To fix a problem caused by the static (de-)initialization order fiasco I tried to use the Nifty Counter idiom aka Schwartz Counter. I noticed, however, that it does not work if the header file containing the static initializer is included inside Visual Studio's precompiled header. In such a case I see in the debugger, that the constructor of the static initializer is called after the constructor of the other static object.
If I declare an additional static initializer right after #include "stdafx.h" or edit the precompiled header to not contain the declaration it works as expected.
Any ideas what might cause this?
EDIT
I was finally able to reproduce this problem in a new dummy project:
Foo.cpp
#include "stdafx.h"
#include "Foo.h"
#include <cassert>
#include <iostream>
#ifdef NIFTY
static int SchwartzCounter; // zero initialized at load time
static typename std::aligned_storage<sizeof(Foo), alignof (Foo)>::type foo_buf;
Foo& foo = reinterpret_cast<Foo&>(foo_buf);
#else
Foo foo;
#endif
Foo::Foo()
{
std::cout << __func__ << std::endl;
}
Foo::~Foo()
{
std::cout << __func__ << std::endl;
}
void Foo::doSomething()
{
std::cout << __func__ << std::endl;
assert(x == 42);
}
#ifdef NIFTY
FooInitializer::FooInitializer()
{
std::cout << __func__ << std::endl;
if (SchwartzCounter++ == 0)
{
new (&foo) Foo();
}
}
FooInitializer::~FooInitializer()
{
std::cout << __func__ << std::endl;
if (--SchwartzCounter == 0)
{
(&foo)->~Foo();
}
}
#endif
Foo.h
#pragma once
class Foo
{
public:
Foo();
~Foo();
void doSomething();
private:
int x = 42;
};
#ifdef NIFTY
extern Foo& foo;
static struct FooInitializer {
FooInitializer();
~FooInitializer();
} fooInitializer;
#else
extern Foo foo;
#endif
Bar.cpp
#include "stdafx.h"
#include "Foo.h"
#include "Bar.h"
#include <cassert>
#include <iostream>
#ifdef NIFTY
static int SchwartzCounter; // zero initialized at load time
static typename std::aligned_storage<sizeof(Bar), alignof (Bar)>::type bar_buf;
Bar& bar = reinterpret_cast<Bar&>(bar_buf);
#else
Bar bar;
#endif
Bar::Bar()
{
std::cout << __func__ << std::endl;
foo.doSomething();
}
Bar::~Bar()
{
std::cout << __func__ << std::endl;
}
void Bar::doSomething()
{
std::cout << __func__ << std::endl;
assert(x == 42);
}
#ifdef NIFTY
BarInitializer::BarInitializer()
{
std::cout << __func__ << std::endl;
if (SchwartzCounter++ == 0)
{
new (&bar) Bar();
}
}
BarInitializer::~BarInitializer()
{
std::cout << __func__ << std::endl;
if (--SchwartzCounter == 0)
{
(&bar)->~Bar();
}
}
#endif
Bar.h
#pragma once
class Bar
{
public:
Bar();
~Bar();
void doSomething();
private:
int x = 42;
};
#ifdef NIFTY
extern Bar& bar;
static struct BarInitializer {
BarInitializer();
~BarInitializer();
} barInitializer;
#else
extern Bar bar;
#endif
stdafx.h
#pragma once
#include "targetver.h"
#include <stdio.h>
#include <tchar.h>
// If the following define is commented out, the nifty counter idiom is not used
#define NIFTY
// If the following include is commented out while the nifty counter idiom is used, the initialization order is correct
#include "Foo.h"