1 files changed, 156 insertions, 0 deletions
diff --git a/nuttx/sched/sched_setparam.c b/nuttx/sched/sched_setparam.c
new file mode 100644
index 000000000..6ea4e8f74
--- /dev/null
+++ b/nuttx/sched/sched_setparam.c
@@ -0,0 +1,156 @@
+/****************************************************************************
+ * sched/sched_setparam.c
+ *
+ *   Copyright (C) 2007, 2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * 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 <errno.h>
+
+#include <nuttx/arch.h>
+
+#include "os_internal.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Type Declarations
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name:  sched_setparam
+ *
+ * Description:
+ *   This function sets the priority of a specified task.
+ *
+ *   NOTE: Setting a task's priority to the same value has a similar effect
+ *   to sched_yield() -- The task will be moved to  after all other tasks
+ *   with the same priority.
+ *
+ * Inputs:
+ *   pid - the task ID of the task to reprioritize.  If pid is zero, the
+ *      priority of the calling task is changed.
+ *   param - A structure whose member sched_priority is the integer priority.
+ *      The range of valid priority numbers is from SCHED_PRIORITY_MIN
+ *      through SCHED_PRIORITY_MAX.
+ *
+ * Return Value:
+ *   On success, sched_setparam() returns 0 (OK). On error, -1 (ERROR) is
+ *   returned, and errno is set appropriately.
+ *
+ *  EINVAL The parameter 'param' is invalid or does not make sense for the
+ *         current scheduling policy.
+ *  EPERM  The calling task does not have appropriate privileges.
+ *  ESRCH  The task whose ID is pid could not be found.
+ *
+ * Assumptions:
+ *
+ ****************************************************************************/
+
+int sched_setparam(pid_t pid, const struct sched_param *param)
+{
+  FAR _TCB  *rtcb;
+  FAR _TCB  *tcb;
+  int        ret;
+
+  /* Verify that the requested priority is in the valid range */
+
+  if (!param)
+    {
+      errno = EINVAL;
+      return ERROR;
+    }
+
+  /* Prohibit modifications to the head of the ready-to-run task
+   * list while adjusting the priority
+   */
+
+  sched_lock();
+
+  /* Check if the task to reprioritize is the calling task */
+
+  rtcb = (FAR _TCB*)g_readytorun.head;
+  if (pid == 0 || pid == rtcb->pid)
+    {
+      tcb = rtcb;
+    }
+
+  /* The pid is not the calling task, we will have to search for it */
+
+  else
+    {
+      tcb = sched_gettcb(pid);
+      if (!tcb)
+        {
+          /* No task with this pid was found */
+
+          errno = ESRCH;
+          sched_unlock();
+          return ERROR;
+        }
+    }
+
+ /* Then perform the reprioritization */
+
+ ret = sched_reprioritize(tcb, param->sched_priority);
+ sched_unlock();
+ return ret;
+}