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Diffstat (limited to 'nuttx/sched/sched_getscheduler.c')
-rw-r--r-- | nuttx/sched/sched_getscheduler.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/nuttx/sched/sched_getscheduler.c b/nuttx/sched/sched_getscheduler.c new file mode 100644 index 0000000000..9406d9774c --- /dev/null +++ b/nuttx/sched/sched_getscheduler.c @@ -0,0 +1,130 @@ +/************************************************************ + * sched_getscheduler.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 <errno.h> +#include <nuttx/arch.h> +#include <nuttx/os_external.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 process identified by pid. If + * pid equals zero, the policy of the calling process 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 = 0) + { + tcb = (_TCB*)g_readytorun.head; + } + else + { + tcb = sched_gettcb(pid); + } + + if (!tcb) + { + *get_errno_ptr() = 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; + } +} |