diff options
Diffstat (limited to 'libodb/odb/details/shared-ptr/base.cxx')
-rw-r--r-- | libodb/odb/details/shared-ptr/base.cxx | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/libodb/odb/details/shared-ptr/base.cxx b/libodb/odb/details/shared-ptr/base.cxx new file mode 100644 index 0000000..d937400 --- /dev/null +++ b/libodb/odb/details/shared-ptr/base.cxx @@ -0,0 +1,83 @@ +// file : odb/details/shared-ptr/base.cxx +// license : GNU GPL v2; see accompanying LICENSE file + +#include <odb/details/shared-ptr/base.hxx> +#include <odb/details/shared-ptr/exception.hxx> + +using std::size_t; + +namespace odb +{ + namespace details + { + share shared = share (1); + share exclusive = share (2); + + const char* not_shared:: + what () const ODB_NOTHROW_NOEXCEPT + { + return "object is not shared"; + } + + not_shared* not_shared:: + clone () const + { + return new not_shared (*this); + } + + namespace bits + { + size_t* locator_common:: + counter (void* x) + { + size_t* p (static_cast<size_t*> (x)); + + if (*(--p) != 0xDEADBEEF) + throw not_shared (); + + return --p; + } + } + } +} + +void* +#ifdef ODB_CXX11 +operator new (size_t n, odb::details::share s) +#else +operator new (size_t n, odb::details::share s) throw (std::bad_alloc) +#endif +{ + if (s == odb::details::shared) + { + // Here we need to make sure we don't break the alignment of the + // returned block. For that we need to know the maximum alignment + // of this platform. Twice the pointer size is a good guess for + // most platforms. + // + size_t* p = static_cast<size_t*> (operator new (n + 2 * sizeof (size_t))); + *p++ = 1; // Initial count. + *p++ = 0xDEADBEEF; // Signature. + return p; + } + else + return operator new (n); + +} + +void +operator delete (void* p, odb::details::share s) ODB_NOTHROW_NOEXCEPT +{ + // This version of operator delete is only called when the c-tor + // fails. In this case there is no object and we can just free the + // memory. + // + if (s == odb::details::shared) + { + size_t* sp = static_cast<size_t*> (p); + sp -= 2; + operator delete (sp); + } + else + operator delete (p); +} |