| 1 | /* The ptid_t type and common functions operating on it. |
| 2 | |
| 3 | Copyright (C) 1986-2020 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #ifndef COMMON_PTID_H |
| 21 | #define COMMON_PTID_H |
| 22 | |
| 23 | /* The ptid struct is a collection of the various "ids" necessary for |
| 24 | identifying the inferior process/thread being debugged. This |
| 25 | consists of the process id (pid), lightweight process id (lwp) and |
| 26 | thread id (tid). When manipulating ptids, the constructors, |
| 27 | accessors, and predicates declared in this file should be used. Do |
| 28 | NOT access the struct ptid members directly. |
| 29 | |
| 30 | process_stratum targets that handle threading themselves should |
| 31 | prefer using the ptid.lwp field, leaving the ptid.tid field for any |
| 32 | thread_stratum target that might want to sit on top. |
| 33 | */ |
| 34 | |
| 35 | class ptid_t |
| 36 | { |
| 37 | public: |
| 38 | /* Must have a trivial defaulted default constructor so that the |
| 39 | type remains POD. */ |
| 40 | ptid_t () noexcept = default; |
| 41 | |
| 42 | /* Make a ptid given the necessary PID, LWP, and TID components. |
| 43 | |
| 44 | A ptid with only a PID (LWP and TID equal to zero) is usually used to |
| 45 | represent a whole process, including all its lwps/threads. */ |
| 46 | |
| 47 | explicit constexpr ptid_t (int pid, long lwp = 0, long tid = 0) |
| 48 | : m_pid (pid), m_lwp (lwp), m_tid (tid) |
| 49 | {} |
| 50 | |
| 51 | /* Fetch the pid (process id) component from the ptid. */ |
| 52 | |
| 53 | constexpr int pid () const |
| 54 | { return m_pid; } |
| 55 | |
| 56 | /* Return true if the ptid's lwp member is non-zero. */ |
| 57 | |
| 58 | constexpr bool lwp_p () const |
| 59 | { return m_lwp != 0; } |
| 60 | |
| 61 | /* Fetch the lwp (lightweight process) component from the ptid. */ |
| 62 | |
| 63 | constexpr long lwp () const |
| 64 | { return m_lwp; } |
| 65 | |
| 66 | /* Return true if the ptid's tid member is non-zero. */ |
| 67 | |
| 68 | constexpr bool tid_p () const |
| 69 | { return m_tid != 0; } |
| 70 | |
| 71 | /* Fetch the tid (thread id) component from a ptid. */ |
| 72 | |
| 73 | constexpr long tid () const |
| 74 | { return m_tid; } |
| 75 | |
| 76 | /* Return true if the ptid represents a whole process, including all its |
| 77 | lwps/threads. Such ptids have the form of (pid, 0, 0), with |
| 78 | pid != -1. */ |
| 79 | |
| 80 | constexpr bool is_pid () const |
| 81 | { |
| 82 | return (*this != make_null () |
| 83 | && *this != make_minus_one () |
| 84 | && m_lwp == 0 |
| 85 | && m_tid == 0); |
| 86 | } |
| 87 | |
| 88 | /* Compare two ptids to see if they are equal. */ |
| 89 | |
| 90 | constexpr bool operator== (const ptid_t &other) const |
| 91 | { |
| 92 | return (m_pid == other.m_pid |
| 93 | && m_lwp == other.m_lwp |
| 94 | && m_tid == other.m_tid); |
| 95 | } |
| 96 | |
| 97 | /* Compare two ptids to see if they are different. */ |
| 98 | |
| 99 | constexpr bool operator!= (const ptid_t &other) const |
| 100 | { |
| 101 | return !(*this == other); |
| 102 | } |
| 103 | |
| 104 | /* Return true if the ptid matches FILTER. FILTER can be the wild |
| 105 | card MINUS_ONE_PTID (all ptids match it); can be a ptid representing |
| 106 | a process (ptid.is_pid () returns true), in which case, all lwps and |
| 107 | threads of that given process match, lwps and threads of other |
| 108 | processes do not; or, it can represent a specific thread, in which |
| 109 | case, only that thread will match true. The ptid must represent a |
| 110 | specific LWP or THREAD, it can never be a wild card. */ |
| 111 | |
| 112 | constexpr bool matches (const ptid_t &filter) const |
| 113 | { |
| 114 | return (/* If filter represents any ptid, it's always a match. */ |
| 115 | filter == make_minus_one () |
| 116 | /* If filter is only a pid, any ptid with that pid |
| 117 | matches. */ |
| 118 | || (filter.is_pid () && m_pid == filter.pid ()) |
| 119 | |
| 120 | /* Otherwise, this ptid only matches if it's exactly equal |
| 121 | to filter. */ |
| 122 | || *this == filter); |
| 123 | } |
| 124 | |
| 125 | /* Make a null ptid. */ |
| 126 | |
| 127 | static constexpr ptid_t make_null () |
| 128 | { return ptid_t (0, 0, 0); } |
| 129 | |
| 130 | /* Make a minus one ptid. */ |
| 131 | |
| 132 | static constexpr ptid_t make_minus_one () |
| 133 | { return ptid_t (-1, 0, 0); } |
| 134 | |
| 135 | private: |
| 136 | /* Process id. */ |
| 137 | int m_pid; |
| 138 | |
| 139 | /* Lightweight process id. */ |
| 140 | long m_lwp; |
| 141 | |
| 142 | /* Thread id. */ |
| 143 | long m_tid; |
| 144 | }; |
| 145 | |
| 146 | /* The null or zero ptid, often used to indicate no process. */ |
| 147 | |
| 148 | extern const ptid_t null_ptid; |
| 149 | |
| 150 | /* The (-1,0,0) ptid, often used to indicate either an error condition |
| 151 | or a "don't care" condition, i.e, "run all threads." */ |
| 152 | |
| 153 | extern const ptid_t minus_one_ptid; |
| 154 | |
| 155 | #endif /* COMMON_PTID_H */ |