From ec919868544f69fe5a212da4d4ace8b53485ed41 Mon Sep 17 00:00:00 2001
From: Vincent Wei <vincent@minigui.org>
Date: Wed, 22 Jan 2020 17:01:42 +0800
Subject: [PATCH] add inline functions for get shm/sem key for system/layer

---
 src/include/sharedres.h | 38 ++++++++++++++++++++++++++++----------
 1 file changed, 28 insertions(+), 10 deletions(-)

diff --git a/src/include/sharedres.h b/src/include/sharedres.h
index 9c105178..766f5f67 100644
--- a/src/include/sharedres.h
+++ b/src/include/sharedres.h
@@ -11,35 +11,35 @@
 //
 //////////////////////////////////////////////////////////////////////////////
 /*
- *   This file is part of MiniGUI, a mature cross-platform windowing 
+ *   This file is part of MiniGUI, a mature cross-platform windowing
  *   and Graphics User Interface (GUI) support system for embedded systems
  *   and smart IoT devices.
- * 
+ *
  *   Copyright (C) 2002~2018, Beijing FMSoft Technologies Co., Ltd.
  *   Copyright (C) 1998~2002, WEI Yongming
- * 
+ *
  *   This program is free software: you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
  *   the Free Software Foundation, either version 3 of the License, or
  *   (at your option) any later version.
- * 
+ *
  *   This program is distributed in the hope that it will be useful,
  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *   GNU General Public License for more details.
- * 
+ *
  *   You should have received a copy of the GNU General Public License
  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
- * 
+ *
  *   Or,
- * 
+ *
  *   As this program is a library, any link to this program must follow
  *   GNU General Public License version 3 (GPLv3). If you cannot accept
  *   GPLv3, you need to be licensed from FMSoft.
- * 
+ *
  *   If you have got a commercial license of this program, please use it
  *   under the terms and conditions of the commercial license.
- * 
+ *
  *   For more information about the commercial license, please refer to
  *   <http://www.minigui.com/blog/minigui-licensing-policy/>.
  */
@@ -70,6 +70,24 @@ enum {
     _NR_SEM
 };
 
+// key base for System V IPC
+#define IPC_KEY_BASE                0x464D4700
+
+inline static key_t get_shm_key_for_system (void)
+{
+    return (key_t)(IPC_KEY_BASE + 0x01);
+}
+
+inline static key_t get_sem_key_for_system (void)
+{
+    return (key_t)(IPC_KEY_BASE + 0x02);
+}
+
+inline static key_t get_sem_key_for_layers (void)
+{
+    return (key_t)(IPC_KEY_BASE + 0x03);
+}
+
 typedef struct tagG_RES {
     int semid;
     int shmid;
@@ -95,7 +113,7 @@ typedef struct tagG_RES {
     int mousebutton;
     int shiftstatus;
     Uint8 kbd_state [MGUI_NR_KEYS + 1];
-    
+
 #ifdef _MGHAVE_CURSOR
     int cursorx, cursory;
     int oldboxleft, oldboxtop;