Replace CL_REQUIRE/CL_PROVIDE(cl_UP_unnamed) with portable code.

The order of initialization of non-local objects in different compilation units
is not specified in C++. Hence special care should be taken to avoid static
initialization order fiasco. CLN solved the problem with some evil (GCC
specific, and even GCC-version-specific) hack. Replace it with a technique
similar to one used in STL to initialize std::cout and friends.

diff --git a/include/cln/univpoly.h b/include/cln/univpoly.h
index 0116827a7052abb8fd04b97152b74020c34322ee..2ede66fb517765f04c0ad5d3a40d35d9e39218b5 100644 (file)
--- a/include/cln/univpoly.h
+++ b/include/cln/univpoly.h
@@ -348,7 +348,6 @@ public:
 
 // Lookup or create the "standard" univariate polynomial ring over a ring r.
 extern const cl_univpoly_ring find_univpoly_ring (const cl_ring& r);
-//CL_REQUIRE(cl_UP_unnamed)
 
 // Lookup or create a univariate polynomial ring with a named variable over r.
 extern const cl_univpoly_ring find_univpoly_ring (const cl_ring& r, const cl_symbol& varname);

diff --git a/src/polynomial/elem/cl_UP_unnamed.cc b/src/polynomial/elem/cl_UP_unnamed.cc
index 0ca47d26358d224d87f63a2d077fa396ee4f19aa..8b0ef32c7b72ba030ec271099b00c994e26e98ff 100644 (file)
--- a/src/polynomial/elem/cl_UP_unnamed.cc
+++ b/src/polynomial/elem/cl_UP_unnamed.cc
@@ -3,8 +3,6 @@
 // General includes.
 #include "cl_sysdep.h"
 
-CL_PROVIDE(cl_UP_unnamed)
-
 // Specification.
 #include "cln/univpoly.h"
 
@@ -34,26 +32,46 @@ static bool maygc_htentry (const cl_htentry_from_rcpointer_to_rcpointer& entry)
        return false;
 }
 
-static const cl_wht_from_rcpointer_to_rcpointer univpoly_ring_table = cl_wht_from_rcpointer_to_rcpointer(maygc_htentry);
+class univpoly_ring_cache
+{
+       static cl_wht_from_rcpointer_to_rcpointer* univpoly_ring_table;
+       static int count;
+public:
+       inline cl_univpoly_ring* get_univpoly_ring(const cl_ring& r)
+       {
+               return (cl_univpoly_ring*) univpoly_ring_table->get(r);
+       }
+       inline void store_univpoly_ring(const cl_univpoly_ring& R)
+       {
+               univpoly_ring_table->put(R->basering(), R);
+       }
+       univpoly_ring_cache();
+       ~univpoly_ring_cache();
+};
+
+cl_wht_from_rcpointer_to_rcpointer* univpoly_ring_cache::univpoly_ring_table = 0;
+int univpoly_ring_cache::count = 0;
 
-static inline cl_univpoly_ring* get_univpoly_ring (const cl_ring& r)
+univpoly_ring_cache::univpoly_ring_cache()
 {
-       return (cl_univpoly_ring*) univpoly_ring_table.get(r);
+       if (count++ == 0)
+               univpoly_ring_table = new cl_wht_from_rcpointer_to_rcpointer(maygc_htentry);
 }
 
-static inline void store_univpoly_ring (const cl_univpoly_ring& R)
+univpoly_ring_cache::~univpoly_ring_cache()
 {
-       univpoly_ring_table.put(R->basering(),R);
+       if (--count == 0)
+               delete univpoly_ring_table;
 }
 
-
 const cl_univpoly_ring find_univpoly_ring (const cl_ring& r)
 {
-       var cl_univpoly_ring* ring_in_table = get_univpoly_ring(r);
+       static univpoly_ring_cache cache;
+       var cl_univpoly_ring* ring_in_table = cache.get_univpoly_ring(r);
        if (!ring_in_table) {
                var cl_univpoly_ring R = cl_make_univpoly_ring(r);
-               store_univpoly_ring(R);
-               ring_in_table = get_univpoly_ring(r);
+               cache.store_univpoly_ring(R);
+               ring_in_table = cache.get_univpoly_ring(r);
                if (!ring_in_table)
                        throw runtime_exception();
        }
@@ -62,4 +80,3 @@ const cl_univpoly_ring find_univpoly_ring (const cl_ring& r)
 
 }  // namespace cln
 
-CL_PROVIDE_END(cl_UP_unnamed)