Commit Graph

3 Commits (056fbee4eff539a564a6a380b1f035d3d1e2a91d)

Author SHA1 Message Date
Avery Pennarun 806de4ac94 portlist: fix "readdirent: no such file or directory" errors on Linux.
This could happen when a process disappeared while we were reading its
file descriptor list.

I was able to replicate the problem by running this in another
terminal:

    while :; do for i in $(seq 10); do
      /bin/true & done >&/dev/null; wait >&/dev/null;
    done

And then running the portlist tests thousands of times.

Fixes #339.

Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
5 years ago
Brad Fitzpatrick f8d67bb591 portlist: ignore ports bound to localhost
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 years ago
Brad Fitzpatrick 120273d7f6 portlist: document, clean up, fix an open fd spike, optimize a bit
I noticed portlist when looking at some profiles and hadn't looked at
the code much before. This is a first pass over it. It allocates a
fair bit. More love remains, but this does a bit:

name       old time/op    new time/op    delta
GetList-8    9.92ms ± 8%    9.64ms ±12%     ~     (p=0.247 n=10+10)

name       old alloc/op   new alloc/op   delta
GetList-8     931kB ± 0%     869kB ± 0%   -6.70%  (p=0.000 n=10+10)

name       old allocs/op  new allocs/op  delta
GetList-8     4.59k ± 0%     3.69k ± 1%  -19.71%  (p=0.000 n=10+10)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 years ago