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 <vector>
22 
23 class Backtrace
24 {
25 public:
26     Backtrace ();
27 
28     ~Backtrace ();
29 
30     void
31     GetFrames ();
32 
33     void
34     Dump () const;
35 
36 private:
37     void *m_sp_this;
38     std::vector<void *> m_frames;
39 };
40 
41 
Backtrace()42 Backtrace::Backtrace () : m_frames()
43 {
44 }
45 
~Backtrace()46 Backtrace::~Backtrace ()
47 {
48 }
49 
50 void
GetFrames()51 Backtrace::GetFrames ()
52 {
53     void *frames[1024];
54     const int count = ::backtrace (frames, sizeof(frames)/sizeof(void*));
55     if (count > 2)
56         m_frames.assign (frames + 2, frames + (count - 2));
57 }
58 
59 void
Dump() const60 Backtrace::Dump () const
61 {
62     if (!m_frames.empty())
63         ::backtrace_symbols_fd (m_frames.data(), m_frames.size(), STDOUT_FILENO);
64     write (STDOUT_FILENO, "\n\n", 2);
65 }
66 
track_sp(void * sp_this,void * ptr,long use_count)67 extern "C" void track_sp (void *sp_this, void *ptr, long use_count)
68 {
69     typedef std::pair<void *, Backtrace> PtrBacktracePair;
70     typedef std::map<void *, PtrBacktracePair> PtrToBacktraceMap;
71     static lldb_private::Mutex g_mutex(lldb_private::Mutex::eMutexTypeNormal);
72     lldb_private::Mutex::Locker locker (g_mutex);
73     static PtrToBacktraceMap g_map;
74 
75     if (sp_this)
76     {
77         printf ("sp(%p) -> %p %lu\n", sp_this, ptr, use_count);
78 
79         if (ptr)
80         {
81             Backtrace bt;
82             bt.GetFrames();
83             g_map[sp_this] = std::make_pair(ptr, bt);
84         }
85         else
86         {
87             g_map.erase (sp_this);
88         }
89     }
90     else
91     {
92         if (ptr)
93             printf ("Searching for shared pointers that are tracking %p: ", ptr);
94         else
95             printf ("Dump all live shared pointres: ");
96 
97         uint32_t matches = 0;
98         PtrToBacktraceMap::iterator pos, end = g_map.end();
99         for (pos = g_map.begin(); pos != end; ++pos)
100         {
101             if (ptr == NULL || pos->second.first == ptr)
102             {
103                 ++matches;
104                 printf ("\nsp(%p): %p\n", pos->first, pos->second.first);
105                 pos->second.second.Dump();
106             }
107         }
108         if (matches == 0)
109         {
110             printf ("none.\n");
111         }
112     }
113 }
114 // Put dump_sp_refs in the lldb namespace to it gets through our exports lists filter in the LLDB.framework or lldb.so
115 namespace lldb {
116 
dump_sp_refs(void * ptr)117     void dump_sp_refs (void *ptr)
118     {
119         // Use a specially crafted call to "track_sp" which will
120         // dump info on all live shared pointers that reference "ptr"
121         track_sp (NULL, ptr, 0);
122     }
123 
124 }
125 
126 #endif
127 
128 namespace lldb_private {
129 
130 namespace imp
131 {
132 
133 
~shared_count()134     shared_count::~shared_count()
135     {
136     }
137 
138     void
add_shared()139     shared_count::add_shared()
140     {
141         increment(shared_owners_);
142     }
143 
144     void
release_shared()145     shared_count::release_shared()
146     {
147         if (decrement(shared_owners_) == -1)
148         {
149             on_zero_shared();
150             delete this;
151         }
152     }
153 
154 } // imp
155 
156 
157 } // namespace lldb
158 
159