NuttX RTOS

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 142 insertions, 0 deletions

diff --git a/nuttx/sched/sched_getparam.c b/nuttx/sched/sched_getparam.c
new file mode 100644
index 000000000..85d8c55c7
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+++ b/nuttx/sched/sched_getparam.c
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+/************************************************************
+ * sched_getparam.c
+ *
+ *   Copyright (C) 2007 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 Gregory Nutt 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"
+
+/************************************************************
+ * Definitions
+ ************************************************************/
+
+/************************************************************
+ * Private Type Declarations
+ ************************************************************/
+
+/************************************************************
+ * Global Variables
+ ************************************************************/
+
+/************************************************************
+ * Private Variables
+ ************************************************************/
+
+/************************************************************
+ * Private Function Prototypes
+ ************************************************************/
+
+/************************************************************
+ * Private Functions
+ ************************************************************/
+
+/************************************************************
+ * Public Functions
+ ************************************************************/
+
+/************************************************************
+ * Name: sched_getparam
+ *
+ * Description:
+ *   This function gets the scheduling priority of the task
+ *  specified by pid.
+ *
+ * Inputs:
+ *   pid - the task ID of the task.  If pid is zero, the priority
+ *     of the calling task is returned.
+ *   param - A structure whose member sched_priority is the integer
+ *     priority.  The task's priority is copied to the sched_priority
+ *     element of this structure.
+ *
+ * Return Value:
+ *    0 (OK) if successful, otherwise -1 (ERROR).
+ *
+ *    This function can fail if param is null or if pid does
+ *    not correspond to any task.
+ *
+ * Assumptions:
+ *
+ ************************************************************/
+
+int sched_getparam (pid_t pid, struct sched_param * param)
+{
+  _TCB *rtcb;
+  _TCB *tcb;
+  int ret = OK;
+
+  if (!param)
+    {
+      return ERROR;
+    }
+
+  /* Check if the task to restart is the calling task */
+
+  rtcb = (_TCB*)g_readytorun.head;
+  if ((pid == 0) || (pid == rtcb->pid))
+    {
+       /* Return the priority if the calling task. */
+
+       param->sched_priority = (int)rtcb->sched_priority;
+    }
+
+  /* Ths pid is not for the calling task, we will have to look it up */
+
+  else
+    {
+      /* Get the TCB associated with this pid */
+
+      sched_lock();
+      tcb = sched_gettcb(pid);
+      if (!tcb)
+        {
+          /* This pid does not correspond to any known task */
+
+          ret = ERROR;
+        }
+      else
+        {
+          /* Return the priority of the task */
+
+          param->sched_priority = (int)tcb->sched_priority;
+        }
+      sched_unlock();
+    }
+
+  return ret;
+}