[GitHub] [incubator-nuttx] xiaoxiang781216 commented on a diff in pull request #7088: sched/msgq: add support of System V message queue

[GitBox <gi...@apache.org>]

xiaoxiang781216 commented on code in PR #7088:
URL: https://github.com/apache/incubator-nuttx/pull/7088#discussion_r970932694


##########
include/nuttx/mqueue.h:
##########
@@ -83,16 +83,23 @@
  * Public Type Declarations
  ****************************************************************************/
 
+/* Common prologue of all message queue structures. */
+
+struct mqueue_comm_s
+{
+  int16_t nwaitnotfull;       /* Number tasks waiting for not full */
+  int16_t nwaitnotempty;      /* Number tasks waiting for not empty */
+};
+
 /* This structure defines a message queue */
 
 struct mqueue_inode_s
 {
+  struct mqueue_comm_s comm;  /* Common prologue */

Review Comment:
   ditto



##########
fs/procfs/fs_procfsproc.c:
##########
@@ -411,7 +411,7 @@ static FAR const char * const g_statenames[] =
   "Inactive",
   "Waiting,Semaphore",
   "Waiting,Signal"
-#ifndef CONFIG_DISABLE_MQUEUE
+#if !defined(CONFIG_DISABLE_MQUEUE) && !defined(CONFIG_DISABLE_MQUEUE_SYSV)

Review Comment:
   could we use a common symbol?



##########
sched/mqueue/msginternal.c:
##########
@@ -0,0 +1,137 @@
+/****************************************************************************
+ * sched/mqueue/msginternal.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/kmalloc.h>
+#include "mqueue/msg.h"
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+struct list_node g_msgfreelist = LIST_INITIAL_VALUE(g_msgfreelist);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static struct list_node g_msgqactivelist =
+                        LIST_INITIAL_VALUE(g_msgqactivelist);
+static struct list_node g_msgqfreelist   =
+                        LIST_INITIAL_VALUE(g_msgqfreelist);
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nxmsg_initialize
+ ****************************************************************************/
+
+void nxmsg_initialize(void)
+{
+  FAR struct msgbuf_s *msg;
+
+  msg = (FAR struct msgbuf_s *)kmm_malloc(sizeof(*msg) *
+                                          CONFIG_PREALLOC_MQ_MSGS);
+  if (msg)
+    {
+      int i;
+      for (i = 0; i < CONFIG_PREALLOC_MQ_MSGS; i++)
+        {
+          list_add_tail(&g_msgfreelist, &msg->node);
+          msg++;
+        }
+    }
+}
+
+/****************************************************************************
+ * Name: nxmsg_alloc
+ ****************************************************************************/
+
+int nxmsg_alloc(FAR struct msgq_s **pmsgq)
+{
+  FAR struct msgq_s *msgq;
+
+  /* Allocate memory for the new message queue. */
+
+  msgq = list_remove_head_type(&g_msgqfreelist, struct msgq_s, node);
+  if (msgq == NULL)
+    {
+      msgq = (FAR struct msgq_s *)kmm_zalloc(sizeof(struct msgq_s));
+    }
+
+  if (msgq == NULL)
+    {
+      return -ENOSPC;
+    }
+
+  /* Initialize the new named message queue */
+
+  list_add_tail(&g_msgqactivelist, &msgq->node);
+  list_initialize(&msgq->msglist);
+
+  msgq->maxmsgs    = MSG_MAX_MSGS;
+  msgq->maxmsgsize = MSG_MAX_BYTES;
+
+  *pmsgq = msgq;
+  return OK;
+}
+
+/****************************************************************************
+ * Name: nxmsg_free
+ ****************************************************************************/
+
+void nxmsg_free(FAR struct msgq_s *msgq)
+{
+  FAR struct msgq_s *entry;
+  FAR struct msgq_s *tmp;
+
+  list_for_every_entry_safe(&msgq->msglist, entry, tmp, struct msgq_s, node)
+    {
+      list_delete(&entry->node);
+      list_add_tail(&g_msgfreelist, &entry->node);
+    }
+
+  list_delete(&msgq->node);
+  list_add_tail(&g_msgqfreelist, &msgq->node);
+}
+
+/****************************************************************************
+ * Name: nxmsg_lookup
+ ****************************************************************************/
+
+FAR struct msgq_s *nxmsg_lookup(key_t key)
+{
+  FAR struct msgq_s *msgq;
+
+  list_for_every_entry(&g_msgqactivelist, msgq, struct msgq_s, node)

Review Comment:
   can we change g_msgqactivelist to an array and identify the msq by index to improve the speed?



##########
include/nuttx/mqueue.h:
##########
@@ -83,16 +83,23 @@
  * Public Type Declarations
  ****************************************************************************/
 
+/* Common prologue of all message queue structures. */
+
+struct mqueue_comm_s

Review Comment:
   comm->cmn like:
   ```
   struct task_tcb_s
   {
     /* Common TCB fields ******************************************************/
   
     struct tcb_s cmn;                      /* Common TCB fields                   */
   
     /* Task Management Fields *************************************************/
   
   #ifdef CONFIG_SCHED_STARTHOOK
     starthook_t starthook;                 /* Task startup function               */
     FAR void *starthookarg;                /* The argument passed to the function */
   #endif
   };
   ```



##########
sched/mqueue/msgget.c:
##########
@@ -0,0 +1,95 @@
+/****************************************************************************
+ * sched/mqueue/msgget.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include "mqueue/msg.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: msgget
+ *
+ * Description:
+ *   Get a System V message queue identifier
+ *   The msgget() system call returns the System V message queue
+ *   identifier associated with the value of the key argument.  It may
+ *   be used either to obtain the identifier of a previously created
+ *   message queue (when msgflg is zero and key does not have the
+ *   value IPC_PRIVATE), or to create a new set.
+ *
+ * Input Parameters:
+ *   key    - Key associated with the message queue
+ *   msgflg - Operations and permissions flag
+ *
+ * Returned Value:
+ *   On success, msgget() returns the message queue identifier (a
+ *   nonnegative integer).  On failure, -1 is returned, and errno is
+ *   set to indicate the error.
+ *
+ ****************************************************************************/
+
+int msgget(key_t key, int msgflg)
+{
+  FAR struct msgq_s *msgq;
+  irqstate_t flags;
+  int ret = OK;
+
+  flags = enter_critical_section();
+
+  msgq = nxmsg_lookup(key);
+
+  if (msgq)
+    {
+      if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL))
+        {
+          ret = -EEXIST;
+        }
+    }
+  else
+    {
+      if (key != IPC_PRIVATE && !(msgflg & IPC_CREAT))

Review Comment:
   how to identify the different private queue



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