fd_array.hh revision 12697
1/* 2 * Copyright (c) 2016 Advanced Micro Devices, Inc. 3 * All rights reserved. 4 * 5 * For use for simulation and test purposes only 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright notice, 11 * this list of conditions and the following disclaimer. 12 * 13 * 2. Redistributions in binary form must reproduce the above copyright notice, 14 * this list of conditions and the following disclaimer in the documentation 15 * and/or other materials provided with the distribution. 16 * 17 * 3. Neither the name of the copyright holder nor the names of its 18 * contributors may be used to endorse or promote products derived from this 19 * software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 25 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 31 * POSSIBILITY OF SUCH DAMAGE. 32 * 33 * Authors: Brandon Potter 34 */ 35 36#ifndef __FD_ARRAY_HH__ 37#define __FD_ARRAY_HH__ 38 39#include <array> 40#include <memory> 41#include <string> 42 43#include "sim/fd_entry.hh" 44 45class FDArray 46{ 47 private: 48 static const int NUM_FDS = 1024; 49 50 public: 51 /** 52 * Initialize the file descriptor array and set the standard file 53 * descriptors to defaults or values passed in with the process 54 * params. 55 * @param input Used to initialize the stdin file descriptor 56 * @param output Used to initialize the stdout file descriptor 57 * @param errout Used to initialize the stderr file descriptor 58 */ 59 FDArray(std::string const& input, std::string const& output, 60 std::string const& errout); 61 62 std::string _input; 63 std::string _output; 64 std::string _errout; 65 66 /** 67 * Figure out the file offsets for all currently open files and save them 68 * the offsets during the calls to drain by the owning process. 69 */ 70 void updateFileOffsets(); 71 72 /** 73 * Restore all offsets for currently open files during the unserialize 74 * phase for the owning process class. 75 */ 76 void restoreFileOffsets(); 77 78 /** 79 * Treat this object like a normal array in using the subscript operator 80 * to pull entries out of it. 81 * @param tgt_fd Use target file descriptors to index the array. 82 */ 83 inline std::shared_ptr<FDEntry> 84 operator[](int tgt_fd) 85 { 86 return getFDEntry(tgt_fd); 87 } 88 89 /** 90 * Step through the file descriptor array and find the first available 91 * entry which is denoted as being free by being a 'nullptr'. That file 92 * descriptor entry is the new target file descriptor entry that we 93 * return as the return parameter. 94 * @param fdp Allocated beforehand and passed into this method; 95 * the fdp is meant to be a generic pointer capable of pointing to 96 * different types of file descriptors. Must cast the pointer to the 97 * correct type before dereferencing to access the needed fields. 98 */ 99 int allocFD(std::shared_ptr<FDEntry> fdp); 100 101 /** 102 * Return the size of the _fdArray field 103 */ 104 int getSize() const { return _fdArray.size(); } 105 106 /** 107 * Put the pointer specified by fdep into the _fdArray entry indexed 108 * by tgt_fd. 109 * @param tgt_fd Use target file descriptors to index the array. 110 * @param fdep Incoming pointer used to set the entry pointed to by tgt_fd. 111 */ 112 void setFDEntry(int tgt_fd, std::shared_ptr<FDEntry> fdep); 113 114 /** 115 * Try to close the host file descriptor. If successful, set the 116 * specified file descriptor entry object pointer to nullptr. 117 * Used to "close" the target file descriptor. 118 * @param tgt_fd Use target file descriptors to index the array. 119 */ 120 int closeFDEntry(int tgt_fd); 121 122 private: 123 /** 124 * Help clarify our intention when opening files in the init and 125 * restoration code. These are helper functions which are not meant to 126 * be exposed to other objects or files. 127 */ 128 int openFile(std::string const& file_name, int flags, mode_t mode) const; 129 int openInputFile(std::string const& file_name) const; 130 int openOutputFile(std::string const& file_name) const; 131 132 /** 133 * Return the file descriptor entry object associated with the index 134 * provided. (The index is protected with bounds checking on the array 135 * size without the use of the array's at operator.) 136 * @param tgt_fd Use target file descriptors to index the array. 137 */ 138 std::shared_ptr<FDEntry> getFDEntry(int tgt_fd); 139 140 /** 141 * Hold pointers to the file descriptor entries. The array size is 142 * statically defined by the operating system. 143 */ 144 std::array<std::shared_ptr<FDEntry>, NUM_FDS> _fdArray; 145 146 /** 147 * Hold strings which represent the default values which are checked 148 * against to initialize the standard file descriptors. If the string 149 * provided doesn't hit against these maps, then a file is opened on the 150 * host instead of using the host's standard file descriptors. 151 */ 152 std::map<std::string, int> imap; 153 std::map<std::string, int> oemap; 154}; 155 156#endif // __FD_ARRAY_HH__ 157