add support for ppoll() and emulate poll() with it when __NR_poll does not exist

3 files changed, 88 insertions, 2 deletions

diff --git a/include/sys/poll.h b/include/sys/poll.h
index 89a27eab2..4085b785e 100644
--- a/include/sys/poll.h
+++ b/include/sys/poll.h
@@ -1,5 +1,5 @@
 /* Compatibility definitions for System V `poll' interface.
-   Copyright (C) 1994,96,97,98,99,2000,2001,2004 Free Software Foundation, Inc.
+   Copyright (C) 1994,1996-2001,2004,2005,2006 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
@@ -24,6 +24,13 @@
 
 /* Get the platform dependent bits of `poll'.  */
 #include <bits/poll.h>
+#ifdef __USE_GNU
+/* Get the __sigset_t definition.  */
+# include <bits/sigset.h>
+/* Get the timespec definition.  */
+# define __need_timespec
+# include <time.h>
+#endif
 
 
 /* Type used for the number of file descriptors.  */
@@ -44,9 +51,24 @@ __BEGIN_DECLS
    FDS.  If TIMEOUT is nonzero and not -1, allow TIMEOUT milliseconds for
    an event to occur; if TIMEOUT is -1, block until an event occurs.
    Returns the number of file descriptors with events, zero if timed out,
-   or -1 for errors.  */
+   or -1 for errors.
+
+   This function is a cancellation point and therefore not marked with
+   __THROW.  */
 extern int poll (struct pollfd *__fds, nfds_t __nfds, int __timeout);
 
+#ifdef __USE_GNU
+/* Like poll, but before waiting the threads signal mask is replaced
+   with that specified in the fourth parameter.  For better usability,
+   the timeout value is specified using a TIMESPEC object.
+
+   This function is a cancellation point and therefore not marked with
+   __THROW.  */
+extern int ppoll (struct pollfd *__fds, nfds_t __nfds,
+		  __const struct timespec *__timeout,
+		  __const __sigset_t *__ss);
+#endif
+
 __END_DECLS
 
 #endif	/* sys/poll.h */
diff --git a/libc/sysdeps/linux/common/poll.c b/libc/sysdeps/linux/common/poll.c
index 2d6da24b8..a8366cd27 100644
--- a/libc/sysdeps/linux/common/poll.c
+++ b/libc/sysdeps/linux/common/poll.c
@@ -23,10 +23,27 @@
 extern __typeof(poll) __libc_poll;
 
 #ifdef __NR_poll
+
 # define __NR___libc_poll __NR_poll
 _syscall3(int, __libc_poll, struct pollfd *, fds,
 	unsigned long int, nfds, int, timeout);
+
+#elif defined(__NR_ppoll)
+
+libc_hidden_proto(ppoll)
+int __libc_poll(struct pollfd *fds, nfds_t nfds, int timeout)
+{
+	struct timespec *ts = NULL, tval;
+	if (timeout > 0) {
+		tval.tv_sec = timeout / 1000;
+		tval.tv_nsec = (timeout % 1000) *1000;
+		ts = &tval;
+	}
+	return ppoll(fds, nfds, ts, NULL);
+}
+
 #else
+/* ugh, this arch lacks poll, so we need to emulate this crap ... */
 
 #include <alloca.h>
 #include <sys/types.h>
diff --git a/libc/sysdeps/linux/common/ppoll.c b/libc/sysdeps/linux/common/ppoll.c
new file mode 100644
index 000000000..e908ea8a4
--- /dev/null
+++ b/libc/sysdeps/linux/common/ppoll.c
@@ -0,0 +1,47 @@
+/* Copyright (C) 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2006.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sys/syscall.h>
+#include <sys/poll.h>
+
+#ifdef __NR_ppoll
+
+# define __NR___libc_ppoll __NR_ppoll
+static inline
+_syscall4(int, __libc_ppoll, struct pollfd *, fds,
+	nfds_t, nfds, const struct timespec *, timeout,
+	const sigset_t *, sigmask);
+
+int
+ppoll (struct pollfd *fds, nfds_t nfds, const struct timespec *timeout,
+       const sigset_t *sigmask)
+{
+  /* The Linux kernel can in some situations update the timeout value.
+     We do not want that so use a local variable.  */
+  struct timespec tval;
+  if (timeout != NULL)
+    {
+      tval = *timeout;
+      timeout = &tval;
+    }
+
+  return __libc_ppoll(fds, nfds, timeout, sigmask);
+}
+
+#endif