atexit() functions now called when task killed by task delete; For MCUs with <= 64Kb of SRAM, CONFIG_MM_SMALL can be defined to reduce the memory allocation overhead

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3648 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 157 insertions, 0 deletions

diff --git a/nuttx/sched/task_exithook.c b/nuttx/sched/task_exithook.c
new file mode 100644
index 000000000..9567f48a9
--- /dev/null
+++ b/nuttx/sched/task_exithook.c
@@ -0,0 +1,157 @@
+/****************************************************************************
+ * sched/task_exithook.c
+ *
+ *   Copyright (C) 2011 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 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 <unistd.h>
+#include <debug.h>
+#include <errno.h>
+
+#include <nuttx/fs.h>
+
+#include "os_internal.h"
+#include "sig_internal.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Type Declarations
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: task_hook
+ *
+ * Description:
+ *   This function implements some of the internal logic of exit() and
+ *   task_delete().  This function performs some cleanup and other actions
+ *   required when a task exists:
+ *
+ *   - All open streams are flushed and closed.
+ *   - All functions registered with atexit() and on_exit() are called, in
+ *     the reverse order of their registration.
+ *
+ *   When called from exit(), the tcb still resides at the head of the ready-
+ *   to-run list.  The following logic is safe because we will not be
+ *   returning from the exit() call.
+ *
+ *   When called from task_delete() we are operating on a different thread;
+ *   on the thread that called task_delete().  In this case, task_delete
+ *   will have already removed the tcb from the ready-to-run list to prevent
+ *   any further action on this task.
+ *
+ ****************************************************************************/
+
+void task_exithook(FAR _TCB *tcb, int status)
+{
+  /* Inform the instrumentation layer that the task has stopped */
+
+  sched_note_stop(tcb);
+
+  /* Flush all streams (File descriptors will be closed when
+   * the TCB is deallocated).
+   */
+
+#if CONFIG_NFILE_STREAMS > 0
+  (void)lib_flushall(tcb->streams);
+#endif
+
+  /* Deallocate anything left in the TCB's queues */
+
+#ifndef CONFIG_DISABLE_SIGNALS
+  sig_cleanup(tcb); /* Deallocate Signal lists */
+#endif
+
+  /* Wakeup any tasks waiting for this task to exit */
+
+#ifdef CONFIG_SCHED_WAITPID /* Experimental */
+  while (tcb->exitsem.semcount < 0)
+    {
+      /* "If more than one thread is suspended in waitpid() awaiting
+       *  termination of the same process, exactly one thread will return
+       *  the process status at the time of the target process termination." 
+       *  Hmmm.. what do we return to the others?
+       */
+
+      if (tcb->stat_loc)
+        {
+          *tcb->stat_loc = status << 8;
+           tcb->stat_loc = NULL;
+        }
+
+      /* Wake up the thread */
+
+      sem_post(&tcb->exitsem);
+    }
+#endif
+
+  /* If an exit function was registered, call it now.  NOTE:  In the case
+   * of task_delete(), the exit function will *not* be called on the thread
+   * execution of the task being deleted!
+   */
+
+#ifdef CONFIG_SCHED_ATEXIT
+  if (tcb->exitfunc)
+    {
+      (*tcb->exitfunc)();
+    }
+#endif
+}