[ODE] stack requirements

[David McClurg]

i just changed dStack to use "new char[max_size]" and it works great for me.  If you can pre-allocate a 1/2 meg or so for ODE then your "real" stack requirements are small.

You can also create a dStrackFrame object to do the popFrame() call automatically for you when you leave the current scope block.  Just declare a dStackFrame at the top of each block that uses dStack::alloc()

// used to auto push/popFrame
class dStackFrame
{
  dStack& stack;
  char* newframe;

public:

  dStackFrame(dStack& stack_) : stack(stack_)
  {
    newframe = stack.pushFrame();
  }

  ~dStackFrame()
  {
    if (stack.popFrame() != newframe)
    {
      dError(0, "stack frame");
    }
  }

};

-----Original Message-----
From: Russ Smith [mailto:russ@q12.org]
Sent: Tuesday, 23 July 2002 8:59 AM
To: ode@q12.org
Subject: Re: [ODE] stack requirements


> ode/src/stack.cpp/h seems to be a *unused* replacement for alloca.  is
> this something that never got finished or didn't work out?  Here's the
> interface...

this was used at one point for the joint groups. the implementation uses
mmap() (or the windows equivalent) to allocate non-physical memory
space, then allocates memory in as needed. this is conceptually nice but
not totally portable to all *nixes (at least not without a pile of
work), which is why it was abandoned.