1 files changed, 76 insertions, 0 deletions
diff --git a/lib/pselect.c b/lib/pselect.c
new file mode 100644
index 0000000000..d8ebc70f6c
--- /dev/null
+++ b/lib/pselect.c
@@ -0,0 +1,76 @@
+/* pselect - synchronous I/O multiplexing
+
+   Copyright 2011-2012 Free Software Foundation, Inc.
+
+   This file is part of gnulib.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, see <http://www.gnu.org/licenses/>.  */
+
+/* written by Paul Eggert */
+
+#include <config.h>
+
+#include <sys/select.h>
+
+#include <errno.h>
+#include <signal.h>
+
+/* Examine the size-NFDS file descriptor sets in RFDS, WFDS, and XFDS
+   to see whether some of their descriptors are ready for reading,
+   ready for writing, or have exceptions pending.  Wait for at most
+   TIMEOUT seconds, and use signal mask SIGMASK while waiting.  A null
+   pointer parameter stands for no descriptors, an infinite timeout,
+   or an unaffected signal mask.  */
+
+int
+pselect (int nfds, fd_set *restrict rfds,
+         fd_set *restrict wfds, fd_set *restrict xfds,
+         struct timespec const *restrict timeout,
+         sigset_t const *restrict sigmask)
+{
+  int select_result;
+  sigset_t origmask;
+  struct timeval tv, *tvp;
+
+  if (timeout)
+    {
+      if (! (0 <= timeout->tv_nsec && timeout->tv_nsec < 1000000000))
+        {
+          errno = EINVAL;
+          return -1;
+        }
+
+      tv.tv_sec = timeout->tv_sec;
+      tv.tv_usec = (timeout->tv_nsec + 999) / 1000;
+      tvp = &tv;
+    }
+  else
+    tvp = NULL;
+
+  /* Signal mask munging should be atomic, but this is the best we can
+     do in this emulation.  */
+  if (sigmask)
+    pthread_sigmask (SIG_SETMASK, sigmask, &origmask);
+
+  select_result = select (nfds, rfds, wfds, xfds, tvp);
+
+  if (sigmask)
+    {
+      int select_errno = errno;
+      pthread_sigmask (SIG_SETMASK, &origmask, NULL);
+      errno = select_errno;
+    }
+
+  return select_result;
+}