#include <RecursionGuard.hpp>

Collaboration diagram for RecursionGuard:

Public Member Functions
	RecursionGuard (RecursionData &data)

	~RecursionGuard ()

Detailed Description

Guard against recursion.

A recursion guard is an RAII (Resource Acquisition Is Initialization) data structure used to raise an error upon recursion. The constructor marks a RecursionData structure, acquiring ownership of the containing function (within the given thread). Recursion guards treat calls from different threads separately, therefore, it will not guard against re-entrantcy.

An example of how to use this is:

#include "RecursionGuard.hpp"
int a_function(int value)
{
    // shared data between calls
    static RecursionData rdata;
    // take ownership of the call
    RecursionGuard rguard(rdata);
    return b_function(value);
    // the recursion guard is released upon destruction of rguard
}

If b_function, or any function it calls, ever calls a_function then this will throw RecursionError. However, if multiple threads call a_function (possibly at the same time) but b_function does not call a_function then no error will be thrown.