hashtable.h (_Hashtable<>::__rehash_policy(const _RehashPolicy&)): Commit the modification of the policy only if no exception occured.

2011-09-17  François Dumont  <fdumont@gcc.gnu.org>

	* include/bits/hashtable.h (_Hashtable<>::__rehash_policy(const
	_RehashPolicy&)): Commit the modification of the policy only if no
	exception occured.
	* testsuite/23_containers/unordered_set/max_load_factor/robustness.cc:
	New.

From-SVN: r178927

3 files changed, 87 insertions, 2 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 910fafc..4e0ddf4 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,11 @@
+2011-09-17  François Dumont  <fdumont@gcc.gnu.org>
+
+	* include/bits/hashtable.h (_Hashtable<>::__rehash_policy(const
+	_RehashPolicy&)): Commit the modification of the policy only if no
+	exception occured.
+	* testsuite/23_containers/unordered_set/max_load_factor/robustness.cc:
+	New.
+
 2011-09-16  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	* testsuite/23_containers/array/comparison_operators/
diff --git a/libstdc++-v3/include/bits/hashtable.h b/libstdc++-v3/include/bits/hashtable.h
index b097ee7..5c74066 100644
--- a/libstdc++-v3/include/bits/hashtable.h
+++ b/libstdc++-v3/include/bits/hashtable.h
@@ -741,10 +741,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
     __rehash_policy(const _RehashPolicy& __pol)
     {
-      _M_rehash_policy = __pol;
       size_type __n_bkt = __pol._M_bkt_for_elements(_M_element_count);
       if (__n_bkt > _M_bucket_count)
-	_M_rehash(__n_bkt, __pol._M_next_resize);
+	_M_rehash(__n_bkt, _M_rehash_policy._M_next_resize);
+      _M_rehash_policy = __pol;
     }
 
   template<typename _Key, typename _Value,
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_set/max_load_factor/robustness.cc b/libstdc++-v3/testsuite/23_containers/unordered_set/max_load_factor/robustness.cc
new file mode 100644
index 0000000..7db51f7
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_set/max_load_factor/robustness.cc
@@ -0,0 +1,77 @@
+// { dg-options "-std=gnu++0x" }
+
+// Copyright (C) 2011 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library 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, or (at your option)
+// any later version.
+//
+// This 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <unordered_set>
+#include <limits>
+#include <ext/throw_allocator.h>
+#include <testsuite_hooks.h>
+
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+
+  typedef std::numeric_limits<std::size_t> nl_size_t;
+  std::unordered_set<int, std::hash<int>, std::equal_to<int>,
+		     __gnu_cxx::throw_allocator_limit<int> > us;
+  int val = 0;
+  for (; val != 100; ++val)
+    {
+      VERIFY( us.insert(val).second) ;
+      VERIFY( us.load_factor() <= us.max_load_factor() );
+    }
+
+  float cur_max_load_factor = us.max_load_factor();
+  int counter = 0;
+  std::size_t thrown_exceptions = 0;
+  while (true)
+    {
+      __gnu_cxx::limit_condition::set_limit(counter++);
+      bool do_break = false;
+      try
+	{
+	  us.max_load_factor(.5f);
+	  do_break = true;
+	}
+      catch (const __gnu_cxx::forced_error&)
+	{
+	  VERIFY( us.max_load_factor() == cur_max_load_factor );
+	  ++thrown_exceptions;
+	}
+      // Lets check that unordered_set will still be correctly resized
+      // when needed
+      __gnu_cxx::limit_condition::set_limit(nl_size_t::max());
+      for (;;)
+	{
+	  VERIFY( us.load_factor() <= us.max_load_factor() );
+	  size_t nbkts = us.bucket_count();
+	  VERIFY( us.insert(val++).second );
+	  if (us.bucket_count() != nbkts)
+	    break;
+	}
+      if (do_break)
+	break;
+    }
+  VERIFY( thrown_exceptions > 0 );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}