RWRecMutex

[xdm]

Hello i have a problem with RWRecMutex

for example if i have the next slice definition

           interface Reader
           {
                      nonmutating double getAmount();
           }

           interface Writer
           {
                     idempotent doSameThing();
           }

           class A implements Writer,Reader
           {
                       double total;
                       dobule rest;
           }

and the c++ implementation

class AI : virtual public A
{
                 virtual doSameThing(const Ice::Current& current);
                 virtual getAmount(const Ice::Current& current)const;
}

in cpp file

AI::getAmount(const Ice::Current& const)const
{
      IceUtil::RWRecMutes::RLock sync(this);
      return total-rest;
}

 AI::doSameThing(const Ice::Current& current)
 {
        IceUtil::RWRecMutex::WLock sync(this);
        if(getAmount()>0)           //Server blocked at this point 
                     rest++;
}

Is normal that the servers block here because i invoke a Read opeation inside a Write operation. In this example can be solved easy with chage the code of getAmount to the doSameThing but this solution don't scale well.

how can aboid this ?

thanks in adavantage

[matthew]

Originally Posted by xdm

...

Is normal that the servers block here because i invoke a Read opeation inside a Write operation. In this example can be solved easy with chage the code of getAmount to the doSameThing but this solution don't scale well.

how can aboid this ?

thanks in adavantage

Its intended that you cannot acquire a read lock while you hold a write lock. This is illegal, and has undefined behaviour. This is the same semantics as POSIX threads. Its arguable whether hanging is nice though

In this case its pretty easy to rearrange your code to use some internal method that doesn't acquire a lock. Then call the internal method from the external methods.

Regards, Matthew