In case IntelliJ IDEA doesn't respond, a thread dump could be taken to help us analyze and fix the problem that you experience.
To get the thread dump you can use jstack command line utility that comes with your JDK and is located in the JDK bin directory. In order to use jstack you need to know the process id of the JVM which runs IntelliJ IDEA. You can use your favorite task manager to get it or use the jps JDK utility. Once the process ID is obtained, run this command in the terminal/command line console:
jstack -l <pid>
Substitute <pid> with the previously obtained process id.
You can also redirect the output to a file that you can attach to your report:
jstack -l <pid> > dump.txt
After the dump is saved you can attach it to the YouTrack issue or send to the support team.
There are also different ways to take thread dumps which are platform specific, use them only in case jstack doesn't work for you.
Run IntelliJ IDEA via IDEA_HOME\bin\idea.bat file. You have to set IDEA_JDK environment variable first which points to 1.6 installation home. One of the ways to set it is to add the following line in the beginning of idea.bat file:
SET IDEA_JDK=C:\Program Files\Java\jdk1.6.0_10
Reproduce the problem. When IntelliJ IDEA hangs, press Ctrl+Break (NOT Ctrl+C) in the console window, copy the thread dump from the console.
Browse to the /Applications/IntelliJ IDEA XX.app/Contents/MacOS/idea in Finder, in the context menu choose Open With, Terminal. To get a thread dump press Ctrl+\ in the Terminal window.
You have to run IntelliJ IDEA with the terminal window shown, start your terminal and run IntelliJ IDEA via IDEA_HOME/idea.sh startup script. Reproduce the problem. Now use the ps utility to find IntelliJ IDEA process (it should be java process started from the idea.sh script), note the process ID (PID). Now open the second terminal window and issue the following command:
kill -QUIT PID
where PID is the the java process ID shown by ps. Thread dump should be printed in the first terminal window.
IntelliJ IDEA also takes thread dumps and saves them automatically on certain conditions under the %idea.system.path%\log directory (in the subdirectories starting with threadDumps). However, in some cases they may not get recorded, therefore it's recommended to take dumps manually as described above at the moments when IntelliJ IDEA doesn't respond.