std::bind not able to call the class member function: C++ - c++11

Question

I have to implement A valve Open function (for specified duration).
I am using boost::asio::deadline_timer
My class member function to open valve is:
bool Valves::valveOpen(ValveType type)
{
switch (type)
{
case eVentValve:
tblMap_.digitalInput[eVentValveK1].setBit();
if (tblMap_.digitalOutput[eOutK1VentValve].getBit())
{
isVentOpen_ = true;
}
return isVentOpen_;
case eVacuumPumpValve:
....
....
}
Class member function to close the valve is:
bool Valves::valveClose(ValveType type)
{
switch (type)
{
case eVentValve:
tblMap_.digitalInput[eVentValveK1].clearBit();
if (!tblMap_.digitalOutput[eOutK1VentValve].getBit())
{
isVentOpen_ = false;
}
return !isVentOpen_;
case eVacuumPumpValve:
....
....
}
I am trying to achieve the timer action as below
bool Valves::valveTimedOpen(ValveType type, int sec)
{
boost::asio::io_service io;
switch (type)
{
case eVentValve:
{
std::bind(&Valves::valveOpen, this, type); //Here
boost::asio::deadline_timer t(io, boost::posix_time::seconds(sec));
t.async_wait(std::bind(&Valves::valveClose, this, type));
boost::thread th(boost::bind(&boost::asio::io_service::run, &io));
return true;
}
case eVacuumPumpValve:
.....
.....
}
The code hits the line Here i.e.
std::bind(&Valves::valveOpen, this, type); but it does not go to bool Valves::valveOpen(ValveType type) function.
Can someone let me know the issue with this code?

Answer 1

Variables io and t go out of scope as soon as valveTimedOpen exits. You need to rethink the way you interact with the boost asio components e.g. the io_service could be a member of your class, and the timer could be dynamically allocated and needs to be deleted in the completion handler.
Also, keep in mind that if you plan on re-using an io_service object, you also need to reset it before calling run again.

Answer 2

auto fn = std::bind(&Test::Open, shared_from_this(), std::placeholders::_1);
fn(type);
Calls the Open() correctly.
io_service and boost::deadline_timer I have to make class member as suggested by #Ralf
Working Code:
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/thread.hpp>
#include <boost/asio.hpp>
class Test : public std::enable_shared_from_this <Test>
{
public:
Test() :io(), timer(io){}
void Open(int num);
void Close(int num);
void TimedOpen(int num, int dur);
void Run();
private:
boost::asio::io_service io;
boost::asio::deadline_timer timer;
};
void Test::Open(int num)
{
std::cout << "Open for Number : " << num << std::endl;
}
void Test::Close(int num)
{
std::cout << "Close for Number : " << num << std::endl;
}
void Test::TimedOpen(int num, int dur)
{
io.reset();
auto fn = std::bind(&Test::Open, shared_from_this(), std::placeholders::_1);
fn(num);
timer.expires_from_now( boost::posix_time::seconds(dur));
timer.async_wait(std::bind(&Test::Close, shared_from_this(), num));
Run();
std::cout << "Function Exiting" << std::endl;
}
void Test::Run()
{
boost::thread th(boost::bind(&boost::asio::io_service::run, &io));
}
int main()
{
auto t = std::make_shared<Test>();
t->TimedOpen(5, 5);
char line[128];
while (std::cin.getline(line, 128))
{
if (strcmp(line, "\n")) break;
}
return 0;
}