wrapper/list.h

   1 #ifndef _LTTNG_WRAPPER_LIST_H
   2 #define _LTTNG_WRAPPER_LIST_H
   3
   4 /*
   5  * wrapper/list.h
   6  *
   7  * wrapper around linux/list.h.
   8  *
   9  * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; only version 2 of the License.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; if not, write to the Free Software Foundation, Inc.,
  22  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  23  *
  24  * This wrapper code is derived from Linux 3.19.2 include/linux/list.h
  25  * and include/linux/rculist.h, hence the GPLv2 license applied to this
  26  * file.
  27  */
  28
  29 #include <linux/list.h>
  30 #include <linux/rculist.h>
  31
  32 #define lttng_hlist_entry_safe(ptr, type, member) \
  33         ({ typeof(ptr) ____ptr = (ptr); \
  34            ____ptr ? hlist_entry(____ptr, type, member) : NULL; \
  35         })
  36
  37 /**
  38  * lttng_hlist_for_each_entry   - iterate over list of given type
  39  * @pos:        the type * to use as a loop cursor.
  40  * @head:       the head for your list.
  41  * @member:     the name of the hlist_node within the struct.
  42  */
  43 #define lttng_hlist_for_each_entry(pos, head, member)                   \
  44         for (pos = lttng_hlist_entry_safe((head)->first, typeof(*(pos)), member);\
  45              pos;                                                       \
  46              pos = lttng_hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
  47
  48 /**
  49  * lttng_hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
  50  * @pos:        the type * to use as a loop cursor.
  51  * @n:          another &struct hlist_node to use as temporary storage
  52  * @head:       the head for your list.
  53  * @member:     the name of the hlist_node within the struct.
  54  */
  55 #define lttng_hlist_for_each_entry_safe(pos, n, head, member)           \
  56         for (pos = lttng_hlist_entry_safe((head)->first, typeof(*pos), member);\
  57              pos && ({ n = pos->member.next; 1; });                     \
  58              pos = lttng_hlist_entry_safe(n, typeof(*pos), member))
  59
  60 #ifndef rcu_dereference_raw_notrace
  61 #define rcu_dereference_raw_notrace(p)  rcu_dereference_raw(p)
  62 #endif
  63
  64 /**
  65  * lttng_hlist_for_each_entry_rcu_notrace - iterate over rcu list of given type (for tracing)
  66  * @pos:        the type * to use as a loop cursor.
  67  * @head:       the head for your list.
  68  * @member:     the name of the hlist_node within the struct.
  69  *
  70  * This list-traversal primitive may safely run concurrently with
  71  * the _rcu list-mutation primitives such as hlist_add_head_rcu()
  72  * as long as the traversal is guarded by rcu_read_lock().
  73  *
  74  * This is the same as hlist_for_each_entry_rcu() except that it does
  75  * not do any RCU debugging or tracing.
  76  */
  77 #define lttng_hlist_for_each_entry_rcu_notrace(pos, head, member)       \
  78         for (pos = lttng_hlist_entry_safe (rcu_dereference_raw_notrace(hlist_first_rcu(head)),\
  79                         typeof(*(pos)), member);                        \
  80                 pos;                                                    \
  81                 pos = lttng_hlist_entry_safe(rcu_dereference_raw_notrace(hlist_next_rcu(\
  82                         &(pos)->member)), typeof(*(pos)), member))
  83
  84 #endif /* _LTTNG_WRAPPER_LIST_H */