Serialize links on Linux. Should fix http://code.google.com/p/chromium/issue...

Serialize links on Linux.  Should fix http://code.google.com/p/chromium/issues/detail?id=3805


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=5131

[dank, 2008-11-06 19:56:55]

This serializes all links, but the extra serialization
shouldn't be harmful.  A lock file is created in the
working directory.

[Evan Martin, 2008-11-06 20:17:42]

I'm glad you're doing this!

http://codereview.chromium.org/9463/diff/1/2
File build/SConscript.main (right):

http://codereview.chromium.org/9463/diff/1/2#newcode464
Line 464: LINK = 'flock linklock.dat $CXX',
Shouldn't the lock file go in the build directory?  (Thinking of the case where
you run "git status" during a build.)

Shouldn't that use the old value of LINK rather than CXX?  (Thinking of the case
where you're using gold instead of g++ for the linker.)

[dank, 2008-11-06 20:49:52]

This time the lock file is in the build directory,
and I reuse the old value of $LINK.

I couldn't figure out how one is supposed to 
use gold as the linker, or I would have tested that.
What's the magic incantation?

[dank, 2008-11-10 21:40:54]

I think it's ok.  Can I get an LGTM?

[Evan Martin, 2008-11-10 22:00:16]

LGTM either way

http://codereview.chromium.org/9463/diff/203/5
File build/SConscript.main (right):

http://codereview.chromium.org/9463/diff/203/5#newcode464
Line 464: LINK = 'flock ' + linux_env['TARGET_ROOT'] + '/linker.lock ' +
linux_env['LINK'],
I wonder if you can get away with the "$FOO" pattern used in the commands
nearby?