/* * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved. * * The contents of this file constitute Original Code as defined in and are * subject to the Apple Public Source License Version 1.2 (the 'License'). * You may not use this file except in compliance with the License. Please obtain * a copy of the License at http://www.apple.com/publicsource and read it before * using this file. * * This Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the * specific language governing rights and limitations under the License. */ // // fdsel - select-style file descriptor set management // #ifndef _H_FDSEL #define _H_FDSEL #include <Security/utilities.h> #include <sys/types.h> #include <Security/debugging.h> namespace Security { namespace UnixPlusPlus { // // An FDSet object maintains a single select(2) compatible bitmap. // Size is implicitly kept by the caller (who needs to call grow() as // needed, starting at zero). As long as this is done correctly, we are // not bound by the FD_SETSIZE limit. // An FDSet can self-copy for select(2) use; after that, the [] operator // investigates the copy. // // Why are we using the FD_* macros even though we know these // are fd_mask arrays? Some implementations use optimized assembly // for these operations, and we want to pick those up. // // This whole mess is completely UNIX specific. If your system has // the poll(2) system call, ditch this and use it. // class FDSet { public: FDSet() : mBits(NULL), mUseBits(NULL) { } ~FDSet(); void grow(int oldWords, int newWords); void set(int fd, bool on); fd_set *make(int words); bool operator [] (int fd) const { return FD_ISSET(fd, (fd_set *)mUseBits); } inline static int words(int fd) { return (fd - 1) / NFDBITS + 1; } private: fd_mask *mBits; // base bits fd_mask *mUseBits; // mutable copy for select(2) void grow(fd_mask * &bits, int oldWords, int newWords); }; } // end namespace UnixPlusPlus } // end namespace Security #endif //_H_FDSEL