Changeset ad83e4 in git for factory

Timestamp:

Oct 25, 2008, 1:05:51 PM (16 years ago)

Author:

Hans Schönemann <hannes@…>

Branches:

(u'spielwiese', 'fe61d9c35bf7c61f2b6cbf1b56e25e2f08d536cc')

Children:

3fe8ed4d13cc002b2f0fb89d6eeacd9ee3f7a568

Parents:

b0e3efca092d580bdd55fac90beff461dacda552

Message:

*hannes: new-nothrow


git-svn-id: file:///usr/local/Singular/svn/trunk@11159 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

• factory/newdelete.cc (modified) (4 diffs)

factory/newdelete.cc

@@ -1 +1 @@
 /* emacs edit mode for this file is -*- C++ -*- */
-/* $Id: newdelete.cc,v 1.2 1997-06-19 12:22:03 schmidt Exp $ */
+/* $Id: newdelete.cc,v 1.3 2008-10-25 11:04:06 Singular Exp $ */
 
 #include <config.h>
@@ -11 +11 @@
 #include "memman.h"
 #endif
+
+// The C++ standard has ratified a change to the new operator.
+//
+//  T *p = new T;
+//
+// Previously, if the call to new above failed, a null pointer would've been returned.
+// Under the ISO C++ Standard, an exception of type std::bad_alloc is thrown.
+// It is possible to suppress this behaviour in favour of the old style
+// by using the nothrow version.
+//
+//  T *p = new (std::nothrow) T;
+//
+// So we have to overload this new also, just to be sure.
+//
+// A further interesting question is, if you don't have enough resources
+// to allocate a request for memory,
+// do you expect to have enough to be able to deal with it?
+// Most operating systems will have slowed to be unusable
+// long before the exception gets thrown.
 
 #ifdef USE_OLD_MEMMAN
@@ -32 +51 @@
 {
     freeBlock( block, 0 );
+}
+
+void * operator new(size_t size, const std::nothrow_t &) throw()
+{
+    return getBlock( size );
+}
+void * operator new[](size_t size, const std::nothrow_t &) throw()
+{
+    return getBlock( size );
 }
 
@@ -56 +84 @@
 }
 
+void * operator new(size_t size, const std::nothrow_t &) throw()
+{
+    return mmAlloc( size );
+}
+void * operator new[](size_t size, const std::nothrow_t &) throw()
+{
+    return mmAlloc( size );
+}
+
 #endif /* USE_OLD_MEMMAN */