Resync new repository with old repo r5166

git-svn-id: http://svn.code.sf.net/p/nuttx/code/trunk@5153 42af7a65-404d-4744-a932-0658087f49c3
2026-10-30 23:51:36 +08:00 · 2012-09-17 18:18:44 +00:00
commit 57623d42eb
5691 changed files with 1361853 additions and 0 deletions
@@ -0,0 +1,218 @@
+/****************************************************************************
+ * net/uip/uip_lock.c
+ *
+ *   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * 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 NuttX 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 <semaphore.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/net/uip/uip.h>
+
+#if defined(CONFIG_NET) && defined(CONFIG_NET_NOINTS)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define NO_HOLDER (pid_t)-1
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static sem_t        g_uipsem;
+static pid_t        g_holder  = NO_HOLDER;
+static unsigned int g_count   = 0;
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: uip_takesem
+ *
+ * Description:
+ *   Take the semaphore
+ *
+ ****************************************************************************/
+
+static void uip_takesem(void)
+{
+  while (sem_wait(&g_uipsem) != 0)
+    {
+      /* The only case that an error should occur here is if the wait was
+       * awakened by a signal.
+       */
+
+      ASSERT(errno == EINTR);
+    }
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: uip_lockinit
+ *
+ * Description:
+ *   Initialize the locking facility
+ *
+ ****************************************************************************/
+
+void uip_lockinit(void)
+{
+  sem_init(&g_uipsem, 0, 1);
+}
+
+/****************************************************************************
+ * Function: uip_lock
+ *
+ * Description:
+ *   Take the lock
+ *
+ ****************************************************************************/
+
+uip_lock_t uip_lock(void)
+{
+  pid_t me = getpid();
+
+  /* Does this thread already hold the semaphore? */
+
+  if (g_holder == me)
+    {
+      /* Yes.. just increment the reference count */
+
+      g_count++;
+    }
+  else
+    {
+      /* No.. take the semaphore (perhaps waiting) */
+
+      uip_takesem();
+
+      /* Now this thread holds the semaphore */
+
+      g_holder = me;
+      g_count  = 1;
+    }
+
+  return 0;
+}
+
+/****************************************************************************
+ * Function: uip_unlock
+ *
+ * Description:
+ *   Release the lock.
+ *
+ ****************************************************************************/
+
+void uip_unlock(uip_lock_t flags)
+{
+  DEBUGASSERT(g_holder == getpid() && g_count > 0);
+
+  /* If the count would go to zero, then release the semaphore */
+
+  if (g_count == 1)
+    {
+      /* We no longer hold the semaphore */
+
+      g_holder = NO_HOLDER;
+      g_count  = 0;
+      sem_post(&g_uipsem);
+    }
+  else
+    {
+      /* We still hold the semaphore. Just decrement the count */
+
+      g_count--;
+    }
+}
+
+/****************************************************************************
+ * Function: uip_lockedwait
+ *
+ * Description:
+ *   Atomically wait for sem while temporarily releasing g_uipsem.
+ *
+ ****************************************************************************/
+
+int uip_lockedwait(sem_t *sem)
+{
+  pid_t        me = getpid();
+  unsigned int count;
+  irqstate_t   flags;
+  int          ret;
+
+  flags = irqsave(); /* No interrupts */
+  sched_lock();      /* No context switches */
+  if (g_holder == me)
+    {
+      /* Release the uIP semaphore, remembering the count */
+ 
+      count    = g_count;
+      g_holder = NO_HOLDER;
+      g_count  = 0;
+      sem_post(&g_uipsem);
+
+      /* Now take the semaphore */
+
+      ret = sem_wait(sem);
+
+      /* Recover the uIP semaphore at the proper count */
+
+      uip_takesem();
+      g_holder = me;
+      g_count  = count;
+    }
+  else
+    {
+      ret = sem_wait(sem);
+    }
+
+  sched_unlock();
+  irqrestore(flags);
+  return ret;
+ }
+
+#endif /* CONFIG_NET */