llvm-project/lldb/source/Utility/SharingPtr.cpp

169 lines
3.5 KiB
C++

//===---------------------SharingPtr.cpp ------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "lldb/Utility/SharingPtr.h"
#if defined (ENABLE_SP_LOGGING)
// If ENABLE_SP_LOGGING is defined, then log all shared pointer assignments
// and allow them to be queried using a pointer by a call to:
#include <execinfo.h>
#include <assert.h>
#include "llvm/ADT/STLExtras.h"
#include <map>
#include <mutex>
#include <vector>
class Backtrace
{
public:
Backtrace ();
~Backtrace ();
void
GetFrames ();
void
Dump () const;
private:
void *m_sp_this;
std::vector<void *> m_frames;
};
Backtrace::Backtrace () : m_frames()
{
}
Backtrace::~Backtrace ()
{
}
void
Backtrace::GetFrames ()
{
void *frames[1024];
const int count = ::backtrace (frames, llvm::array_lengthof(frames));
if (count > 2)
m_frames.assign (frames + 2, frames + (count - 2));
}
void
Backtrace::Dump () const
{
if (!m_frames.empty())
::backtrace_symbols_fd (m_frames.data(), m_frames.size(), STDOUT_FILENO);
write (STDOUT_FILENO, "\n\n", 2);
}
extern "C" void track_sp (void *sp_this, void *ptr, long use_count)
{
typedef std::pair<void *, Backtrace> PtrBacktracePair;
typedef std::map<void *, PtrBacktracePair> PtrToBacktraceMap;
static std::mutex g_mutex;
std::lock_guard<std::mutex> guard(g_mutex);
static PtrToBacktraceMap g_map;
if (sp_this)
{
printf ("sp(%p) -> %p %lu\n", sp_this, ptr, use_count);
if (ptr)
{
Backtrace bt;
bt.GetFrames();
g_map[sp_this] = std::make_pair(ptr, bt);
}
else
{
g_map.erase (sp_this);
}
}
else
{
if (ptr)
printf ("Searching for shared pointers that are tracking %p: ", ptr);
else
printf ("Dump all live shared pointres: ");
uint32_t matches = 0;
PtrToBacktraceMap::iterator pos, end = g_map.end();
for (pos = g_map.begin(); pos != end; ++pos)
{
if (ptr == NULL || pos->second.first == ptr)
{
++matches;
printf ("\nsp(%p): %p\n", pos->first, pos->second.first);
pos->second.second.Dump();
}
}
if (matches == 0)
{
printf ("none.\n");
}
}
}
// Put dump_sp_refs in the lldb namespace to it gets through our exports lists filter in the LLDB.framework or lldb.so
namespace lldb {
void dump_sp_refs (void *ptr)
{
// Use a specially crafted call to "track_sp" which will
// dump info on all live shared pointers that reference "ptr"
track_sp (NULL, ptr, 0);
}
}
#endif
namespace lldb_private {
namespace imp
{
shared_count::~shared_count()
{
}
void
shared_count::add_shared()
{
#ifdef _MSC_VER
_InterlockedIncrement(&shared_owners_);
#else
++shared_owners_;
#endif
}
void
shared_count::release_shared()
{
#ifdef _MSC_VER
if (_InterlockedDecrement(&shared_owners_) == -1)
#else
if (--shared_owners_ == -1)
#endif
{
on_zero_shared();
delete this;
}
}
} // imp
} // namespace lldb