2006-09-28 Paolo Bonzini <bonzini@gnu.org>

[gnulib.git] / lib / poll.c

diff --git a/lib/poll.c b/lib/poll.c
index 8070885..78af62d 100644 (file)
--- a/lib/poll.c
+++ b/lib/poll.c
@@ -1,7 +1,7 @@
 /* Emulation for poll(2)
    Contributed by Paolo Bonzini.
 
-   Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
+   Copyright 2001, 2002, 2003, 2006 Free Software Foundation, Inc.
 
    This file is part of gnulib.
 
@@ -19,9 +19,7 @@
    with this program; if not, write to the Free Software Foundation,
    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
 
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include "config.h"
 
 #include <sys/types.h>
 #include "poll.h"
@@ -31,6 +29,13 @@
 #include <sys/select.h>
 #include <unistd.h>
 
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+#ifdef HAVE_SYS_FILIO_H
+#include <sys/filio.h>
+#endif
+
 #if TIME_WITH_SYS_TIME
 # include <sys/time.h>
 # include <time.h>
@@ -60,7 +65,6 @@ poll (pfd, nfd, timeout)
   struct timeval tv, *ptv;
   int maxfd, rc, happened;
   nfds_t i;
-  char data[64];
 
 #ifdef _SC_OPEN_MAX
   if (nfd > sysconf (_SC_OPEN_MAX))
@@ -153,15 +157,40 @@ poll (pfd, nfd, timeout)
          happened = 0;
          if (FD_ISSET (pfd[i].fd, &rfds))
            {
-             /* support for POLLHUP.  An hung up descriptor does not
-                increase the return value! */
-             if (recv (pfd[i].fd, data, 64, MSG_PEEK) == -1)
+             int r;
+             long avail = -1;
+             /* support for POLLHUP.  */
+#if defined __MACH__ && defined __APPLE__
+             /* There is a bug in Mac OS X that causes it to ignore MSG_PEEK for
+                some kinds of descriptors.  Use FIONREAD to emulate POLLHUP.
+                It is still not completely POSIX compliant (it does not fully
+                work on TTYs), but at least it does not delete data!  For other
+                platforms, we still use MSG_PEEK because it was proved to be
+                reliable, and I a leery of changing it.  */
+             do
+               r = ioctl (pfd[i].fd, FIONREAD, &avail);
+             while (r == -1 && (errno == EAGAIN || errno == EINTR));
+             if (avail < 0)
+               avail = 0;
+#else
+             char data[64];
+             r = recv (pfd[i].fd, data, 64, MSG_PEEK);
+             if (r == -1)
                {
-                 if (errno == ESHUTDOWN || errno == ECONNRESET
-                     || errno == ECONNABORTED || errno == ENETRESET)
-                   pfd[i].revents |= POLLHUP;
+                 avail = (errno == ESHUTDOWN || errno == ECONNRESET ||
+                          errno == ECONNABORTED || errno == ENETRESET) ? 0 : -1;
+                 errno = 0;
                }
              else
+               avail = r;
+#endif
+
+             /* An hung up descriptor does not increase the return value! */
+             if (avail == 0)
+               pfd[i].revents |= POLLHUP;
+             else if (avail == -1)
+               pfd[i].revents |= POLLERR;
+             else
                happened |= POLLIN | POLLRDNORM;
            }