kakoune/src/safe_ptr.hh
2015-02-23 20:39:56 +00:00

103 lines
2.5 KiB
C++

#ifndef safe_ptr_hh_INCLUDED
#define safe_ptr_hh_INCLUDED
// #define SAFE_PTR_TRACK_CALLSTACKS
#include "assert.hh"
#include "ref_ptr.hh"
#include <type_traits>
#include <utility>
#ifdef SAFE_PTR_TRACK_CALLSTACKS
#include "vector.hh"
#include <algorithm>
#endif
namespace Kakoune
{
// *** SafePtr: objects that assert nobody references them when they die ***
class SafeCountable
{
public:
#ifdef KAK_DEBUG
SafeCountable() : m_count(0) {}
~SafeCountable()
{
kak_assert(m_count == 0);
#ifdef SAFE_PTR_TRACK_CALLSTACKS
kak_assert(m_callstacks.empty());
#endif
}
friend void inc_ref_count(const SafeCountable* sc, void* ptr)
{
++sc->m_count;
#ifdef SAFE_PTR_TRACK_CALLSTACKS
sc->m_callstacks.emplace_back(ptr);
#endif
}
friend void dec_ref_count(const SafeCountable* sc, void* ptr)
{
--sc->m_count;
kak_assert(sc->m_count >= 0);
#ifdef SAFE_PTR_TRACK_CALLSTACKS
auto it = std::find_if(sc->m_callstacks.begin(), sc->m_callstacks.end(),
[=](const Callstack& cs) { return cs.ptr == ptr; });
kak_assert(it != sc->m_callstacks.end());
sc->m_callstacks.erase(it);
#endif
}
friend void ref_ptr_moved(const SafeCountable* sc, void* from, void* to)
{
#ifdef SAFE_PTR_TRACK_CALLSTACKS
auto it = std::find_if(sc->m_callstacks.begin(), sc->m_callstacks.end(),
[=](const Callstack& cs) { return cs.ptr == from; });
kak_assert(it != sc->m_callstacks.end());
it->ptr = to;
#endif
}
private:
#ifdef SAFE_PTR_TRACK_CALLSTACKS
struct Backtrace
{
static constexpr int max_frames = 16;
void* stackframes[max_frames];
int num_frames = 0;
Backtrace();
const char* desc() const;
};
struct Callstack
{
Callstack(void* p) : ptr(p) {}
void* ptr;
Backtrace bt;
};
mutable Vector<Callstack> m_callstacks;
#endif
mutable int m_count;
#else
[[gnu::always_inline]]
friend void inc_ref_count(const SafeCountable* sc, void* ptr) {}
[[gnu::always_inline]]
friend void dec_ref_count(const SafeCountable* sc, void* ptr) {}
#endif
};
template<typename T> using SafePtr =
RefPtr<T, typename std::conditional<std::is_const<T>::value,
const SafeCountable, SafeCountable>::type>;
}
#endif // safe_ptr_hh_INCLUDED