Files
pvData/src/misc/pv/debugPtr.h
Michael Davidsaver 187fe67ffa fixup debugPtr
2017-11-14 17:13:43 -06:00

329 lines
9.2 KiB
C++

/*
* Copyright information and license terms for this software can be
* found in the file LICENSE that is included with the distribution
*/
/* Author: Michael Davidsaver */
/* wrapper around shared_ptr which tracks backwards references.
* Can help to find ref. leaks, loops, and other exciting bugs.
* See comments in sharedPtr.h
*/
#ifndef DEBUGPTR_H
#define DEBUGPTR_H
#if __cplusplus<201103L
# error c++11 required
#endif
#include <ostream>
#include <memory>
#include <set>
#include <pv/epicsException.h>
#include <shareLib.h>
//! User code should test this macro
//! before calling epics::debug::shared_ptr::show_refs()
#define HAVE_SHOW_REFS
namespace epics {
namespace debug {
struct tracker;
class shared_ptr_base;
class epicsShareClass ptr_base {
friend class shared_ptr_base;
template<typename A>
friend class shared_ptr;
template<typename A>
friend class weak_ptr;
protected:
typedef std::shared_ptr<tracker> track_t;
track_t track;
ptr_base() noexcept : track() {}
ptr_base(const track_t& track) :track(track) {}
ptr_base(const ptr_base&) = delete;
ptr_base(ptr_base&&) = delete;
ptr_base& operator=(const ptr_base&) = delete;
public:
typedef std::set<const shared_ptr_base *> ref_set_t;
void show_refs(std::ostream&, bool self=true, bool weak=false) const;
void spy_refs(ref_set_t&) const;
};
class epicsShareClass weak_ptr_base : public ptr_base {
protected:
weak_ptr_base() {}
weak_ptr_base(const track_t& track) :ptr_base(track) {}
};
class epicsShareClass shared_ptr_base : public ptr_base {
protected:
shared_ptr_base() noexcept
#ifndef EXCEPT_USE_NONE
:m_stack(), m_depth(0)
#endif
{}
shared_ptr_base(const track_t& track) :ptr_base(track)
#ifndef EXCEPT_USE_NONE
,m_stack(), m_depth(0)
#endif
{}
~shared_ptr_base() {track_clear();}
// add ourselves to tracker
void track_new();
// create new tracker if ptr!=nullptr, otherwise clear
void track_new(void* ptr);
// copy tracker and add ourself
void track_assign(const shared_ptr_base& o);
void track_clear();
void swap(shared_ptr_base& o);
void snap_stack();
#ifndef EXCEPT_USE_NONE
void *m_stack[EXCEPT_DEPTH];
int m_depth; // always <= EXCEPT_DEPTH
#endif
public:
void show_stack(std::ostream&) const;
};
template<typename T>
class shared_ptr;
template<typename T>
class weak_ptr;
template<class Base>
class enable_shared_from_this;
template<typename Store, typename Actual>
inline void
do_enable_shared_from_this(const shared_ptr<Store>& dest,
enable_shared_from_this<Actual>* self
);
template<typename T>
inline void
do_enable_shared_from_this(const shared_ptr<T>&, ...) {}
template<typename T>
class shared_ptr : public shared_ptr_base {
typedef ::std::shared_ptr<T> real_type;
real_type real;
template<typename A>
friend class shared_ptr;
template<typename A>
friend class weak_ptr;
// ctor for casts
shared_ptr(const real_type& r, const ptr_base::track_t& t)
:shared_ptr_base(t), real(r)
{track_new();}
public:
typedef typename real_type::element_type element_type;
typedef weak_ptr<T> weak_type;
// new NULL
shared_ptr() noexcept {}
// copy existing same type
shared_ptr(const shared_ptr& o) :shared_ptr_base(o.track), real(o.real) {track_new();}
// copy existing of implicitly castable type
template<typename A>
shared_ptr(const shared_ptr<A>& o) :shared_ptr_base(o.track), real(o.real) {track_new();}
// construct around new pointer
template<typename A, class ... Args>
explicit shared_ptr(A* a, Args ... args) : shared_ptr_base(), real(a, args...) {
track_new(a);
do_enable_shared_from_this(*this, a);
}
// make strong ref from weak
template<typename A>
shared_ptr(const weak_ptr<A>& o) :shared_ptr_base(o.track), real(o.real) {track_new();}
// takeover from unique_ptr
template<typename A>
shared_ptr(std::unique_ptr<A>&& a) : shared_ptr_base(), real(a.release()) {track_new();}
~shared_ptr() {}
shared_ptr& operator=(const shared_ptr& o) {
if(this!=&o) {
real = o.real;
track_assign(o);
}
return *this;
}
template<typename A>
shared_ptr& operator=(const shared_ptr<A>& o) {
if(get()!=o.get()) {
real = o.real;
track_assign(o);
}
return *this;
}
void reset() noexcept { real.reset(); track_clear(); }
template<typename A, class ... Args>
void reset(A* a, Args ... args)
{
real.reset(a, args...);
track_new(a);
do_enable_shared_from_this(*this, a);
}
void swap(shared_ptr &o) noexcept
{
if(this!=&o) {
real.swap(o.real);
shared_ptr_base::swap(o);
}
}
// proxy remaining to underlying shared_ptr
T* get() const noexcept { return real.get(); }
typename std::add_lvalue_reference<T>::type operator*() const noexcept { return *real; }
T* operator->() const noexcept { return real.get(); }
long use_count() const noexcept { return real.use_count(); }
bool unique() const noexcept { return real.unique(); }
explicit operator bool() const noexcept { return bool(real); }
bool operator==(const shared_ptr<T>& o) const { return real==o.real; }
bool operator!=(const shared_ptr<T>& o) const { return real!=o.real; }
bool operator<(const shared_ptr<T>& o) const { return real<o.real; }
template<typename A>
bool owner_before(const shared_ptr<A>& o) { return real.owner_before(o); }
template<typename A>
bool owner_before(const weak_ptr<A>& o) { return real.owner_before(o); }
template<typename TO, typename FROM>
friend
shared_ptr<TO> static_pointer_cast(const shared_ptr<FROM>& src);
template<typename TO, typename FROM>
friend
shared_ptr<TO> const_pointer_cast(const shared_ptr<FROM>& src);
template<typename TO, typename FROM>
friend
shared_ptr<TO> dynamic_pointer_cast(const shared_ptr<FROM>& src);
template<typename Store, typename Actual>
friend void
do_enable_shared_from_this(const shared_ptr<Store>& dest,
enable_shared_from_this<Actual>* self
);
};
template<typename TO, typename FROM>
shared_ptr<TO> static_pointer_cast(const shared_ptr<FROM>& src) {
return shared_ptr<TO>(std::static_pointer_cast<TO>(src.real), src.track);
}
template<typename TO, typename FROM>
shared_ptr<TO> const_pointer_cast(const shared_ptr<FROM>& src) {
return shared_ptr<TO>(std::const_pointer_cast<TO>(src.real), src.track);
}
template<typename TO, typename FROM>
shared_ptr<TO> dynamic_pointer_cast(const shared_ptr<FROM>& src) {
return shared_ptr<TO>(std::dynamic_pointer_cast<TO>(src.real), src.track);
}
template<typename T>
class weak_ptr : public weak_ptr_base {
typedef ::std::weak_ptr<T> real_type;
real_type real;
template<typename A>
friend class shared_ptr;
template<typename A>
friend class weak_ptr;
public:
typedef typename real_type::element_type element_type;
typedef weak_ptr<T> weak_type;
// new NULL
weak_ptr() noexcept {}
// copy existing same type
weak_ptr(const weak_ptr& o) :weak_ptr_base(o.track), real(o.real) {}
// copy existing of similar type
template<typename A>
weak_ptr(const weak_ptr<A>& o) :weak_ptr_base(o.track), real(o.real) {}
// create week ref from strong ref
template<typename A>
weak_ptr(const shared_ptr<A>& o) :weak_ptr_base(o.track), real(o.real) {}
~weak_ptr() {}
weak_ptr& operator=(const weak_ptr& o) {
if(this!=&o) {
real = o.real;
track = o.track;
}
return *this;
}
template<typename A>
weak_ptr& operator=(const shared_ptr<A>& o) {
real = o.real;
track = o.track;
return *this;
}
shared_ptr<T> lock() const noexcept { return shared_ptr<T>(real.lock(), track); }
void reset() noexcept { track.reset(); real.reset(); }
long use_count() const noexcept { return real.use_count(); }
bool unique() const noexcept { return real.unique(); }
};
template<class Base>
class enable_shared_from_this {
mutable weak_ptr<Base> xxInternalSelf;
template<typename Store, typename Actual>
friend
void
do_enable_shared_from_this(const shared_ptr<Store>& dest,
enable_shared_from_this<Actual>* self
);
public:
shared_ptr<Base> shared_from_this() const {
return shared_ptr<Base>(xxInternalSelf);
}
};
template<typename Store, typename Actual>
inline void
do_enable_shared_from_this(const shared_ptr<Store>& dest,
enable_shared_from_this<Actual>* self
)
{
shared_ptr<Actual> actual(dynamic_pointer_cast<Actual>(dest));
if(!actual)
throw std::logic_error("epics::debug::enabled_shared_from_this fails");
self->xxInternalSelf = actual;
}
}} // namespace epics::debug
template<typename T>
inline std::ostream& operator<<(std::ostream& strm, const epics::debug::shared_ptr<T>& ptr)
{
strm<<ptr.get();
return strm;
}
#endif // DEBUGPTR_H