socket: memoize common socket families in fptr->mode

This provides a minor speedup by avoiding an extra syscall

	require 'socket'
	require 'benchmark'
	nr = 100000
	msg = 'hello world'
	buf = ''
	size = msg.bytesize
	puts(Benchmark.measure do
	  UNIXSocket.pair(:SEQPACKET) do |a, b|
	    nr.times do
	      a.sendmsg_nonblock(msg, 0, exception: false)
	      b.recv(size, 0, buf)
	    end
	  end
	end)

             user     system      total        real
before:  0.330000   0.340000   0.670000 (  0.678235)
 after:  0.290000   0.240000   0.530000 (  0.534527)

* ext/socket/rubysocket.h: flags for common socket families
  (rsock_getfamily): update signature
* include/ruby/io.h: comment socket FMODE flags
* ext/socket/init.c (rsock_getfamily): memoize family
* ext/socket/basicsocket.c: adjust rsock_getfamily calls
* ext/socket/ancdata.c: ditto
  [ruby-core:69713] [Feature #11298]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51097 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 21 insertions, 2 deletions

diff --git a/ext/socket/init.c b/ext/socket/init.c
index 34f6a116f0..00e20fa308 100644
--- a/ext/socket/init.c
+++ b/ext/socket/init.c
@@ -624,15 +624,34 @@ rsock_s_accept(VALUE klass, int fd, struct sockaddr *sockaddr, socklen_t *len)
 }
 
 int
-rsock_getfamily(int sockfd)
+rsock_getfamily(rb_io_t *fptr)
 {
     union_sockaddr ss;
     socklen_t sslen = (socklen_t)sizeof(ss);
+    int cached = fptr->mode & FMODE_SOCK;
+
+    if (cached) {
+        switch (cached) {
+#ifdef AF_UNIX
+	    case FMODE_UNIX: return AF_UNIX;
+#endif
+	    case FMODE_INET: return AF_INET;
+	    case FMODE_INET6: return AF_INET6;
+	}
+    }
 
     ss.addr.sa_family = AF_UNSPEC;
-    if (getsockname(sockfd, &ss.addr, &sslen) < 0)
+    if (getsockname(fptr->fd, &ss.addr, &sslen) < 0)
         return AF_UNSPEC;
 
+    switch (ss.addr.sa_family) {
+#ifdef AF_UNIX
+      case AF_UNIX: fptr->mode |= FMODE_UNIX; break;
+#endif
+      case AF_INET: fptr->mode |= FMODE_INET; break;
+      case AF_INET6: fptr->mode |= FMODE_INET6; break;
+    }
+
     return ss.addr.sa_family;
 }