Introduce loadable pseudo-random number generators.

N.B. The PRNG interface introduced here is subject to review and may change.

PRNGs are per-thread and may be changed with the new loadrng() standard
function. Two PRNGs are present:
   IconEx   A reimplementation of the traditional generator
            as a loadable library.
   Rabbit   A cryptographically strong PRNG from the eSTREAM project.
Other PRNGs -- probably RanLux and the Mersenne Twister -- will follow.

Makedefs.in

@@ -118,9 +118,11 @@ datarootdir=@datarootdir@
 docdir=@docdir@
 mandir=@mandir@
 htmldir=@htmldir@
-
-SQLITE=@SQLITE@
 
+# Used by plugins
+SQLITE=@SQLITE@
+GSLRNG=@GSLRNG@
+RNGLIBS=@RNGLIBS@
 
 #  configuration parameters
 

Makefile

@@ -301,6 +301,7 @@ install Install:
 	  $(INST) -m 644 uni/$$d/*.* $(DESTDIR)$(ULB)/$$d; \
 	done
 #       plugins
+	@$(MAKE) -C plugins/rngLibraries install
 	@$(INST) -m 644 plugins/lib/*.* $(DESTDIR)$(UPLUGINS)/ || true
 #	docs and man
 	@echo "Installing $(DESTDIR)$(mandir)/man1/unicon.1 ..."

Makefile.in

@@ -301,6 +301,7 @@ install Install:
 	  $(INST) -m 644 uni/$$d/*.* $(DESTDIR)$(ULB)/$$d; \
 	done
 #       plugins
+	@$(MAKE) -C plugins/rngLibraries install
 	@$(INST) -m 644 plugins/lib/*.* $(DESTDIR)$(UPLUGINS)/ || true
 #	docs and man
 	@echo "Installing $(DESTDIR)$(mandir)/man1/unicon.1 ..."

configure

@@ -639,7 +639,9 @@ XL
 GRAPHICS
 XLIBS
 CXXCPP
+GSLRNG
 SQLITE
+RNGLIBS
 LIBOBJS
 HTMLDOC
 UDOC
@@ -763,6 +765,7 @@ enable_iconcurrency
 enable_ovld
 enable_udbtools
 enable_progs
+enable_rnglibs
 enable_verbosebuild
 enable_doc
 enable_htmldoc
@@ -1444,6 +1447,7 @@ Optional Features:
   --enable-ovld           Enable operator overloading
   --enable-udbtools       Enable Unicon debugger tools
   --enable-progs          Enable Unicon programs
+  --enable-rnglibs        Enable loadable random number generators
   --enable-verbosebuild   Show full CC build lines with all compiler arguments
   --enable-doc            Add makefile rule to build documentation
   --enable-htmldoc        Add makefile rule to html documentation
@@ -3216,6 +3220,13 @@ else
   verifyheap=no
 fi
 
+# Check whether --enable-rnglibs was given.
+if test "${enable_rnglibs+set}" = set; then :
+  enableval=$enable_rnglibs; rnglibs=yes
+else
+  rnglibs=no
+fi
+
 # Check whether --enable-devmode was given.
 if test "${enable_devmode+set}" = set; then :
   enableval=$enable_devmode; devmode=yes
@@ -4695,6 +4706,7 @@ else
 			CFLAGS="$ac_c_flag_save"
 			{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
+
 			 ARCHFLAG=""
 
 
@@ -4755,6 +4767,14 @@ $as_echo "#define VerifyHeap 1" >>confdefs.h
 
 fi
 
+if test x"$rnglibs" = x"yes" ; then
+
+$as_echo "#define RngLibrary 1" >>confdefs.h
+
+RNGLIBS=1
+
+fi
+
 if test x"$udbtools" = x"yes" ; then
   UDBTOOLS=udbtools
 fi
@@ -7624,7 +7644,7 @@ _ACEOF
 fi
 
 
-# we don't need sqlite to be added to $LIBS, not yet at least
+# Check for libs for plugin use, don't add to these to $LIBS
 saved_libs="$LIBS"
 for ac_header in sqlite3.h
 do :
@@ -7683,6 +7703,63 @@ _ACEOF
 
 fi
 
+for ac_header in gsl/gsl_rng.h
+do :
+  ac_fn_c_check_header_mongrel "$LINENO" "gsl/gsl_rng.h" "ac_cv_header_gsl_gsl_rng_h" "$ac_includes_default"
+if test "x$ac_cv_header_gsl_gsl_rng_h" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_GSL_GSL_RNG_H 1
+_ACEOF
+
+fi
+
+done
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for gsl_rng_set in -lgsl" >&5
+$as_echo_n "checking for gsl_rng_set in -lgsl... " >&6; }
+if ${ac_cv_lib_gsl_gsl_rng_set+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lgsl  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char gsl_rng_set ();
+int
+main ()
+{
+return gsl_rng_set ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_gsl_gsl_rng_set=yes
+else
+  ac_cv_lib_gsl_gsl_rng_set=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_gsl_gsl_rng_set" >&5
+$as_echo "$ac_cv_lib_gsl_gsl_rng_set" >&6; }
+if test "x$ac_cv_lib_gsl_gsl_rng_set" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBGSL 1
+_ACEOF
+
+  LIBS="-lgsl $LIBS"
+
+fi
+
+
 LIBS="$saved_libs"
 
 if test "x$ac_cv_header_sqlite3_h" = "xyes" -a  "x$ac_cv_lib_sqlite3_sqlite3_config" = "xyes"; then
@@ -7691,6 +7768,14 @@ else
   SQLITE=""
 fi
 
+if test "x$ac_cv_header_gsl_gsl_rng_h" = "xyes" -a  "x$ac_cv_lib_gsl_gsl_rng_set" = "xyes"; then
+  GSLRNG="gsl"
+else
+  GSLRNG=""
+fi
+
+
+
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing getaddrinfo" >&5
 $as_echo_n "checking for library containing getaddrinfo... " >&6; }

configure.ac

@@ -153,6 +153,10 @@ AC_ARG_ENABLE([progs],
 	[AS_HELP_STRING([--enable-progs], [Enable Unicon programs])],
 			[progs=yes], [progs=no])
 
+AC_ARG_ENABLE([rnglibs],
+	[AS_HELP_STRING([--enable-rnglibs], [Enable loadable random number generators])],
+			[rnglibs=yes], [rnglibs=no])
+
 AC_ARG_ENABLE([verbosebuild],
 	[AS_HELP_STRING([--enable-verbosebuild], [Show full CC build lines with all compiler arguments])],
 			[verbosebuild=yes], [verbosebuild=no])
@@ -259,6 +263,11 @@ if test x"$verifyheap" = x"yes" ; then
   AC_DEFINE([VerifyHeap], [1], [Verify Heap])
 fi
 
+if test x"$rnglibs" = x"yes" ; then
+  AC_DEFINE([RngLibrary], [1], [Rng Library])
+  AC_SUBST(RNGLIBS,1)
+fi
+
 if test x"$udbtools" = x"yes" ; then
   UDBTOOLS=udbtools
 fi
@@ -545,18 +554,30 @@ AC_FUNC_FORK()
 AC_CHECK_LIB(dbm,main)
 AC_CHECK_LIB(ndbm,main)
 
-# we don't need sqlite to be added to $LIBS, not yet at least
+# Check for libs for plugin use, don't add to these to $LIBS
 saved_libs="$LIBS"
 AC_CHECK_HEADERS([sqlite3.h])
 AC_CHECK_LIB(sqlite3, sqlite3_config)
+
+AC_CHECK_HEADERS([gsl/gsl_rng.h])
+AC_CHECK_LIB(gsl, gsl_rng_set)
+
 LIBS="$saved_libs"
 
 if test "x$ac_cv_header_sqlite3_h" = "xyes" -a  "x$ac_cv_lib_sqlite3_sqlite3_config" = "xyes"; then
   SQLITE="sqlite"
 else
   SQLITE=""
 fi
+
+if test "x$ac_cv_header_gsl_gsl_rng_h" = "xyes" -a  "x$ac_cv_lib_gsl_gsl_rng_set" = "xyes"; then
+  GSLRNG="gsl"
+else
+  GSLRNG=""
+fi
+
 AC_SUBST(SQLITE)
+AC_SUBST(GSLRNG)
 
 AC_SEARCH_LIBS([getaddrinfo],[socket],
 	[AC_DEFINE([HAVE_GETADDRINFO], [1], [getaddinfo])])

doc/book/experimental.tex

@@ -43,6 +43,42 @@ \section{Extensions to \texttt{\&random}}
 This feature allows the programmer to choose from a portfolio of different
 random number generators (in addition to the one provided by Icon). It is also
 possible to implement other generators and use them without rebuilding Unicon.
-More than one generator may be in use at the same time.
-It may be enabled by defining the C preprocessor symbol \texttt{RngLibrary}
-before rebuilding the Unicon system.
+More than one generator may be in use at the same time.  It may be enabled by
+using the \texttt{-{}-enable-rnglibs} option to \texttt{configure} before
+rebuilding the Unicon system.
+
+If the extension is enabled four new standard functions are defined:
+\bigskip\hrule\vspace{0.1cm}
+\noindent
+{\bf loadrng(s) : string? } \hfill {\bf load PRNG}
+
+\noindent
+\texttt{loadrng(s)} replaces the generator in use by the current thread with the generator
+denoted by \texttt{s}. \texttt{loadrng("rngIcon")} will reload the default generator.
+\texttt{loadrng()} returns the name of the generator in use. The \texttt{?} operator will
+use the loaded generator to produce random numbers.
+
+\bigskip\hrule\vspace{0.1cm}
+\noindent
+{\bf rngbits(i) : array? } \hfill {\bf return random bits}
+
+\noindent
+\texttt{rngbits(n)} returns an integer array that contains at least \texttt{n} randomly
+generated bits. If \texttt{n} is negative no bits are returned but the generator will skip
+ahead as if the bits were actually returned. If \texttt{n} is zero it is an invitation to
+supply the ``natural size'' of the generator (which is probably a power of two).
+
+\bigskip\hrule\vspace{0.1cm}
+\noindent
+{\bf rngbitstring(i) : string? } \hfill {\bf return random bits}
+
+\noindent
+\texttt{rngbitstring(n)} returns a string that contains \texttt{n}
+randomly generated \texttt{0} and \texttt{1} characters.
+
+\bigskip\hrule\vspace{0.1cm}
+\noindent
+{\bf rngval() : integer? } \hfill {\bf return random value}
+
+\noindent
+\texttt{rngval()} returns a  randomly generated integer value.