gdbserver/gdbthread.h

   1 /* Multi-thread control defs for remote server for GDB.
   2    Copyright (C) 1993-2024 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/function-view.h"
  23 #include "gdbsupport/intrusive_list.h"
  24
  25 struct btrace_target_info;
  26 struct regcache;
  27
  28 struct thread_info : public intrusive_list_node<thread_info>
  29 {
  30   thread_info (ptid_t id, process_info *process, void *target_data)
  31     : id (id), target_data (target_data), m_process (process)
  32   {}
  33
  34   ~thread_info ()
  35   {
  36     free_register_cache (this->regcache_data);
  37   }
  38
  39   /* Return the process owning this thread.  */
  40   process_info *process () const
  41   { return m_process; }
  42
  43   /* The id of this thread.  */
  44   ptid_t id;
  45
  46   void *target_data;
  47   struct regcache *regcache_data = nullptr;
  48
  49   /* The last resume GDB requested on this thread.  */
  50   enum resume_kind last_resume_kind = resume_continue;
  51
  52   /* The last wait status reported for this thread.  */
  53   struct target_waitstatus last_status;
  54
  55   /* True if LAST_STATUS hasn't been reported to GDB yet.  */
  56   int status_pending_p = 0;
  57
  58   /* Given `while-stepping', a thread may be collecting data for more
  59      than one tracepoint simultaneously.  E.g.:
  60
  61     ff0001  INSN1 <-- TP1, while-stepping 10 collect $regs
  62     ff0002  INSN2
  63     ff0003  INSN3 <-- TP2, collect $regs
  64     ff0004  INSN4 <-- TP3, while-stepping 10 collect $regs
  65     ff0005  INSN5
  66
  67    Notice that when instruction INSN5 is reached, the while-stepping
  68    actions of both TP1 and TP3 are still being collected, and that TP2
  69    had been collected meanwhile.  The whole range of ff0001-ff0005
  70    should be single-stepped, due to at least TP1's while-stepping
  71    action covering the whole range.
  72
  73    On the other hand, the same tracepoint with a while-stepping action
  74    may be hit by more than one thread simultaneously, hence we can't
  75    keep the current step count in the tracepoint itself.
  76
  77    This is the head of the list of the states of `while-stepping'
  78    tracepoint actions this thread is now collecting; NULL if empty.
  79    Each item in the list holds the current step of the while-stepping
  80    action.  */
  81   struct wstep_state *while_stepping = nullptr;
  82
  83   /* Branch trace target information for this thread.  */
  84   struct btrace_target_info *btrace = nullptr;
  85
  86   /* Thread options GDB requested with QThreadOptions.  */
  87   gdb_thread_options thread_options = 0;
  88
  89 private:
  90   process_info *m_process;
  91 };
  92
  93 /* Return a pointer to the first thread, or NULL if there isn't one.  */
  94
  95 struct thread_info *get_first_thread (void);
  96
  97 struct thread_info *find_thread_ptid (ptid_t ptid);
  98
  99 /* Find any thread of the PID process.  Returns NULL if none is
 100    found.  */
 101 struct thread_info *find_any_thread_of_pid (int pid);
 102
 103 /* Find the first thread for which FUNC returns true.  Return NULL if no thread
 104    satisfying FUNC is found.  */
 105
 106 thread_info *find_thread (gdb::function_view<bool (thread_info *)> func);
 107
 108 /* Like the above, but only consider threads with pid PID.  */
 109
 110 thread_info *find_thread (int pid,
 111                           gdb::function_view<bool (thread_info *)> func);
 112
 113 /* Find the first thread that matches FILTER for which FUNC returns true.
 114    Return NULL if no thread satisfying these conditions is found.  */
 115
 116 thread_info *find_thread (ptid_t filter,
 117                           gdb::function_view<bool (thread_info *)> func);
 118
 119 /* Invoke FUNC for each thread.  */
 120
 121 void for_each_thread (gdb::function_view<void (thread_info *)> func);
 122
 123 /* Like the above, but only consider threads matching PTID.  */
 124
 125 void for_each_thread
 126   (ptid_t ptid, gdb::function_view<void (thread_info *)> func);
 127
 128 /* Find a random thread that matches PTID and for which FUNC (THREAD)
 129    returns true.  If no entry is found then return nullptr.  */
 130
 131 thread_info *find_thread_in_random
 132   (gdb::function_view<bool (thread_info *)> func);
 133
 134 /* Like the above, but only consider threads matching PTID.  */
 135
 136 thread_info *find_thread_in_random
 137   (ptid_t ptid, gdb::function_view<bool (thread_info *)> func);
 138
 139 /* Switch the current thread.  */
 140
 141 void switch_to_thread (thread_info *thread);
 142
 143 /* Save/restore current thread.  */
 144
 145 class scoped_restore_current_thread
 146 {
 147 public:
 148   scoped_restore_current_thread ();
 149   ~scoped_restore_current_thread ();
 150
 151   DISABLE_COPY_AND_ASSIGN (scoped_restore_current_thread);
 152
 153   /* Cancel restoring on scope exit.  */
 154   void dont_restore () { m_dont_restore = true; }
 155
 156 private:
 157   bool m_dont_restore = false;
 158   process_info *m_process;
 159   thread_info *m_thread;
 160 };
 161
 162 #endif /* GDBSERVER_GDBTHREAD_H */