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1 | /* This testcase is part of GDB, the GNU debugger. |
2 | ||
b811d2c2 | 3 | Copyright 2018-2020 Free Software Foundation, Inc. |
d27d16bf RB |
4 | |
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU General Public License as published by | |
7 | the Free Software Foundation; either version 3 of the License, or | |
8 | (at your option) any later version. | |
9 | ||
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | GNU General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU General Public License | |
16 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
17 | ||
18 | #include <stdio.h> | |
19 | #include <stdlib.h> | |
20 | #include <pthread.h> | |
21 | ||
22 | /* This defines the number of threads to spawn. */ | |
23 | #define THREADCOUNT 4 | |
24 | ||
25 | /* Global barrier type to control synchronization between threads. */ | |
26 | static pthread_barrier_t print_barrier; | |
27 | ||
28 | /* Define global thread identifiers. */ | |
29 | static pthread_t threads[THREADCOUNT]; | |
30 | ||
31 | /* Hold values for each thread at the index supplied to the thread | |
32 | on creation. */ | |
33 | static int thread_ids[THREADCOUNT]; | |
34 | ||
35 | /* Find the value associated with the calling thread. */ | |
36 | static int | |
37 | get_value () | |
38 | { | |
39 | for (int tid = 0; tid < THREADCOUNT; ++tid) | |
40 | { | |
41 | if (pthread_equal (threads[tid], pthread_self ())) | |
42 | return thread_ids[tid]; | |
43 | } | |
44 | /* Value for the main thread. */ | |
45 | return 1; | |
46 | } | |
47 | ||
48 | /* Return the nth Fibonacci number. */ | |
49 | static unsigned long | |
50 | fast_fib (unsigned int n) | |
51 | { | |
52 | int a = 0; | |
53 | int b = 1; | |
54 | int t; | |
55 | for (unsigned int i = 0; i < n; ++i) | |
56 | { | |
57 | t = b; | |
58 | b = a + b; | |
59 | a = t; | |
60 | } | |
61 | return a; | |
62 | } | |
63 | ||
64 | /* Encapsulate the synchronization of the threads. Perform a barrier before | |
65 | and after the computation. */ | |
66 | static void * | |
67 | thread_function (void *args) | |
68 | { | |
69 | int tid = *((int *) args); | |
70 | int status = pthread_barrier_wait (&print_barrier); | |
71 | if (status == PTHREAD_BARRIER_SERIAL_THREAD) | |
72 | printf ("All threads entering compute region\n"); | |
73 | ||
74 | unsigned long result = fast_fib (100); /* testmarker01 */ | |
75 | status = pthread_barrier_wait (&print_barrier); | |
76 | if (status == PTHREAD_BARRIER_SERIAL_THREAD) | |
77 | printf ("All threads outputting results\n"); | |
78 | ||
79 | pthread_barrier_wait (&print_barrier); | |
80 | printf ("Thread %d Result: %lu\n", tid, result); | |
81 | } | |
82 | ||
83 | int | |
84 | main (void) | |
85 | { | |
86 | int err = pthread_barrier_init (&print_barrier, NULL, THREADCOUNT); | |
87 | if (err != 0) | |
88 | { | |
89 | fprintf (stderr, "Barrier creation failed\n"); | |
90 | return EXIT_FAILURE; | |
91 | } | |
92 | /* Create the worker threads (main). */ | |
93 | printf ("Spawning worker threads\n"); | |
94 | for (int tid = 0; tid < THREADCOUNT; ++tid) | |
95 | { | |
96 | /* Add 2 so the value maps to the debugger's thread identifiers. */ | |
97 | thread_ids[tid] = tid + 2; /* prethreadcreationmarker */ | |
98 | err = pthread_create (&threads[tid], NULL, thread_function, | |
99 | (void *) &thread_ids[tid]); | |
100 | if (err != 0) | |
101 | { | |
102 | fprintf (stderr, "Thread creation failed\n"); | |
103 | return EXIT_FAILURE; | |
104 | } | |
105 | } | |
106 | /* Wait for the threads to complete then exit. */ | |
107 | for (int tid = 0; tid < THREADCOUNT; ++tid) | |
108 | pthread_join (threads[tid], NULL); | |
109 | ||
110 | return EXIT_SUCCESS; | |
111 | } |