* Added a tool to find additional roots for the garbage collector,

such as open files, current directories, mmaped files, etc.  This is
  inherently unportable, but it's easy to adapt this script to other
  platforms.  Currently we call `lsof' and try to read various bits in
  /proc/NNN.

  The goal is to prevent the garbage collector from removing store
  paths that are no longer reachable from a permanent root but that
  are still in use (for instance, after the user has done "nix-env -e"
  on a running program).
This commit is contained in:
Eelco Dolstra 2006-07-19 16:49:59 +00:00
parent 88e54153dc
commit ebcccbd358
2 changed files with 62 additions and 2 deletions

View file

@ -7,13 +7,14 @@ noinst_SCRIPTS = nix-profile.sh generate-patches.pl
nix-pull nix-push: readmanifest.pm readconfig.pm download-using-manifests.pl
install-exec-local: readmanifest.pm download-using-manifests.pl
install-exec-local: readmanifest.pm download-using-manifests.pl find-runtime-roots.pl
$(INSTALL) -d $(DESTDIR)$(sysconfdir)/profile.d
$(INSTALL_PROGRAM) nix-profile.sh $(DESTDIR)$(sysconfdir)/profile.d/nix.sh
$(INSTALL) -d $(DESTDIR)$(libexecdir)/nix
$(INSTALL_DATA) readmanifest.pm $(DESTDIR)$(libexecdir)/nix
$(INSTALL_DATA) readconfig.pm $(DESTDIR)$(libexecdir)/nix
$(INSTALL_PROGRAM) download-using-manifests.pl $(DESTDIR)$(libexecdir)/nix
$(INSTALL_PROGRAM) find-runtime-roots.pl $(DESTDIR)$(libexecdir)/nix
$(INSTALL) -d $(DESTDIR)$(sysconfdir)/nix
include ../substitute.mk
@ -27,4 +28,5 @@ EXTRA_DIST = nix-collect-garbage.in \
nix-build.in \
download-using-manifests.pl.in \
generate-patches.pl.in \
nix-pack-closure.in nix-unpack-closure.in
nix-pack-closure.in nix-unpack-closure.in \
find-runtime-roots.pl.in

View file

@ -0,0 +1,58 @@
#! @perl@ -w
use strict;
my $procDir = "/proc";
sub readProc {
return unless -d $procDir;
opendir DIR, $procDir or return;
foreach my $name (readdir DIR) {
next unless $name =~ /^\d+$/;
my $process = "$procDir/$name";
#print STDERR "=== $process\n";
my $target;
print "$target\n" if $target = readlink "$process/exe";
print "$target\n" if $target = readlink "$process/cwd";
if (opendir FDS, "$process/fd") {
foreach my $name (readdir FDS) {
$target = readlink "$process/fd/$name";
print "$target\n" if $target && substr($target, 0, 1) eq "/";
}
closedir FDS;
}
if (open MAP, "<$process/maps") {
while (<MAP>) {
next unless /^ \s* \S+ \s+ \S+ \s+ \S+ \s+ \S+ \s+ \S+ \s+ (\/\S+) \s* $/x;
print "$1\n";
}
close MAP;
}
}
closedir DIR;
}
sub lsof {
return unless open LSOF, "lsof -b -w -F n |";
while (<LSOF>) {
next unless /^n (\/ .*)$/x;
print $1, "\n";
}
close LSOF;
}
readProc;
lsof;