc. Live football streaming is a great opportunity to watch your favourite games online absolutely free.

todaypklive said...

Georgia Bulldogs college football 2019 live

Georgia Bulldogs college football 2019 live.The Georgia Bulldogs football program speaks to the University of Georgia in the game of American football. The Bulldogs contend in the Football Bowl Subdivision (FBS) of the National Collegiate Athletic Association (NCAA) and the Eastern Division of the Southeastern Conference (SEC). They play their home amusements at noteworthy Sanford Stadium on the college's Athens, Georgia, grounds. Georgia's debut season was in 1892. UGA claims two agreement national titles (1942 and 1980); the AP and Coaches Polls have each casted a ballot the Bulldogs the national victor once (1980); Georgia has likewise been named the National Champion by at any rate one surveying specialist in three different seasons (1927, 1946 and 1968).[3] The Bulldogs have won 16 gathering titles, including 13 SEC titles (tied for second-most record-breaking), and have showed up in 55 bowl diversions, tied for second-most record-breaking. The program has likewise created two Heisman Trophy champs, four number-one National Football League (NFL) draft picks, and numerous victors of other national honors. The group is known for its storied history, exceptional customs, and out of control fan base, known as the "Bulldog Nation". Georgia has prevailed upon 800 diversions in their history, putting them eleventh unsurpassed in wins.

Unknown said...

Notre Dame season opener against Louisville Cardinals will mark the first Thursday night season opener Memorial Stadium history. Saturday night Notre Dame Football Live watch online NCAA Football Game tv. All kind of information was relesied recently. The teams met in a 49-21 Clemson victory in Atlanta last season, as Clemson’s 49 points were the most scored by the school all-time at Grant Field in Atlanta since the field’s opening in 1913. It will be the first game ever to be broadcast on the soon-to-be-launched ACC Network.

Unknown said...

Ohio State vs Michigan State Live NBC.The two Midwest state Colleges at first met in 1897, and the dispute has been played each year since 1918. The game has been had toward the impact of the deal season since 1935. Since 1918, the games site has moved forward and backward between Columbus, Ohio, and Ann Arbor, Michigan. Besides, has been played in Ohio Arena since 1922 and Michigan Arena since 1927. Through 2010, Ohio State and Michigan have picked the Enormous Ten Meeting title between themselves. On 22 unmistakable occasions, and have affected the affirmation of the gathering title an extra on various occasions. The 2015 game in Ann Arbor signified Harbaugh' first game as a head coach in the dispute. His Michigan gathering was 9–2 coming into the game and Ohio State was 10–1. Because since 2006, the two gatherings were situated in the principle 10, with Ohio State at 8 and Michigan at 10. The fundamental half was close, with Michigan scoring a touchdown by and by before halftime to restrict Ohio States lead to 14–10. Ohio State, in any case, scored touchdowns on all of its underlying 4 resources in the consequent half. While Michigan could simply marshal a single field objective. The last score was 42–13, for Ohio State.

Rugby said...

Springboks vs All Blacks How To Watch All Blacks vs Springboks Live Live Stream Watch Free 2019 Rugby World Cup Online tv Channel with 4K September 3, 2019

Sumon The MUSAFIR said...

Rugby World Cup 2019 will air on September 2019. You have not enough time to get ready. Your favorite All Blacks vs Canada match also here under this RWC 2019.All Blacks vs canada rugby Live online As a die-hard fan of rugby, you need to know some essential element about this game. Because you are willing to enjoy the match. You should know about this match. Since the official site consistently gives the news which is identified with the occasion. What’s more, this data is extremely basic for all.

Titanic said...

hen and Where will All Blacks vs Italy Live Stream
All Blacks vs Italy Online tv
The match between All Blacks vs Italy will air at 5.45 AM BST On Saturday, October 12, 2019. The match will one of the best match on the Rugby World Cup 2019

Rugby said...

Mr. Olympia is the title granted to Mr. Olympia 2019 the victor of the expert men’s lifting weights challenge at Joe Weider’s Olympia Wellness and Execution Weekend—a universal working out challenge that is held every year by the Global Alliance of Lifting weights and Wellness. Joe Weider made the challenge to empower the Mr. Universe champs to keep contending and to acquire cash. The primary Mr. Olympia was hung on September 18, 1965, at the Brooklyn Foundation of Music, New York City, with Larry Scott winning his first of two straight titles. The record number of wins is eight each by Lee Haney and Ronnie Coleman. Shawn Rhoden as of now holds the title. The film

Rugby said...

Another body building championship Mr. Olympia 2019 Live HD Mr. Olympia 2019 Is Comming soon. In this Event, the bodybuilders show their body and their perfect fitness. It is amazing to see. If you are a fan of Bodybuilding contest, we have a piece of news for you that, 2019 Mr. Olympia will begin on September 12-15. So, Get ready to enjoy and support your favorite Bodybuilds. Don’t miss the competition. Because it is the most popular Bodybuilding contest in the World. You should have some knowledge about Mr. Olympia 2019. Let’s know about.

Unknown said...

Solheim Cup 2019 will start after some days.Solheim Cup 2019 Live Stream It will start on 13–15 September 2019. There is not enough time in your hand to know about Solheim Cup. But we can give you some knowledge of shorte. Because is badly in need of you. So, Get ready to know about that. Let’s start about the Solheim Cup.

Rugby said...

NRL Grand Final 2019 is the up and NRL Grand Final 2019 Schedule coming high-voltage occasion in Australia. All the native of Australia preparing to appreciate this occasion. This is so fight game you have ever observed. Therefore, the AFL Grand Final is one of the well known game. This is the reason you need to get data about this. You will get all the data from the official page. Since the official site consistently gives the news which is identified with the occasion. What’s more, this data is extremely basic for all.

Titanic said...

Wallabies vs Fiji Rugby Rivalry
Australia and Fiji have played each other a total of 21 times of which Australia has won the
Fiji vs Wallabies Live Free
most at 18. Fiji won two of the first four matches between the sides. But have not beaten Australia since then. Their first meeting was in 1952. Australia won this match 15-9.

Titanic said...

The 2019 Australian Football Association season is the 123rd period of the world-class
AFL Grand Final 2019 Live online
Australian guidelines football rivalry. What’s more, the 30th under the name Australian Football Association having changed from Victorian Football Group after 1989. There are 18 groups contending in the alliance. Equivalent to the past seven seasons. The primary game was played on Thursday, 21 Walk. The season is booked to close with the 2019 AFL Amazing Last on Saturday

Unknown said...

Rugby World Cup 2019 will air on September 2019. You have not enough time to get ready. Your favorite Wallabies vs Wales match also here under this RWC 2019.Wallabies vs Wales Rugby live stream As a die-hard fan of rugby, you need to know some essential element about this game. Because you are willing to enjoy the match. You should know about this match.

sujoysports said...

Are you looking for the best way to watch the Grey Cup 2019 live streaming Online? You have come to the right page since we are going to share the best legit ways for you. So, stay tuned.Watch Grey Cup 2019 Online

sujoysports said...

Grey Cup is the prestigious event of the championship game of the Canadian Football League or CFL. The victorious team playing the Canadian football is eligible to get the trophy when winning the competition. 107th Grey Cup 2019 Live Broadcasting

MR. Salvi said...

Melbourne Cup 2019 Online Game
If you are willing to enjoy Melbourne Cup 2019 hole tournament you have to stay in Australia. So, you need to know about the travel package. There are many hotels in Australia which will provide your room and all kinds of facilities for spending money. You have to stay in Melbourne for Some days to enjoy Melbourne Cup 2019. Some days you have to spend $8000-10,000$. You will get a twins room or single room. You can enjoy the tournament with your family. You and your family have to stay here for Some days. This not a big cast for you.

mohidul said...

The Macy’s Thanksgiving Day Parade begins promptly at 9 a.m. on Thursday, Nov. 28, 2019, at Watch Thanksgiving Day Parade 2019 Online
the corner of 77th Street and Central Park West. It will travel south to Columbus Circle, where it will turn east onto Central Park South before turning onto 6th Avenue. After traveling down 6th from 59th Street to 34th Street, the parade will turn right and end at Macy’s in Herald Square. The parade lasts about three hours, ending at noon.

Sohanur Rahman said...

We are living in a modern era. In this recent time, Social Network is Most Popular Option For American Music Awards 2019 Live Streaming. Most Of The People Want’s To Enjoy AMAs 2019 On Facebook Live Streaming, AMAS 2019 Live Stream Reddit Is Also a Better Option To Enjoy American Music Awards 2019, Twitter is A Good Option To Get News About AMAS 2019, You can also enjoy the event by using Instagram and YouTube. The Web-Based Social Networking Will Boost The Content From The American Music Awards 2019 Voluntarily. Chances Are You Will Catch Up With All The Event Through All The Popular Social Media Sites. Let’s know the details about social media.

Sohanur Rahman said...

Facebook is the most popular social media. Though it is very popular, people will come to Facebook to get information about AMAs 2019. Facebook also added the live telecast in recent times. In this recent time, American Music Awards of 2019 Live Facebook starts high voltage event streaming. So, people can get Red off from wasting time to find American Music Awards 2019 live streaming site. As per, Facebook is streaming AMAs live, you should not find anything without Facebook. Facebook streaming is one of the best ways to watch American Music Awards 2019 Live online

mohidul said...

Presidents Cup is one of the elevated golf events on the planet. It is an incredibly notable Presidents Cup 2019 Live Online golf event. The Presidents Cup is a movement of men’s golf facilitates between a gathering addressing the US. Furthermore, an All-inclusive Gathering addressing the rest of the world less Europe. Europe battles with the US in a near yet astonishingly progressively prepared event, the Ryder Cup. The Presidents Cup started in 1994

mohidul said...

Presidents Cup is one of the elevated golf events on the planet. It is an incredibly notable Watch Presidents Cup 2019 Live golf event. The Presidents Cup is a movement of men’s golf facilitates between a gathering addressing the US. Furthermore, an All-inclusive Gathering addressing the rest of the world less Europe. Europe battles with the US in a near yet astonishingly progressively prepared event, the Ryder Cup. The Presidents Cup started in 1994

Enamul said...

The National Finals Rodeo, organized by the Professional Rodeo Cowboys Association. It is the premier championship NFR 2019 Live Stream FREE rodeo event in the United States. The NFR showcases the talents of the PRCA’s top 15 money-winners in each event. As they compete for the world title. The NFR is held each year in the first full week of December. At the Thomas & Mack justify on the campus of the University of Nevada, Las Vegas

Enamul said...

The National Finals Rodeo, National Finals Rodeo 2019 Live online organized by the Professional Rodeo Cowboys Association. It is the premier championship rodeo event in the United States. The NFR showcases the talents of the PRCA’s top 15 money-winners in each event.

Titanic said...

Mr. Olympia Rivalrymr olympia 2019 live stream
Mr. Olympia is the title granted to the victor of the expert men’s lifting weights challenge at Joe Weider’s Olympia Wellness and Execution Weekend—a universal working out challenge that is held

sujoysports said...

The National Finals Rodeo, organized by the Professional Rodeo Cowboys Association. It is the premier championship rodeo event in the United States NFR 2019 Live Stream free

Enamul said...

American Famous Music Awards in AMAs. It is also known as the American Music Awards Show. In this year another Watch AMAS 2019 Live AMAs is knocking at the door. American Music Awards 2019 will air on November 24, 2019. It is one of the most popular awards in the world. People all over the world are waiting to enjoy this AMAs 2019 Live. So, you have not enough time in your hand to enjoy your favorite American Music Awards Live Stream. You need to know some important information about AMAs 2019. This is why we are ready to give you important information about American Music Awards 2019.

mohidul said...

The Melbourne Cup isn’t just about steed dashing. Watch 2019 Melbourne Cup Streaming Online The official name of the enormous occasion is the Melbourne Cup Festival. It is the world-class occasion that offers dynamic occasions including the aggressive pony dashing, stimulation, style, sustenance and wine, and other select things, across the board place. These occasions occur in one spot called Flemington Racecourse. For some individuals, the Melbourne Cup Fair is the greatest seven day stretch of the year. All things considered, the members just have seven days to appreciate the glitzy and blissful occasion directly from their seats. Everybody will without a doubt appreciate the festival.

Titanic said...

Thanksgiving Day Parade 2019 Live Stream Onlinehe Macy’s Thanksgiving Day Parade 2019 guide
Before America gets turnt on turkey and settles in to observe some football, everyone’s eyes go to Manhattan during the Macy’s Thanksgiving Day March 2019

Unknown said...

Chili Bowl Nationals 2020 Live Tonight.The beginning to the 33rd yearly Lucas Oil Stew Bowl Nationals showed by General Tire is nearly wrapped up. Happening January 13-18, 2019, the mix of running capacity set to meet on the Waterway Soul Expo legitimize in Tulsa, Okla. stays at 355 areas from 33 states and five countries. For the 2020 event, the extension of Monday qualifying has adjusted the course of action possibly. The principle change to the Fundamental Night association is the best two in consistently's An Element will verify in Saturday's 55-lap title event.