1 /* The ptid_t type and common functions operating on it. 2 3 Copyright (C) 1986-2023 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 #include <functional> 36 #include <string> 37 #include "gdbsupport/common-types.h" 38 39 class ptid_t 40 { 41 public: 42 /* Must have a trivial defaulted default constructor so that the 43 type remains POD. */ 44 ptid_t () noexcept = default; 45 46 /* Make a ptid given the necessary PID, LWP, and TID components. 47 48 A ptid with only a PID (LWP and TID equal to zero) is usually used to 49 represent a whole process, including all its lwps/threads. */ 50 51 explicit constexpr ptid_t (int pid, long lwp = 0, ULONGEST tid = 0) 52 : m_pid (pid), m_lwp (lwp), m_tid (tid) 53 {} 54 55 /* Fetch the pid (process id) component from the ptid. */ 56 57 constexpr int pid () const 58 { return m_pid; } 59 60 /* Return true if the ptid's lwp member is non-zero. */ 61 62 constexpr bool lwp_p () const 63 { return m_lwp != 0; } 64 65 /* Fetch the lwp (lightweight process) component from the ptid. */ 66 67 constexpr long lwp () const 68 { return m_lwp; } 69 70 /* Return true if the ptid's tid member is non-zero. */ 71 72 constexpr bool tid_p () const 73 { return m_tid != 0; } 74 75 /* Fetch the tid (thread id) component from a ptid. */ 76 77 constexpr ULONGEST tid () const 78 { return m_tid; } 79 80 /* Return true if the ptid represents a whole process, including all its 81 lwps/threads. Such ptids have the form of (pid, 0, 0), with 82 pid != -1. */ 83 84 constexpr bool is_pid () const 85 { 86 return (*this != make_null () 87 && *this != make_minus_one () 88 && m_lwp == 0 89 && m_tid == 0); 90 } 91 92 /* Compare two ptids to see if they are equal. */ 93 94 constexpr bool operator== (const ptid_t &other) const 95 { 96 return (m_pid == other.m_pid 97 && m_lwp == other.m_lwp 98 && m_tid == other.m_tid); 99 } 100 101 /* Compare two ptids to see if they are different. */ 102 103 constexpr bool operator!= (const ptid_t &other) const 104 { 105 return !(*this == other); 106 } 107 108 /* Return true if the ptid matches FILTER. FILTER can be the wild 109 card MINUS_ONE_PTID (all ptids match it); can be a ptid representing 110 a process (ptid.is_pid () returns true), in which case, all lwps and 111 threads of that given process match, lwps and threads of other 112 processes do not; or, it can represent a specific thread, in which 113 case, only that thread will match true. The ptid must represent a 114 specific LWP or THREAD, it can never be a wild card. */ 115 116 constexpr bool matches (const ptid_t &filter) const 117 { 118 return (/* If filter represents any ptid, it's always a match. */ 119 filter == make_minus_one () 120 /* If filter is only a pid, any ptid with that pid 121 matches. */ 122 || (filter.is_pid () && m_pid == filter.pid ()) 123 124 /* Otherwise, this ptid only matches if it's exactly equal 125 to filter. */ 126 || *this == filter); 127 } 128 129 /* Return a string representation of the ptid. 130 131 This is only meant to be used in debug messages. */ 132 133 std::string to_string () const; 134 135 /* Make a null ptid. */ 136 137 static constexpr ptid_t make_null () 138 { return ptid_t (0, 0, 0); } 139 140 /* Make a minus one ptid. */ 141 142 static constexpr ptid_t make_minus_one () 143 { return ptid_t (-1, 0, 0); } 144 145 private: 146 /* Process id. */ 147 int m_pid; 148 149 /* Lightweight process id. */ 150 long m_lwp; 151 152 /* Thread id. */ 153 ULONGEST m_tid; 154 }; 155 156 /* Functor to hash a ptid. */ 157 158 struct hash_ptid 159 { 160 size_t operator() (const ptid_t &ptid) const 161 { 162 std::hash<long> long_hash; 163 164 return (long_hash (ptid.pid ()) 165 + long_hash (ptid.lwp ()) 166 + long_hash (ptid.tid ())); 167 } 168 }; 169 170 /* The null or zero ptid, often used to indicate no process. */ 171 172 extern const ptid_t null_ptid; 173 174 /* The (-1,0,0) ptid, often used to indicate either an error condition 175 or a "don't care" condition, i.e, "run all threads." */ 176 177 extern const ptid_t minus_one_ptid; 178 179 #endif /* COMMON_PTID_H */ 180