errno was clobbered by mm_trysemaphore when task exists

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@591 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 141 insertions, 0 deletions

diff --git a/nuttx/sched/task_deletecurrent.c b/nuttx/sched/task_deletecurrent.c
new file mode 100644
index 000000000..8246bb471
--- /dev/null
+++ b/nuttx/sched/task_deletecurrent.c
@@ -0,0 +1,141 @@
+/****************************************************************************
+ * sched/task_deletecurrent.c
+ *
+ *   Copyright (C) 2008 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  <sys/types.h>
+#include  <sched.h>
+#include  "os_internal.h"
+#ifndef CONFIG_DISABLE_SIGNALS
+# include "sig_internal.h"
+#endif
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Type Declarations
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: task_delete
+ *
+ * Description:
+ *   This function causes the currently running task (i.e., the task at the
+ *   head of the ready-to-run list) to cease to exist.  This is a part of
+ *   the logic used to implement _exit().  The full implementation of _exit()
+ *   is architecture-dependent.  This function should never be called from
+ *   normal user code, but only from the architecture-specific implementation
+ *   of exit.
+ *
+ * Inputs:
+ *   None
+ *
+ * Return Value:
+ *   OK on success; or ERROR on failure
+ *
+ ****************************************************************************/
+
+STATUS task_deletecurrent(void)
+{
+  FAR _TCB  *dtcb = (FAR _TCB*)g_readytorun.head;
+  FAR _TCB  *rtcb;
+
+  /* Remove the TCB of the current task from the ready-to-run list.  A context
+   * switch will definitely be necessary -- that must be done by the
+   * architecture-specific logic.
+   *
+   * sched_removereadytorun will mark the task at the head of the ready-to-run
+   * with state == TSTATE_TASK_RUNNING
+   */
+
+  (void)sched_removereadytorun(dtcb);
+  rtcb = (FAR _TCB*)g_readytorun.head;
+
+  /* We are not in a bad state -- the head of the ready to run task list
+   * does not correspond to the thread that is running.  Disabling pre-
+   * emption on this TCB and marking the new ready-to-run task as not
+   * running (see, for example, get_errno_ptr()).
+   */
+
+  sched_lock();
+  rtcb->task_state = TSTATE_TASK_READYTORUN;
+
+  /* Move the TCB to the specified blocked task list and delete it */
+
+  sched_addblocked(dtcb, TSTATE_TASK_INACTIVE);
+  task_delete(dtcb->pid);
+  rtcb->task_state = TSTATE_TASK_RUNNING;
+
+  /* If there are any pending tasks, then add them to the ready-to-run
+   * task list now
+   */
+
+  if (g_pendingtasks.head)
+    {
+      (void)sched_mergepending();
+    }
+
+  /* Now calling sched_unlock() should have no effect */
+
+  sched_unlock();
+  return OK;
+}
+