I'm a Community College instructor grading student C++ coding assignments. Been doing the same task all semester. Suddenly, this morning, CLion is building extremely slowly, perhaps even hanging, the second time I build/run a project. WTF? The projects are very small. One source file, one header, no libraries.
What changed? And why would a second build be the problem? It's usually first builds that are slow.
What changed? My harddrive backup software. I told my auto-backup to take 2 hours off and have had no problem since.
I was recently forced to switch from the Code42 CrashPlan software I've been using for years to Carbonite. Code42 is getting out of the end-user backup business.
Note that I believe this problem is at least 95% user error, in how I configured my backup, and max 5% anything to do with Carbonite's implementation. Maybe their file locking strategy is different from CrashPlan's; I don't know.
I did think twice before I configured my CLion Projects folder to be backed up. I knew that backing up object files would be a waste of backup cycles/space. But I was in a hurry and wanted my solution source code to get backed up by Carbonite until I can check it into a repository of some sort at the end of the semester. I'm pretty sure I can go in and refine my backup strategy to NOT include the object/executable folders.
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I've been looking for an IDE or Text Editor that can save "snapshots" of my code. I have been coding in a lot of new languages lately using a lot of trial and error. I often find myself wanting to revert a file or multiple files because of a coding/design decisions made in the last couple of hours or even days. It would be nice if I could take a snapshot of my code periodically and reverting to a past snapshot rather than manually making copies of my files on intervals.
I'd imagine that there has to be atleast an editor that shows version-history of a file. ( I realize I could use git or svn or any other versioning solution, but I'd like a more automated process.)
(if not an IDE, does anyone know how to configure Windows-ShadowCopy, OSX-TimeMachine, to make backups of my development folder on 45min intervals... or even a third-party program.)
Eclipse takes a local history on a per file basis... but personally I would strongly suggest using source control for this. If you use something like git or Mercurial, your commits are all local anyway - and it means you'll have a consistent snapshot at moments where you believe you've reached a useful point.
With a bit of experience it only takes a few seconds to commit your current work, and I think it's likely to prove more useful over time than automatically snapshotting either every save or at random intervals.
(It's hard to know whether Eclipse will actually be useful to you, as you haven't specified which language you'll be programming in. Admittedly there are plugins for a fair number of languages in Eclipse...)
I know there are other applications also, but considering yum/apt-get/aptitude/pacman are you core package managers for linux distributions.
Today I saw on my fedora 13 box:
(7/7): yum-3.2.28-4.fc13_3.2.28-5.fc13.noarch.drpm | 42 kB 00:00
And I started to wonder how does such a package update itself? What design is needed to ensure a program can update itself?
Perhaps this question is too general but I felt SO was more appropriate than programmers.SE for such a question being that it is more technical in nature. If there is a more appropriate place for this question feel free to let me know and I can close or a moderator can move.
Thanks.
I've no idea how those particular systems work, but...
Modern unix systems will generally tolerate overwriting a running executable without a hiccup, so in theory you could just do it.
You could do it in a chroot jail and then move or something similar to reduce the time during which the system is vulnerable. Add a journalling filesystem and this is a little safer still.
It occurs to me that the package-manager needs to hold the package access database in memory as well to insure against a race condition there. Again, the chroot jail and copy option is available as a lower risk alternative.
And I started to wonder how does such a package update itself? What
design is needed to ensure a program can update itself?
It's like a lot of things, you don't need to "design" specifically to solve this problem ... but you do need to be aware of certain "gotchas".
For instance Unix helps by reference counting inodes so "you" can delete a file you are still using, and it's fine. However this implies a few things you have to do, for instance if you have plugins then you need to load them all before you run start a transaction ... even if the plugin would only run at the end of the transaction (because you might have a different version at the end).
There are also some things that you need to do to make sure that anything you are updating works, like: Put new files down before removing old files. And don't truncate old files, just unlink. But those also help you :).
Using external problems, which you communicate with, can be tricky (because you can't exec a new copy of the old version after it's been updated). But this isn't often done, and when it is it's for things like downloading ... which can somewhat easily be made to happen before any updates.
There are also things which aren't a concern in the cmd line clients like yum/apt, for instance if you have a program which is going to run 2+ "updates" then you can have problems if the first update was to the package manager. downgrades make this even more fun :).
Also daemon like processes should basically never "load" the package manager, but as with other gotchas ... you tend to want to follow this anyway, for other reasons.
I have a VS 2008 VB.NET Solution, which is quite large. Every once in a while, if I take latest code from source control, I get hundreds of errors. These aren't real errors. They are all about classes not implementing functions/events from interfaces (which they DO implement).
"Class [class name] must implement [event or function name] for interface [interface name]"
I usually end up spending couple of hours doing a combination of: building/rebuilding the solution project by project, cleaning the solution, deleting everything locally, taking latest... etc. At some point, everything just magically builds. Does anyone have any idea what is causing this? Other people on my team experience this as well. I do not see any circular references.
Yes, I've been there.
The root of the problem is that some projects are trying to build and they are dependent on the dll's that other projects generate.
You can solve this by modifying the build order of your projects.
Once you do this, everything should work fine on the first build attempt after check out.
I've seen it as well.
I think it's related to some of the metadata/files Visual studio keeps around..my running theory is that VS isn't refreshing it's internal stuff when you do the latest pull from source control. Thus it tries to do a build, it thinks some files haven't been "updated" (thus it has an old intermediate object file lying around it uses instead) gets confused, and fails.
Generally doing a combination of Build->Clean Solution, Build->Build Solution solves it most of the time. I have, twice, had to blow away the entire build directory and pull a fresh copy from source control (Clearcase) and do a fresh build.
Edit: I have Clearcase integrated with VS2008, and do my checkouts/checkins/version history from within VS2008. Not sure if using the standalone windows tool would solve this issue, and haven't the time to test (not to mention being unable to reproduce the error consistantly)
Edit2: When i say twice, i mean twice in the last 12 months or so.
About 2 months ago I overtook building proccess in current company. Even though I don't have much knowledge of it, I was the only with enough time, so I didn't have much choice.
Situation is not that good, and I would like to do following:
Labeling files in SourceSafe with version (example ProjectName PV 1.2)
GetFiles from SourceSafe to specific directory
Build vb6/c++/c# projects(yes, there are all kinds of them)
Build InstallShield setups
This is for now partly done using batch scripts(one for labeling and getting, one for building, etc..). So when building start I pretty much have babysit it.
Good part of this code could be reused.
Any recommendations on how to do it better? One big problem is whole bunch of dependencies between projects. Also labeling has to increment version and if necessary change PV to EV.
I would like to minimize user interaction as much as possible. One click on one build script(Spolsky is god) and all is done, no need to increment version, to set where to get files and similar stuff.
Is the batch scripting best way to go? Should I do some functionality with msbuild. Are there any other options?
Specific code is not need, for now I just need a way how to improve it, even though it wouldn't hurt.
Tnx,
Marko
Since you already have a build system (even though some of it currently "manual"), whatever you do, don't start over from scratch.
(1) Make sure you have a test machine (or Virtual Machine) on which to work. Thus you can make changes and improvements without having to worry about breaking anything.
(2) Put all of your build scripts and tools in version control, not just the source code. Then as you make changes, see if they work. If they do, then save them to version control. If they don't, then roll them back.
(3) Choose one area to work on at a time. Don't try to do everything at once. Going from a lot of manual work to "one-click" will take time no matter what build system you're working with.
Sounds like you want a continuous integration solution, like CC.Net. It has configuration options to do all the things you want and a great community to answer questions.
Also, batch scripting is probably not a good option. Sophisticated build and integration tools will let you feed parameters into the build and create different builds for different environments (test, production, etc.). Batch scripting will involve a lot of hand-coding and glue.
I am not an experimented user of SCM tools, even though I am convinced of their usefulness, of course.
I used some obscure commercial tool in a former job, Perforce in the current one, and played a bit with TortoiseSVN for my little personal projects, but I disliked having lot of .svn folders all over the place, making searches, backups and such more difficult.
Then I discovered the interest of distributed SCM and I chose to go the apparently simpler (than git) Mercurial way, still for my personal, individual needs. I am in the process of learning to use it properly, having read part of the wiki and being in the middle of the excellent PDF book.
I see often repeated, for example in Mercurial working practices, "don't hesitate to use multiple trees locally. Mercurial makes this fast and light-weight." and "for each feature you work on, create a new tree.".
These are interesting and sensible advices, but they hurt a bit my little habits with centralized SCM, where we have a "holy" central repository where branches are carefully planned (and handled by administrators), changelists must be checked by (senior) peers and must not break the builds, etc. :-) Starting to work on a new branch takes quite some time...
So I have two questions in the light of above:
How practical is it to do lot of clones, in the context of IDEs and such? What if the project has configuration/settings files, makefiles or Ant scripts or shell scripts or whatever, needing path updates? (yes, probably a bad idea...) For example, in Eclipse, if I want to compile and run a clone, I have to do yet another project, tweaking the Java build path, the Run/Debug targets, and so on. Unless an Eclipse plugin ease that task. Do I miss some facility here?
How do that scale? I have read Hg is OK for large code bases, but I am perplex. At my job, we have a Java application (well, several around a big common kernel) of some 2 millions of lines, weighting some 110MB for code alone. Doing a clean compile on my old (2004) Windows workstation takes some 15 minutes to generate the 50MB of class files! I don't see myself cloning the whole project to change 3 files. So what are the practices here?
I haven't yet seen these questions addressed in my readings, so I hope this will make a useful thread.
You raise some good points!
How practical is it to do lot of clones, in the context of IDEs and such?
You're right that it can be difficult to manage many clones when IDEs and other tools depend on absolute paths. Part of it can be solved by always using relative paths in your configuration files -- making sure that a source checkout can compile from any location is a good goal in itself, no matter what revision control system you use :-)
But when you cannot or dont want to bother with several clones, then please note that a single clone can cope with multiple branches. The "hgbook" emphasizes many clones since this is a conceptually simple and very safe way of working. When you get more experience you'll see that you can use multiple heads in a single repository (perhaps by naming them with bookmarks) to do the same.
How do that scale?
Cloning a 110 MB repository should be quite fast: it depends on how long it takes to write 110 MB to your disk. In a recent message to the Mercurial mailinglist it was reported that cloning 6.3 GB took 4 minutes -- scaling that down to 110 MB gives about 4 seconds. That should be fast enough that your tea is still warm :-) Part of the trick is that the history data are simply hard-linked (yes, also on Windows) and so it is only a matter of writing out the files in the working copy.
PhiLo: I'm new at this, but mercurial also has "internal branches" that you can use within a single repository instead of cloning it.
Instead of
hg clone toto toto-bug-434
you can do
cd toto
hg branch bug-434
hg update bug-434
...
hg commit
hg update default
to create a branch and switch back and forth. Your built files not under rev control won't go away when you switch branches, some of them will just go out of date as the underlying sources are modified. Your IDE will rebuild what's needed and no more. It works much like CVS or subversion.
You should still have clean 'incoming' and 'outgoing' repositories in addition to your 'work' repository. Just that your 'work' can serve multiple purposes.
That said, you should clone your work repo before attempting anything intricate. If anything goes wrong you can throw the clone away and start over.
Question 1:
PIDA IDE has pretty good Mercurial integration. We also use Mercurial for development itself. Personally I have about 15 concurrent clones going of some projects, and the IDE copes fine. We don't have the trouble of tweaking build scripts etc, we can "clone and go".
It is so easy that in many cases I will clone to the bug number like:
hg clone http://pida.co.uk/hg pida-345
For bug #345, and I am ready to fix.
If you are having to tweak build scripts depending on the actual checkout directory of your application, I might consider that your build scripts should be using some kind of project-relative path, rather than hard-coded paths.