1 // RUN: %libomp-compile && env OMP_MAX_TASK_PRIORITY='2' %libomp-run
2 
3 // Test OMP 4.5 task priorities
4 // Higher priority task supposed to be executed before lower priority task.
5 
6 #include <stdio.h>
7 #include <omp.h>
8 
9 #include "omp_my_sleep.h"
10 // delay(n) - sleep n ms
11 #define delay(n) my_sleep(((double)n)/1000.0)
12 
13 int main ( void ) {
14   int passed;
15   passed = (omp_get_max_task_priority() == 2);
16   printf("Got %d max priority via env\n", omp_get_max_task_priority());
17   if(!passed) {
18     printf( "failed\n" );
19     return 1;
20   }
21   printf("parallel 1 spawns 4 tasks for primary thread to execute\n");
22   #pragma omp parallel num_threads(2)
23   {
24     int th = omp_get_thread_num();
25     if (th == 0) // primary thread
26     {
27       #pragma omp task priority(1)
28       { // middle priority
29         int val, t = omp_get_thread_num();
30         #pragma omp atomic capture
31           val = passed++;
32         printf("P1:    val = %d, thread gen %d, thread exe %d\n", val, th, t);
33         delay(10); // sleep 10 ms
34       }
35       #pragma omp task priority(2)
36       { // high priority
37         int val, t = omp_get_thread_num();
38         #pragma omp atomic capture
39           val = passed++;
40         printf("P2:    val = %d, thread gen %d, thread exe %d\n", val, th, t);
41         delay(20); // sleep 20 ms
42       }
43       #pragma omp task priority(0)
44       { // low priority specified explicitly
45         int val, t = omp_get_thread_num();
46         #pragma omp atomic capture
47           val = passed++;
48         printf("P0exp: val = %d, thread gen %d, thread exe %d\n", val, th, t);
49         delay(1); // sleep 1 ms
50       }
51       #pragma omp task
52       { // low priority by default
53         int val, t = omp_get_thread_num();
54         #pragma omp atomic capture
55           val = passed++;
56         printf("P0imp: val = %d, thread gen %d, thread exe %d\n", val, th, t);
57         delay(1); // sleep 1 ms
58       }
59     } else {
60       // wait for the primary thread to finish all tasks
61       int wait = 0;
62       do {
63         delay(5);
64         #pragma omp atomic read
65           wait = passed;
66       } while (wait < 5);
67     }
68   }
69   printf("parallel 2 spawns 4 tasks for worker thread to execute\n");
70   #pragma omp parallel num_threads(2)
71   {
72     int th = omp_get_thread_num();
73     if (th == 0) // primary thread
74     {
75       #pragma omp task priority(1)
76       { // middle priority
77         int val, t = omp_get_thread_num();
78         #pragma omp atomic capture
79           val = passed++;
80         printf("P1:    val = %d, thread gen %d, thread exe %d\n", val, th, t);
81         delay(10); // sleep 10 ms
82       }
83       #pragma omp task priority(2)
84       { // high priority
85         int val, t = omp_get_thread_num();
86         #pragma omp atomic capture
87           val = passed++;
88         printf("P2:    val = %d, thread gen %d, thread exe %d\n", val, th, t);
89         delay(20); // sleep 20 ms
90       }
91       #pragma omp task priority(0)
92       { // low priority specified explicitly
93         int val, t = omp_get_thread_num();
94         #pragma omp atomic capture
95           val = passed++;
96         printf("P0exp: val = %d, thread gen %d, thread exe %d\n", val, th, t);
97         delay(1); // sleep 1 ms
98       }
99       #pragma omp task
100       { // low priority by default
101         int val, t = omp_get_thread_num();
102         #pragma omp atomic capture
103           val = passed++;
104         printf("P0imp: val = %d, thread gen %d, thread exe %d\n", val, th, t);
105         delay(1); // sleep 1 ms
106       }
107       // signal creation of all tasks: passed = 5 + 1 = 6
108       #pragma omp atomic
109         passed++;
110       // wait for completion of all 4 tasks
111       int wait = 0;
112       do {
113         delay(5);
114         #pragma omp atomic read
115           wait = passed;
116       } while (wait < 10); // passed = 6 + 4 = 10
117     } else {
118       // wait for the primary thread to create all tasks
119       int wait = 0;
120       do {
121         delay(5);
122         #pragma omp atomic read
123           wait = passed;
124       } while (wait < 6);
125       // go execute 4 tasks created by primary thread
126     }
127   }
128   if (passed != 10) {
129     printf("failed, passed = %d (should be 10)\n", passed);
130     return 1;
131   }
132   printf("passed\n");
133   return 0;
134 }
135 // CHECK: parallel 1
136 // CHECK-NEXT: P2
137 // CHECK-NEXT: P1
138 // CHECK-NEXT: P0
139 // CHECK-NEXT: P0
140 // CHECK-NEXT: parallel 2
141 // CHECK-NEXT: P2
142 // CHECK-NEXT: P1
143 // CHECK-NEXT: P0
144 // CHECK-NEXT: P0
145 // CHECK: passed
146