• Ulrich Drepper's avatar
    flag parameters: NONBLOCK in signalfd · 5fb5e049
    Ulrich Drepper authored
    This patch adds support for the SFD_NONBLOCK flag to signalfd4.  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 <signal.h>
    #include <stdio.h>
    #include <unistd.h>
    #include <sys/syscall.h>
    
    #ifndef __NR_signalfd4
    # ifdef __x86_64__
    #  define __NR_signalfd4 289
    # elif defined __i386__
    #  define __NR_signalfd4 327
    # else
    #  error "need __NR_signalfd4"
    # endif
    #endif
    
    #define SFD_NONBLOCK O_NONBLOCK
    
    int
    main (void)
    {
      sigset_t ss;
      sigemptyset (&ss);
      sigaddset (&ss, SIGUSR1);
      int fd = syscall (__NR_signalfd4, -1, &ss, 8, 0);
      if (fd == -1)
        {
          puts ("signalfd4(0) failed");
          return 1;
        }
      int fl = fcntl (fd, F_GETFL);
      if (fl == -1)
        {
          puts ("fcntl failed");
          return 1;
        }
      if (fl & O_NONBLOCK)
        {
          puts ("signalfd4(0) set non-blocking mode");
          return 1;
        }
      close (fd);
    
      fd = syscall (__NR_signalfd4, -1, &ss, 8, SFD_NONBLOCK);
      if (fd == -1)
        {
          puts ("signalfd4(SFD_NONBLOCK) failed");
          return 1;
        }
      fl = fcntl (fd, F_GETFL);
      if (fl == -1)
        {
          puts ("fcntl failed");
          return 1;
        }
      if ((fl & O_NONBLOCK) == 0)
        {
          puts ("signalfd4(SFD_NONBLOCK) does not set non-blocking mode");
          return 1;
        }
      close (fd);
    
      puts ("OK");
    
      return 0;
    }
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Signed-off-by: default avatarUlrich Drepper <drepper@redhat.com>
    Acked-by: default avatarDavide Libenzi <davidel@xmailserver.org>
    Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    5fb5e049
signalfd.h 1.44 KB