1 files changed, 156 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/cortexm3/up_unblocktask.c b/nuttx/arch/arm/src/cortexm3/up_unblocktask.c
new file mode 100755
index 000000000..0fce2d706
--- /dev/null
+++ b/nuttx/arch/arm/src/cortexm3/up_unblocktask.c
@@ -0,0 +1,156 @@
+/****************************************************************************
+ *  arch/arm/src/cortexm3/up_unblocktask.c
+ *
+ *   Copyright (C) 2007-2009 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 <debug.h>
+#include <nuttx/arch.h>
+#include "os_internal.h"
+#include "clock_internal.h"
+#include "up_internal.h"
+
+/****************************************************************************
+ * Private Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_unblock_task
+ *
+ * Description:
+ *   A task is currently in an inactive task list
+ *   but has been prepped to execute.  Move the TCB to the
+ *   ready-to-run list, restore its context, and start execution.
+ *
+ * Inputs:
+ *   tcb: Refers to the tcb to be unblocked.  This tcb is
+ *     in one of the waiting tasks lists.  It must be moved to
+ *     the ready-to-run list and, if it is the highest priority
+ *     ready to run taks, executed.
+ *
+ ****************************************************************************/
+
+void up_unblock_task(_TCB *tcb)
+{
+  /* Verify that the context switch can be performed */
+
+  if ((tcb->task_state < FIRST_BLOCKED_STATE) ||
+      (tcb->task_state > LAST_BLOCKED_STATE))
+    {
+      PANIC(OSERR_BADUNBLOCKSTATE);
+    }
+  else
+    {
+      _TCB *rtcb = (_TCB*)g_readytorun.head;
+
+      /* Remove the task from the blocked task list */
+
+      sched_removeblocked(tcb);
+
+      /* Reset its timeslice.  This is only meaningful for round
+       * robin tasks but it doesn't here to do it for everything
+       */
+
+#if CONFIG_RR_INTERVAL > 0
+      tcb->timeslice = CONFIG_RR_INTERVAL / MSEC_PER_TICK;
+#endif
+
+      /* Add the task in the correct location in the prioritized
+       * g_readytorun task list
+       */
+
+      if (sched_addreadytorun(tcb))
+        {
+          /* The currently active task has changed! We need to do
+           * a context switch to the new task.
+           *
+           * Are we in an interrupt handler? 
+           */
+
+          if (current_regs)
+            {
+              /* Yes, then we have to do things differently.
+               * Just copy the current_regs into the OLD rtcb.
+               */
+
+               up_savestate(rtcb->xcp.regs);
+
+              /* Restore the exception context of the rtcb at the (new) head 
+               * of the g_readytorun task list.
+               */
+
+              rtcb = (_TCB*)g_readytorun.head;
+
+              /* Then switch contexts */
+
+              up_restorestate(rtcb->xcp.regs);
+            }
+
+          /* No, then we will need to perform the user context switch */
+
+          else
+            {
+              /* Switch context to the context of the task at the head of the
+               * ready to run list.
+               */
+
+               _TCB *nexttcb = (_TCB*)g_readytorun.head;
+               up_switchcontext(rtcb->xcp.regs, nexttcb->xcp.regs);
+
+              /* up_switchcontext forces a context switch to the task at the
+               * head of the ready-to-run list.  It does not 'return' in the
+               * normal sense.  When it does return, it is because the blocked
+               * task is again ready to run and has execution priority.
+               */
+           }
+        }
+    }
+}