diff options
Diffstat (limited to 'nuttx/sched/sched_getscheduler.c')
-rw-r--r-- | nuttx/sched/sched_getscheduler.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/nuttx/sched/sched_getscheduler.c b/nuttx/sched/sched_getscheduler.c new file mode 100644 index 000000000..5771e86ff --- /dev/null +++ b/nuttx/sched/sched_getscheduler.c @@ -0,0 +1,131 @@ +/************************************************************************ + * sched/sched_getscheduler.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_getscheduler + * + * Description: + * sched_getscheduler() returns the scheduling policy currently + * applied to the task identified by pid. If pid equals zero, the + * policy of the calling task will be retrieved. + * + * Inputs: + * pid - the task ID of the task to query. If pid is zero, the + * calling task is queried. + * + * Return Value: + * On success, sched_getscheduler() returns the policy for the task + * (either SCHED_FIFO or SCHED_RR). On error, ERROR (-1) is + * returned, and errno is set appropriately: + * + * ESRCH The task whose ID is pid could not be found. + * + * Assumptions: + * + ************************************************************************/ + +int sched_getscheduler(pid_t pid) +{ + _TCB *tcb; + + /* Verify that the pid corresponds to a real task */ + + if (!pid) + { + tcb = (_TCB*)g_readytorun.head; + } + else + { + tcb = sched_gettcb(pid); + } + + if (!tcb) + { + set_errno(ESRCH); + return ERROR; + } +#if CONFIG_RR_INTERVAL > 0 + else if ((tcb->flags & TCB_FLAG_ROUND_ROBIN) != 0) + { + return SCHED_RR; + } +#endif + else + { + return SCHED_FIFO; + } +} |