CODEWITHSUNDEEP
javaeclipsedebugging
Michael McGowan
Michael McGowan

Reputation: 6608

File I/O is incredibly slow in Eclipse debug mode

I've often found the debug mode of Eclipse useful over relying on print statements or logging. However, I've found that the debug mode's performance seems to be particularly sensitive to file I/O. Loading a file can be way slower (taking ~25 times as long), and since my workflow requires loading a rather large file before I get to anything interesting, this is particularly inconvenient for me.

Is there any sensible workaround for this issue? I don't actually need the debugging during the file loading part, so is there perhaps a way to only jump into debug mode at a certain point in the process?

Note that, unlike this question, I do not believe this is a problem with the state of my workspace.

Upvotes: 3

Views: 561

Answers (2)

nansen
nansen

Reputation: 2962

You can hook into a running application with eclipse's remote debuging feature. You have to start your app with some parameters:

java -Xdebug -Xrunjdwp:transport=dt_socket,address=8001,server=y suspend=y -jar yourapp.jar

Then in your debug configuration choose Remote Java Application using port 8001.

More detailed with pics here

Upvotes: 2

Brendan Long
Brendan Long

Reputation: 54242

It's possible you're doing IO in a slow way (reading in small pieces), and debugging is just amplifying that, since there's overhead for every function call.

NetBeans has a way to specify which functions to profile, so I'd look for a similar option in Eclipse, and then tell it not to profile anything in the java.* namespace, or any of your IO specific code if that doesn't help.

I'd also make sure you're reading your file in a fast way (using buffered input streams, not using Scanner, etc.). There may also be things in NIO that could help, but I'm not that familiar with it.

Upvotes: 1

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