Interlocked.CompareExchange

T location1 = v1;

T value = v2;

T res = Interlocked.CompareExchange(ref location1, value, conparand)

=

if(location1 == conparand){
　　res = location1;

　　location1 = value;

}

else{
　　res = location1;

}

原文：http://www.cnblogs.com/tq1226112215/p/4517879.html