/************************************************************ * 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 "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) { 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; } }