xref: /netbsd-src/external/gpl3/gdb/dist/gdb/thread-iter.h (revision d16b7486a53dcb8072b60ec6fcb4373a2d0c27b7)
1 /* Thread iterators and ranges for GDB, the GNU debugger.
2    Copyright (C) 2018-2023 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 */
253