1 /*
2 * Copyright (c) 2004, QUALCOMM Inc. All rights reserved.
3 * Created by: abisain REMOVE-THIS AT qualcomm DOT com
4 * This file is licensed under the GPL license. For the full content
5 * of this license, see the COPYING file at the top level of this
6 * source tree.
7 *
8 * Test that pthread_barrier_wait()
9 * shall wakeup a high priority thread even when a low priority thread
10 * is running
11 *
12 * Steps:
13 * 1. Create a barrier object
14 * 2. Create a high priority thread and make it wait on the barrier
15 * 3. Create a low priority thread and let it busy-loop
16 * 4. Both low and high prio threads run on same CPU
17 * 5. Call the final barrier_wait from main
18 * 6. Check that the higher priority thread got woken up
19 * and preempted low priority thread
20 */
21
22 #include "affinity.h"
23 #include <pthread.h>
24 #include <stdlib.h>
25 #include <stdio.h>
26 #include <unistd.h>
27 #include <sys/time.h>
28 #include "posixtest.h"
29 #include "safe_helpers.h"
30
31 #define TEST "5-4"
32 #define AREA "scheduler"
33 #define ERROR_PREFIX "unexpected error: " AREA " " TEST ": "
34
35 #define HIGH_PRIORITY 10
36 #define LOW_PRIORITY 5
37 #define RUNTIME 5
38
39 pthread_barrier_t barrier;
40 static volatile int woken_up;
41 static volatile int low_done;
42
timediff(struct timespec t2,struct timespec t1)43 float timediff(struct timespec t2, struct timespec t1)
44 {
45 float diff = t2.tv_sec - t1.tv_sec;
46 diff += (t2.tv_nsec - t1.tv_nsec) / 1000000000.0;
47 return diff;
48 }
49
my_pthread_barrier_wait(pthread_barrier_t * p)50 int my_pthread_barrier_wait(pthread_barrier_t *p)
51 {
52 int rc;
53
54 rc = pthread_barrier_wait(p);
55 if (rc == PTHREAD_BARRIER_SERIAL_THREAD)
56 rc = 0;
57 return rc;
58 }
59
hi_prio_thread(void * tmp)60 void *hi_prio_thread(void *tmp)
61 {
62 struct sched_param param;
63 int policy;
64
65 (void) tmp;
66 set_affinity_single();
67
68 SAFE_PFUNC(pthread_getschedparam(pthread_self(), &policy, ¶m));
69 if (policy != SCHED_RR || param.sched_priority != HIGH_PRIORITY) {
70 printf("Error: the policy or priority not correct\n");
71 exit(PTS_UNRESOLVED);
72 }
73
74 SAFE_PFUNC(my_pthread_barrier_wait(&barrier));
75
76 /* This variable is unprotected because the scheduling removes
77 * the contention
78 */
79 if (!low_done)
80 woken_up = 1;
81
82 pthread_exit(NULL);
83 }
84
low_prio_thread(void * tmp)85 void *low_prio_thread(void *tmp)
86 {
87 struct timespec start_timespec, current_timespec;
88 struct sched_param param;
89 int policy;
90
91 (void) tmp;
92 set_affinity_single();
93
94 SAFE_PFUNC(pthread_getschedparam(pthread_self(), &policy, ¶m));
95 if (policy != SCHED_RR || param.sched_priority != LOW_PRIORITY) {
96 printf("Error: the policy or priority not correct\n");
97 exit(PTS_UNRESOLVED);
98 }
99
100 clock_gettime(CLOCK_REALTIME, &start_timespec);
101 while (!woken_up) {
102 clock_gettime(CLOCK_REALTIME, ¤t_timespec);
103 if (timediff(current_timespec, start_timespec) > RUNTIME)
104 break;
105 }
106 low_done = 1;
107
108 pthread_exit(NULL);
109 }
110
main()111 int main()
112 {
113 pthread_t high_id, low_id;
114 pthread_attr_t high_attr;
115 struct sched_param param;
116
117 SAFE_PFUNC(pthread_barrier_init(&barrier, NULL, 2));
118
119 /* Create the higher priority */
120 SAFE_PFUNC(pthread_attr_init(&high_attr));
121 SAFE_PFUNC(pthread_attr_setinheritsched(&high_attr, PTHREAD_EXPLICIT_SCHED));
122 SAFE_PFUNC(pthread_attr_setschedpolicy(&high_attr, SCHED_RR));
123 param.sched_priority = HIGH_PRIORITY;
124 SAFE_PFUNC(pthread_attr_setschedparam(&high_attr, ¶m));
125 SAFE_PFUNC(pthread_create(&high_id, &high_attr, hi_prio_thread, NULL));
126
127 /* run main with same priority as low prio thread */
128 param.sched_priority = LOW_PRIORITY;
129 SAFE_PFUNC(pthread_setschedparam(pthread_self(), SCHED_RR, ¶m));
130
131 /* Create the low priority thread (inherits sched policy from main) */
132 SAFE_PFUNC(pthread_create(&low_id, NULL, low_prio_thread, NULL));
133
134 sleep(1);
135 SAFE_PFUNC(my_pthread_barrier_wait(&barrier));
136
137 /* Wait for the threads to exit */
138 SAFE_PFUNC(pthread_join(low_id, NULL));
139 if (!woken_up) {
140 printf("High priority was not woken up. Test FAILED\n");
141 exit(PTS_FAIL);
142 }
143 SAFE_PFUNC(pthread_join(high_id, NULL));
144
145 printf("Test PASSED\n");
146 exit(PTS_PASS);
147 }
148