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authorEric Wong <e@80x24.org>2015-02-18 09:22:56 +0000
committerEric Wong <e@80x24.org>2015-04-22 18:57:27 +0000
commit0d9b834624f5c74200c7d7f5ba42b0d8557c674b (patch)
treedbb35fa68d9c62a174b7dbb96dbe700e46ae6b06
parente407195b12e454ea3fbc0d28ec61b5ed587b5c53 (diff)
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:
unicorn-public@bogomips.org

No registration, no real name policy, no terms-of-service, just
plain-text.  Feel free to use Tor, mixmaster or any anonymity
service, too.
-rw-r--r--lib/unicorn/http_server.rb4
1 files changed, 4 insertions, 0 deletions
diff --git a/lib/unicorn/http_server.rb b/lib/unicorn/http_server.rb
index 509fb36..329c5bf 100644
--- a/lib/unicorn/http_server.rb
+++ b/lib/unicorn/http_server.rb
@@ -389,6 +389,10 @@ class Unicorn::HttpServer
 
   # wait for a signal hander to wake us up and then consume the pipe
   def master_sleep(sec)
+    # 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:
     IO.select([ SELF_PIPE[0] ], nil, nil, sec) or return
     SELF_PIPE[0].kgio_tryread(11)
   end