1/* 2 * Copyright (c) 2000-2001,2003-2004 Apple Computer, Inc. All Rights Reserved. 3 * 4 * @APPLE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. Please obtain a copy of the License at 10 * http://www.opensource.apple.com/apsl/ and read it before using this 11 * file. 12 * 13 * The Original Code and all software distributed under the License are 14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 18 * Please see the License for the specific language governing rights and 19 * limitations under the License. 20 * 21 * @APPLE_LICENSE_HEADER_END@ 22 */ 23 24 25// 26// fdsel - select-style file descriptor set management 27// 28#ifndef _H_FDSEL 29#define _H_FDSEL 30 31#include <security_utilities/utilities.h> 32#include <sys/types.h> 33#include <security_utilities/debugging.h> 34 35 36namespace Security { 37namespace UnixPlusPlus { 38 39 40// 41// An FDSet object maintains a single select(2) compatible bitmap. 42// Size is implicitly kept by the caller (who needs to call grow() as 43// needed, starting at zero). As long as this is done correctly, we are 44// not bound by the FD_SETSIZE limit. 45// An FDSet can self-copy for select(2) use; after that, the [] operator 46// investigates the copy. 47// 48// Why are we using the FD_* macros even though we know these 49// are fd_mask arrays? Some implementations use optimized assembly 50// for these operations, and we want to pick those up. 51// 52// This whole mess is completely UNIX specific. If your system has 53// the poll(2) system call, ditch this and use it. 54// 55class FDSet { 56public: 57 FDSet() : mBits(NULL), mUseBits(NULL) { } 58 ~FDSet(); 59 60 void grow(int oldWords, int newWords); 61 void set(int fd, bool on); 62 63 fd_set *make(int words); 64 bool operator [] (int fd) const { return FD_ISSET(fd, (fd_set *)mUseBits); } 65 66 inline static int words(int fd) { return (fd - 1) / NFDBITS + 1; } 67 68private: 69 fd_mask *mBits; // base bits 70 fd_mask *mUseBits; // mutable copy for select(2) 71 72 void grow(fd_mask * &bits, int oldWords, int newWords); 73}; 74 75 76} // end namespace UnixPlusPlus 77} // end namespace Security 78 79 80#endif //_H_FDSEL 81