socket: allow exception-free nonblocking sendmsg/recvmsg

As documented before, exceptions are expensive and IO::Wait*able are too
common in socket applications to be the exceptional case.  Datagram
sockets deserve the same API which stream sockets are allowed with
read_nonblock and write_nonblock.

Note: this does not offer a performance advantage under optimal
conditions when both ends are equally matched in speed, but it it
does make debug output cleaner by avoiding exceptions whenever
the receiver slows down.

* ext/socket/ancdata.c (bsock_sendmsg_internal, bsock_recvmsg_internal):
  support "exception: false" kwarg
* ext/socket/init.c (rsock_s_recvfrom_nonblock):
  ditto
* ext/socket/init.c (rsock_s_recvfrom_nonblock): use rsock_opt_false_p
* ext/socket/socket.c (sock_connect_nonblock): ditto
* ext/socket/rubysocket.h (rsock_opt_false_p): new function
* ext/socket/basicsocket.c (bsock_recv_nonblock): update rdoc
* ext/socket/udpsocket.c (udp_recvfrom_nonblock): ditto
* test/socket/test_nonblock.rb: new tests

[ruby-core:69542] [Feature #11229]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50910 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 5 insertions, 6 deletions

diff --git a/ext/socket/init.c b/ext/socket/init.c
index 455652d082..5f0d445c70 100644
--- a/ext/socket/init.c
+++ b/ext/socket/init.c
@@ -188,9 +188,10 @@ rsock_s_recvfrom_nonblock(VALUE sock, int argc, VALUE *argv, enum sock_recv_type
     long slen;
     int fd, flags;
     VALUE addr = Qnil;
+    VALUE opts = Qnil;
     socklen_t len0;
 
-    rb_scan_args(argc, argv, "11", &len, &flg);
+    rb_scan_args(argc, argv, "11:", &len, &flg, &opts);
 
     if (flg == Qnil) flags = 0;
     else             flags = NUM2INT(flg);
@@ -226,6 +227,8 @@ rsock_s_recvfrom_nonblock(VALUE sock, int argc, VALUE *argv, enum sock_recv_type
 #if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
 	  case EWOULDBLOCK:
 #endif
+            if (rsock_opt_false_p(opts, sym_exception))
+		return sym_wait_readable;
             rb_readwrite_sys_fail(RB_IO_WAIT_READABLE, "recvfrom(2) would block");
 	}
 	rb_sys_fail("recvfrom(2)");
@@ -528,14 +531,10 @@ rsock_s_accept_nonblock(int argc, VALUE *argv, VALUE klass, rb_io_t *fptr,
 			struct sockaddr *sockaddr, socklen_t *len)
 {
     int fd2;
-    int ex = 1;
     VALUE opts = Qnil;
 
     rb_scan_args(argc, argv, "0:", &opts);
 
-    if (!NIL_P(opts) && Qfalse == rb_hash_lookup2(opts, sym_exception, Qundef))
-	ex = 0;
-
     rb_secure(3);
     rb_io_set_nonblock(fptr);
     fd2 = cloexec_accept(fptr->fd, (struct sockaddr*)sockaddr, len, 1);
@@ -549,7 +548,7 @@ rsock_s_accept_nonblock(int argc, VALUE *argv, VALUE klass, rb_io_t *fptr,
 #if defined EPROTO
 	  case EPROTO:
 #endif
-            if (!ex)
+            if (rsock_opt_false_p(opts, sym_exception))
 		return sym_wait_readable;
             rb_readwrite_sys_fail(RB_IO_WAIT_READABLE, "accept(2) would block");
 	}