Added support for socket descriptors

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@318 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 171 insertions, 0 deletions

diff --git a/nuttx/net/net_sockets.c b/nuttx/net/net_sockets.c
new file mode 100644
index 000000000..fb4927e72
--- /dev/null
+++ b/nuttx/net/net_sockets.c
@@ -0,0 +1,171 @@
+/****************************************************************************
+ * net_sockets.c
+ *
+ *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name Gregory Nutt nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <string.h>
+#include <semaphore.h>
+#include <assert.h>
+#include <sched.h>
+#include <errno.h>
+#include <nuttx/net.h>
+#include <nuttx/kmalloc.h>
+#include "net_internal.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+static void _net_semtake(FAR struct socketlist *list)
+{
+  /* Take the semaphore (perhaps waiting) */
+
+  while (sem_wait(&list->sl_sem) != 0)
+    {
+      /* The only case that an error should occr here is if
+       * the wait was awakened by a signal.
+       */
+
+      ASSERT(*get_errno_ptr() == EINTR);
+    }
+}
+
+#define _net_semgive(list) sem_post(&list->sl_sem)
+
+/****************************************************************************
+ * Pulblic Functions
+ ****************************************************************************/
+
+/* This is called from the initialization logic to configure the socket layer */
+
+void net_initialize(void)
+{
+}
+
+/* Allocate a list of files for a new task */
+
+FAR struct socketlist *net_alloclist(void)
+{
+  FAR struct socketlist *list;
+  list = (FAR struct socketlist*)kzmalloc(sizeof(struct socketlist));
+  if (list)
+    {
+       /* Start with a reference count of one */
+
+       list->sl_crefs = 1;
+
+       /* Initialize the list access mutex */
+
+      (void)sem_init(&list->sl_sem, 0, 1);
+    }
+  return list;
+}
+
+/* Increase the reference count on a file list */
+
+int net_addreflist(FAR struct socketlist *list)
+{
+  if (list)
+    {
+       /* Increment the reference count on the list.
+        * NOTE: that we disable interrupts to do this
+        * (vs. taking the list semaphore).  We do this
+        * because file cleanup operations often must be
+        * done from the IDLE task which cannot wait
+        * on semaphores.
+        */
+
+       register irqstate_t flags = irqsave();
+       list->sl_crefs++;
+       irqrestore(flags);
+    }
+  return OK;
+}
+
+/* Release a reference to the file list */
+
+int net_releaselist(FAR struct socketlist *list)
+{
+  int crefs;
+  if (list)
+    {
+       /* Decrement the reference count on the list.
+        * NOTE: that we disable interrupts to do this
+        * (vs. taking the list semaphore).  We do this
+        * because file cleanup operations often must be
+        * done from the IDLE task which cannot wait
+        * on semaphores.
+        */
+
+       irqstate_t flags = irqsave();
+       crefs = --(list->sl_crefs);
+       irqrestore(flags);
+
+       /* If the count decrements to zero, then there is no reference
+        * to the structure and it should be deallocated.  Since there
+        * are references, it would be an error if any task still held
+        * a reference to the list's semaphore.
+        */
+
+       if (crefs <= 0)
+          {
+             /* Destroy the semaphore and release the filelist */
+
+             (void)sem_destroy(&list->sl_sem);
+             sched_free(list);
+          }
+    }
+  return OK;
+}
+