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 e x e c . l i b r a r y                                    FindSemaphore 

REPORT          Forbid() missing, unreliable result

SEVERITY        Level 2

EXPLANATION     You MUST freeze multitasking before searching a
                public Semaphore. Otherwise the semaphore could be
                removed shortly after you've got the pointer. An access
                to the structure will then throw Enforcer hits in best
                case, or it will just trash memory. Also see AutoDocs!

DEADLY          In DEADLY mode, this function call will return the
                true return code only if multitasking was forbidden.
                Otherwise it will pass NULL if the Semaphore wasn't
                there anyhow, or 0xFACEDEAD if the Semaphore was found.
                So, just finding out if this semaphore existed will still
                work, but accessing it will cause Enforcer hits.

REMARK          Some people claim that this hit is annoying, since they
                consider this practice to be legal if you only want to
                find out if a port is available or not.

                I don't think so. There is still a slight chance to
                crash the system. Imagine your program is iterating the
                list without Forbid(), looking for a certain Node B
                which comes after Node A. Now, while FindPort() is
                fetching Node A, a scheduling occurs and another process
                gets the processor. This other process now removes Node A
                from the list and changes its memory contents. If your
                program then gets the processor back, it will get a
                completely messed up 'Node A', and will crash.

                It is sad, but as long as AmigaOS does not provide a
                semaphore mechanism for public lists, we must use Forbid()
                if we iterate through them.