Author Archives: Jeanne Boyarsky

jeanne’s attempt at pomodoro

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When I work at home on personal computer projects, I have one of two problems:

  1. getting distracted from my main task by other computer things or other items that need doing around the house
  2. getting so absorbed in my task that I forget to look away from the computer causing me to get a headache and need to stop
Neither of these is an issue at work and I can usually get a couple hours of personal project stuff done on a given weekend day before it becomes a big problem.  Which is all the time I usually have anyway.  One weekend was different.  I was technical proofreading a 300-400 page book (The Well Grounded Java Developer) and needed to get a lot done in a short time.  I blocked out my weekend to have 15-20 hours to do it.  Then all I needed was focus.
I’d read about Pomodoro and decided it to try it with this particular project.  (which is evidence of problem #1 – I was experimenting with Pomodoro when I should be reading.)
Installing software
First I installed the GNU pomodairo app.  Including the download of Adobe AIR itself, this took less than ten minutes.  I added my tasks and kicked it off.
How it went
The beginning two Pomodoros were the toughest.
  1. On the first one, I got water 2 minutes before the break. I needed to trust it and wait longer.  The sound was a bit jarring.  I only read 3 pages (and played with an example.)  Not much momentum yet.
  2. On the second one, I worked a whole pomodoro but only read one page (and fiddled with examples).  I did get in the zone although I could have stayed there longer.  I took a break anyway to avoid burnout.  I did successfully wait out the Pomodoro to check my e-mail (which I noticed because gmail automatically pulls mail and I needed to refer to one as part of my task).  I learned the tool shows your pomodoro as interrupted if you don’t click the right button at the end of a Pomodoro.
  3. On the third one I was starting to feel the flow.  That time I did get fully into what I was doing in 25 minutes and got two tiny chores done during the break.
  4. At this point, it started working.  I got absorbed during every Pomodoro.
My stats weren’t correct.  I lost two pomodoros on the second chapter I read. I think it was because I didn’t explicitly select the next task when I finished the first one.  But the stats didn’t matter.  What mattered is that I was able to get focus and momentum going.  And I didn’t have a headache at the end of the day.
Conclusion
I’m not sure if it was the Pomodoros themselves that helped me or the fact that I was doing something different so felt obligated to be responsible.  Hmm.  That sounds like a good question to post on productivity.stackexchange.com.  Did so here.

installing postgres and tomcat on the mac

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Back when I was setting up my Mac, I installed Eclipse 3.7.  I also installed Postgres and Tomcat so I could run locally.  Postgres was either unnecessarily frustrating or it required knowledge I didn’t know I was missing.  The whole shared memory thing should have been a clue.  The good news is that I think I did almost everything wrong one could so I have a nice list of problems.  I wrote this up two months ago, but waited to post until I understood better what was going on.

I learned I didn’t know where the applications folder is on the hard drive.   First I learned you can view the path of a file in the finder. Which is all well and good.  It tells me the path is Macintosh HD > Applications > Eclipse.  Awesome.  On a UNIX file system, a directory has a slash up front.  Ok.  So I’m now at a UNIX prompt looking for it.  No Mac HD at the root level.  Volumes looks promising so I cd there and see Macintosh HD as a choice.  Great.  And there’s even an Applications folder under it with my apps!  I found it without having to use “find.”  That wasn’t bad, but it was more surprising than I expected.  I also noticed there is /Applications which will be more convenient next time.

Also, the “one click installer that doesn’t tell you what it is doing” installs some things by unzipping to the directory you are in, some files to /Library and presumably some files to who knows where.  Now I see the scripts I was expecting.

initdb doesn’t have enough privileges as me so I tried root and got initdb cannot be run as root.  Ok so it’s a real UNIX install where I need a user to run as.  I wasn’t expecting this because all my previous installs on the Mac have shielded me from a real UNIX install.

I thought I needed to create a  postgres user to run the database.  In Apple’s system preferences it tells me an id with that name already exists.  But /etc/passwd says nothing about it.  Running

dscl . -list /Users UniqueID

does turn up a postgres id. I need to figure out how the Mac Directory Service thing works.  Anyway, now that I know the postgres users exists I did “sudo passwd postgres” to reset the password to something I know.  Turns out the “sorry” message when trying to sudo to postgres wasn’t from an incorrect password.  Eureka!  I needed to type “sudo su postgres” and then type *my* admin password to switch.  Which kind of makes sense because my regular id isn’t allowed to switch user but my sudo admin user is.

I then changed owner of /Library/PostgreSQL recursively to postgres user.  A nice easy step.  (sudo chown -R postgres /Library/Post*)

Finally, I could run initdb and get prompted for the new superuser password!

I then tried to start the database and got a complaint the lock file already exists.

FATAL:  lock file “/tmp/.s.PGSQL.5432.lock” already exists

HINT:  Is another postmaster (PID 94) using socket file “/tmp/.s.PGSQL.5432”?bash-3.2$

Tried rebooting.  Error still there.  Turns out postgres automatically starts up.  I went on to create a user and database using the usual commands.

Then I opened pgadmin to see if I could access the database.

Connected – maintenance db is database name.

Almost there.  I used the wrong password for the id I created in postgres.  (This matters because the coderanch integration tests assume a certain password.  And because the one I picked I will never remember.)

alter user postgres with password ‘better_password’;

Importing data from file went smoothly.

Ongoing Little problems

  1. Copy paste from Eclipse doesn’t work.  You have to go through textedit.
  2. Postgres uses shift arrow key to select a line.  I wish Apple apps would all use the same convention.

Resources

  • http://developer.apple.com/internet/opensource/postgres.html
  • http://zanshin.net/2009/09/07/installing-postgresql-on-mac-10-6-snow-leopard/ – except for the building from source parts this was useful

Tomcat

Given how many problems I had with Postgres, I decided to follow a tutorial for Tomcat.  This one was easy to understand.  I know enough about the Mac to understand what the sudo is for (to be an admin.)  And the rest is pure UNIX – permissions, making a symbolic link, etc.

java 7 from the nyjavasig

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Google java 7 a bug’s life – for approach to bug

Java 7 has come a long way since the Java road show 14 months ago when I blogged about what may or may not be in Java 7. And not always forwards. Oracle sent Donald Smith (director of project management with some coding knowledge) to the NY Java Sig.  In this blog entry, we’ll look at what features made it in, the strategy discussion from Oracle and then some details.

How does Java 7 shape up compared to the road show?

Before we get to what actually happened at the sig, let’s see how Java 7 shaped up compared to the road show.

Category Feature How to Use or Status
Modularity Project Jigsaw Java 8 – modularize the JDK to address the “Java is too big” problem.  Will not replace OSGi.
Multi-lingual Support DaVinci Machine Includes invokedynamic and more. See docs
invokeDynamic Implemented in virtual machine/bytecode to make dynamic languages faster. Invokevirtual was closest but slow because doing extra type checking. Builds CallSite so only does that extra work once and improves performance of subsequent calls. JRuby noted 20% perfromance increase.
Small languages changes (Project Coin) Diamond Operator List>Map<String, Integer> list = new ArrayList<>();
Integer Literals int num = 1_234_567;
Try Catch With Resources try (InputStream s = …) {  … }
Collection literals (like associative array) Didn’t go anywhere. Haven’t seen talked about for Java 8 either.
Other While other (undetermined) features weren’t publicized last year, they will be part of Java 8.
Performance Fork Join New APIs in Java 7.  See end of post for details.
ParallelIntArray Not in Java 7. Didn’t go anywhere.
Closures Closures/Lambda Expressions Deferred to Java 8.  Will include support for multi-core.

High Level/Strategy

Donald didn’t sound like a typical Oracle speaker. He was funny, easy to relate to and started out by talking about his biases/background It felt more personal than corporate. Usualy when Oracle prents something it sounds like legal reviewed it and stripped out a lot. The slide deck did have the standard nine line Oracle disclaimer. He did note that IBM’s Sarbanes Oxley disclaimer is twice as long as Oracle’s. People asked tough questions and he answered honestly when not knowing the answer.

Interesting things from Strategy and Q&A

  1. Timelines
    • Java 6 came out in 2006.  The four years to Java 7 was the longest time between releases anywhere.
    • Java 7 update 1 is due out in early September and will contain the major bug fixes.
    • Java 7 update 2 is due out in October and will contain garbage collection enhancements.
    • Java 8 is targeting 2012.  The speaker thinks 18 months is too soon for Java 8 because the industry is no longer used to a 2 year release cycle anymore, let alone more frequent..  He thinks we need time for the tooling to catch up.
  2. Java heath (just Java; doesn’t include JVM languages)
  3. Official terms for past are “legacy sun employee” or “legacy bea employee”.
  4. HotSpot vs JRockit
    • Survey says 70% use Sun JDK and only 5% use JRockit.
    • Oracle decided to officially kill the JRockit JVM and just use the JRockit tooling. (Mission Control, Flight Recorder and RT)
    • Over time, the two will merge with the JRockit tools being premium features.
    • Oracle emphasized performance will also be free and part of the main JDK.
    • Googlefight between the two shows Hotspot as the clear winner.
  5. JavaOne – Oracle is holding back announcements for JavaOne.  Expect some on
    • Java 7 Certifications
    • Something about the Mac.  Maybe with respect to Java 8.  (Oracle claims the delay in Java 7 on the Mac is to “make things right” with the Apple UI.)
    • Recognition that Oracle needs to clean up their name in community by announcing things at JavaOne and doing them without surprises.
  6. Open jdk is slowly becoming more open. For example, Oracle recognizes the need to open bugs to public before Oracle sees/runs triage. Looking at using jira for this.
  7. Java 7 theme is “moving Java forward.”  In other words, just get something out without waiting for all the features.

More on Java 7

The emphasis was the need to be careful about protecting the platform, the amount of work in the smallest of changes and the desire to not change the type system.  Changes fall into three categories:

  1. Language changes
    • All project coin changes noted in table up top
    • + Allowing Strings in the switch statement
    • + @SafeVarargs allowing the method itself to declare safety so all callers don’t have to suppress warnings.
    • + AutoClosable interface for I/O and JDBC 4.1 resources.  Using these within the try with resources syntax in the table above means they will get automatically closed.  It also means exceptions thrown in that auto generated finally will be suppressed but still available in the stack trace.
    • + Catching multiple unrelated exceptions catch(ExceptionType1 | ExceptionType2 e)
  2. Library changes
    • NIO – Better exceptions, more extensible to different file systems, rename behavior more consistent , more access to metadata
      • Path is the replacement for File. It understands symbolic links cross platform consistently and provides many methods.
      • Lots of methods to create/navigate/transform paths
      • Can call path.toFile() to get file from path to call old apis
      • Paths helper class to get path
      • Files helper class to copy files with lots of options such as copy with attributes or replacing exisiting attributes.  Also supports atomic move.
    • Concurrency (Fork/Join)
      • Phaser class which is similar to the cyclic barrier and countdown latch but has better synchronization and deadlock protection.  Can also add and remove threads on fly.
      • TransferQueue interface which is implmented by LinkedTransferQueue – the producer or consumer can block while waiting so dont get too far ahead
      • The key class to implement your logic in should implement RecursiveTask.  It is like RecursiveAction except that it returns a result.  All you have to do is implement the compute() method.
      • The ForkJoinPool is the executor so you can submit your task to have it run.  Methods are provided to see if it is done and get the result.  By default it uses the # available processors or you can specify explicitly.
  3. Runtime changes
    • See table up top for changes.
    • Oracle listed all the languages that can run on a JVM.  They noted that some are research projects by students and not “real” or “ready.”  I laughed because C# was on the list.  Why would you want to run C# on a JRE?
  4. Other
    • Swing nimbus look and feel is completed.  Metal is still the default.
    • Eliptic curve cryptography
    • Deadlock avoidance in classloader
    • Close method for UrlClassloader
    • Javadoc now has support for CSS.  Which means the JavaDoc now has “nice looking annoying frames”