Kernel build mostly successful

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3454 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 117 insertions, 0 deletions

diff --git a/nuttx/sched/errno_getptr.c b/nuttx/sched/errno_getptr.c
new file mode 100644
index 000000000..8daf5b2cc
--- /dev/null
+++ b/nuttx/sched/errno_getptr.c
@@ -0,0 +1,117 @@
+/****************************************************************************
+ * sched/errno_getptr.c
+ *
+ *   Copyright (C) 2007, 2008, 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 <sched.h>
+#include <errno.h>
+#include <nuttx/arch.h>
+#include "os_internal.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#undef get_errno_ptr
+#undef errno
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static int g_irqerrno;
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function:  get_errno_ptr
+ *
+ * Description:
+ *   Return a pointer to the thread specific errno.
+ *
+ * Parameters:
+ *   None
+ *
+ * Return Value:
+ *   A pointer to the per-thread errno variable.
+ *
+ * Assumptions:
+ *
+ ****************************************************************************/
+
+FAR int *get_errno_ptr(void)
+{
+  /* Check if this function was called from an interrupt handler.  In that
+   * case, we have to do things a little differently to prevent the interrupt
+   * handler from modifying the tasks errno value.
+   */
+
+  if (!up_interrupt_context())
+    {
+      /* We were called from the normal tasking context.  Verify that the
+       * task at the head of the ready-to-run list is actually running.  It
+       * may not be running during very brief times during context switching
+       * logic (see, for example, task_deletecurrent.c).
+       */
+
+      FAR _TCB *rtcb = (FAR _TCB*)g_readytorun.head;
+      if (rtcb->task_state == TSTATE_TASK_RUNNING)
+        {
+          /* Yes.. the task is running normally.  Return a reference to the
+           * thread-private errno in the TCB of the running task.
+           */
+
+          return &rtcb->pterrno;
+        }
+    }
+
+  /* We were called either from (1) an interrupt handler or (2) from normally
+   * code but in an unhealthy state.  In either event, do not permit access to
+   * the errno in the TCB of the task at the head of the ready-to-run list.
+   * Instead, use a separate errno just for interrupt handlers.  Of course, this
+   * would have to change if we ever wanted to support nested interrupts or if
+   * we really cared about the stability of the errno during those "unhealthy
+   * states."
+   */
+
+  return &g_irqerrno;
+}
+
+