Hi Ian, > Thanks guys I knew that I could count on you all for help. volatile, > that's new to me I'll look it up. Kernighan and Ritchie say what you > all say but ANSI C says it's implementation dependent, as long as it > works.
FYI: ANSI C is also out of date. These days it is the ISO C99 standard that you need to check. In there you will find: 6.7.3 Type qualifiers [...] 6 An object that has volatile-qualified type may be modified in ways unknown to the implementation or have other unknown side effects. Therefore any expression referring to such an object shall be evaluated strictly according to the rules of the abstract machine, as described in 5.1.2.3. Furthermore, at every sequence point the value last stored in the object shall agree with that prescribed by the abstract machine, except as modified by the unknown factors mentioned previously. (114) What constitutes an access to an object that has volatile-qualified type is implementation-defined. [...] 114) A volatile declaration may be used to describe an object corresponding to a memory-mapped input/output port or an object accessed by an asynchronously interrupting function. Actions on objects so declared shall not be ‘‘optimized out’’ by an implementation or reordered except as permitted by the rules for evaluating expressions. Cheers Nick ------------------------------------------------------------------------------ Presto, an open source distributed SQL query engine for big data, initially developed by Facebook, enables you to easily query your data on Hadoop in a more interactive manner. Teradata is also now providing full enterprise support for Presto. Download a free open source copy now. http://pubads.g.doubleclick.net/gampad/clk?id=250295911&iu=/4140 _______________________________________________ Mspgcc-users mailing list Mspgcc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mspgcc-users