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/next-iterator.h"
  24 #include "gdbsupport/safe-iterator.h"
  25
  26 /* A forward iterator that iterates over a given inferior's
  27    threads.  */
  28
  29 using inf_threads_iterator = next_iterator<thread_info>;
  30
  31 /* A forward iterator that iterates over all threads of all
  32    inferiors.  */
  33
  34 class all_threads_iterator
  35 {
  36 public:
  37   typedef all_threads_iterator self_type;
  38   typedef struct thread_info *value_type;
  39   typedef struct thread_info *&reference;
  40   typedef struct thread_info **pointer;
  41   typedef std::forward_iterator_tag iterator_category;
  42   typedef int difference_type;
  43
  44   /* Tag type.  */
  45   struct begin_t {};
  46
  47   /* Create an iterator that points to the first thread of the first
  48      inferior.  */
  49   explicit all_threads_iterator (begin_t);
  50
  51   /* Create a one-past-end iterator.  */
  52   all_threads_iterator ()
  53     : m_thr (nullptr)
  54   {}
  55
  56   thread_info *operator* () const { return m_thr; }
  57
  58   all_threads_iterator &operator++ ()
  59   {
  60     advance ();
  61     return *this;
  62   }
  63
  64   bool operator== (const all_threads_iterator &other) const
  65   { return m_thr == other.m_thr; }
  66
  67   bool operator!= (const all_threads_iterator &other) const
  68   { return m_thr != other.m_thr; }
  69
  70 private:
  71   /* Advance to the next thread.  */
  72   void advance ();
  73
  74 private:
  75   /* The current inferior and thread.  M_THR is NULL if we reached the
  76      end of the threads list of the last inferior.  */
  77   inferior *m_inf;
  78   thread_info *m_thr;
  79 };
  80
  81 /* Iterate over all threads that match a given PTID.  */
  82
  83 class all_matching_threads_iterator
  84 {
  85 public:
  86   typedef all_matching_threads_iterator self_type;
  87   typedef struct thread_info *value_type;
  88   typedef struct thread_info *&reference;
  89   typedef struct thread_info **pointer;
  90   typedef std::forward_iterator_tag iterator_category;
  91   typedef int difference_type;
  92
  93   /* Creates an iterator that iterates over all threads that match
  94      FILTER_PTID.  */
  95   all_matching_threads_iterator (process_stratum_target *filter_target,
  96                                  ptid_t filter_ptid);
  97
  98   /* Create a one-past-end iterator.  */
  99   all_matching_threads_iterator ()
 100     : m_inf (nullptr),
 101       m_thr (nullptr),
 102       m_filter_target (nullptr),
 103       m_filter_ptid (minus_one_ptid)
 104   {}
 105
 106   thread_info *operator* () const { return m_thr; }
 107
 108   all_matching_threads_iterator &operator++ ()
 109   {
 110     advance ();
 111     return *this;
 112   }
 113
 114   bool operator== (const all_matching_threads_iterator &other) const
 115   { return m_thr == other.m_thr; }
 116
 117   bool operator!= (const all_matching_threads_iterator &other) const
 118   { return m_thr != other.m_thr; }
 119
 120 private:
 121   /* Advance to next thread, skipping filtered threads.  */
 122   void advance ();
 123
 124   /* True if M_INF matches the process identified by
 125      M_FILTER_PTID.  */
 126   bool m_inf_matches ();
 127
 128 private:
 129   /* The current inferior.  */
 130   inferior *m_inf;
 131
 132   /* The current thread.  */
 133   thread_info *m_thr;
 134
 135   /* The filter.  */
 136   process_stratum_target *m_filter_target;
 137   ptid_t m_filter_ptid;
 138 };
 139
 140 /* Filter for filtered_iterator.  Filters out exited threads.  */
 141
 142 struct non_exited_thread_filter
 143 {
 144   bool operator() (struct thread_info *thr) const
 145   {
 146     return thr->state != THREAD_EXITED;
 147   }
 148 };
 149
 150 /* Iterate over all non-exited threads that match a given PTID.  */
 151
 152 using all_non_exited_threads_iterator
 153   = filtered_iterator<all_matching_threads_iterator, non_exited_thread_filter>;
 154
 155 /* Iterate over all non-exited threads of an inferior.  */
 156
 157 using inf_non_exited_threads_iterator
 158   = filtered_iterator<inf_threads_iterator, non_exited_thread_filter>;
 159
 160 /* Iterate over all threads of all inferiors, safely.  */
 161
 162 using all_threads_safe_iterator
 163   = basic_safe_iterator<all_threads_iterator>;
 164
 165 /* Iterate over all threads of an inferior, safely.  */
 166
 167 using safe_inf_threads_iterator
 168   = basic_safe_iterator<inf_threads_iterator>;
 169
 170 /* A range adapter that makes it possible to iterate over all threads
 171    of an inferior with range-for.  */
 172
 173 using inf_threads_range
 174   = next_adapter<thread_info, inf_threads_iterator>;
 175
 176 /* A range adapter that makes it possible to iterate over all
 177    non-exited threads of an inferior with range-for.  */
 178
 179 using inf_non_exited_threads_range
 180   = next_adapter<thread_info, inf_non_exited_threads_iterator>;
 181
 182 /* A range adapter that makes it possible to iterate over all threads
 183    of an inferior with range-for, safely.  */
 184
 185 using safe_inf_threads_range
 186   = next_adapter<thread_info, safe_inf_threads_iterator>;
 187
 188 /* A range adapter that makes it possible to iterate over all threads
 189    of all inferiors with range-for.  */
 190
 191 struct all_threads_range
 192 {
 193   all_threads_iterator begin () const
 194   { return all_threads_iterator (all_threads_iterator::begin_t {}); }
 195   all_threads_iterator end () const
 196   { return all_threads_iterator (); }
 197 };
 198
 199 /* A range adapter that makes it possible to iterate over all threads
 200    with range-for "safely".  I.e., it is safe to delete the
 201    currently-iterated thread.  */
 202
 203 struct all_threads_safe_range
 204 {
 205   all_threads_safe_iterator begin () const
 206   { return all_threads_safe_iterator (all_threads_iterator::begin_t {}); }
 207   all_threads_safe_iterator end () const
 208   { return all_threads_safe_iterator (); }
 209 };
 210
 211 /* A range adapter that makes it possible to iterate over all threads
 212    that match a PTID filter with range-for.  */
 213
 214 struct all_matching_threads_range
 215 {
 216 public:
 217   all_matching_threads_range (process_stratum_target *filter_target,
 218                               ptid_t filter_ptid)
 219     : m_filter_target (filter_target), m_filter_ptid (filter_ptid)
 220   {}
 221   all_matching_threads_range ()
 222     : m_filter_target (nullptr), m_filter_ptid (minus_one_ptid)
 223   {}
 224
 225   all_matching_threads_iterator begin () const
 226   { return all_matching_threads_iterator (m_filter_target, m_filter_ptid); }
 227   all_matching_threads_iterator end () const
 228   { return all_matching_threads_iterator (); }
 229
 230 private:
 231   /* The filter.  */
 232   process_stratum_target *m_filter_target;
 233   ptid_t m_filter_ptid;
 234 };
 235
 236 /* A range adapter that makes it possible to iterate over all
 237    non-exited threads of all inferiors, with range-for.
 238    Threads/inferiors that do not match FILTER_PTID are filtered
 239    out.  */
 240
 241 class all_non_exited_threads_range
 242 {
 243 public:
 244   all_non_exited_threads_range (process_stratum_target *filter_target,
 245                                 ptid_t filter_ptid)
 246     : m_filter_target (filter_target), m_filter_ptid (filter_ptid)
 247   {}
 248
 249   all_non_exited_threads_range ()
 250     : m_filter_target (nullptr), m_filter_ptid (minus_one_ptid)
 251   {}
 252
 253   all_non_exited_threads_iterator begin () const
 254   { return all_non_exited_threads_iterator (m_filter_target, m_filter_ptid); }
 255   all_non_exited_threads_iterator end () const
 256   { return all_non_exited_threads_iterator (); }
 257
 258 private:
 259   process_stratum_target *m_filter_target;
 260   ptid_t m_filter_ptid;
 261 };
 262
 263 #endif /* THREAD_ITER_H */