send_io(p1)
public
Sends io as file descriptor passing.
s1, s2 = UNIXSocket.pair
s1.send_io STDOUT
stdout = s2.recv_io
p STDOUT.fileno
p stdout.fileno
stdout.puts "hello"
static VALUE
unix_send_io(VALUE sock, VALUE val)
{
int fd;
rb_io_t *fptr;
struct iomsg_arg arg;
struct iovec vec[1];
char buf[1];
#if FD_PASSING_BY_MSG_CONTROL
struct {
struct cmsghdr hdr;
char pad[8+sizeof(int)+8];
} cmsg;
#endif
if (rb_obj_is_kind_of(val, rb_cIO)) {
rb_io_t *valfptr;
GetOpenFile(val, valfptr);
fd = valfptr->fd;
}
else if (FIXNUM_P(val)) {
fd = FIX2INT(val);
}
else {
rb_raise(rb_eTypeError, "neither IO nor file descriptor");
}
GetOpenFile(sock, fptr);
arg.msg.msg_name = NULL;
arg.msg.msg_namelen = 0;
/* Linux and Solaris doesn't work if msg_iov is NULL. */
buf[0] = '\0';
vec[0].iov_base = buf;
vec[0].iov_len = 1;
arg.msg.msg_iov = vec;
arg.msg.msg_iovlen = 1;
#if FD_PASSING_BY_MSG_CONTROL
arg.msg.msg_control = (caddr_t)&cmsg;
arg.msg.msg_controllen = (socklen_t)CMSG_LEN(sizeof(int));
arg.msg.msg_flags = 0;
MEMZERO((char*)&cmsg, char, sizeof(cmsg));
cmsg.hdr.cmsg_len = (socklen_t)CMSG_LEN(sizeof(int));
cmsg.hdr.cmsg_level = SOL_SOCKET;
cmsg.hdr.cmsg_type = SCM_RIGHTS;
memcpy(CMSG_DATA(&cmsg.hdr), &fd, sizeof(int));
#else
arg.msg.msg_accrights = (caddr_t)&fd;
arg.msg.msg_accrightslen = sizeof(fd);
#endif
arg.fd = fptr->fd;
while ((int)BLOCKING_REGION_FD(sendmsg_blocking, &arg) == -1) {
if (!rb_io_wait_writable(arg.fd))
rb_sys_fail("sendmsg(2)");
}
return Qnil;
}