GL_BIT_PENDING
new = (old & ~GL_BIT_PENDING) | GL_BIT_OWNED;
new |= GL_BIT_PENDING;
return ((new & GL_BIT_PENDING) == 0);
new = old & ~(GL_BIT_PENDING | GL_BIT_OWNED);
return ((old & GL_BIT_PENDING) != 0);
new = (old & ~GL_BIT_PENDING) | GL_BIT_OWNED;
new |= GL_BIT_PENDING;
return ((new & GL_BIT_PENDING) == 0);
new = old & ~(GL_BIT_PENDING | GL_BIT_OWNED);
return ((old & GL_BIT_PENDING) != 0);