From f67bc808ccdf5b68a930d20007dae6df2c8a28a8 Mon Sep 17 00:00:00 2001
From: belliash <belliash@codingworkshop.eu.org>
Date: Sat, 13 Aug 2022 23:15:06 +0200
Subject: [PATCH] Basic support for double linked lists

---
 sdk/xtklib/CMakeLists.txt    |  1 +
 sdk/xtklib/includes/librtl.h | 13 ++++++++
 sdk/xtklib/rtl/plist.c       | 63 ++++++++++++++++++++++++++++++++++++
 3 files changed, 77 insertions(+)
 create mode 100644 sdk/xtklib/rtl/plist.c

diff --git a/sdk/xtklib/CMakeLists.txt b/sdk/xtklib/CMakeLists.txt
index 69e47de..e2fdf10 100644
--- a/sdk/xtklib/CMakeLists.txt
+++ b/sdk/xtklib/CMakeLists.txt
@@ -10,6 +10,7 @@ include_directories(
 list(APPEND XTKLIB_SOURCE
     ${XTKLIB_SOURCE_DIR}/hl/cport.c
     ${XTKLIB_SOURCE_DIR}/hl/${ARCH}/cpufunc.c
+    ${XTKLIB_SOURCE_DIR}/rtl/plist.c
     ${XTKLIB_SOURCE_DIR}/rtl/widestr.c)
 
 # Add library
diff --git a/sdk/xtklib/includes/librtl.h b/sdk/xtklib/includes/librtl.h
index 9e28cfe..c9218af 100644
--- a/sdk/xtklib/includes/librtl.h
+++ b/sdk/xtklib/includes/librtl.h
@@ -10,9 +10,22 @@
 #define __XTKLIB_LIBRTL_H
 
 #include "xtdefs.h"
+#include "xtstruct.h"
 #include "xttypes.h"
 
 
+XTINLINE
+VOID
+RtlInitializeListHead(IN PLIST_ENTRY ListHead);
+
+XTINLINE
+VOID
+RtlInitializeListHead32(IN PLIST_ENTRY32 ListHead);
+
+XTINLINE
+BOOLEAN
+RtlListEmpty(PLIST_ENTRY ListHead);
+
 INT
 RtlWideStringCompare(IN CONST PWCHAR String1,
                      IN CONST PWCHAR String2,
diff --git a/sdk/xtklib/rtl/plist.c b/sdk/xtklib/rtl/plist.c
new file mode 100644
index 0000000..82892ff
--- /dev/null
+++ b/sdk/xtklib/rtl/plist.c
@@ -0,0 +1,63 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            sdk/xtklib/rtl/plist.c
+ * DESCRIPTION:     Linked list manipulation routines
+ * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ */
+
+#include <xtkmapi.h>
+
+
+/**
+ * This routine initializes a structure representing the head of a double-linked list.
+ *
+ * @param ListHead
+ *        Pointer to a structure that serves as the list header.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+XTINLINE
+VOID
+RtlInitializeListHead(IN PLIST_ENTRY ListHead)
+{
+    ListHead->Blink = ListHead;
+    ListHead->Flink = ListHead;
+}
+
+/**
+ * This routine initializes a structure representing the head of a 32bit double-linked list.
+ *
+ * @param ListHead
+ *        Pointer to a structure that serves as the list header.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+XTINLINE
+VOID
+RtlInitializeListHead32(IN PLIST_ENTRY32 ListHead)
+{
+    ListHead->Blink = PtrToUlong(ListHead);
+    ListHead->Flink = PtrToUlong(ListHead);
+}
+
+/**
+ * Indicates whether a doubly linked list structure is empty.
+ *
+ * @param ListHead
+ *        Pointer to a structure that represents the head of the list.
+ *
+ * @return TRUE if there are currently no entries in the list or FALSE otherwise.
+ *
+ * @since XT 1.0
+ */
+XTINLINE
+BOOLEAN
+RtlListEmpty(PLIST_ENTRY ListHead)
+{
+    return (ListHead->Flink == ListHead);
+}