1 files changed, 187 insertions, 0 deletions
diff --git a/nuttx/sched/sched_setscheduler.c b/nuttx/sched/sched_setscheduler.c
new file mode 100644
index 000000000..7f7f345b4
--- /dev/null
+++ b/nuttx/sched/sched_setscheduler.c
@@ -0,0 +1,187 @@
+/****************************************************************************
+ * sched/sched_setscheduler.c
+ *
+ *   Copyright (C) 2007, 2009, 2012 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 <unistd.h>
+#include <sched.h>
+#include <errno.h>
+
+#include <nuttx/arch.h>
+
+#include "os_internal.h"
+#include "clock_internal.h"
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Type Declarations
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name:sched_setscheduler
+ *
+ * Description:
+ *   sched_setscheduler() sets both the scheduling policy and the priority
+ *   for the task identified by pid. If pid equals zero, the scheduler of
+ *   the calling task will be set.  The parameter 'param' holds the priority
+ *   of the thread under the new policy.
+ *
+ * Inputs:
+ *   pid - the task ID of the task to modify.  If pid is zero, the calling
+ *      task is modified.
+ *   policy - Scheduling policy requested (either SCHED_FIFO or SCHED_RR)
+ *   param - A structure whose member sched_priority is the new priority.
+ *      The range of valid priority numbers is from SCHED_PRIORITY_MIN
+ *      through SCHED_PRIORITY_MAX.
+ *
+ * Return Value:
+ *   On success, sched_setscheduler() returns OK (zero).  On error, ERROR
+ *   (-1) is returned, and errno is set appropriately:
+ *
+ *   EINVAL The scheduling policy is not one of the recognized policies.
+ *   ESRCH  The task whose ID is pid could not be found.
+ *
+ * Assumptions:
+ *
+ ****************************************************************************/
+
+int sched_setscheduler(pid_t pid, int policy,
+                       const struct sched_param *param)
+{
+  FAR _TCB *tcb;
+#if CONFIG_RR_INTERVAL > 0
+  irqstate_t saved_state;
+#endif
+  int ret;
+
+  /* Check for supported scheduling policy */
+
+#if CONFIG_RR_INTERVAL > 0
+  if (policy != SCHED_FIFO && policy != SCHED_RR)
+#else
+  if (policy != SCHED_FIFO)
+#endif
+    {
+      errno = EINVAL;
+      return ERROR;
+    }
+
+  /* Check if the task to modify the calling task */
+
+  if (pid == 0 )
+    {
+      pid = getpid();
+    }
+
+  /* Verify that the pid corresponds to a real task */
+
+  tcb = sched_gettcb(pid);
+  if (!tcb)
+    {
+      errno = ESRCH;
+      return ERROR;
+    }
+
+  /* Prohibit any context switches while we muck with priority and scheduler
+   * settings.
+   */
+
+  sched_lock();
+
+#if CONFIG_RR_INTERVAL > 0
+  /* Further, disable timer interrupts while we set up scheduling policy. */
+
+  saved_state = irqsave();
+  if (policy == SCHED_RR)
+    {
+      /* Set round robin scheduling */
+
+      tcb->flags    |= TCB_FLAG_ROUND_ROBIN;
+      tcb->timeslice = CONFIG_RR_INTERVAL / MSEC_PER_TICK;
+    }
+  else
+    {
+      /* Set FIFO scheduling */
+
+      tcb->flags    &= ~TCB_FLAG_ROUND_ROBIN;
+      tcb->timeslice = 0;
+    }
+
+  irqrestore(saved_state);
+#endif
+
+  /* Set the new priority */
+
+  ret = sched_reprioritize(tcb, param->sched_priority);
+  sched_unlock();
+
+  if (ret != OK)
+    {
+      return ERROR;
+    }
+  else
+    {
+      return OK;
+    }
+}
+