| 1 | /* Multi-thread control defs for remote server for GDB. |
| 2 | Copyright (C) 1993-2020 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 3 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #ifndef GDBSERVER_GDBTHREAD_H |
| 20 | #define GDBSERVER_GDBTHREAD_H |
| 21 | |
| 22 | #include "gdbsupport/common-gdbthread.h" |
| 23 | #include "inferiors.h" |
| 24 | |
| 25 | #include <list> |
| 26 | |
| 27 | struct btrace_target_info; |
| 28 | struct regcache; |
| 29 | |
| 30 | struct thread_info |
| 31 | { |
| 32 | /* The id of this thread. */ |
| 33 | ptid_t id; |
| 34 | |
| 35 | void *target_data; |
| 36 | struct regcache *regcache_data; |
| 37 | |
| 38 | /* The last resume GDB requested on this thread. */ |
| 39 | enum resume_kind last_resume_kind; |
| 40 | |
| 41 | /* The last wait status reported for this thread. */ |
| 42 | struct target_waitstatus last_status; |
| 43 | |
| 44 | /* True if LAST_STATUS hasn't been reported to GDB yet. */ |
| 45 | int status_pending_p; |
| 46 | |
| 47 | /* Given `while-stepping', a thread may be collecting data for more |
| 48 | than one tracepoint simultaneously. E.g.: |
| 49 | |
| 50 | ff0001 INSN1 <-- TP1, while-stepping 10 collect $regs |
| 51 | ff0002 INSN2 |
| 52 | ff0003 INSN3 <-- TP2, collect $regs |
| 53 | ff0004 INSN4 <-- TP3, while-stepping 10 collect $regs |
| 54 | ff0005 INSN5 |
| 55 | |
| 56 | Notice that when instruction INSN5 is reached, the while-stepping |
| 57 | actions of both TP1 and TP3 are still being collected, and that TP2 |
| 58 | had been collected meanwhile. The whole range of ff0001-ff0005 |
| 59 | should be single-stepped, due to at least TP1's while-stepping |
| 60 | action covering the whole range. |
| 61 | |
| 62 | On the other hand, the same tracepoint with a while-stepping action |
| 63 | may be hit by more than one thread simultaneously, hence we can't |
| 64 | keep the current step count in the tracepoint itself. |
| 65 | |
| 66 | This is the head of the list of the states of `while-stepping' |
| 67 | tracepoint actions this thread is now collecting; NULL if empty. |
| 68 | Each item in the list holds the current step of the while-stepping |
| 69 | action. */ |
| 70 | struct wstep_state *while_stepping; |
| 71 | |
| 72 | /* Branch trace target information for this thread. */ |
| 73 | struct btrace_target_info *btrace; |
| 74 | }; |
| 75 | |
| 76 | extern std::list<thread_info *> all_threads; |
| 77 | |
| 78 | void remove_thread (struct thread_info *thread); |
| 79 | struct thread_info *add_thread (ptid_t ptid, void *target_data); |
| 80 | |
| 81 | /* Return a pointer to the first thread, or NULL if there isn't one. */ |
| 82 | |
| 83 | struct thread_info *get_first_thread (void); |
| 84 | |
| 85 | struct thread_info *find_thread_ptid (ptid_t ptid); |
| 86 | |
| 87 | /* Find any thread of the PID process. Returns NULL if none is |
| 88 | found. */ |
| 89 | struct thread_info *find_any_thread_of_pid (int pid); |
| 90 | |
| 91 | /* Find the first thread for which FUNC returns true. Return NULL if no thread |
| 92 | satisfying FUNC is found. */ |
| 93 | |
| 94 | template <typename Func> |
| 95 | static thread_info * |
| 96 | find_thread (Func func) |
| 97 | { |
| 98 | std::list<thread_info *>::iterator next, cur = all_threads.begin (); |
| 99 | |
| 100 | while (cur != all_threads.end ()) |
| 101 | { |
| 102 | next = cur; |
| 103 | next++; |
| 104 | |
| 105 | if (func (*cur)) |
| 106 | return *cur; |
| 107 | |
| 108 | cur = next; |
| 109 | } |
| 110 | |
| 111 | return NULL; |
| 112 | } |
| 113 | |
| 114 | /* Like the above, but only consider threads with pid PID. */ |
| 115 | |
| 116 | template <typename Func> |
| 117 | static thread_info * |
| 118 | find_thread (int pid, Func func) |
| 119 | { |
| 120 | return find_thread ([&] (thread_info *thread) |
| 121 | { |
| 122 | return thread->id.pid () == pid && func (thread); |
| 123 | }); |
| 124 | } |
| 125 | |
| 126 | /* Find the first thread that matches FILTER for which FUNC returns true. |
| 127 | Return NULL if no thread satisfying these conditions is found. */ |
| 128 | |
| 129 | template <typename Func> |
| 130 | static thread_info * |
| 131 | find_thread (ptid_t filter, Func func) |
| 132 | { |
| 133 | return find_thread ([&] (thread_info *thread) { |
| 134 | return thread->id.matches (filter) && func (thread); |
| 135 | }); |
| 136 | } |
| 137 | |
| 138 | /* Invoke FUNC for each thread. */ |
| 139 | |
| 140 | template <typename Func> |
| 141 | static void |
| 142 | for_each_thread (Func func) |
| 143 | { |
| 144 | std::list<thread_info *>::iterator next, cur = all_threads.begin (); |
| 145 | |
| 146 | while (cur != all_threads.end ()) |
| 147 | { |
| 148 | next = cur; |
| 149 | next++; |
| 150 | func (*cur); |
| 151 | cur = next; |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | /* Like the above, but only consider threads with pid PID. */ |
| 156 | |
| 157 | template <typename Func> |
| 158 | static void |
| 159 | for_each_thread (int pid, Func func) |
| 160 | { |
| 161 | for_each_thread ([&] (thread_info *thread) |
| 162 | { |
| 163 | if (pid == thread->id.pid ()) |
| 164 | func (thread); |
| 165 | }); |
| 166 | } |
| 167 | |
| 168 | /* Find the a random thread for which FUNC (THREAD) returns true. If |
| 169 | no entry is found then return NULL. */ |
| 170 | |
| 171 | template <typename Func> |
| 172 | static thread_info * |
| 173 | find_thread_in_random (Func func) |
| 174 | { |
| 175 | int count = 0; |
| 176 | int random_selector; |
| 177 | |
| 178 | /* First count how many interesting entries we have. */ |
| 179 | for_each_thread ([&] (thread_info *thread) { |
| 180 | if (func (thread)) |
| 181 | count++; |
| 182 | }); |
| 183 | |
| 184 | if (count == 0) |
| 185 | return NULL; |
| 186 | |
| 187 | /* Now randomly pick an entry out of those. */ |
| 188 | random_selector = (int) |
| 189 | ((count * (double) rand ()) / (RAND_MAX + 1.0)); |
| 190 | |
| 191 | thread_info *thread = find_thread ([&] (thread_info *thr_arg) { |
| 192 | return func (thr_arg) && (random_selector-- == 0); |
| 193 | }); |
| 194 | |
| 195 | gdb_assert (thread != NULL); |
| 196 | |
| 197 | return thread; |
| 198 | } |
| 199 | |
| 200 | /* Get current thread ID (Linux task ID). */ |
| 201 | #define current_ptid (current_thread->id) |
| 202 | |
| 203 | /* Get the ptid of THREAD. */ |
| 204 | |
| 205 | static inline ptid_t |
| 206 | ptid_of (const thread_info *thread) |
| 207 | { |
| 208 | return thread->id; |
| 209 | } |
| 210 | |
| 211 | /* Get the pid of THREAD. */ |
| 212 | |
| 213 | static inline int |
| 214 | pid_of (const thread_info *thread) |
| 215 | { |
| 216 | return thread->id.pid (); |
| 217 | } |
| 218 | |
| 219 | /* Get the lwp of THREAD. */ |
| 220 | |
| 221 | static inline long |
| 222 | lwpid_of (const thread_info *thread) |
| 223 | { |
| 224 | return thread->id.lwp (); |
| 225 | } |
| 226 | |
| 227 | #endif /* GDBSERVER_GDBTHREAD_H */ |