Personally, I don't much like sentinel values, even if they have their occasional use.
Do we need to provide an authentic infinite value? 64-bit MAXINT is nearly 10 quintillion. At 10GHz, that still takes almost three years. If each retry takes as much as 10ms, we're still looking at "retry for as long as the earth has existed." 32-bit's is much more attainable, of course, but I think the point stands -- if you need to retry that much, something else is very wrong. In the more general sense, I struggle to think of a context where an authentic infinity is meaningfully distinct in application from a massive finite like MAXINT. But I could be wrong and would love to hear what other people think. On Wed, Aug 30, 2017 at 1:26 PM, Mark Hanson <mhan...@pivotal.io> wrote: > Hi All, > > > *Question: how should we deal in a very forward and clean fashion with the > implicit ambiguity of -1 or all, or infinite, or forever?* > > > *Background:* > > > We are looking to get some feedback on the subject of infinite/all/forever > in the geode/geode-native code. > > > In looking at the code, we see an example function, > > > setRetryAttempts > <https://github.com/apache/geode-native/blob/ > 006df0e70eeb481ef5e9e821dba0050dee9c6893/cppcache/include/ > geode/PoolFactory.hpp#L327>() > [1] currently -1 means try all servers before failing. 0 means try 1 server > before failing, and a number greater than 0 means try number of servers +1 > before failing. In the case of setRetryAttempts, we don’t know how many > servers there are. This means that -1 for "All" servers has no relation to > the actual number of servers that we have. Perhaps setRetryAttempts could > be renamed to setNumberOfAttempts to clarify as well, but the problem still > stands... > > > *Discussion:* > > > In an attempt to provide the best code possible to the geode community, > there has been some discussion of the use of infinite/all/forever as an > overload of a count. Often -1 indicates infinite, while 0 indicates never, > and 1 to MAXINT, inclusive, indicates a count. > > > There are three obvious approaches to solve the problem of the overloading > of -1. The first approach is do nothing… Status quo. > > > The second approach to clarify things would be to create an enumeration > that would be passed in as well as the number or an object.. > > > struct Retries > > { > > typedef enum { eINFINITE, eCOUNT, eNONE} eCount; > > eCount approach; > > unsigned int count; > > }; > > > > The third approach would be to pass a continue object of some sort such > that it tells you if it is ok to continue through the use of an algorithm. > > > An example would be > > > class Continue > > { > > virtual bool Continue() = 0; > > } > > > class InfiniteContinue : public Continue > > { > > bool Continue() > > { > > return true; > > } > > } > > > Continue co = InfiniteContinue; > > > while( co.Continue() ) > > { > > //do a thing > > } > > > Another example would be a Continue limited to 5 let’s say, > > > class CountContinue : public Continue > > { > > private: > > int count; > > > public: > > CountContinue(int count) > > { > > this.count = count; > > } > > bool Continue() > > { > > return count— > 0; > > } > > } > > > In both of these cases what is happening is that the algorithm is being > outsourced. > > > *Conclusion:* > > > We are putting this out, to start a discussion on the best way to move this > forward… *What do people think? What direction would be the best going > forward?* > > > [1] > https://github.com/apache/geode-native/blob/006df0e70eeb481ef5e9e821dba005 > 0dee9c6893/cppcache/include/geode/PoolFactory.hpp#L327 >
