fd_entry.hh revision 11800:54436a1784dc 
1/*
2 * Copyright (c) 2015 Advanced Micro Devices, Inc.
3 * Copyright (c) 2001-2005 The Regents of The University of Michigan
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Nathan Binkert
29 *          Steve Reinhardt
30 */
31
32#ifndef __FD_ENTRY_HH__
33#define __FD_ENTRY_HH__
34
35#include <ostream>
36#include <string>
37
38#include "sim/serialize.hh"
39
40class EmulatedDriver;
41
42/**
43 * FDEntry is used to manage a single file descriptor mapping and metadata
44 * for processes.
45 * Note that the fields are all declared publicly since system calls have a
46 * habit of only needing to access a single field at a time and accessor
47 * methods seem like overkill.
48 */
49class FDEntry : public Serializable
50{
51  public:
52    /**
53     * Constructor contains default values
54     * The file descriptor is free.
55     */
56    FDEntry()
57        : fd(-1), mode(0), flags(0), isPipe(false), readPipeSource(0),
58          fileOffset(0), filename(""), driver(NULL)
59    { }
60
61    void serialize(CheckpointOut &cp) const override;
62    void unserialize(CheckpointIn &cp) override;
63
64    /**
65     * Check if the target file descriptor is in use.
66     * @return value denoting if target file descriptor already used
67     */
68    bool isFree();
69
70    /**
71     * Fill in members for this file descriptor entry.
72     * @param sim_fd host file descriptor
73     * @param name filename string
74     * @param flags current flags of the file descriptor
75     * @param mode current mode of the file descriptor
76     * @param pipe denotes whether the file descriptor belongs to a pipe
77     */
78    void set(int sim_fd, const std::string name, int flags, int mode,
79             bool pipe);
80
81    /** Reset members to their default values. */
82    void reset();
83
84    int fd;
85    int mode;
86    int flags;
87    bool isPipe;
88    int readPipeSource;
89    uint64_t fileOffset;
90    std::string filename;
91    EmulatedDriver *driver;
92};
93
94#endif // __FD_ENTRY_HH__
95