flag parameters: NONBLOCK in timerfd_create
This patch adds support for the TFD_NONBLOCK flag to timerfd_create. The
additional changes needed are minimal.
The following test must be adjusted for architectures other than x86 and
x86-64 and in case the syscall numbers changed.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include <fcntl.h>
#include <stdio.h>
#include <time.h>
#include <unistd.h>
#include <sys/syscall.h>
#ifndef __NR_timerfd_create
# ifdef __x86_64__
# define __NR_timerfd_create 283
# elif defined __i386__
# define __NR_timerfd_create 322
# else
# error "need __NR_timerfd_create"
# endif
#endif
#define TFD_NONBLOCK O_NONBLOCK
int
main (void)
{
int fd = syscall (__NR_timerfd_create, CLOCK_REALTIME, 0);
if (fd == -1)
{
puts ("timerfd_create(0) failed");
return 1;
}
int fl = fcntl (fd, F_GETFL);
if (fl == -1)
{
puts ("fcntl failed");
return 1;
}
if (fl & O_NONBLOCK)
{
puts ("timerfd_create(0) set non-blocking mode");
return 1;
}
close (fd);
fd = syscall (__NR_timerfd_create, CLOCK_REALTIME, TFD_NONBLOCK);
if (fd == -1)
{
puts ("timerfd_create(TFD_NONBLOCK) failed");
return 1;
}
fl = fcntl (fd, F_GETFL);
if (fl == -1)
{
puts ("fcntl failed");
return 1;
}
if ((fl & O_NONBLOCK) == 0)
{
puts ("timerfd_create(TFD_NONBLOCK) set non-blocking mode");
return 1;
}
close (fd);
puts ("OK");
return 0;
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/timerfd.h b/include/linux/timerfd.h
index 96ed97d..86cb050 100644
--- a/include/linux/timerfd.h
+++ b/include/linux/timerfd.h
@@ -8,7 +8,7 @@
#ifndef _LINUX_TIMERFD_H
#define _LINUX_TIMERFD_H
-/* For O_CLOEXEC */
+/* For O_CLOEXEC and O_NONBLOCK */
#include <linux/fcntl.h>
/* Flags for timerfd_settime. */
@@ -16,6 +16,7 @@
/* Flags for timerfd_create. */
#define TFD_CLOEXEC O_CLOEXEC
+#define TFD_NONBLOCK O_NONBLOCK
#endif /* _LINUX_TIMERFD_H */