1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
|
// file : odb/details/shared-ptr/base.cxx
// copyright : Copyright (c) 2009-2015 Code Synthesis Tools CC
// 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 throw ()
{
return "object is not shared";
}
not_shared* not_shared::
clone () const
{
return new not_shared (*this);
}
bool shared_base::
_dec_ref_callback ()
{
bool r (--counter_ == 0);
if (r)
r = callback_->zero_counter (callback_->arg);
return r;
}
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*
operator new (size_t n, odb::details::share s) throw (std::bad_alloc)
{
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) throw ()
{
// 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);
}
|
