* In the build hook, temporarily register the derivation and its

output as GC roots.  This prevents a race if the garbage collector
  is running during the build.
This commit is contained in:
Eelco Dolstra 2010-08-25 11:54:11 +00:00
parent 1e5f5ea2e9
commit 95deba581d

View file

@ -192,7 +192,6 @@ if ($x ne "okay") {
}
# Do the actual build.
print STDERR "building `$drvPath' on `$hostName'\n";
my $inputs = `cat inputs`; die if ($? != 0);
@ -201,17 +200,29 @@ $inputs =~ s/\n/ /g;
my $outputs = `cat outputs`; die if ($? != 0);
$outputs =~ s/\n/ /g;
print "copying inputs...\n";
my $maybeSign = "";
$maybeSign = "--sign" if -e "/nix/etc/nix/signing-key.sec";
# Register the derivation as a temporary GC root. Note that $PPID is
# the PID of the remote SSH process, which, due to the use of a
# persistant SSH connection, should be the same across all remote
# command invocations for this session.
my $rootsDir = "@localstatedir@/nix/gcroots/tmp";
system("ssh $hostName @sshOpts 'mkdir -m 1777 -p $rootsDir; ln -sfn $drvPath $rootsDir/\$PPID.drv'");
sub removeRoots {
system("ssh $hostName @sshOpts 'rm -f $rootsDir/\$PPID.drv $rootsDir/\$PPID.out'");
}
# Copy the derivation and its dependencies to the build machine.
system("NIX_SSHOPTS=\"@sshOpts\" @bindir@/nix-copy-closure $hostName $maybeSign $drvPath $inputs") == 0
or die "cannot copy inputs to $hostName: $?";
print "building...\n";
my $buildFlags = "--max-silent-time $maxSilentTime --fallback";
# Perform the build.
my $buildFlags = "--max-silent-time $maxSilentTime --fallback --add-root $rootsDir/\$PPID.out";
# `-tt' forces allocation of a pseudo-terminal. This is required to
# make the remote nix-store process receive a signal when the
@ -226,11 +237,14 @@ if (system("ssh $hostName @sshOpts -tt 'nix-store -r $drvPath $buildFlags > /dev
# the first is a transient failure and the latter is permanent.
my $res = $? == -1 || ($? >> 8) == 255 ? 1 : 100;
print STDERR "build of `$drvPath' on `$hostName' failed with exit code $?\n";
removeRoots;
exit $res;
}
print "build of `$drvPath' on `$hostName' succeeded\n";
# Copy the output from the build machine.
foreach my $output (split '\n', $outputs) {
my $maybeSignRemote = "";
$maybeSignRemote = "--sign" if $UID != 0;
@ -238,3 +252,7 @@ foreach my $output (split '\n', $outputs) {
system("ssh $hostName @sshOpts 'nix-store --export $maybeSignRemote $output' | @bindir@/nix-store --import > /dev/null") == 0
or die "cannot copy $output from $hostName: $?";
}
# Get rid of the temporary GC roots.
removeRoots;