Oops, this should've been explained long ago but apparently not. In response to a comment on http://www.sitepoint.com/the-self-pipe-trick-explained/
> Does anybody know why both unicorn and foreman read 11 bytes from > self-pipe? Unfortunately I couldn't find a way to comment on the site on a JavaScript-free browser nor does it seem possible without registering. Again, anybody can send plain-text mail to: [email protected] No registration, no real name policy, no terms-of-service, just plain-text. Feel free to use Tor, mixmaster or any anonymity service, too. --- lib/unicorn/http_server.rb | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/unicorn/http_server.rb b/lib/unicorn/http_server.rb index 015bd94..683eb82 100644 --- a/lib/unicorn/http_server.rb +++ b/lib/unicorn/http_server.rb @@ -370,6 +370,10 @@ class Unicorn::HttpServer # wait for a signal hander to wake us up and then consume the pipe def master_sleep(sec) IO.select([ @self_pipe[0] ], nil, nil, sec) or return + # 11 bytes is the maximum string length which can be embedded within + # the Ruby itself and not require a separate malloc (on 32-bit MRI 1.9+). + # Most reads are only one byte here and uncommon, so it's not worth a + # persistent buffer, either: @self_pipe[0].kgio_tryread(11) end -- EW
