ECE 126
GWU
Author: Tom Farmer

Tutorial: Removing Cadence Lock Files



What is a Lock File?

When one opens up a cadence cell for editing (schematic, layout, symbol, etc),
Cadence automatically creates a temporary file called a lock file.  The lock
file prevents another user from opening up the same file for edit.  

As an example, when one creates a "inv" cell for an inverter, and creates a "layout" view
a file called: cadence\Digital\inv\layout\layout.cdb is created to store all of the layout.

When one is working on the inverter, cadence creates a "lock" file called:
cadence\Digital\inv\layout\layout.cdb.cdslck  <--notice the "lock" extension

This makes it so only the person who has the file open can edit/change the inverter's layout.

When one saves and closes the layout file, the "lock" file is deleted, so that in the
future it can be opened for edit again.




What is the problem?

If one is editing the inverter's layout in cadence, and for some reason cadence crashes
or exits for some unexpected reason, the "layout.cdb.cdslck" file may not be deleted, due
to the crash.

When this happens, once cadence is restarted, the lock file is still in place.  This
will make it so you cannot open the inverter's layout.  We must remove this lock file
manually, as cadence is not intelligent enough on its own to understand what is happening.




What are the symptoms of a left behind lock file?

Two situations may occur:
1) When you start cadence, it takes a very long time to startup, and when it does, it gives the warning:
*WARNING* file /home/ugrad/(yourusernamehere)/CDS.log Connection refused

2) Once cadence is open you attempt to open up a view in cadence, say your inverter's layout as an example,
it may take a very, very long time to open.  It may never open.  In this case, you probably have a left behind
lock file.


How do I remove the lock files?

It is very simple.  Follow these steps:
1) login to a unix workstation (or ssh to hobbes from home)
2) EXIT cadence (if you have it open)
3) from the terminal type in the following commands:

   cd ~
   rm -rf *.cdslck

   cd ~/cadence
   find . -name '*.cdslck' -exec rm {} \;
   find . -name '*.oacache' -exec rm {} \;

It should not prompt you to delete, but if it prompts you to "delete" a file, say yes!


4) Now start cadence, and it should be cleared up