[PATCH] socket: reload fptr->fd after blocking operations

[Eric Wong <e@80x24.org>]

IO objects may be closed by other threads while inside an I/O
blocking region, setting fptr->fd to -1.  So we must reload it
to avoid waiting on an invalid FD.

FIXME: need tests
---
 ext/socket/basicsocket.c | 3 ++-
 ext/socket/unixsocket.c  | 6 ++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/ext/socket/basicsocket.c b/ext/socket/basicsocket.c
index 3b6f22f36a..f79ab2d7cf 100644
--- a/ext/socket/basicsocket.c
+++ b/ext/socket/basicsocket.c
@@ -551,7 +551,8 @@ rsock_bsock_send(int argc, VALUE *argv, VALUE sock)
     arg.flags = NUM2INT(flags);
     while (rsock_maybe_fd_writable(arg.fd),
 	   (n = (ssize_t)BLOCKING_REGION_FD(func, &arg)) < 0) {
-	if (rb_io_wait_writable(arg.fd)) {
+	if (rb_io_wait_writable(fptr->fd)) {
+	    arg.fd = fptr->fd;
 	    continue;
 	}
 	rb_sys_fail("send(2)");
diff --git a/ext/socket/unixsocket.c b/ext/socket/unixsocket.c
index 5a44b552f8..669b33428b 100644
--- a/ext/socket/unixsocket.c
+++ b/ext/socket/unixsocket.c
@@ -264,8 +264,9 @@ unix_send_io(VALUE sock, VALUE val)
 
     arg.fd = fptr->fd;
     while ((int)BLOCKING_REGION_FD(sendmsg_blocking, &arg) == -1) {
-	if (!rb_io_wait_writable(arg.fd))
+	if (!rb_io_wait_writable(fptr->fd))
 	    rsock_sys_fail_path("sendmsg(2)", fptr->pathv);
+	arg.fd = fptr->fd;
     }
 
     return Qnil;
@@ -359,8 +360,9 @@ unix_recv_io(int argc, VALUE *argv, VALUE sock)
 
     arg.fd = fptr->fd;
     while ((int)BLOCKING_REGION_FD(recvmsg_blocking, &arg) == -1) {
-	if (!rb_io_wait_readable(arg.fd))
+	if (!rb_io_wait_readable(fptr->fd))
 	    rsock_sys_fail_path("recvmsg(2)", fptr->pathv);
+	arg.fd = fptr->fd;
     }
 
 #if FD_PASSING_BY_MSG_CONTROL
-- 
EW