1 /* The ptid_t type and common functions operating on it. 2 3 Copyright (C) 1986-2024 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 using pid_type = int; 43 using lwp_type = long; 44 using tid_type = ULONGEST; 45 46 /* Must have a trivial defaulted default constructor so that the 47 type remains POD. */ 48 ptid_t () noexcept = default; 49 50 /* Make a ptid given the necessary PID, LWP, and TID components. 51 52 A ptid with only a PID (LWP and TID equal to zero) is usually used to 53 represent a whole process, including all its lwps/threads. */ 54 55 explicit constexpr ptid_t (pid_type pid, lwp_type lwp = 0, tid_type tid = 0) 56 : m_pid (pid), m_lwp (lwp), m_tid (tid) 57 {} 58 59 /* Fetch the pid (process id) component from the ptid. */ 60 61 constexpr pid_type pid () const 62 { return m_pid; } 63 64 /* Return true if the ptid's lwp member is non-zero. */ 65 66 constexpr bool lwp_p () const 67 { return m_lwp != 0; } 68 69 /* Fetch the lwp (lightweight process) component from the ptid. */ 70 71 constexpr lwp_type lwp () const 72 { return m_lwp; } 73 74 /* Return true if the ptid's tid member is non-zero. */ 75 76 constexpr bool tid_p () const 77 { return m_tid != 0; } 78 79 /* Fetch the tid (thread id) component from a ptid. */ 80 81 constexpr tid_type tid () const 82 { return m_tid; } 83 84 /* Return true if the ptid represents a whole process, including all its 85 lwps/threads. Such ptids have the form of (pid, 0, 0), with 86 pid != -1. */ 87 88 constexpr bool is_pid () const 89 { 90 return (*this != make_null () 91 && *this != make_minus_one () 92 && m_lwp == 0 93 && m_tid == 0); 94 } 95 96 /* Compare two ptids to see if they are equal. */ 97 98 constexpr bool operator== (const ptid_t &other) const 99 { 100 return (m_pid == other.m_pid 101 && m_lwp == other.m_lwp 102 && m_tid == other.m_tid); 103 } 104 105 /* Compare two ptids to see if they are different. */ 106 107 constexpr bool operator!= (const ptid_t &other) const 108 { 109 return !(*this == other); 110 } 111 112 /* Return true if the ptid matches FILTER. FILTER can be the wild 113 card MINUS_ONE_PTID (all ptids match it); can be a ptid representing 114 a process (ptid.is_pid () returns true), in which case, all lwps and 115 threads of that given process match, lwps and threads of other 116 processes do not; or, it can represent a specific thread, in which 117 case, only that thread will match true. The ptid must represent a 118 specific LWP or THREAD, it can never be a wild card. */ 119 120 constexpr bool matches (const ptid_t &filter) const 121 { 122 return (/* If filter represents any ptid, it's always a match. */ 123 filter == make_minus_one () 124 /* If filter is only a pid, any ptid with that pid 125 matches. */ 126 || (filter.is_pid () && m_pid == filter.pid ()) 127 128 /* Otherwise, this ptid only matches if it's exactly equal 129 to filter. */ 130 || *this == filter); 131 } 132 133 /* Return a string representation of the ptid. 134 135 This is only meant to be used in debug messages. */ 136 137 std::string to_string () const; 138 139 /* Make a null ptid. */ 140 141 static constexpr ptid_t make_null () 142 { return ptid_t (0, 0, 0); } 143 144 /* Make a minus one ptid. */ 145 146 static constexpr ptid_t make_minus_one () 147 { return ptid_t (-1, 0, 0); } 148 149 private: 150 /* Process id. */ 151 pid_type m_pid; 152 153 /* Lightweight process id. */ 154 lwp_type m_lwp; 155 156 /* Thread id. */ 157 tid_type m_tid; 158 }; 159 160 namespace std 161 { 162 template<> 163 struct hash<ptid_t> 164 { 165 size_t operator() (const ptid_t &ptid) const 166 { 167 std::hash<long> long_hash; 168 169 return (long_hash (ptid.pid ()) 170 + long_hash (ptid.lwp ()) 171 + long_hash (ptid.tid ())); 172 } 173 }; 174 } 175 176 /* The null or zero ptid, often used to indicate no process. */ 177 178 extern const ptid_t null_ptid; 179 180 /* The (-1,0,0) ptid, often used to indicate either an error condition 181 or a "don't care" condition, i.e, "run all threads." */ 182 183 extern const ptid_t minus_one_ptid; 184 185 #endif /* COMMON_PTID_H */ 186