Wednesday, July 2, 2014

false negatives and false positives


Result of validation could be false negatives (no issue reported) or false positives (incorrect issues reported).

Friday, June 27, 2014

Google Java Style - mandatory braces rules

During development of Checkstyle configuration for Google Java Style,  we found two rules that are looks like conflicting . 

In 4.1.1 Google say:
Braces are used with if, else, for, do and while statements, even when the body is empty or contains only a single statement.

in 4.1.3 Google say:
An empty block or block-like construct may be closed immediately after it is opened, with no characters or line break in between ({}), unless it is part of a multi-block statement (one that directly contains multiple blocks: if/else-if/else or try/catch/finally).

So in 4.1.1 IF-ELSE could be {}, but in 4.1.3 there is unclear "unless" that either conflict with 4.1.1 or mean smth else that it not described.

After long discussion with friends and investigation :

Rule 4.1.1 tell us to always use braces for statements that use blocks

// BAD
if () {
  ...
} else
  i++;

It must be
// GOOD
if () {
  ...
} else {
  i++;
}

// it is OK, old fashioned but ok
int index = 0;
for (; index < s.length() && s[index] != 'x'; index++) {}

// OK, side effect in condition expression is bad design , but it is not matter of style/formatting 
while ((r = in.read()) != 0) {}

So ELSE is just another structure that could have braces so it have to have braces no matter what.


Rule 4.1.3 extend 4.1.1 and demand that braces should not be empty in multi-block statements, small wording conflict in ELSE case is not intentional and if apply rules in sequence 4.1.1 and then 4.1.3 all will be fine:

// BAD
try {
  doX();
} catch (Exception e) {}

// BETTER
try {
  doX();
} catch (Exception e) {
  // Here's why I'm swallowing this exception
}

// BAD
if (expr) {} else {
  doSomething();
}

// BETTER
if (expr) {
  // Here's why I'm not doing anything here....
} else {
  doSomething();
}

Get java process heap dump and analyse it by jhat


1. Get all java processes ids
17:17 ~/java $ jps -vm
14970 Jps -vm -Dapplication.home=/usr/lib/jvm/java-7-oracle -Xms8m
8850 org.eclipse.equinox.launcher_1.3.0.v20130327-1440.jar -data /home/rivanov/workspace -os linux -ws gtk -arch x86_64 -showsplash /home/rivanov/ ..................... -Dosgi.requiredJavaVersion=1.6 -XX:MaxPermSize=256m -Xms40m -Xmx512m

2. generate heap dump for application, in my case it is Eclipse.
17:19 ~/java $ jmap -dump:format=b,file=eclipse_heap.bin 8850
Dumping heap to /home/rivanov/java/git/dmt/eclipse_heap.bin ...
Heap dump file created

3. run jhat tool from JDK to analyse heap dump.
17:19 ~/java $ jhat eclipse_heap.bin 
Reading from eclipse_heap.bin...
Dump file created Fri Jun 27 17:19:37 PDT 2014
Snapshot read, resolving...
Resolving 1548547 objects...
Chasing references, expect 309 dots.....................................................................................................................................................................................................................................................................................................................
Eliminating duplicate references.....................................................................................................................................................................................................................................................................................................................
Snapshot resolved.
Started HTTP server on port 7000
Server is ready.


4. Open in browser "http://localhost:7000/".
jhat is far from fancy heap dump analyser in comparison to Eclipse's MAT, jvisualvm, ...... but it is provided together with JDK and nothing should be installed .


Saturday, June 14, 2014

"Skipping JaCoCo execution ...." problem in maven project


For Checkstyle project I decided to use coveralls.io service to show UTs coverage as banner.
I used that instruction to make it for java maven project. Amazing documentation with example description worked fire for simple projects(sevntu.checkstyle , dsm-maven-plugin).

But For Checkstyle I had an error:

[romani]$ mvn jacoco:report coveralls:jacoco

...

[INFO] Skipping JaCoCo execution due to missing execution data file:/home/travis/build/checkstyle/checkstyle/target/jacoco.exec

...

[ERROR] Failed to execute goal org.eluder.coveralls:coveralls-maven-plugin:2.2.0:jacoco (default-cli) on project checkstyle: I/O operation failed: /home/travis/build/checkstyle/checkstyle/target/site/jacoco/jacoco.xml (No such file or directory) -> [Help 1]


That problem is happening when jacoco failed or did not registered his agent to instrument some code and gather statistics before tests are launched. 

Problem was in surefire-plugin, that was declared as:
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>2.9</version>
        <configuration>
          <argLine>-Duser.language=en -Duser.country=US</argLine>
        </configuration>
      </plugin>

Proper configuration is (attention to bold part):
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>2.9</version>
        <configuration>
          <argLine>${argLine} -Duser.language=en -Duser.country=US</argLine>
        </configuration>
      </plugin>
.

final version of my pom.xml (see "travis" profile) and travis.yml.

Useful links that I used for investigation:

Saturday, June 7, 2014

My donation for Ubuntu 14.04


Just because it is cool and useful - 22$:

DescriptionUnit priceQtyAmount
Ubuntu Desktop$20.00 USD1$20.00 USD
...


Tip to Canonical$2.00 USD1$2.00 USD

Thursday, May 8, 2014

Maven release plugin skipped version bump



How to fix the problem - just do that version bump yourself manually, second time it will work automatically

Here is history of commands of my failed 6.6.15 and 6.6.16, and how I made it work:

git tag -d 6.6.15
git tag -d 6.6.16
git push origin :/ref/tags/6.6.15
git push origin :refs/tags/6.6.16
mvn release:clean release:prepare -Darguments='-DskipTests=true'
gitk --all
git reset HEAD~1 --hard
git clean -fx
git pull
gitk --all
mvn versions:set -DnewVersion=6.6.16-SNAPSHOT
git status
git clean -fx
git diff
git add .
git commit -m "manual version bump"
git push
mvn release:clean release:prepare -Darguments='-DskipTests=true'
git pull
git clean -fx
Another way to fix similar problem is to update maven-release-plugin to new version:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-release-plugin</artifactId>
<version>2.5</version>


 </plugin>

result in tag commited to remote but version bump was not happen to snapshot, see logs for details



outputs from picture provided below.


problematic launch output:
===================================================
[INFO] [INFO] Building jar: /home/rivanov/java/git/feed/extract/target/extractor-tests.jar
[INFO] [INFO] ------------------------------------------------------------------------
[INFO] [INFO] Reactor Summary:
[INFO] [INFO] 
[INFO] [INFO] feed ............................................. SUCCESS [  X.XXX s]
[INFO] [INFO] feed-access ...................................... SUCCESS [  X.XXX s]
[INFO] [INFO] feed-extract ..................................... SUCCESS [  X.XXX s]
[INFO] [INFO] ------------------------------------------------------------------------
[INFO] [INFO] BUILD SUCCESS
[INFO] [INFO] ------------------------------------------------------------------------
[INFO] [INFO] Total time: 4.597 s
[INFO] [INFO] Finished at: 2014-03-27T15:17:56-08:00
[INFO] [INFO] Final Memory: 34M/222M
[INFO] [INFO] ------------------------------------------------------------------------
[INFO] Checking in modified POMs...
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed && git add -- pom.xml access/pom.xml extract/pom.xml
[INFO] Working directory: /home/rivanov/java/git/feed
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed && git status
[INFO] Working directory: /home/rivanov/java/git/feed











[INFO] Tagging release with the label 6.6.15...
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed && git 
tag -F /tmp/maven-scm-1595271495.commit 6.6.15
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed 
&& git push git@git.mycompany.com:feed 6.6.15
[INFO] Working directory: /home/rivanov/java/git/feed
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed && git ls-files
[INFO] Working directory: /home/rivanov/java/git/feed
[INFO] Transforming 'feed'...
[INFO] Transforming 'feed-access'...
[INFO] Transforming 'feed-extract'...
[INFO] Not removing release POMs
[INFO] Checking in modified POMs...
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed && git add -- pom.xml access/pom.xml extract/pom.xml
[INFO] Working directory: /home/rivanov/java/git/feed
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed && git status
[INFO] Working directory: /home/rivanov/java/git/feed
[INFO] Release preparation complete.
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO] 
[INFO] feed ............................................. SUCCESS [ 11.454 s]
[INFO] feed-access ...................................... SKIPPED
[INFO] feed-extract ..................................... SKIPPED






correct launch output:
====================================================
[INFO] [INFO] Building jar: /home/rivanov/java/git/feed/extract/target/extractor-tests.jar
[INFO] [INFO] ------------------------------------------------------------------------
[INFO] [INFO] Reactor Summary:
[INFO] [INFO] 
[INFO] [INFO] feed ............................................. SUCCESS [  X.XXX s]
[INFO] [INFO] feed-access ...................................... SUCCESS [  X.XXX s]
[INFO] [INFO] feed-extract ..................................... SUCCESS [  X.XXX s]
[INFO] [INFO] ------------------------------------------------------------------------
[INFO] [INFO] BUILD SUCCESS
[INFO] [INFO] ------------------------------------------------------------------------
[INFO] [INFO] Total time: 4.597 s
[INFO] [INFO] Finished at: 2014-03-27T15:17:56-08:00
[INFO] [INFO] Final Memory: 34M/222M
[INFO] [INFO] ------------------------------------------------------------------------
[INFO] Checking in modified POMs...
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed && git add -- pom.xml access/pom.xml extract/pom.xml
[INFO] Working directory: /home/rivanov/java/git/feed
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed && git status
[INFO] Working directory: /home/rivanov/java/git/feed

============================
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed 
&& git commit --verbose -F /tmp/maven-scm-218607872.commit pom.xml access/pom.xml extract/pom.xml
[INFO] Working directory: /home/rivanov/java/git/feed
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed && git symbolic-ref HEAD
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed 
&& git push git@git.mycompany.com:feed test-mvn-release:test-mvn-release
[INFO] Working directory: /home/rivanov/java/git/feed
============================

[INFO] Tagging release with the label 6.6.17...
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed 
&& git tag -F /tmp/maven-scm-1830116578.commit 6.6.17
[INFO] Working directory: /home/rivanov/java/git/feed
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed 
&& git push git@git.mycompany.com:feed 6.6.17
[INFO] Working directory: /home/rivanov/java/git/feed
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed && git ls-files
[INFO] Working directory: /home/rivanov/java/git/feed
[INFO] Transforming 'feed'...
[INFO] Transforming 'feed-access'...
[INFO] Transforming 'feed-extract'...
[INFO] Not removing release POMs
[INFO] Checking in modified POMs...
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed && git add -- pom.xml access/pom.xml extract/pom.xml
[INFO] Working directory: /home/rivanov/java/git/feed
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed && git status
============================
[INFO] Working directory: /home/rivanov/java/git/feed
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed 
&& git commit --verbose -F /tmp/maven-scm-1562430778.commit pom.xml access/pom.xml extract/pom.xml
[INFO] Working directory: /home/rivanov/java/git/feed
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed && git symbolic-ref HEAD
[INFO] Working directory: /home/rivanov/java/git/feed
[INFO] Executing: /bin/sh -c cd /home/rivanov/java/git/feed 
&& git push git@git.mycompany.com:feed test-mvn-release:test-mvn-release
============================
[INFO] Working directory: /home/rivanov/java/git/feed
[INFO] Release preparation complete.
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO] 
[INFO] feed ............................................. SUCCESS [ 11.454 s]
[INFO] feed-access ...................................... SKIPPED
[INFO] feed-extract ..................................... SKIPPED


====================================================


GSoC materials to read for first year organization

For organization:
http://en.flossmanuals.net/melange/
and attention to ideas page suggestions at http://en.flossmanuals.net/GSoCMentoring/
Must read for first year organizations - http://www.google-melange.com/gsoc/document/show/gsoc_program/google/gsoc2014/studentallocations

For mentor:
http://en.flossmanuals.net/GSoCMentoring/

For students:
http://en.flossmanuals.net/gsocstudentguide/
http://www.google-melange.com/document/show/gsoc_program/google/gsoc2014/help_page#4._What_documentation_is_required_from



Post registration plan, that was for GSoC 2014:
Congratulations on almost getting through student proposal submissions! Welcome to GSoC 2014! We're looking forward to spending this program with you.

This is an email that contains all the information your organization needs for the next month. Please read it thoroughly and follow the steps through to the end.

Step One: You have between now and 17 April to review and accept, ignore, and rank (if applicable) your student proposals. How you decide which proposals you accept is up to you. Keep in mind that ranking (the "star system" on the proposals) has no bearing on what students are accepted. Only students who you explicitly accept and assign a mentor to will be accepted. You can also accept students in bulk on the dashboard if you so choose.

Step Two: (Org Admins Only) By 24:00UTC on 7 April, please make sure your slot allocation request is accurate. Go to My Dashboard --> Managed Organizations, click on your organization. Click on the Preferences tab of your profile. You'll see two slot numbers on the page: "min" and "max." "Min" is your lower threshold - this is the number of slots you would need to accommodate your absolutely most amazing proposals. "Max" is your upper threshold - this is the number of slots you would love to have in an ideal world. You may also want to read the Notes on Allocations [1] document, particularly if you're a new org, to get a sense of how we do this process and what's rational to expect. If you do not fill in your slot allocation request by the deadline you will be allocated 1 slot for your org this year.

Step Three: (Org Admins Only) I will announce slot allocations Wednesday, 9 April after the close of business pacific time. If you are happy with your slot allocation for this year, you can continue accepting and rejecting proposals until 17 April. If your org ends up with more slots than it has excellent proposals (or available mentors), you will be able to give back slots to the pool. To do this, you'll need to go to your Organization profile again and you will now be able to click on the "Slots Transfer" tab. Select how many slots you want to give away. Add a note to us if you'd like to give them to a particular org. We will approve each of these trades individually. Conversely, if your org ends up with not enough slots for all the proposals you want to accept this year, please email me directly I will make a note of it on our waiting list. You will be given more slots when and if some come back into the pool.

Step Four: (Org Admins Only) Please assign mentors to all the proposals you plan to accept (or even hope to accept) ASAP. **You will not be able to accept a proposal that does not have a mentor assigned even if you have the slots to accommodate the proposal and mark it as accepted.**

Step Five: (Org Admins Only) On 15 April I will run our first round of deduplication [2] checks. After that, if you are in a duplicate situation with another org, you will be able to see a list in red of the student proposals on the review proposal page that are in this situation. You will also see a way to contact the fellow org to work it out. We will have four days to try to resolve as many of these as we can. You may consult with the student about his/her preference on which org he/she would like to be accepted for, but you do not have to. We assume that students have not applied for any org they would not be willing to work with.

Step Six: The final point at which we can resolve these situations is in the Deduplication Meeting. You must attend this IRC meeting (in #gsoc on freenode) on Friday, 18 April at 19:00 UTC. Even if you are one of the lucky orgs to not have any duplicates with a fellow org immediately preceding the meeting, you are still required to have someone(s) attend the meeting who can make a decision on your behalf when and if our playing around with the system happens to put you in a duplicate situation. This IRC meeting is the last point at which student decisions can be made, so please know your preferences when you go into it. The decisions made in this meeting are final, and will be made by myself (arbitrarily) if neither organization can come to an agreement. **If no one is in the meeting to represent your org and we need input from you, the student will automatically go to the other org.**
Step Seven: (Org Admins Only) Please make sure that you have looked over the welcome message your organization will be sending your accepted students as part of their acceptance email to make sure it's accurate. To do this, you'll need to click on the Preferences tab from your Organization profile again. Scroll down to "Message to accepted students" and make sure it looks correct. Save the profile if you make any changes.


Step Eight: Please do not discuss acceptance or rejection with the students until I have announced it on Monday, 21 April.

Thanks for your help, everyone!

[1] - http://www.google-melange.com/gsoc/document/show/gsoc_program/google/gsoc2014/studentallocations
[2] - For those of you who don't know, "duplication" means a student submitted proposals to multiple orgs and has been accepted by more than one of them. We have to resolve all these duplicate issues before we announce accepted students on 21 April.

Other:

from mentors mail-list, reply of Carol :

1) Can your organization use one slot and accept two different people and have them both work on one project together for the summer? 
No. I've answered why this is on this list, but here's a pointer in case you need it: https://groups.google.com/d/msg/google-summer-of-code-mentors-list/QvCrlS2c7Uc/v4Yxt0cX-_AJ

2) Can your organization use two slots and have two different people work on one project? 
Yes, assuming they are not dependent on each other's code or milestones or timelines in any way. If you feel a project on your ideas page absolutely needs a solution this year and you have to have two different people working on it to make sure the best solution gets produced by the end of the summer, you're welcome to use your slots that way to do that.


3) How to deliver t-shirt and certificate to Ukraine and Russia
examples of t-shirt and certificates.
there is delivery problem to that countries
http://www.google-melange.com/gsoc/document/show/gsoc_program/google/gsoc2014/help_page#4._Who_is_not_eligible_to_participate_as
https://www.google-melange.com/gsoc/document/show/gsoc_program/google/gsoc2013/help_page#7._Is_there_a_t-shirt_involved

But it is possible to change shipping address to any other address (USA address for example) after students got their welcome package and credit card. That have to be done after receiving credit card and before August.

4) Mentor summit/student reunion! 
It will be on 23-26 October this year. Yes, it is a supersized mentor summit: that's 3 full days and an evening of events. GSoC organization, allowed to send two delegates to the summit at Google's expense. Mentors that failed to report about user progress during summer will disqualified.

A delegate is defined as a student, mentor, or organization administrator who has participated in any instance of the GSoC program from 2005 - 2014 and is chosen to attend the GSoC Reunion by a mentoring organization that is participating in our 2014 program. The decision of which people will be delegates for the 2014 organizations is left to the organization administrators for each organization. Each 2014 organization can send a maximum of two delegates. These delegates will have their expenses to the Reunion paid for by Google as per the information in question #2 below.

5) Payments at GSoC
http://www.google-melange.com/gsoc/document/show/gsoc_program/google/gsoc2014/help_page#1._How_do_payments_work

Attention: you have to pay taxes from Google payments, for non US organization W-8 is required

In W-8, we needed to put "RUSSIAN FEDERATION" in 9th line. Nothing in 10th line.

sources: