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