1 //===---------------------SharingPtr.cpp ------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/Utility/SharingPtr.h"
11 
12 #if defined (ENABLE_SP_LOGGING)
13 
14 // If ENABLE_SP_LOGGING is defined, then log all shared pointer assignements
15 // and allow them to be queried using a pointer by a call to:
16 #include <execinfo.h>
17 #include <map>
18 #include <assert.h>
19 #include "lldb/Host/Mutex.h"
20 
21 #include "llvm/ADT/STLExtras.h"
22 
23 #include <vector>
24 
25 class Backtrace
26 {
27 public:
28     Backtrace ();
29 
30     ~Backtrace ();
31 
32     void
33     GetFrames ();
34 
35     void
36     Dump () const;
37 
38 private:
39     void *m_sp_this;
40     std::vector<void *> m_frames;
41 };
42 
43 
44 Backtrace::Backtrace () : m_frames()
45 {
46 }
47 
48 Backtrace::~Backtrace ()
49 {
50 }
51 
52 void
53 Backtrace::GetFrames ()
54 {
55     void *frames[1024];
56     const int count = ::backtrace (frames, llvm::array_lengthof(frames));
57     if (count > 2)
58         m_frames.assign (frames + 2, frames + (count - 2));
59 }
60 
61 void
62 Backtrace::Dump () const
63 {
64     if (!m_frames.empty())
65         ::backtrace_symbols_fd (m_frames.data(), m_frames.size(), STDOUT_FILENO);
66     write (STDOUT_FILENO, "\n\n", 2);
67 }
68 
69 extern "C" void track_sp (void *sp_this, void *ptr, long use_count)
70 {
71     typedef std::pair<void *, Backtrace> PtrBacktracePair;
72     typedef std::map<void *, PtrBacktracePair> PtrToBacktraceMap;
73     static lldb_private::Mutex g_mutex(lldb_private::Mutex::eMutexTypeNormal);
74     lldb_private::Mutex::Locker locker (g_mutex);
75     static PtrToBacktraceMap g_map;
76 
77     if (sp_this)
78     {
79         printf ("sp(%p) -> %p %lu\n", sp_this, ptr, use_count);
80 
81         if (ptr)
82         {
83             Backtrace bt;
84             bt.GetFrames();
85             g_map[sp_this] = std::make_pair(ptr, bt);
86         }
87         else
88         {
89             g_map.erase (sp_this);
90         }
91     }
92     else
93     {
94         if (ptr)
95             printf ("Searching for shared pointers that are tracking %p: ", ptr);
96         else
97             printf ("Dump all live shared pointres: ");
98 
99         uint32_t matches = 0;
100         PtrToBacktraceMap::iterator pos, end = g_map.end();
101         for (pos = g_map.begin(); pos != end; ++pos)
102         {
103             if (ptr == NULL || pos->second.first == ptr)
104             {
105                 ++matches;
106                 printf ("\nsp(%p): %p\n", pos->first, pos->second.first);
107                 pos->second.second.Dump();
108             }
109         }
110         if (matches == 0)
111         {
112             printf ("none.\n");
113         }
114     }
115 }
116 // Put dump_sp_refs in the lldb namespace to it gets through our exports lists filter in the LLDB.framework or lldb.so
117 namespace lldb {
118 
119     void dump_sp_refs (void *ptr)
120     {
121         // Use a specially crafted call to "track_sp" which will
122         // dump info on all live shared pointers that reference "ptr"
123         track_sp (NULL, ptr, 0);
124     }
125 
126 }
127 
128 #endif
129 
130 namespace lldb_private {
131 
132 namespace imp
133 {
134 
135 
136     shared_count::~shared_count()
137     {
138     }
139 
140     void
141     shared_count::add_shared()
142     {
143 #ifdef _MSC_VER
144         _InterlockedIncrement(&shared_owners_);
145 #else
146         ++shared_owners_;
147 #endif
148     }
149 
150     void
151     shared_count::release_shared()
152     {
153 #ifdef _MSC_VER
154         if (_InterlockedDecrement(&shared_owners_) == -1)
155 #else
156         if (--shared_owners_ == -1)
157 #endif
158         {
159             on_zero_shared();
160             delete this;
161         }
162     }
163 
164 } // imp
165 
166 
167 } // namespace lldb
168 
169