[COMMITTED] Clean up allocrtsig code.

--- a/signal/allocrtsig.c
+++ b/signal/allocrtsig.c
@@ -1,4 +1,4 @@ 
-/* Handle real-time signal allocation.
+/* Handle real-time signal allocation.  Generic version.
    Copyright (C) 1997-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
@@ -19,36 +19,18 @@ 
 
 #include <signal.h>
 
+/* Another sysdeps file can #define this and then #include this file.  */
+#ifndef RESERVED_SIGRT
+# define RESERVED_SIGRT 0
+#endif
+
 /* In these variables we keep track of the used variables.  If the
    platform does not support any real-time signals we will define the
    values to some unreasonable value which will signal failing of all
    the functions below.  */
-#ifndef __SIGRTMIN
-static int current_rtmin = -1;
-static int current_rtmax = -1;
-#else
-static int current_rtmin;
-static int current_rtmax;
-
-static int initialized;
-
-#include <testrtsig.h>
-
-static void
-init (void)
-{
-  if (!kernel_has_rtsig ())
-    {
-      current_rtmin = -1;
-      current_rtmax = -1;
-    }
-  else
-    {
-      current_rtmin = __SIGRTMIN;
-      current_rtmax = __SIGRTMAX;
-    }
-  initialized = 1;
-}
+#ifdef __SIGRTMIN
+static int current_rtmin = __SIGRTMIN + RESERVED_SIGRT;
+static int current_rtmax = __SIGRTMAX;
 #endif
 
 /* Return number of available real-time signal with highest priority.  */
@@ -56,24 +38,26 @@  int
 __libc_current_sigrtmin (void)
 {
 #ifdef __SIGRTMIN
-  if (!initialized)
-    init ();
-#endif
   return current_rtmin;
+#else
+  return -1;
+#endif
 }
 libc_hidden_def (__libc_current_sigrtmin)
+strong_alias (__libc_current_sigrtmin, __libc_current_sigrtmin_private)
 
 /* Return number of available real-time signal with lowest priority.  */
 int
 __libc_current_sigrtmax (void)
 {
 #ifdef __SIGRTMIN
-  if (!initialized)
-    init ();
-#endif
   return current_rtmax;
+#else
+  return -1;
+#endif
 }
 libc_hidden_def (__libc_current_sigrtmax)
+strong_alias (__libc_current_sigrtmax, __libc_current_sigrtmax_private)
 
 /* Allocate real-time signal with highest/lowest available
    priority.  Please note that we don't use a lock since we assume
@@ -84,12 +68,11 @@  __libc_allocate_rtsig (int high)
 #ifndef __SIGRTMIN
   return -1;
 #else
-  if (!initialized)
-    init ();
   if (current_rtmin == -1 || current_rtmin > current_rtmax)
-    /* We don't have anymore signal available.  */
+    /* We don't have any more signals available.  */
     return -1;
 
   return high ? current_rtmin++ : current_rtmax--;
 #endif
 }
+strong_alias (__libc_allocate_rtsig, __libc_allocate_rtsig_private)
--- a/sysdeps/generic/testrtsig.h
+++ /dev/null
@@ -1,27 +0,0 @@ 
-/* Test whether RT signals are really available.
-   Copyright (C) 1997-2015 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
-
-   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, see
-   <http://www.gnu.org/licenses/>.  */
-
-#include <string.h>
-#include <sys/utsname.h>
-
-static int
-kernel_has_rtsig (void)
-{
-  return 0;
-}
--- /dev/null
+++ b/sysdeps/nptl/allocrtsig.c
@@ -0,0 +1,49 @@ 
+/* Handle real-time signal allocation.  NPTL version.
+   Copyright (C) 2015 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 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, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <nptl/pthreadP.h>
+
+/* Up to three special signals might be used privately by libpthread.
+   Figure out how many unique ones are actually used.  */
+
+#ifdef SIGCANCEL
+# define SIGCANCEL_CONSUMES     1
+#else
+# define SIGCANCEL_CONSUMES     0
+#endif
+
+#if defined SIGTIMER && (!defined SIGCANCEL || SIGTIMER != SIGCANCEL)
+# define SIGTIMER_CONSUMES      1
+#else
+# define SIGTIMER_CONSUMES      0
+#endif
+
+#if (defined SIGSETXID \
+     && (!defined SIGCANCEL || SIGSETXID != SIGCANCEL) \
+     && (!defined SIGTIMER || SIGSETXID != SIGTIMER))
+# define SIGSETXID_CONSUMES     1
+#else
+# define SIGSETXID_CONSUMES     0
+#endif
+
+/* This tells the generic code (included below) how many signal
+   numbers need to be reserved for libpthread's private uses.  */
+#define RESERVED_SIGRT          \
+  (SIGCANCEL_CONSUMES + SIGTIMER_CONSUMES + SIGSETXID_CONSUMES)
+
+#include <signal/allocrtsig.c>
--- a/sysdeps/unix/sysv/linux/allocrtsig.c
+++ /dev/null
@@ -1,55 +0,0 @@ 
-/* Copyright (C) 2002-2015 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
-
-   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, see
-   <http://www.gnu.org/licenses/>.  */
-
-#include <signal.h>
-
-
-static int current_rtmin = __SIGRTMIN + 2;
-static int current_rtmax = __SIGRTMAX;
-
-
-/* We reserve __SIGRTMIN for use as the cancelation signal.  This
-   signal is used internally.  */
-int
-__libc_current_sigrtmin (void)
-{
-  return current_rtmin;
-}
-libc_hidden_def (__libc_current_sigrtmin)
-strong_alias (__libc_current_sigrtmin, __libc_current_sigrtmin_private)
-
-
-int
-__libc_current_sigrtmax (void)
-{
-  return current_rtmax;
-}
-libc_hidden_def (__libc_current_sigrtmax)
-strong_alias (__libc_current_sigrtmax, __libc_current_sigrtmax_private)
-
-
-int
-__libc_allocate_rtsig (int high)
-{
-  if (current_rtmin == -1 || current_rtmin > current_rtmax)
-    /* We don't have anymore signal available.  */
-    return -1;
-
-  return high ? current_rtmin++ : current_rtmax--;
-}
-strong_alias (__libc_allocate_rtsig, __libc_allocate_rtsig_private)
--- a/sysdeps/unix/sysv/linux/testrtsig.h
+++ /dev/null
@@ -1,27 +0,0 @@ 
-/* Test whether RT signals are really available.
-   Copyright (C) 1997-2015 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
-
-   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, see
-   <http://www.gnu.org/licenses/>.  */
-
-#include <string.h>
-#include <sys/utsname.h>
-
-static int
-kernel_has_rtsig (void)
-{
-  return 1;
-}