1 files changed, 157 insertions, 0 deletions
diff --git a/nuttx/sched/sched_rrgetinterval.c b/nuttx/sched/sched_rrgetinterval.c
new file mode 100644
index 000000000..961c58ec5
--- /dev/null
+++ b/nuttx/sched/sched_rrgetinterval.c
@@ -0,0 +1,157 @@
+/************************************************************************
+ * sched/sched_rrgetinterval.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"
+#include "clock_internal.h"
+
+/************************************************************************
+ * Definitions
+ ************************************************************************/
+
+/************************************************************************
+ * Private Type Declarations
+ ************************************************************************/
+
+/************************************************************************
+ * Global Variables
+ ************************************************************************/
+
+/************************************************************************
+ * Private Variables
+ ************************************************************************/
+
+/************************************************************************
+ * Private Function Prototypes
+ ************************************************************************/
+
+/************************************************************************
+ * Private Functions
+ ************************************************************************/
+
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
+
+/************************************************************************
+ * Name: sched_rr_get_interval
+ *
+ * Description:
+ *   sched_rr_get_interval()  writes  the timeslice interval for task
+ *   identified by 'pid' into  the timespec structure pointed to by
+ *   'interval.'  If pid is zero, the timeslice for the calling process
+ *   is written into 'interval.  The identified process should be running
+ *   under the SCHED_RRscheduling policy.'
+ *
+ * Inputs:
+ *   pid - the task ID of the task.  If pid is zero, the priority of the
+ *         calling task is returned.
+ *   interval - a structure used to return the time slice
+ *
+ * Return Value:
+ *   On success, sched_rr_get_interval() returns OK (0).  On error,
+ *   ERROR (-1) is returned, and errno is set to:
+ *
+ *   EFAULT -- Cannot copy to interval
+ *   EINVAL Invalid pid.
+ *   ENOSYS The system call is not yet implemented.
+ *   ESRCH  The process whose ID is pid could not be found.
+ *
+ * Assumptions:
+ *
+ ************************************************************************/
+
+int sched_rr_get_interval(pid_t pid, struct timespec *interval)
+{
+#if CONFIG_RR_INTERVAL > 0
+  FAR _TCB  *rrtcb;
+
+  /* If pid is zero, the timeslice for the calling process is written
+   * into 'interval.'
+   */
+
+  if (!pid)
+    {
+      rrtcb = (FAR _TCB*)g_readytorun.head;
+    }
+
+  /* Return a special error code on invalid PID */
+
+  else if (pid < 0)
+    {
+      set_errno(EINVAL);
+      return ERROR;
+    }
+
+  /* Otherwise, lookup the TCB associated with this pid */
+
+  else
+    {
+      rrtcb = sched_gettcb(pid);
+      if (!rrtcb)
+        {
+          set_errno(ESRCH);
+          return ERROR;
+        }
+    }
+
+  if (!interval)
+    {
+      set_errno(EFAULT);
+      return ERROR;
+    }
+
+  /* Convert the timeslice value from ticks to timespec */
+
+  interval->tv_sec  =  CONFIG_RR_INTERVAL / MSEC_PER_SEC;
+  interval->tv_nsec = (CONFIG_RR_INTERVAL % MSEC_PER_SEC) * NSEC_PER_MSEC;
+
+  return OK;
+#else
+  set_errno(ENOSYS);
+  return ERROR;
+#endif
+}