Add on_exit(); Re-order some logic in the task shutdown sequence. Sometimes some complex logic needs to execute when closing file descriptors and this needs to happen early while the task is still healthy

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4354 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 127 insertions, 0 deletions

diff --git a/nuttx/sched/on_exit.c b/nuttx/sched/on_exit.c
new file mode 100644
index 000000000..9824ec735
--- /dev/null
+++ b/nuttx/sched/on_exit.c
@@ -0,0 +1,127 @@
+/************************************************************************
+ * sched/on_exit.c
+ *
+ *   Copyright (C) 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 <stdlib.h>
+#include <assert.h>
+#include <unistd.h>
+#include <debug.h>
+#include <errno.h>
+
+#include <nuttx/fs.h>
+
+#include "os_internal.h"
+
+#ifdef CONFIG_SCHED_ONEXIT
+
+/************************************************************************
+ * Pre-processor Definitions
+ ************************************************************************/
+
+/************************************************************************
+ * Private Type Declarations
+ ************************************************************************/
+
+/************************************************************************
+ * Global Variables
+ ************************************************************************/
+
+/************************************************************************
+ * Private Variables
+ ************************************************************************/
+
+/************************************************************************
+ * Private Function Prototypes
+ ************************************************************************/
+
+/************************************************************************
+ * Private Functions
+ ************************************************************************/
+
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
+
+/************************************************************************
+ * Function:  atexit
+ *
+ * Description:
+ *    Registers a function to be called at program exit.
+ *    The on_exit() function registers the given function to be called
+ *    at normal process termination, whether via exit or via return from
+ *    the program's main(). The function is passed the status argument
+ *    given to the last call to exit and the arg argument from on_exit().
+ *
+ *    Limitiations in the current implementation:
+ *
+ *      1. Only a single on_exit function can be registered.
+ *      2. on_exit functions are not inherited when a new task is
+ *         created.
+ *
+ * Parameters:
+ *   func
+ *
+ * Return Value:
+ *   Zero on success. Non-zero on failure.
+ *
+ ************************************************************************/
+
+int on_exit(CODE void (*func)(int, FAR void *), FAR void *arg)
+{
+  _TCB *tcb = (_TCB*)g_readytorun.head;
+  int   ret = ERROR;
+
+  /* The following must be atomic */
+
+  sched_lock();
+  if (func && !tcb->onexitfunc)
+    {
+      tcb->onexitfunc = func;
+      tdb->onexitarg  = arg;
+      ret = OK;
+    }
+
+  sched_unlock();
+  return ret;
+}
+
+#endif /* CONFIG_SCHED_ATEXIT */
+
+