Wt

I have encountered this issue multiple times, and it's always difficult for me to track down, so I thought I'd see if anyone else has any similar issues.

Basically, I set up a timer to call a function that modifies a member variables of my widget class. Then, before the timer finishes and executes the function, the user navigates away from the page and causes destruction of the widget class. However, the timer still appears to be running, and will eventually execute the code in the function it is pointing at. This, in turn, causes a segfault because the function is modifying class variables that no longer exist.

Specifically, this is what I see:

void MyClass::Foo()
{
    Wt::WTimer::singleShot(1000, this, &MyClass::Bar);
}

void MyClass::Bar()
{
    classBool = false;
}

Here, MyClass will call Foo() just before the user navigates away from the page and causes destruction of MyClass. However, Bar() will still be executed and will encounter a segfault when modifying the value of classBool.

Is this intended behavior? I have tried making the timer a member variable and explicitly checking and stopping it in the destructor, but I still seem to have the issue. So far, removing the timer and refactoring the code is the only solution I have found. Which leads me to wonder what the intended use is for timers when page contents are so dynamic.

Any help or suggestions would be greatly appreciated. Thanks!