1 /* 2 * This program is free software; you can redistribute it and/or modify 3 * it under the terms of the GNU General Public License version 2. 4 * 5 * This program is distributed in the hope that it will be useful, 6 * but WITHOUT ANY WARRANTY; without even the implied warranty of 7 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 8 * GNU General Public License for more details. 9 * 10 * 11 * Test that the function return the former scheduling policy of the specified 12 * process upon successful completion. 13 * 14 * Steps: 15 * 1. Get the old policy. 16 * 2. Set a new policy. 17 * 3. Check that sched_setscheduler return the old policy. 18 */ 19 #include <sched.h> 20 #include <stdio.h> 21 #include <errno.h> 22 #include <unistd.h> 23 #include "posixtest.h" 24 25 int main(void) 26 { 27 int result, old_policy, new_policy; 28 struct sched_param param; 29 30 old_policy = sched_getscheduler(getpid()); 31 if (old_policy == -1) { 32 perror("An error occurs when calling sched_getscheduler()"); 33 return PTS_UNRESOLVED; 34 } 35 36 /* Make sure new_policy != old_policy */ 37 new_policy = (old_policy == SCHED_FIFO) ? SCHED_RR : SCHED_FIFO; 38 39 param.sched_priority = sched_get_priority_max(new_policy); 40 result = sched_setscheduler(0, new_policy, ¶m); 41 42 if (result == old_policy) { 43 printf("Test PASSED\n"); 44 return PTS_PASS; 45 } else if (result == -1 && errno == EPERM) { 46 printf 47 ("The process have not permission to change its own policy.\nTry to launch this test as root.\n"); 48 return PTS_UNRESOLVED; 49 } 50 51 printf("Returned code == %i.\n", result); 52 perror("Unknow error"); 53 return PTS_FAIL; 54 55 } 56
