1 files changed, 108 insertions, 0 deletions
diff --git a/nsprpub/pr/include/prclist.h b/nsprpub/pr/include/prclist.h
new file mode 100644
index 0000000000..a069176055
--- /dev/null
+++ b/nsprpub/pr/include/prclist.h
@@ -0,0 +1,108 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef prclist_h___
+#define prclist_h___
+
+#include "prtypes.h"
+
+typedef struct PRCListStr PRCList;
+
+/*
+** Circular linked list
+*/
+struct PRCListStr {
+    PRCList *next;
+    PRCList *prev;
+};
+
+/*
+** Insert element "_e" into the list, before "_l".
+*/
+#define PR_INSERT_BEFORE(_e,_l)  \
+    PR_BEGIN_MACRO       \
+    (_e)->next = (_l);   \
+    (_e)->prev = (_l)->prev; \
+    (_l)->prev->next = (_e); \
+    (_l)->prev = (_e);   \
+    PR_END_MACRO
+
+/*
+** Insert element "_e" into the list, after "_l".
+*/
+#define PR_INSERT_AFTER(_e,_l)   \
+    PR_BEGIN_MACRO       \
+    (_e)->next = (_l)->next; \
+    (_e)->prev = (_l);   \
+    (_l)->next->prev = (_e); \
+    (_l)->next = (_e);   \
+    PR_END_MACRO
+
+/*
+** Return the element following element "_e"
+*/
+#define PR_NEXT_LINK(_e)     \
+        ((_e)->next)
+/*
+** Return the element preceding element "_e"
+*/
+#define PR_PREV_LINK(_e)     \
+        ((_e)->prev)
+
+/*
+** Append an element "_e" to the end of the list "_l"
+*/
+#define PR_APPEND_LINK(_e,_l) PR_INSERT_BEFORE(_e,_l)
+
+/*
+** Insert an element "_e" at the head of the list "_l"
+*/
+#define PR_INSERT_LINK(_e,_l) PR_INSERT_AFTER(_e,_l)
+
+/* Return the head/tail of the list */
+#define PR_LIST_HEAD(_l) (_l)->next
+#define PR_LIST_TAIL(_l) (_l)->prev
+
+/*
+** Remove the element "_e" from it's circular list.
+*/
+#define PR_REMOVE_LINK(_e)         \
+    PR_BEGIN_MACRO             \
+    (_e)->prev->next = (_e)->next; \
+    (_e)->next->prev = (_e)->prev; \
+    PR_END_MACRO
+
+/*
+** Remove the element "_e" from it's circular list. Also initializes the
+** linkage.
+*/
+#define PR_REMOVE_AND_INIT_LINK(_e)    \
+    PR_BEGIN_MACRO             \
+    (_e)->prev->next = (_e)->next; \
+    (_e)->next->prev = (_e)->prev; \
+    (_e)->next = (_e);         \
+    (_e)->prev = (_e);         \
+    PR_END_MACRO
+
+/*
+** Return non-zero if the given circular list "_l" is empty, zero if the
+** circular list is not empty
+*/
+#define PR_CLIST_IS_EMPTY(_l) \
+    ((_l)->next == (_l))
+
+/*
+** Initialize a circular list
+*/
+#define PR_INIT_CLIST(_l)  \
+    PR_BEGIN_MACRO     \
+    (_l)->next = (_l); \
+    (_l)->prev = (_l); \
+    PR_END_MACRO
+
+#define PR_INIT_STATIC_CLIST(_l) \
+    {(_l), (_l)}
+
+#endif /* prclist_h___ */