phoenix-firestorm/indra/llcommon/llmemory.h

400 lines
9.5 KiB
C++

/**
* @file llmemory.h
* @brief Memory allocation/deallocation header-stuff goes here.
*
* Copyright (c) 2002-$CurrentYear$, Linden Research, Inc.
* $License$
*/
#ifndef LL_MEMORY_H
#define LL_MEMORY_H
#include <new>
#include <cstdlib>
#include "llerror.h"
extern S32 gTotalDAlloc;
extern S32 gTotalDAUse;
extern S32 gDACount;
const U32 LLREFCOUNT_SENTINEL_VALUE = 0xAAAAAAAA;
//----------------------------------------------------------------------------
class LLMemory
{
public:
static void initClass();
static void cleanupClass();
static void freeReserve();
private:
static char* reserveMem;
};
//----------------------------------------------------------------------------
// RefCount objects should generally only be accessed by way of LLPointer<>'s
// NOTE: LLPointer<LLFoo> x = new LLFoo(); MAY NOT BE THREAD SAFE
// if LLFoo::LLFoo() does anything like put itself in an update queue.
// The queue may get accessed before it gets assigned to x.
// The correct implementation is:
// LLPointer<LLFoo> x = new LLFoo; // constructor does not do anything interesting
// x->instantiate(); // does stuff like place x into an update queue
// see llthread.h for LLThreadSafeRefCount
//----------------------------------------------------------------------------
class LLRefCount
{
protected:
LLRefCount(const LLRefCount&); // not implemented
private:
LLRefCount&operator=(const LLRefCount&); // not implemented
protected:
virtual ~LLRefCount(); // use unref()
public:
LLRefCount();
void ref()
{
mRef++;
}
S32 unref()
{
llassert(mRef >= 1);
if (0 == --mRef)
{
delete this;
return 0;
}
return mRef;
}
S32 getNumRefs() const
{
return mRef;
}
private:
S32 mRef;
};
//----------------------------------------------------------------------------
// Note: relies on Type having ref() and unref() methods
template <class Type> class LLPointer
{
public:
LLPointer() :
mPointer(NULL)
{
}
LLPointer(Type* ptr) :
mPointer(ptr)
{
ref();
}
LLPointer(const LLPointer<Type>& ptr) :
mPointer(ptr.mPointer)
{
ref();
}
// support conversion up the type hierarchy. See Item 45 in Effective C++, 3rd Ed.
template<typename Subclass>
LLPointer(const LLPointer<Subclass>& ptr) :
mPointer(ptr.get())
{
ref();
}
~LLPointer()
{
unref();
}
Type* get() const { return mPointer; }
const Type* operator->() const { return mPointer; }
Type* operator->() { return mPointer; }
const Type& operator*() const { return *mPointer; }
Type& operator*() { return *mPointer; }
operator BOOL() const { return (mPointer != NULL); }
operator bool() const { return (mPointer != NULL); }
bool operator!() const { return (mPointer == NULL); }
bool isNull() const { return (mPointer == NULL); }
bool notNull() const { return (mPointer != NULL); }
operator Type*() const { return mPointer; }
operator const Type*() const { return mPointer; }
bool operator !=(Type* ptr) const { return (mPointer != ptr); }
bool operator ==(Type* ptr) const { return (mPointer == ptr); }
bool operator ==(const LLPointer<Type>& ptr) const { return (mPointer == ptr.mPointer); }
bool operator < (const LLPointer<Type>& ptr) const { return (mPointer < ptr.mPointer); }
bool operator > (const LLPointer<Type>& ptr) const { return (mPointer > ptr.mPointer); }
LLPointer<Type>& operator =(Type* ptr)
{
if( mPointer != ptr )
{
unref();
mPointer = ptr;
ref();
}
return *this;
}
LLPointer<Type>& operator =(const LLPointer<Type>& ptr)
{
if( mPointer != ptr.mPointer )
{
unref();
mPointer = ptr.mPointer;
ref();
}
return *this;
}
// support assignment up the type hierarchy. See Item 45 in Effective C++, 3rd Ed.
template<typename Subclass>
LLPointer<Type>& operator =(const LLPointer<Subclass>& ptr)
{
if( mPointer != ptr.get() )
{
unref();
mPointer = ptr.get();
ref();
}
return *this;
}
// Just exchange the pointers, which will not change the reference counts.
static void swap(LLPointer<Type>& a, LLPointer<Type>& b)
{
Type* temp = a.mPointer;
a.mPointer = b.mPointer;
b.mPointer = temp;
}
protected:
void ref()
{
if (mPointer)
{
mPointer->ref();
}
}
void unref()
{
if (mPointer)
{
Type *tempp = mPointer;
mPointer = NULL;
tempp->unref();
if (mPointer != NULL)
{
llwarns << "Unreference did assignment to non-NULL because of destructor" << llendl;
unref();
}
}
}
protected:
Type* mPointer;
};
//template <class Type>
//class LLPointerTraits
//{
// static Type* null();
//};
//
// Expands LLPointer to return a pointer to a special instance of class Type instead of NULL.
// This is useful in instances where operations on NULL pointers are semantically safe and/or
// when error checking occurs at a different granularity or in a different part of the code
// than when referencing an object via a LLHandle.
//
template <class Type>
class LLHandle
{
public:
LLHandle() :
mPointer(NULL)
{
}
LLHandle(Type* ptr) :
mPointer(NULL)
{
assign(ptr);
}
LLHandle(const LLHandle<Type>& ptr) :
mPointer(NULL)
{
assign(ptr.mPointer);
}
// support conversion up the type hierarchy. See Item 45 in Effective C++, 3rd Ed.
template<typename Subclass>
LLHandle(const LLHandle<Subclass>& ptr) :
mPointer(NULL)
{
assign(ptr.get());
}
~LLHandle()
{
unref();
}
const Type* operator->() const { return nonNull(mPointer); }
Type* operator->() { return nonNull(mPointer); }
Type* get() const { return mPointer; }
// we disallow these operations as they expose our null objects to direct manipulation
// and bypass the reference counting semantics
//const Type& operator*() const { return *nonNull(mPointer); }
//Type& operator*() { return *nonNull(mPointer); }
operator BOOL() const { return mPointer != NULL; }
operator bool() const { return mPointer != NULL; }
bool operator!() const { return mPointer == NULL; }
bool isNull() const { return mPointer == NULL; }
bool notNull() const { return mPointer != NULL; }
operator Type*() const { return mPointer; }
operator const Type*() const { return mPointer; }
bool operator !=(Type* ptr) const { return (mPointer != ptr); }
bool operator ==(Type* ptr) const { return (mPointer == ptr); }
bool operator ==(const LLHandle<Type>& ptr) const { return (mPointer == ptr.mPointer); }
bool operator < (const LLHandle<Type>& ptr) const { return (mPointer < ptr.mPointer); }
bool operator > (const LLHandle<Type>& ptr) const { return (mPointer > ptr.mPointer); }
LLHandle<Type>& operator =(Type* ptr)
{
assign(ptr);
return *this;
}
LLHandle<Type>& operator =(const LLHandle<Type>& ptr)
{
assign(ptr.mPointer);
return *this;
}
// support assignment up the type hierarchy. See Item 45 in Effective C++, 3rd Ed.
template<typename Subclass>
LLHandle<Type>& operator =(const LLHandle<Subclass>& ptr)
{
assign(ptr.get());
return *this;
}
public:
typedef Type* (*NullFunc)();
static const NullFunc sNullFunc;
protected:
void ref()
{
if (mPointer)
{
mPointer->ref();
}
}
void unref()
{
if (mPointer)
{
Type *tempp = mPointer;
mPointer = NULL;
tempp->unref();
if (mPointer != NULL)
{
llwarns << "Unreference did assignment to non-NULL because of destructor" << llendl;
unref();
}
}
}
void assign(Type* ptr)
{
if( mPointer != ptr )
{
unref();
mPointer = ptr;
ref();
}
}
static Type* nonNull(Type* ptr)
{
return ptr == NULL ? sNullFunc() : ptr;
}
protected:
Type* mPointer;
};
// LLInitializedPointer is just a pointer with a default constructor that initializes it to NULL
// NOT a smart pointer like LLPointer<>
// Useful for example in std::map<int,LLInitializedPointer<LLFoo> >
// (std::map uses the default constructor for creating new entries)
template <typename T> class LLInitializedPointer
{
public:
LLInitializedPointer() : mPointer(NULL) {}
~LLInitializedPointer() { delete mPointer; }
const T* operator->() const { return mPointer; }
T* operator->() { return mPointer; }
const T& operator*() const { return *mPointer; }
T& operator*() { return *mPointer; }
operator const T*() const { return mPointer; }
operator T*() { return mPointer; }
T* operator=(T* x) { return (mPointer = x); }
operator bool() const { return mPointer != NULL; }
bool operator!() const { return mPointer == NULL; }
bool operator==(T* rhs) { return mPointer == rhs; }
bool operator==(const LLInitializedPointer<T>* rhs) { return mPointer == rhs.mPointer; }
protected:
T* mPointer;
};
//----------------------------------------------------------------------------
// LLSingleton implements the getInstance() method part of the Singleton pattern. It can't make
// the derived class constructors protected, though, so you have to do that yourself.
// The proper way to use LLSingleton is to inherit from it while using the typename that you'd
// like to be static as the template parameter, like so:
// class FooBar: public LLSingleton<FooBar>
// As currently written, it is not thread-safe.
template <typename T>
class LLSingleton
{
public:
static T* getInstance()
{
static T instance;
return &instance;
}
};
//----------------------------------------------------------------------------
#endif