no point in non-blocking for fd notifications

It's not needed since the native thread will retry in the
unlikely case of EINTR/EAGAIN.  And writing one byte to a pipe
that's guaranteed by POSIX to be at least 512 bytes is highly
unlikely.

It's also bad because F_SETFL takes the big kernel lock under
Linux (and possibly other systems), and doing it unnecessarily
is a waste of system cycles.

1 files changed, 0 insertions, 14 deletions

diff --git a/ext/posix_mq/posix_mq.c b/ext/posix_mq/posix_mq.c
index 3972620..6480645 100644
--- a/ext/posix_mq/posix_mq.c
+++ b/ext/posix_mq/posix_mq.c
@@ -730,23 +730,9 @@ static void setup_notify_io(struct sigevent *not, VALUE io)
 {
         VALUE fileno = rb_funcall(io, id_fileno, 0, 0);
         int fd = NUM2INT(fileno);
-        int flags;
         pthread_attr_t attr;
         int e;
 
-        /*
-         * fd going to be written to inside a native thread,
-         * make it blocking for simplicity
-         */
-        flags = fcntl(fd, F_GETFL);
-        if (flags < 0) {
-                rb_sys_fail("fcntl F_GETFL");
-        } else if (flags & O_NONBLOCK) {
-                flags = fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
-                if (flags < 0)
-                        rb_sys_fail("fcntl F_SETFL");
-        }
-
         if ((e = pthread_attr_init(&attr)))
                 goto err;
         if ((e = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED)))