gdb/thread-iter.h

   1 /* Thread iterators and ranges for GDB, the GNU debugger.
   2    Copyright (C) 2018-2020 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 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   explicit all_matching_threads_iterator (ptid_t filter_ptid);
  96
  97   /* Create a one-past-end iterator.  */
  98   all_matching_threads_iterator ()
  99     : m_inf (nullptr),
 100       m_thr (nullptr),
 101       m_filter_ptid (minus_one_ptid)
 102   {}
 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 matches the process identified by
 123      M_FILTER_PTID.  */
 124   bool m_inf_matches ();
 125
 126 private:
 127   /* The current inferior.  */
 128   inferior *m_inf;
 129
 130   /* The current thread.  */
 131   thread_info *m_thr;
 132
 133   /* The filter.  */
 134   ptid_t m_filter_ptid;
 135 };
 136
 137 /* Filter for filtered_iterator.  Filters out exited threads.  */
 138
 139 struct non_exited_thread_filter
 140 {
 141   bool operator() (struct thread_info *thr) const
 142   {
 143     return thr->state != THREAD_EXITED;
 144   }
 145 };
 146
 147 /* Iterate over all non-exited threads that match a given PTID.  */
 148
 149 using all_non_exited_threads_iterator
 150   = filtered_iterator<all_matching_threads_iterator, non_exited_thread_filter>;
 151
 152 /* Iterate over all non-exited threads of an inferior.  */
 153
 154 using inf_non_exited_threads_iterator
 155   = filtered_iterator<inf_threads_iterator, non_exited_thread_filter>;
 156
 157 /* Iterate over all threads of all inferiors, safely.  */
 158
 159 using all_threads_safe_iterator
 160   = basic_safe_iterator<all_threads_iterator>;
 161
 162 /* Iterate over all threads of an inferior, safely.  */
 163
 164 using safe_inf_threads_iterator
 165   = basic_safe_iterator<inf_threads_iterator>;
 166
 167 /* A range adapter that makes it possible to iterate over all threads
 168    of an inferior with range-for.  */
 169
 170 using inf_threads_range
 171   = next_adapter<thread_info, inf_threads_iterator>;
 172
 173 /* A range adapter that makes it possible to iterate over all
 174    non-exited threads of an inferior with range-for.  */
 175
 176 using inf_non_exited_threads_range
 177   = next_adapter<thread_info, inf_non_exited_threads_iterator>;
 178
 179 /* A range adapter that makes it possible to iterate over all threads
 180    of an inferior with range-for, safely.  */
 181
 182 using safe_inf_threads_range
 183   = next_adapter<thread_info, safe_inf_threads_iterator>;
 184
 185 /* A range adapter that makes it possible to iterate over all threads
 186    of all inferiors with range-for.  */
 187
 188 struct all_threads_range
 189 {
 190   all_threads_iterator begin () const
 191   { return all_threads_iterator (all_threads_iterator::begin_t {}); }
 192   all_threads_iterator end () const
 193   { return all_threads_iterator (); }
 194 };
 195
 196 /* A range adapter that makes it possible to iterate over all threads
 197    with range-for "safely".  I.e., it is safe to delete the
 198    currently-iterated thread.  */
 199
 200 struct all_threads_safe_range
 201 {
 202   all_threads_safe_iterator begin () const
 203   { return all_threads_safe_iterator (all_threads_iterator::begin_t {}); }
 204   all_threads_safe_iterator end () const
 205   { return all_threads_safe_iterator (); }
 206 };
 207
 208 /* A range adapter that makes it possible to iterate over all threads
 209    that match a PTID filter with range-for.  */
 210
 211 struct all_matching_threads_range
 212 {
 213 public:
 214   explicit all_matching_threads_range (ptid_t filter_ptid)
 215     : m_filter_ptid (filter_ptid)
 216   {}
 217   all_matching_threads_range ()
 218     : m_filter_ptid (minus_one_ptid)
 219   {}
 220
 221   all_matching_threads_iterator begin () const
 222   { return all_matching_threads_iterator (m_filter_ptid); }
 223   all_matching_threads_iterator end () const
 224   { return all_matching_threads_iterator (); }
 225
 226 private:
 227   /* The filter.  */
 228   ptid_t m_filter_ptid;
 229 };
 230
 231 /* A range adapter that makes it possible to iterate over all
 232    non-exited threads of all inferiors, with range-for.
 233    Threads/inferiors that do not match FILTER_PTID are filtered
 234    out.  */
 235
 236 class all_non_exited_threads_range
 237 {
 238 public:
 239   explicit all_non_exited_threads_range (ptid_t filter_ptid)
 240     : m_filter_ptid (filter_ptid)
 241   {}
 242
 243   all_non_exited_threads_range ()
 244     : m_filter_ptid (minus_one_ptid)
 245   {}
 246
 247   all_non_exited_threads_iterator begin () const
 248   { return all_non_exited_threads_iterator (m_filter_ptid); }
 249   all_non_exited_threads_iterator end () const
 250   { return all_non_exited_threads_iterator (); }
 251
 252 private:
 253   ptid_t m_filter_ptid;
 254 };
 255
 256 #endif /* THREAD_ITER_H */