1 files changed, 124 insertions, 0 deletions
diff --git a/lib/nanosleep.c b/lib/nanosleep.c
new file mode 100644
index 0000000..fa20785
--- /dev/null
+++ b/lib/nanosleep.c
@@ -0,0 +1,124 @@
+/* Provide a replacement for the POSIX nanosleep function.
+   Copyright (C) 1999, 2000, 2002, 2004, 2005 Free Software Foundation, Inc.
+
+   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 2, 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, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* written by Jim Meyering */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+/* Undefine nanosleep here so any prototype is not redefined to be a
+   prototype for rpl_nanosleep. (they'd conflict e.g., on alpha-dec-osf3.2)  */
+#undef nanosleep
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <signal.h>
+
+#include <errno.h>
+
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+
+#include "timespec.h"
+
+/* Some systems (MSDOS) don't have SIGCONT.
+   Using SIGTERM here turns the signal-handling code below
+   into a no-op on such systems. */
+#ifndef SIGCONT
+# define SIGCONT SIGTERM
+#endif
+
+#if ! HAVE_SIGINTERRUPT
+# define siginterrupt(sig, flag) /* empty */
+#endif
+
+static sig_atomic_t volatile suspended;
+
+/* Handle SIGCONT. */
+
+static void
+sighandler (int sig)
+{
+  suspended = 1;
+}
+
+/* FIXME: comment */
+
+static void
+my_usleep (const struct timespec *ts_delay)
+{
+  struct timeval tv_delay;
+  tv_delay.tv_sec = ts_delay->tv_sec;
+  tv_delay.tv_usec = (ts_delay->tv_nsec + 999) / 1000;
+  if (tv_delay.tv_usec == 1000000)
+    {
+      tv_delay.tv_sec++;
+      tv_delay.tv_usec = 0;
+    }
+  select (0, NULL, NULL, NULL, &tv_delay);
+}
+
+/* FIXME: comment */
+
+int
+rpl_nanosleep (const struct timespec *requested_delay,
+	       struct timespec *remaining_delay)
+{
+  static bool initialized;
+
+  /* set up sig handler */
+  if (! initialized)
+    {
+#ifdef SA_NOCLDSTOP
+      struct sigaction oldact, newact;
+      newact.sa_handler = sighandler;
+      sigemptyset (&newact.sa_mask);
+      newact.sa_flags = 0;
+
+      sigaction (SIGCONT, NULL, &oldact);
+      if (oldact.sa_handler != SIG_IGN)
+	sigaction (SIGCONT, &newact, NULL);
+#else
+      if (signal (SIGCONT, SIG_IGN) != SIG_IGN)
+	{
+	  signal (SIGCONT, sighandler);
+	  siginterrupt (SIGCONT, 1);
+	}
+#endif
+      initialized = true;
+    }
+
+  suspended = 0;
+
+  my_usleep (requested_delay);
+
+  if (suspended)
+    {
+      /* Calculate time remaining.  */
+      /* FIXME: the code in sleep doesn't use this, so there's no
+	 rush to implement it.  */
+
+      errno = EINTR;
+    }
+
+  /* FIXME: Restore sig handler?  */
+
+  return suspended;
+}