/* 
 * Testcase causing segmentation fault under Cygwin and Linux 
 * Boris Schaeling (boriss@web.de) 
 * 
 * Compile:   g++ -otestcase testcase.cpp 
 * Run:       ./testcase 
 */ 

#include <iostream> 
#include <list> 

extern "C" { 
#include <poll.h> 
} 

/* ********** observer_base & observer ********** */ 

class observer_base 
{ 
public: 
	virtual void run(void) { } 
}; 

class observer : public observer_base 
{ 
public: 
	observer(); 
	void run(void) { std::cout << "Hello" << std::endl; } 
}; 

/* ********** adapter_base & adapter ********** */ 

class adapter_base 
{ 
protected: 
	observer_base *Observer; 
public: 
	virtual void set_observer(observer_base *O) { Observer = O; } 
	virtual void run(void) { } 
}; 

class adapter : public adapter_base 
{ 
public: 
	void run(void) { Observer->run(); }    /* <--- SEGMENTATION FAULT?! */ 
}; 

/* ********** select_data & select ********** */ 

class select_data 
{ 
public: 
	adapter_base *Adapter; 
	select_data() { } 
	select_data(adapter_base *A) : Adapter(A) { } 
	void run(void) { Adapter->run(); } 
}; 

class select 
{ 
private: 
	adapter Adapter; 
	select_data Data[1]; 
	std::list<observer> Observers;    /* <--- CHANGE THIS TO: observer *Observer; */ 
public: 
	select() 
	{ 
		select_data data(&Adapter); 
		Data[0] = data; 
		Observers.push_back(observer());    /* <--- AND CHANGE THIS TO: Observer = new observer; AND EVERYTHING WORKS */ 
	} 
	void give(observer_base *O) { Data[0].Adapter->set_observer(O); } 
	void run(void) 
	{ 
		poll(NULL, 0, 2000);   /* <--- OR REMOVE THIS LINE AND EVERYTHING WORKS */ 
		Data[0].run(); 
	} 
}; 

/* ********** something else ********** */ 

class select Select; 

observer::observer() { Select.give(this); } 

/* ********** main ********** */ 

int main() 
{ 
	Select.run(); 
}