(This article is translate version , original version written in chinese , you can see it at http://www.cnblogs.com/xdesigner/archive/2006/08/02/465483.html )
I bring out a easy to check recursion , just call an universal function .
When we develop complex software , maybe handle recursion , for example , some code modify object1's data , then object2's data has been modified automatic . but when code modify object2's data , then object1's data has been modified automatic too , so there are a recursion , if this recursion is un-control , then system must throw out StackOverflowException . I think somebody must meet this thing .
Against this recursion cycle , It is nature to define a flag variable and use this variable to check recursion . When system modify object1's data , before modify , check this flat , if this flat has been set , then cancel modify operation , else , set this flag , modify object1's data , after modify operation , clear this flag . In this way , you can check recursion and avoid recursion cycle .
But in this way , you must define flag varible and maintains this flag , when system modify object's data and throw out exception , forget clear flag, then system can not modify object's data for ever.This is not expediently .
At there , I bring out a method to resolve this proplem . In fact , we can use system callback stack to check resursion . In .net software , we can get current thread's call stack from type System.Diagnostics.StackTrace . StackTract's FrameCount property means stack layer count , and GetFrame function returns StackFrame object which maintains single stack layer's information , we can enumerate all call stack and check recursion . So I write a universal function to check recursion as following
public static bool CheckRecursion()
System.Diagnostics.StackTrace myTrace = new System.Diagnostics.StackTrace();
if (myTrace.FrameCount < 3)
System.IntPtr mh = myTrace.GetFrame(1).GetMethod().MethodHandle.Value;
for (int iCount = 2; iCount < myTrace.FrameCount; iCount++)
System.Reflection.MethodBase m = myTrace.GetFrame(iCount).GetMethod();
if (m.MethodHandle.Value == mh)
you can use this function anywhere , for example
We can expend this function , for example , where an universal function to return how many times recursion.
This function is easy to use , but I test that it is run slowly , so I suggest you can not use it continual . When you must check recursion continual , you have to define flag variable and check recursion fast .
XDesigner Studio ( http://www.xdesigner.cn/default-eng.htm ) 2006-10-10