gdb/thread-iter.h

   1 /* Thread iterators and ranges for GDB, the GNU debugger.
   2    Copyright (C) 2018-2021 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 THREAD_ITER_H
  20 #define THREAD_ITER_H
  21
  22 #include "gdbsupport/filtered-iterator.h"
  23 #include "gdbsupport/iterator-range.h"
  24 #include "gdbsupport/next-iterator.h"
  25 #include "gdbsupport/reference-to-pointer-iterator.h"
  26 #include "gdbsupport/safe-iterator.h"
  27
  28 /* A forward iterator that iterates over a given inferior's
  29    threads.  */
  30
  31 using inf_threads_iterator
  32   = reference_to_pointer_iterator<intrusive_list<thread_info>::iterator>;
  33
  34 /* A forward iterator that iterates over all threads of all
  35    inferiors.  */
  36
  37 class all_threads_iterator
  38 {
  39 public:
  40   typedef all_threads_iterator self_type;
  41   typedef struct thread_info *value_type;
  42   typedef struct thread_info *&reference;
  43   typedef struct thread_info **pointer;
  44   typedef std::forward_iterator_tag iterator_category;
  45   typedef int difference_type;
  46
  47   /* Tag type.  */
  48   struct begin_t {};
  49
  50   /* Create an iterator that points to the first thread of the first
  51      inferior.  */
  52   explicit all_threads_iterator (begin_t);
  53
  54   /* Create a one-past-end iterator.  */
  55   all_threads_iterator ()
  56     : m_thr (nullptr)
  57   {}
  58
  59   thread_info *operator* () const { return m_thr; }
  60
  61   all_threads_iterator &operator++ ()
  62   {
  63     advance ();
  64     return *this;
  65   }
  66
  67   bool operator== (const all_threads_iterator &other) const
  68   { return m_thr == other.m_thr; }
  69
  70   bool operator!= (const all_threads_iterator &other) const
  71   { return m_thr != other.m_thr; }
  72
  73 private:
  74   /* Advance to the next thread.  */
  75   void advance ();
  76
  77 private:
  78   /* The current inferior and thread.  M_THR is NULL if we reached the
  79      end of the threads list of the last inferior.  */
  80   inferior *m_inf;
  81   thread_info *m_thr;
  82 };
  83
  84 /* Iterate over all threads that match a given PTID.  */
  85
  86 class all_matching_threads_iterator
  87 {
  88 public:
  89   typedef all_matching_threads_iterator self_type;
  90   typedef struct thread_info *value_type;
  91   typedef struct thread_info *&reference;
  92   typedef struct thread_info **pointer;
  93   typedef std::forward_iterator_tag iterator_category;
  94   typedef int difference_type;
  95
  96   /* Creates an iterator that iterates over all threads that match
  97      FILTER_PTID.  */
  98   all_matching_threads_iterator (process_stratum_target *filter_target,
  99                                  ptid_t filter_ptid);
 100
 101   /* Create a one-past-end iterator.  */
 102   all_matching_threads_iterator () = default;
 103
 104   thread_info *operator* () const { return m_thr; }
 105
 106   all_matching_threads_iterator &operator++ ()
 107   {
 108     advance ();
 109     return *this;
 110   }
 111
 112   bool operator== (const all_matching_threads_iterator &other) const
 113   { return m_thr == other.m_thr; }
 114
 115   bool operator!= (const all_matching_threads_iterator &other) const
 116   { return m_thr != other.m_thr; }
 117
 118 private:
 119   /* Advance to next thread, skipping filtered threads.  */
 120   void advance ();
 121
 122   /* True if M_INF has the process target M_FILTER_TARGET.  */
 123   bool m_inf_matches ();
 124
 125 private:
 126   enum class mode
 127   {
 128     /* All threads, possibly filtered down to a single target.  */
 129     ALL_THREADS,
 130
 131     /* All threads of the given inferior.  */
 132     ALL_THREADS_OF_INFERIOR,
 133
 134     /* A specific thread.  */
 135     SINGLE_THREAD,
 136   } m_mode;
 137
 138   /* The current inferior.  */
 139   inferior *m_inf = nullptr;
 140
 141   /* The current thread.  */
 142   thread_info *m_thr = nullptr;
 143
 144   /* The target we filter on (may be nullptr).  */
 145   process_stratum_target *m_filter_target;
 146 };
 147
 148 /* Filter for filtered_iterator.  Filters out exited threads.  */
 149
 150 struct non_exited_thread_filter
 151 {
 152   bool operator() (struct thread_info *thr) const
 153   {
 154     return thr->state != THREAD_EXITED;
 155   }
 156 };
 157
 158 /* Iterate over all non-exited threads that match a given PTID.  */
 159
 160 using all_non_exited_threads_iterator
 161   = filtered_iterator<all_matching_threads_iterator, non_exited_thread_filter>;
 162
 163 /* Iterate over all non-exited threads of an inferior.  */
 164
 165 using inf_non_exited_threads_iterator
 166   = filtered_iterator<inf_threads_iterator, non_exited_thread_filter>;
 167
 168 /* Iterate over all threads of all inferiors, safely.  */
 169
 170 using all_threads_safe_iterator
 171   = basic_safe_iterator<all_threads_iterator>;
 172
 173 /* Iterate over all threads of an inferior, safely.  */
 174
 175 using safe_inf_threads_iterator
 176   = basic_safe_iterator<inf_threads_iterator>;
 177
 178 /* A range adapter that makes it possible to iterate over all threads
 179    of an inferior with range-for.  */
 180
 181 using inf_threads_range = iterator_range<inf_threads_iterator>;
 182
 183 /* A range adapter that makes it possible to iterate over all
 184    non-exited threads of an inferior with range-for.  */
 185
 186 using inf_non_exited_threads_range
 187   = iterator_range<inf_non_exited_threads_iterator>;
 188
 189 /* A range adapter that makes it possible to iterate over all threads
 190    of an inferior with range-for, safely.  */
 191
 192 using safe_inf_threads_range = iterator_range<safe_inf_threads_iterator>;
 193
 194 /* A range adapter that makes it possible to iterate over all threads
 195    with range-for "safely".  I.e., it is safe to delete the
 196    currently-iterated thread.  */
 197
 198 using all_threads_safe_range = iterator_range<all_threads_safe_iterator>;
 199
 200 /* A range adapter that makes it possible to iterate over all threads
 201    that match a PTID filter with range-for.  */
 202
 203 struct all_matching_threads_range
 204 {
 205 public:
 206   all_matching_threads_range (process_stratum_target *filter_target,
 207                               ptid_t filter_ptid)
 208     : m_filter_target (filter_target), m_filter_ptid (filter_ptid)
 209   {}
 210   all_matching_threads_range ()
 211     : m_filter_target (nullptr), m_filter_ptid (minus_one_ptid)
 212   {}
 213
 214   all_matching_threads_iterator begin () const
 215   { return all_matching_threads_iterator (m_filter_target, m_filter_ptid); }
 216   all_matching_threads_iterator end () const
 217   { return all_matching_threads_iterator (); }
 218
 219 private:
 220   /* The filter.  */
 221   process_stratum_target *m_filter_target;
 222   ptid_t m_filter_ptid;
 223 };
 224
 225 /* A range adapter that makes it possible to iterate over all
 226    non-exited threads of all inferiors, with range-for.
 227    Threads/inferiors that do not match FILTER_PTID are filtered
 228    out.  */
 229
 230 class all_non_exited_threads_range
 231 {
 232 public:
 233   all_non_exited_threads_range (process_stratum_target *filter_target,
 234                                 ptid_t filter_ptid)
 235     : m_filter_target (filter_target), m_filter_ptid (filter_ptid)
 236   {}
 237
 238   all_non_exited_threads_range ()
 239     : m_filter_target (nullptr), m_filter_ptid (minus_one_ptid)
 240   {}
 241
 242   all_non_exited_threads_iterator begin () const
 243   { return all_non_exited_threads_iterator (m_filter_target, m_filter_ptid); }
 244   all_non_exited_threads_iterator end () const
 245   { return all_non_exited_threads_iterator (); }
 246
 247 private:
 248   process_stratum_target *m_filter_target;
 249   ptid_t m_filter_ptid;
 250 };
 251
 252 #endif /* THREAD_ITER_H */