Implement poll function by falling back to select-based implementation

if syscall isn't available.

1 files changed, 58 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/poll.c b/sysdeps/unix/sysv/linux/poll.c
index 198819970a..875c3b48f8 100644
--- a/sysdeps/unix/sysv/linux/poll.c
+++ b/sysdeps/unix/sysv/linux/poll.c
@@ -1 +1,59 @@
+/* Poll system call, with emulation if it is not available.
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <errno.h>
+#include <sys/poll.h>
+
+extern int __syscall_poll __P ((struct pollfd *fds, unsigned int nfds,
+				int timeout));
+weak_extern (__syscall_poll)
+
+static int __emulate_poll __P ((struct pollfd *fds, unsigned long int nfds,
+				int timeout));
+
+/* The real implementation.  */
+int
+poll (fds, nfds, timeout)
+     struct pollfd *fds;
+     unsigned long int nfds;
+     int timeout;
+{
+  static int must_emulate = 0;
+  int (*syscall) __P ((struct pollfd *, unsigned int, int)) = __syscall_poll;
+
+  if (!must_emulate)
+    {
+      if (syscall)
+	{
+	  int retval = __syscall_poll (fds, nfds, timeout);
+
+	  if (retval >= 0 || errno != ENOSYS)
+	    return retval;
+	}
+
+      must_emulate = 1;
+    }
+
+  return __emulate_poll (fds, nfds, timeout);
+}
+
+
+/* Get the emulation code.  */
+#define poll(fds, nfds, timeout) static __emulate_poll (fds, nfds, timeout)
 #include <sysdeps/unix/bsd/poll.c>