thodg/cgminer

diff --git a/compat.h b/compat.h
index 77b1340..7ea9c63 100644
--- a/compat.h
+++ b/compat.h
@@ -1,6 +1,10 @@
 #ifndef __COMPAT_H__
 #define __COMPAT_H__
 
+#ifndef __SUSECONDS_T_TYPE
+typedef long suseconds_t;
+#endif
+
 #ifdef WIN32
 
 #include <windows.h>
diff --git a/lib/.gitignore b/lib/.gitignore
deleted file mode 100644
index e69de29..0000000
--- a/lib/.gitignore
+++ /dev/null
diff --git a/lib/Makefile.am b/lib/Makefile.am
index a643eeb..bb78703 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -9,7 +9,7 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=. --no-conditional-dependencies --no-libtool --macro-prefix=gl memmem
+# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=. --no-conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files memmem sigaction signal
 
 AUTOMAKE_OPTIONS = 1.5 gnits
 
@@ -102,6 +102,60 @@ EXTRA_libgnu_a_SOURCES += memmem.c
 
 ## end   gnulib module memmem-simple
 
+## begin gnulib module sigaction
+
+
+EXTRA_DIST += sig-handler.h sigaction.c
+
+EXTRA_libgnu_a_SOURCES += sigaction.c
+
+## end   gnulib module sigaction
+
+## begin gnulib module signal
+
+BUILT_SOURCES += signal.h
+
+# We need the following in order to create <signal.h> when the system
+# doesn't have a complete one.
+signal.h: signal.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H) $(WARN_ON_USE_H)
+	$(AM_V_GEN)rm -f $@-t $@ && \
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */' && \
+	  sed -e 's|@''GUARD_PREFIX''@|GL|g' \
+	      -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \
+	      -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
+	      -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
+	      -e 's|@''NEXT_SIGNAL_H''@|$(NEXT_SIGNAL_H)|g' \
+	      -e 's/@''GNULIB_SIGNAL_H_SIGPIPE''@/$(GNULIB_SIGNAL_H_SIGPIPE)/g' \
+	      -e 's/@''GNULIB_SIGPROCMASK''@/$(GNULIB_SIGPROCMASK)/g' \
+	      -e 's/@''GNULIB_SIGACTION''@/$(GNULIB_SIGACTION)/g' \
+	      -e 's|@''HAVE_POSIX_SIGNALBLOCKING''@|$(HAVE_POSIX_SIGNALBLOCKING)|g' \
+	      -e 's|@''HAVE_SIGSET_T''@|$(HAVE_SIGSET_T)|g' \
+	      -e 's|@''HAVE_SIGINFO_T''@|$(HAVE_SIGINFO_T)|g' \
+	      -e 's|@''HAVE_SIGACTION''@|$(HAVE_SIGACTION)|g' \
+	      -e 's|@''HAVE_STRUCT_SIGACTION_SA_SIGACTION''@|$(HAVE_STRUCT_SIGACTION_SA_SIGACTION)|g' \
+	      -e 's|@''HAVE_TYPE_VOLATILE_SIG_ATOMIC_T''@|$(HAVE_TYPE_VOLATILE_SIG_ATOMIC_T)|g' \
+	      -e 's|@''HAVE_SIGHANDLER_T''@|$(HAVE_SIGHANDLER_T)|g' \
+	      -e '/definitions of _GL_FUNCDECL_RPL/r $(CXXDEFS_H)' \
+	      -e '/definition of _GL_ARG_NONNULL/r $(ARG_NONNULL_H)' \
+	      -e '/definition of _GL_WARN_ON_USE/r $(WARN_ON_USE_H)' \
+	      < $(srcdir)/signal.in.h; \
+	} > $@-t && \
+	mv $@-t $@
+MOSTLYCLEANFILES += signal.h signal.h-t
+
+EXTRA_DIST += signal.in.h
+
+## end   gnulib module signal
+
+## begin gnulib module sigprocmask
+
+
+EXTRA_DIST += sigprocmask.c
+
+EXTRA_libgnu_a_SOURCES += sigprocmask.c
+
+## end   gnulib module sigprocmask
+
 ## begin gnulib module stddef
 
 BUILT_SOURCES += $(STDDEF_H)
diff --git a/lib/sig-handler.h b/lib/sig-handler.h
new file mode 100644
index 0000000..abb660c
--- /dev/null
+++ b/lib/sig-handler.h
@@ -0,0 +1,44 @@
+/* Convenience declarations when working with <signal.h>.
+
+   Copyright (C) 2008-2011 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 3 of the License, 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/>.  */
+
+#ifndef _GL_SIG_HANDLER_H
+#define _GL_SIG_HANDLER_H
+
+#include <signal.h>
+
+/* Convenience type when working with signal handlers.  */
+typedef void (*sa_handler_t) (int);
+
+/* Return the handler of a signal, as a sa_handler_t value regardless
+   of its true type.  The resulting function can be compared to
+   special values like SIG_IGN but it is not portable to call it.  */
+static inline sa_handler_t
+get_handler (struct sigaction const *a)
+{
+#ifdef SA_SIGINFO
+  /* POSIX says that special values like SIG_IGN can only occur when
+     action.sa_flags does not contain SA_SIGINFO.  But in Linux 2.4,
+     for example, sa_sigaction and sa_handler are aliases and a signal
+     is ignored if sa_sigaction (after casting) equals SIG_IGN.  So
+     use (and cast) sa_sigaction in that case.  */
+  if (a->sa_flags & SA_SIGINFO)
+    return (sa_handler_t) a->sa_sigaction;
+#endif
+  return a->sa_handler;
+}
+
+#endif /* _GL_SIG_HANDLER_H */
diff --git a/lib/sigaction.c b/lib/sigaction.c
new file mode 100644
index 0000000..e6a55da
--- /dev/null
+++ b/lib/sigaction.c
@@ -0,0 +1,204 @@
+/* POSIX compatible signal blocking.
+   Copyright (C) 2008-2011 Free Software Foundation, Inc.
+   Written by Eric Blake <ebb9@byu.net>, 2008.
+
+   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 of the License, 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/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <signal.h>
+
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+/* This implementation of sigaction is tailored to Woe32 behavior:
+   signal() has SysV semantics (ie. the handler is uninstalled before
+   it is invoked).  This is an inherent data race if an asynchronous
+   signal is sent twice in a row before we can reinstall our handler,
+   but there's nothing we can do about it.  Meanwhile, sigprocmask()
+   is not present, and while we can use the gnulib replacement to
+   provide critical sections, it too suffers from potential data races
+   in the face of an ill-timed asynchronous signal.  And we compound
+   the situation by reading static storage in a signal handler, which
+   POSIX warns is not generically async-signal-safe.  Oh well.
+
+   Additionally:
+     - We don't implement SA_NOCLDSTOP or SA_NOCLDWAIT, because SIGCHLD
+       is not defined.
+     - We don't implement SA_ONSTACK, because sigaltstack() is not present.
+     - We ignore SA_RESTART, because blocking Win32 calls are not interrupted
+       anyway when an asynchronous signal occurs, and the MSVCRT runtime
+       never sets errno to EINTR.
+     - We don't implement SA_SIGINFO because it is impossible to do so
+       portably.
+
+   POSIX states that an application should not mix signal() and
+   sigaction().  We support the use of signal() within the gnulib
+   sigprocmask() substitute, but all other application code linked
+   with this module should stick with only sigaction().  */
+
+/* Check some of our assumptions.  */
+#if defined SIGCHLD || defined HAVE_SIGALTSTACK || defined HAVE_SIGINTERRUPT
+# error "Revisit the assumptions made in the sigaction module"
+#endif
+
+/* Out-of-range substitutes make a good fallback for uncatchable
+   signals.  */
+#ifndef SIGKILL
+# define SIGKILL (-1)
+#endif
+#ifndef SIGSTOP
+# define SIGSTOP (-1)
+#endif
+
+/* On native Windows, as of 2008, the signal SIGABRT_COMPAT is an alias
+   for the signal SIGABRT.  Only one signal handler is stored for both
+   SIGABRT and SIGABRT_COMPAT.  SIGABRT_COMPAT is not a signal of its own.  */
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+# undef SIGABRT_COMPAT
+# define SIGABRT_COMPAT 6
+#endif
+
+/* A signal handler.  */
+typedef void (*handler_t) (int signal);
+
+/* Set of current actions.  If sa_handler for an entry is NULL, then
+   that signal is not currently handled by the sigaction handler.  */
+static struct sigaction volatile action_array[NSIG] /* = 0 */;
+
+/* Signal handler that is installed for signals.  */
+static void
+sigaction_handler (int sig)
+{
+  handler_t handler;
+  sigset_t mask;
+  sigset_t oldmask;
+  int saved_errno = errno;
+  if (sig < 0 || NSIG <= sig || !action_array[sig].sa_handler)
+    {
+      /* Unexpected situation; be careful to avoid recursive abort.  */
+      if (sig == SIGABRT)
+        signal (SIGABRT, SIG_DFL);
+      abort ();
+    }
+
+  /* Reinstall the signal handler when required; otherwise update the
+     bookkeeping so that the user's handler may call sigaction and get
+     accurate results.  We know the signal isn't currently blocked, or
+     we wouldn't be in its handler, therefore we know that we are not
+     interrupting a sigaction() call.  There is a race where any
+     asynchronous instance of the same signal occurring before we
+     reinstall the handler will trigger the default handler; oh
+     well.  */
+  handler = action_array[sig].sa_handler;
+  if ((action_array[sig].sa_flags & SA_RESETHAND) == 0)
+    signal (sig, sigaction_handler);
+  else
+    action_array[sig].sa_handler = NULL;
+
+  /* Block appropriate signals.  */
+  mask = action_array[sig].sa_mask;
+  if ((action_array[sig].sa_flags & SA_NODEFER) == 0)
+    sigaddset (&mask, sig);
+  sigprocmask (SIG_BLOCK, &mask, &oldmask);
+
+  /* Invoke the user's handler, then restore prior mask.  */
+  errno = saved_errno;
+  handler (sig);
+  saved_errno = errno;
+  sigprocmask (SIG_SETMASK, &oldmask, NULL);
+  errno = saved_errno;
+}
+
+/* Change and/or query the action that will be taken on delivery of
+   signal SIG.  If not NULL, ACT describes the new behavior.  If not
+   NULL, OACT is set to the prior behavior.  Return 0 on success, or
+   set errno and return -1 on failure.  */
+int
+sigaction (int sig, const struct sigaction *restrict act,
+           struct sigaction *restrict oact)
+{
+  sigset_t mask;
+  sigset_t oldmask;
+  int saved_errno;
+
+  if (sig < 0 || NSIG <= sig || sig == SIGKILL || sig == SIGSTOP
+      || (act && act->sa_handler == SIG_ERR))
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
+#ifdef SIGABRT_COMPAT
+  if (sig == SIGABRT_COMPAT)
+    sig = SIGABRT;
+#endif
+
+  /* POSIX requires sigaction() to be async-signal-safe.  In other
+     words, if an asynchronous signal can occur while we are anywhere
+     inside this function, the user's handler could then call
+     sigaction() recursively and expect consistent results.  We meet
+     this rule by using sigprocmask to block all signals before
+     modifying any data structure that could be read from a signal
+     handler; this works since we know that the gnulib sigprocmask
+     replacement does not try to use sigaction() from its handler.  */
+  if (!act && !oact)
+    return 0;
+  sigfillset (&mask);
+  sigprocmask (SIG_BLOCK, &mask, &oldmask);
+  if (oact)
+    {
+      if (action_array[sig].sa_handler)
+        *oact = action_array[sig];
+      else
+        {
+          /* Safe to change the handler at will here, since all
+             signals are currently blocked.  */
+          oact->sa_handler = signal (sig, SIG_DFL);
+          if (oact->sa_handler == SIG_ERR)
+            goto failure;
+          signal (sig, oact->sa_handler);
+          oact->sa_flags = SA_RESETHAND | SA_NODEFER;
+          sigemptyset (&oact->sa_mask);
+        }
+    }
+
+  if (act)
+    {
+      /* Safe to install the handler before updating action_array,
+         since all signals are currently blocked.  */
+      if (act->sa_handler == SIG_DFL || act->sa_handler == SIG_IGN)
+        {
+          if (signal (sig, act->sa_handler) == SIG_ERR)
+            goto failure;
+          action_array[sig].sa_handler = NULL;
+        }
+      else
+        {
+          if (signal (sig, sigaction_handler) == SIG_ERR)
+            goto failure;
+          action_array[sig] = *act;
+        }
+    }
+  sigprocmask (SIG_SETMASK, &oldmask, NULL);
+  return 0;
+
+ failure:
+  saved_errno = errno;
+  sigprocmask (SIG_SETMASK, &oldmask, NULL);
+  errno = saved_errno;
+  return -1;
+}
diff --git a/lib/signal.in.h b/lib/signal.in.h
new file mode 100644
index 0000000..bcf7935
--- /dev/null
+++ b/lib/signal.in.h
@@ -0,0 +1,376 @@
+/* A GNU-like <signal.h>.
+
+   Copyright (C) 2006-2011 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 3 of the License, 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/>.  */
+
+#if __GNUC__ >= 3
+@PRAGMA_SYSTEM_HEADER@
+#endif
+@PRAGMA_COLUMNS@
+
+#if defined __need_sig_atomic_t || defined __need_sigset_t
+/* Special invocation convention inside glibc header files.  */
+
+# @INCLUDE_NEXT@ @NEXT_SIGNAL_H@
+
+#else
+/* Normal invocation convention.  */
+
+#ifndef _@GUARD_PREFIX@_SIGNAL_H
+
+/* The include_next requires a split double-inclusion guard.  */
+#@INCLUDE_NEXT@ @NEXT_SIGNAL_H@
+
+#ifndef _@GUARD_PREFIX@_SIGNAL_H
+#define _@GUARD_PREFIX@_SIGNAL_H
+
+/* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
+
+/* The definition of _GL_ARG_NONNULL is copied here.  */
+
+/* The definition of _GL_WARN_ON_USE is copied here.  */
+
+/* Define pid_t, uid_t.
+   Also, mingw defines sigset_t not in <signal.h>, but in <sys/types.h>.  */
+#include <sys/types.h>
+
+/* On AIX, sig_atomic_t already includes volatile.  C99 requires that
+   'volatile sig_atomic_t' ignore the extra modifier, but C89 did not.
+   Hence, redefine this to a non-volatile type as needed.  */
+#if ! @HAVE_TYPE_VOLATILE_SIG_ATOMIC_T@
+# if !GNULIB_defined_sig_atomic_t
+typedef int rpl_sig_atomic_t;
+#  undef sig_atomic_t
+#  define sig_atomic_t rpl_sig_atomic_t
+#  define GNULIB_defined_sig_atomic_t 1
+# endif
+#endif
+
+/* A set or mask of signals.  */
+#if !@HAVE_SIGSET_T@
+# if !GNULIB_defined_sigset_t
+typedef unsigned int sigset_t;
+#  define GNULIB_defined_sigset_t 1
+# endif
+#endif
+
+/* Define sighandler_t, the type of signal handlers.  A GNU extension.  */
+#if !@HAVE_SIGHANDLER_T@
+# ifdef __cplusplus
+extern "C" {
+# endif
+# if !GNULIB_defined_sighandler_t
+typedef void (*sighandler_t) (int);
+#  define GNULIB_defined_sighandler_t 1
+# endif
+# ifdef __cplusplus
+}
+# endif
+#endif
+
+
+#if @GNULIB_SIGNAL_H_SIGPIPE@
+# ifndef SIGPIPE
+/* Define SIGPIPE to a value that does not overlap with other signals.  */
+#  define SIGPIPE 13
+#  define GNULIB_defined_SIGPIPE 1
+/* To actually use SIGPIPE, you also need the gnulib modules 'sigprocmask',
+   'write', 'stdio'.  */
+# endif
+#endif
+
+
+/* Maximum signal number + 1.  */
+#ifndef NSIG
+# if defined __TANDEM
+#  define NSIG 32
+# endif
+#endif
+
+
+#if @GNULIB_SIGPROCMASK@
+# if !@HAVE_POSIX_SIGNALBLOCKING@
+
+/* Maximum signal number + 1.  */
+#  ifndef NSIG
+#   define NSIG 32
+#  endif
+
+/* This code supports only 32 signals.  */
+#  if !GNULIB_defined_verify_NSIG_constraint
+typedef int verify_NSIG_constraint[NSIG <= 32 ? 1 : -1];
+#   define GNULIB_defined_verify_NSIG_constraint 1
+#  endif
+
+# endif
+
+/* Test whether a given signal is contained in a signal set.  */
+# if @HAVE_POSIX_SIGNALBLOCKING@
+/* This function is defined as a macro on MacOS X.  */
+#  if defined __cplusplus && defined GNULIB_NAMESPACE
+#   undef sigismember
+#  endif
+# else
+_GL_FUNCDECL_SYS (sigismember, int, (const sigset_t *set, int sig)
+                                    _GL_ARG_NONNULL ((1)));
+# endif
+_GL_CXXALIAS_SYS (sigismember, int, (const sigset_t *set, int sig));
+_GL_CXXALIASWARN (sigismember);
+
+/* Initialize a signal set to the empty set.  */
+# if @HAVE_POSIX_SIGNALBLOCKING@
+/* This function is defined as a macro on MacOS X.  */
+#  if defined __cplusplus && defined GNULIB_NAMESPACE
+#   undef sigemptyset
+#  endif
+# else
+_GL_FUNCDECL_SYS (sigemptyset, int, (sigset_t *set) _GL_ARG_NONNULL ((1)));
+# endif
+_GL_CXXALIAS_SYS (sigemptyset, int, (sigset_t *set));
+_GL_CXXALIASWARN (sigemptyset);
+
+/* Add a signal to a signal set.  */
+# if @HAVE_POSIX_SIGNALBLOCKING@
+/* This function is defined as a macro on MacOS X.  */
+#  if defined __cplusplus && defined GNULIB_NAMESPACE
+#   undef sigaddset
+#  endif
+# else
+_GL_FUNCDECL_SYS (sigaddset, int, (sigset_t *set, int sig)
+                                  _GL_ARG_NONNULL ((1)));
+# endif
+_GL_CXXALIAS_SYS (sigaddset, int, (sigset_t *set, int sig));
+_GL_CXXALIASWARN (sigaddset);
+
+/* Remove a signal from a signal set.  */
+# if @HAVE_POSIX_SIGNALBLOCKING@
+/* This function is defined as a macro on MacOS X.  */
+#  if defined __cplusplus && defined GNULIB_NAMESPACE
+#   undef sigdelset
+#  endif
+# else
+_GL_FUNCDECL_SYS (sigdelset, int, (sigset_t *set, int sig)
+                                  _GL_ARG_NONNULL ((1)));
+# endif
+_GL_CXXALIAS_SYS (sigdelset, int, (sigset_t *set, int sig));
+_GL_CXXALIASWARN (sigdelset);
+
+/* Fill a signal set with all possible signals.  */
+# if @HAVE_POSIX_SIGNALBLOCKING@
+/* This function is defined as a macro on MacOS X.  */
+#  if defined __cplusplus && defined GNULIB_NAMESPACE
+#   undef sigfillset
+#  endif
+# else
+_GL_FUNCDECL_SYS (sigfillset, int, (sigset_t *set) _GL_ARG_NONNULL ((1)));
+# endif
+_GL_CXXALIAS_SYS (sigfillset, int, (sigset_t *set));
+_GL_CXXALIASWARN (sigfillset);
+
+/* Return the set of those blocked signals that are pending.  */
+# if !@HAVE_POSIX_SIGNALBLOCKING@
+_GL_FUNCDECL_SYS (sigpending, int, (sigset_t *set) _GL_ARG_NONNULL ((1)));
+# endif
+_GL_CXXALIAS_SYS (sigpending, int, (sigset_t *set));
+_GL_CXXALIASWARN (sigpending);
+
+/* If OLD_SET is not NULL, put the current set of blocked signals in *OLD_SET.
+   Then, if SET is not NULL, affect the current set of blocked signals by
+   combining it with *SET as indicated in OPERATION.
+   In this implementation, you are not allowed to change a signal handler
+   while the signal is blocked.  */
+# if !@HAVE_POSIX_SIGNALBLOCKING@
+#  define SIG_BLOCK   0  /* blocked_set = blocked_set | *set; */
+#  define SIG_SETMASK 1  /* blocked_set = *set; */
+#  define SIG_UNBLOCK 2  /* blocked_set = blocked_set & ~*set; */
+_GL_FUNCDECL_SYS (sigprocmask, int,
+                  (int operation, const sigset_t *set, sigset_t *old_set));
+# endif
+_GL_CXXALIAS_SYS (sigprocmask, int,
+                  (int operation, const sigset_t *set, sigset_t *old_set));
+_GL_CXXALIASWARN (sigprocmask);
+
+/* Install the handler FUNC for signal SIG, and return the previous
+   handler.  */
+# ifdef __cplusplus
+extern "C" {
+# endif
+# if !GNULIB_defined_function_taking_int_returning_void_t
+typedef void (*_gl_function_taking_int_returning_void_t) (int);
+#  define GNULIB_defined_function_taking_int_returning_void_t 1
+# endif
+# ifdef __cplusplus
+}
+# endif
+# if !@HAVE_POSIX_SIGNALBLOCKING@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define signal rpl_signal
+#  endif
+_GL_FUNCDECL_RPL (signal, _gl_function_taking_int_returning_void_t,
+                  (int sig, _gl_function_taking_int_returning_void_t func));
+_GL_CXXALIAS_RPL (signal, _gl_function_taking_int_returning_void_t,
+                  (int sig, _gl_function_taking_int_returning_void_t func));
+# else
+_GL_CXXALIAS_SYS (signal, _gl_function_taking_int_returning_void_t,
+                  (int sig, _gl_function_taking_int_returning_void_t func));
+# endif
+_GL_CXXALIASWARN (signal);
+
+/* Raise signal SIG.  */
+# if !@HAVE_POSIX_SIGNALBLOCKING@ && GNULIB_defined_SIGPIPE
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef raise
+#   define raise rpl_raise
+#  endif
+_GL_FUNCDECL_RPL (raise, int, (int sig));
+_GL_CXXALIAS_RPL (raise, int, (int sig));
+# else
+_GL_CXXALIAS_SYS (raise, int, (int sig));
+# endif
+_GL_CXXALIASWARN (raise);
+
+#elif defined GNULIB_POSIXCHECK
+# undef sigaddset
+# if HAVE_RAW_DECL_SIGADDSET
+_GL_WARN_ON_USE (sigaddset, "sigaddset is unportable - "
+                 "use the gnulib module sigprocmask for portability");
+# endif
+# undef sigdelset
+# if HAVE_RAW_DECL_SIGDELSET
+_GL_WARN_ON_USE (sigdelset, "sigdelset is unportable - "
+                 "use the gnulib module sigprocmask for portability");
+# endif
+# undef sigemptyset
+# if HAVE_RAW_DECL_SIGEMPTYSET
+_GL_WARN_ON_USE (sigemptyset, "sigemptyset is unportable - "
+                 "use the gnulib module sigprocmask for portability");
+# endif
+# undef sigfillset
+# if HAVE_RAW_DECL_SIGFILLSET
+_GL_WARN_ON_USE (sigfillset, "sigfillset is unportable - "
+                 "use the gnulib module sigprocmask for portability");
+# endif
+# undef sigismember
+# if HAVE_RAW_DECL_SIGISMEMBER
+_GL_WARN_ON_USE (sigismember, "sigismember is unportable - "
+                 "use the gnulib module sigprocmask for portability");
+# endif
+# undef sigpending
+# if HAVE_RAW_DECL_SIGPENDING
+_GL_WARN_ON_USE (sigpending, "sigpending is unportable - "
+                 "use the gnulib module sigprocmask for portability");
+# endif
+# undef sigprocmask
+# if HAVE_RAW_DECL_SIGPROCMASK
+_GL_WARN_ON_USE (sigprocmask, "sigprocmask is unportable - "
+                 "use the gnulib module sigprocmask for portability");
+# endif
+#endif /* @GNULIB_SIGPROCMASK@ */
+
+
+#if @GNULIB_SIGACTION@
+# if !@HAVE_SIGACTION@
+
+#  if !@HAVE_SIGINFO_T@
+
+#   if !GNULIB_defined_siginfo_types
+
+/* Present to allow compilation, but unsupported by gnulib.  */
+union sigval
+{
+  int sival_int;
+  void *sival_ptr;
+};
+
+/* Present to allow compilation, but unsupported by gnulib.  */
+struct siginfo_t
+{
+  int si_signo;
+  int si_code;
+  int si_errno;
+  pid_t si_pid;
+  uid_t si_uid;
+  void *si_addr;
+  int si_status;
+  long si_band;
+  union sigval si_value;
+};
+typedef struct siginfo_t siginfo_t;
+
+#    define GNULIB_defined_siginfo_types 1
+#   endif
+
+#  endif /* !@HAVE_SIGINFO_T@ */
+
+/* We assume that platforms which lack the sigaction() function also lack
+   the 'struct sigaction' type, and vice versa.  */
+
+#  if !GNULIB_defined_struct_sigaction
+
+struct sigaction
+{
+  union
+  {
+    void (*_sa_handler) (int);
+    /* Present to allow compilation, but unsupported by gnulib.  POSIX
+       says that implementations may, but not must, make sa_sigaction
+       overlap with sa_handler, but we know of no implementation where
+       they do not overlap.  */
+    void (*_sa_sigaction) (int, siginfo_t *, void *);
+  } _sa_func;
+  sigset_t sa_mask;
+  /* Not all POSIX flags are supported.  */
+  int sa_flags;
+};
+#   define sa_handler _sa_func._sa_handler
+#   define sa_sigaction _sa_func._sa_sigaction
+/* Unsupported flags are not present.  */
+#   define SA_RESETHAND 1
+#   define SA_NODEFER 2
+#   define SA_RESTART 4
+
+#   define GNULIB_defined_struct_sigaction 1
+#  endif
+
+_GL_FUNCDECL_SYS (sigaction, int, (int, const struct sigaction *restrict,
+                                   struct sigaction *restrict));
+
+# elif !@HAVE_STRUCT_SIGACTION_SA_SIGACTION@
+
+#  define sa_sigaction sa_handler
+
+# endif /* !@HAVE_SIGACTION@, !@HAVE_STRUCT_SIGACTION_SA_SIGACTION@ */
+
+_GL_CXXALIAS_SYS (sigaction, int, (int, const struct sigaction *restrict,
+                                   struct sigaction *restrict));
+_GL_CXXALIASWARN (sigaction);
+
+#elif defined GNULIB_POSIXCHECK
+# undef sigaction
+# if HAVE_RAW_DECL_SIGACTION
+_GL_WARN_ON_USE (sigaction, "sigaction is unportable - "
+                 "use the gnulib module sigaction for portability");
+# endif
+#endif
+
+/* Some systems don't have SA_NODEFER.  */
+#ifndef SA_NODEFER
+# define SA_NODEFER 0
+#endif
+
+
+#endif /* _@GUARD_PREFIX@_SIGNAL_H */
+#endif /* _@GUARD_PREFIX@_SIGNAL_H */
+#endif
diff --git a/lib/sigprocmask.c b/lib/sigprocmask.c
new file mode 100644
index 0000000..6780a37
--- /dev/null
+++ b/lib/sigprocmask.c
@@ -0,0 +1,329 @@
+/* POSIX compatible signal blocking.
+   Copyright (C) 2006-2011 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+   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 of the License, 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/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <signal.h>
+
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+/* We assume that a platform without POSIX signal blocking functions
+   also does not have the POSIX sigaction() function, only the
+   signal() function.  We also assume signal() has SysV semantics,
+   where any handler is uninstalled prior to being invoked.  This is
+   true for Woe32 platforms.  */
+
+/* We use raw signal(), but also provide a wrapper rpl_signal() so
+   that applications can query or change a blocked signal.  */
+#undef signal
+
+/* Provide invalid signal numbers as fallbacks if the uncatchable
+   signals are not defined.  */
+#ifndef SIGKILL
+# define SIGKILL (-1)
+#endif
+#ifndef SIGSTOP
+# define SIGSTOP (-1)
+#endif
+
+/* On native Windows, as of 2008, the signal SIGABRT_COMPAT is an alias
+   for the signal SIGABRT.  Only one signal handler is stored for both
+   SIGABRT and SIGABRT_COMPAT.  SIGABRT_COMPAT is not a signal of its own.  */
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+# undef SIGABRT_COMPAT
+# define SIGABRT_COMPAT 6
+#endif
+#ifdef SIGABRT_COMPAT
+# define SIGABRT_COMPAT_MASK (1U << SIGABRT_COMPAT)
+#else
+# define SIGABRT_COMPAT_MASK 0
+#endif
+
+typedef void (*handler_t) (int);
+
+/* Handling of gnulib defined signals.  */
+
+#if GNULIB_defined_SIGPIPE
+static handler_t SIGPIPE_handler = SIG_DFL;
+#endif
+
+#if GNULIB_defined_SIGPIPE
+static handler_t
+ext_signal (int sig, handler_t handler)
+{
+  switch (sig)
+    {
+    case SIGPIPE:
+      {
+        handler_t old_handler = SIGPIPE_handler;
+        SIGPIPE_handler = handler;
+        return old_handler;
+      }
+    default: /* System defined signal */
+      return signal (sig, handler);
+    }
+}
+# define signal ext_signal
+#endif
+
+int
+sigismember (const sigset_t *set, int sig)
+{
+  if (sig >= 0 && sig < NSIG)
+    {
+      #ifdef SIGABRT_COMPAT
+      if (sig == SIGABRT_COMPAT)
+        sig = SIGABRT;
+      #endif
+
+      return (*set >> sig) & 1;
+    }
+  else
+    return 0;
+}
+
+int
+sigemptyset (sigset_t *set)
+{
+  *set = 0;
+  return 0;
+}
+
+int
+sigaddset (sigset_t *set, int sig)
+{
+  if (sig >= 0 && sig < NSIG)
+    {
+      #ifdef SIGABRT_COMPAT
+      if (sig == SIGABRT_COMPAT)
+        sig = SIGABRT;
+      #endif
+
+      *set |= 1U << sig;
+      return 0;
+    }
+  else
+    {
+      errno = EINVAL;
+      return -1;
+    }
+}
+
+int
+sigdelset (sigset_t *set, int sig)
+{
+  if (sig >= 0 && sig < NSIG)
+    {
+      #ifdef SIGABRT_COMPAT
+      if (sig == SIGABRT_COMPAT)
+        sig = SIGABRT;
+      #endif
+
+      *set &= ~(1U << sig);
+      return 0;
+    }
+  else
+    {
+      errno = EINVAL;
+      return -1;
+    }
+}
+
+
+int
+sigfillset (sigset_t *set)
+{
+  *set = ((2U << (NSIG - 1)) - 1) & ~ SIGABRT_COMPAT_MASK;
+  return 0;
+}
+
+/* Set of currently blocked signals.  */
+static volatile sigset_t blocked_set /* = 0 */;
+
+/* Set of currently blocked and pending signals.  */
+static volatile sig_atomic_t pending_array[NSIG] /* = { 0 } */;
+
+/* Signal handler that is installed for blocked signals.  */
+static void
+blocked_handler (int sig)
+{
+  /* Reinstall the handler, in case the signal occurs multiple times
+     while blocked.  There is an inherent race where an asynchronous
+     signal in between when the kernel uninstalled the handler and
+     when we reinstall it will trigger the default handler; oh
+     well.  */
+  signal (sig, blocked_handler);
+  if (sig >= 0 && sig < NSIG)
+    pending_array[sig] = 1;
+}
+
+int
+sigpending (sigset_t *set)
+{
+  sigset_t pending = 0;
+  int sig;
+
+  for (sig = 0; sig < NSIG; sig++)
+    if (pending_array[sig])
+      pending |= 1U << sig;
+  *set = pending;
+  return 0;
+}
+
+/* The previous signal handlers.
+   Only the array elements corresponding to blocked signals are relevant.  */
+static volatile handler_t old_handlers[NSIG];
+
+int
+sigprocmask (int operation, const sigset_t *set, sigset_t *old_set)
+{
+  if (old_set != NULL)
+    *old_set = blocked_set;
+
+  if (set != NULL)
+    {
+      sigset_t new_blocked_set;
+      sigset_t to_unblock;
+      sigset_t to_block;
+
+      switch (operation)
+        {
+        case SIG_BLOCK:
+          new_blocked_set = blocked_set | *set;
+          break;
+        case SIG_SETMASK:
+          new_blocked_set = *set;
+          break;
+        case SIG_UNBLOCK:
+          new_blocked_set = blocked_set & ~*set;
+          break;
+        default:
+          errno = EINVAL;
+          return -1;
+        }
+      to_unblock = blocked_set & ~new_blocked_set;
+      to_block = new_blocked_set & ~blocked_set;
+
+      if (to_block != 0)
+        {
+          int sig;
+
+          for (sig = 0; sig < NSIG; sig++)
+            if ((to_block >> sig) & 1)
+              {
+                pending_array[sig] = 0;
+                if ((old_handlers[sig] = signal (sig, blocked_handler)) != SIG_ERR)
+                  blocked_set |= 1U << sig;
+              }
+        }
+
+      if (to_unblock != 0)
+        {
+          sig_atomic_t received[NSIG];
+          int sig;
+
+          for (sig = 0; sig < NSIG; sig++)
+            if ((to_unblock >> sig) & 1)
+              {
+                if (signal (sig, old_handlers[sig]) != blocked_handler)
+                  /* The application changed a signal handler while the signal
+                     was blocked, bypassing our rpl_signal replacement.
+                     We don't support this.  */
+                  abort ();
+                received[sig] = pending_array[sig];
+                blocked_set &= ~(1U << sig);
+                pending_array[sig] = 0;
+              }
+            else
+              received[sig] = 0;
+
+          for (sig = 0; sig < NSIG; sig++)
+            if (received[sig])
+              raise (sig);
+        }
+    }
+  return 0;
+}
+
+/* Install the handler FUNC for signal SIG, and return the previous
+   handler.  */
+handler_t
+rpl_signal (int sig, handler_t handler)
+{
+  /* We must provide a wrapper, so that a user can query what handler
+     they installed even if that signal is currently blocked.  */
+  if (sig >= 0 && sig < NSIG && sig != SIGKILL && sig != SIGSTOP
+      && handler != SIG_ERR)
+    {
+      #ifdef SIGABRT_COMPAT
+      if (sig == SIGABRT_COMPAT)
+        sig = SIGABRT;
+      #endif
+
+      if (blocked_set & (1U << sig))
+        {
+          /* POSIX states that sigprocmask and signal are both
+             async-signal-safe.  This is not true of our
+             implementation - there is a slight data race where an
+             asynchronous interrupt on signal A can occur after we
+             install blocked_handler but before we have updated
+             old_handlers for signal B, such that handler A can see
+             stale information if it calls signal(B).  Oh well -
+             signal handlers really shouldn't try to manipulate the
+             installed handlers of unrelated signals.  */
+          handler_t result = old_handlers[sig];
+          old_handlers[sig] = handler;
+          return result;
+        }
+      else
+        return signal (sig, handler);
+    }
+  else
+    {
+      errno = EINVAL;
+      return SIG_ERR;
+    }
+}
+
+#if GNULIB_defined_SIGPIPE
+/* Raise the signal SIG.  */
+int
+rpl_raise (int sig)
+# undef raise
+{
+  switch (sig)
+    {
+    case SIGPIPE:
+      if (blocked_set & (1U << sig))
+        pending_array[sig] = 1;
+      else
+        {
+          handler_t handler = SIGPIPE_handler;
+          if (handler == SIG_DFL)
+            exit (128 + SIGPIPE);
+          else if (handler != SIG_IGN)
+            (*handler) (sig);
+        }
+      return 0;
+    default: /* System defined signal */
+      return raise (sig);
+    }
+}
+#endif
diff --git a/m4/.gitignore b/m4/.gitignore
deleted file mode 100644
index e69de29..0000000
--- a/m4/.gitignore
+++ /dev/null
diff --git a/m4/gnulib-cache.m4 b/m4/gnulib-cache.m4
index 1d268d5..09970a0 100644
--- a/m4/gnulib-cache.m4
+++ b/m4/gnulib-cache.m4
@@ -15,12 +15,14 @@
 
 
 # Specification in the form of a command-line invocation:
-#   gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=. --no-conditional-dependencies --no-libtool --macro-prefix=gl memmem
+#   gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=. --no-conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files memmem sigaction signal
 
 # Specification in the form of a few gnulib-tool.m4 macro invocations:
 gl_LOCAL_DIR([])
 gl_MODULES([
   memmem
+  sigaction
+  signal
 ])
 gl_AVOID([])
 gl_SOURCE_BASE([lib])
@@ -33,3 +35,4 @@ gl_MAKEFILE_NAME([])
 gl_MACRO_PREFIX([gl])
 gl_PO_DOMAIN([])
 gl_WITNESS_C_DOMAIN([])
+gl_VC_FILES([false])
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index d0ae0c1..ba727d7 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -15,6 +15,7 @@
 # In projects that use version control, this file can be treated like
 # other built files.
 
+
 # This macro should be invoked from ./configure.ac, in the section
 # "Checks for programs", right after AC_PROG_CC, and certainly before
 # any checks for libraries, header files, types and library functions.
@@ -34,6 +35,9 @@ AC_DEFUN([gl_EARLY],
   # Code from module memmem:
   # Code from module memmem-simple:
   # Code from module multiarch:
+  # Code from module sigaction:
+  # Code from module signal:
+  # Code from module sigprocmask:
   # Code from module stddef:
   # Code from module stdint:
   # Code from module string:
@@ -72,6 +76,19 @@ if test $HAVE_MEMMEM = 0 || test $REPLACE_MEMMEM = 1; then
 fi
 gl_STRING_MODULE_INDICATOR([memmem])
 gl_MULTIARCH
+gl_SIGACTION
+if test $HAVE_SIGACTION = 0; then
+  AC_LIBOBJ([sigaction])
+  gl_PREREQ_SIGACTION
+fi
+gl_SIGNAL_MODULE_INDICATOR([sigaction])
+gl_SIGNAL_H
+gl_SIGNALBLOCKING
+if test $HAVE_POSIX_SIGNALBLOCKING = 0; then
+  AC_LIBOBJ([sigprocmask])
+  gl_PREREQ_SIGPROCMASK
+fi
+gl_SIGNAL_MODULE_INDICATOR([sigprocmask])
 gl_STDDEF_H
 gl_STDINT_H
 gl_HEADER_STRING_H
@@ -222,6 +239,10 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/memchr.c
   lib/memchr.valgrind
   lib/memmem.c
+  lib/sig-handler.h
+  lib/sigaction.c
+  lib/signal.in.h
+  lib/sigprocmask.c
   lib/stddef.in.h
   lib/stdint.in.h
   lib/str-two-way.h
@@ -236,6 +257,9 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/mmap-anon.m4
   m4/multiarch.m4
   m4/onceonly.m4
+  m4/sigaction.m4
+  m4/signal_h.m4
+  m4/signalblocking.m4
   m4/stddef_h.m4
   m4/stdint.m4
   m4/string_h.m4
diff --git a/m4/sigaction.m4 b/m4/sigaction.m4
new file mode 100644
index 0000000..b365e26
--- /dev/null
+++ b/m4/sigaction.m4
@@ -0,0 +1,43 @@
+# sigaction.m4 serial 6
+dnl Copyright (C) 2008-2011 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+# Determine if sigaction interface is present.
+AC_DEFUN([gl_SIGACTION],
+[
+  AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])
+  AC_CHECK_FUNCS_ONCE([sigaction])
+  if test $ac_cv_func_sigaction = yes; then
+    AC_CHECK_MEMBERS([struct sigaction.sa_sigaction], , ,
+                     [[#include <signal.h>]])
+    if test $ac_cv_member_struct_sigaction_sa_sigaction = no; then
+      HAVE_STRUCT_SIGACTION_SA_SIGACTION=0
+    fi
+  else
+    HAVE_SIGACTION=0
+  fi
+])
+
+# Prerequisites of the part of lib/signal.in.h and of lib/sigaction.c.
+AC_DEFUN([gl_PREREQ_SIGACTION],
+[
+  AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])
+  AC_REQUIRE([AC_C_RESTRICT])
+  AC_REQUIRE([AC_TYPE_UID_T])
+  AC_REQUIRE([gl_PREREQ_SIG_HANDLER_H])
+  AC_CHECK_FUNCS_ONCE([sigaltstack siginterrupt])
+  AC_CHECK_TYPES([siginfo_t], [], [], [[
+#include <signal.h>
+  ]])
+  if test $ac_cv_type_siginfo_t = no; then
+    HAVE_SIGINFO_T=0
+  fi
+])
+
+# Prerequisites of lib/sig-handler.h.
+AC_DEFUN([gl_PREREQ_SIG_HANDLER_H],
+[
+  AC_REQUIRE([AC_C_INLINE])
+])
diff --git a/m4/signal_h.m4 b/m4/signal_h.m4
new file mode 100644
index 0000000..459ec00
--- /dev/null
+++ b/m4/signal_h.m4
@@ -0,0 +1,58 @@
+# signal_h.m4 serial 12
+dnl Copyright (C) 2007-2011 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_SIGNAL_H],
+[
+  AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])
+  gl_NEXT_HEADERS([signal.h])
+
+# AIX declares sig_atomic_t to already include volatile, and C89 compilers
+# then choke on 'volatile sig_atomic_t'.  C99 requires that it compile.
+  AC_CHECK_TYPE([volatile sig_atomic_t], [],
+    [HAVE_TYPE_VOLATILE_SIG_ATOMIC_T=0], [[
+#include <signal.h>
+    ]])
+
+  AC_REQUIRE([AC_TYPE_UID_T])
+
+  dnl Persuade glibc <signal.h> to define sighandler_t.
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+  AC_CHECK_TYPE([sighandler_t], [], [HAVE_SIGHANDLER_T=0], [[
+#include <signal.h>
+    ]])
+
+  dnl Check for declarations of anything we want to poison if the
+  dnl corresponding gnulib module is not in use.
+  gl_WARN_ON_USE_PREPARE([[#include <signal.h>
+    ]], [sigaction sigaddset sigdelset sigemptyset sigfillset sigismember
+    sigpending sigprocmask])
+])
+
+AC_DEFUN([gl_SIGNAL_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])
+  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
+  dnl Define it also as a C macro, for the benefit of the unit tests.
+  gl_MODULE_INDICATOR_FOR_TESTS([$1])
+])
+
+AC_DEFUN([gl_SIGNAL_H_DEFAULTS],
+[
+  GNULIB_SIGNAL_H_SIGPIPE=0;   AC_SUBST([GNULIB_SIGNAL_H_SIGPIPE])
+  GNULIB_SIGPROCMASK=0;        AC_SUBST([GNULIB_SIGPROCMASK])
+  GNULIB_SIGACTION=0;          AC_SUBST([GNULIB_SIGACTION])
+  dnl Assume proper GNU behavior unless another module says otherwise.
+  HAVE_POSIX_SIGNALBLOCKING=1; AC_SUBST([HAVE_POSIX_SIGNALBLOCKING])
+  HAVE_SIGSET_T=1;             AC_SUBST([HAVE_SIGSET_T])
+  HAVE_SIGINFO_T=1;            AC_SUBST([HAVE_SIGINFO_T])
+  HAVE_SIGACTION=1;            AC_SUBST([HAVE_SIGACTION])
+  HAVE_STRUCT_SIGACTION_SA_SIGACTION=1;
+                               AC_SUBST([HAVE_STRUCT_SIGACTION_SA_SIGACTION])
+  HAVE_TYPE_VOLATILE_SIG_ATOMIC_T=1;
+                               AC_SUBST([HAVE_TYPE_VOLATILE_SIG_ATOMIC_T])
+  HAVE_SIGHANDLER_T=1;         AC_SUBST([HAVE_SIGHANDLER_T])
+])
diff --git a/m4/signalblocking.m4 b/m4/signalblocking.m4
new file mode 100644
index 0000000..6e83f1b
--- /dev/null
+++ b/m4/signalblocking.m4
@@ -0,0 +1,40 @@
+# signalblocking.m4 serial 11
+dnl Copyright (C) 2001-2002, 2006-2011 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+# Determine available signal blocking primitives. Three different APIs exist:
+# 1) POSIX: sigemptyset, sigaddset, sigprocmask
+# 2) SYSV: sighold, sigrelse
+# 3) BSD: sigblock, sigsetmask
+# For simplicity, here we check only for the POSIX signal blocking.
+AC_DEFUN([gl_SIGNALBLOCKING],
+[
+  AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])
+  signals_not_posix=
+  AC_EGREP_HEADER([sigset_t], [signal.h], , [signals_not_posix=1])
+  if test -z "$signals_not_posix"; then
+    AC_CHECK_FUNC([sigprocmask], [gl_cv_func_sigprocmask=1])
+  fi
+  if test -z "$gl_cv_func_sigprocmask"; then
+    HAVE_POSIX_SIGNALBLOCKING=0
+  fi
+])
+
+# Prerequisites of the part of lib/signal.in.h and of lib/sigprocmask.c.
+AC_DEFUN([gl_PREREQ_SIGPROCMASK],
+[
+  AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])
+  AC_CHECK_TYPES([sigset_t],
+    [gl_cv_type_sigset_t=yes], [gl_cv_type_sigset_t=no],
+    [#include <signal.h>
+/* Mingw defines sigset_t not in <signal.h>, but in <sys/types.h>.  */
+#include <sys/types.h>])
+  if test $gl_cv_type_sigset_t != yes; then
+    HAVE_SIGSET_T=0
+  fi
+  dnl HAVE_SIGSET_T is 1 if the system lacks the sigprocmask function but has
+  dnl the sigset_t type.
+  AC_SUBST([HAVE_SIGSET_T])
+])