1 #define _GNU_SOURCE
2 #include <errno.h>
3 #include <string.h>
4 #include <pthread.h>
5 #include <stdlib.h>
6 #include <stdio.h>
7 #include <fcntl.h>
8 #include <unistd.h>
9 #include <sys/types.h>
10 #include <sys/syscall.h>
11 #include <sched.h>
12 #include <signal.h>
13 static int loops = 15; // each thread+main will do this amount of loop
14 static int sleepms = 1000; // in each loop, will sleep "sleepms" milliseconds
15 static int burn = 0; // after each sleep, will burn cpu in a tight 'burn' loop
16 static void setup_sigusr_handler(void); // sigusr1 and 2 sigaction setup.
17
gettid()18 static pid_t gettid()
19 {
20 #ifdef __NR_gettid
21 return syscall(__NR_gettid);
22 #else
23 return getpid();
24 #endif
25 }
26 // will be invoked from gdb.
27 static void whoami(char *msg) __attribute__((unused));
whoami(char * msg)28 static void whoami(char *msg)
29 {
30 fprintf(stderr, "pid %ld Thread %ld %s\n", (long) getpid(), (long) gettid(),
31 msg);
32 fflush(stderr);
33 }
34
35
do_burn()36 static void do_burn ()
37 {
38 int i;
39 int loopnr = 0;
40 // one single line for the below, to ensure interrupt on this line.
41 for (i = 0; i < burn; i++) loopnr++;
42 }
43
44 static int thread_ready = 0;
45 static pthread_cond_t ready = PTHREAD_COND_INITIALIZER;
46 static pthread_mutex_t ready_mutex = PTHREAD_MUTEX_INITIALIZER;
signal_ready(void)47 static void signal_ready (void)
48 {
49 int rc;
50 rc = pthread_mutex_lock(&ready_mutex);
51 if (rc != 0)
52 fprintf(stderr, "signal_ready lock error %d_n", rc);
53 thread_ready = 1;
54 rc = pthread_cond_signal(&ready);
55 if (rc != 0)
56 fprintf(stderr, "signal_ready signal error %d_n", rc);
57 rc = pthread_mutex_unlock(&ready_mutex);
58 if (rc != 0)
59 fprintf(stderr, "signal_ready unlock error %d_n", rc);
60 }
61
62 struct spec {
63 char *name;
64 int sleep;
65 int burn;
66 int t;
67 };
68 static struct timeval t[4];
69 static int nr_sleeper_or_burner = 0;
70 static volatile int report_finished = 1;
71 // set to 0 to have no finish msg (as order is non-deterministic)
sleeper_or_burner(void * v)72 static void *sleeper_or_burner(void *v)
73 {
74 int i = 0;
75 struct spec* s = (struct spec*)v;
76 int ret;
77 fprintf(stderr, "%s ready to sleep and/or burn\n", s->name);
78 fflush (stderr);
79 signal_ready();
80 nr_sleeper_or_burner++;
81
82 for (i = 0; i < loops; i++) {
83 if (sleepms > 0 && s->sleep) {
84 t[s->t].tv_sec = sleepms / 1000;
85 t[s->t].tv_usec = (sleepms % 1000) * 1000;
86 ret = select (0, NULL, NULL, NULL, &t[s->t]);
87 /* We only expect a timeout result or EINTR from the above. */
88 if (ret != 0 && errno != EINTR)
89 perror("unexpected result from select");
90 }
91 if (burn > 0 && s->burn)
92 do_burn();
93 }
94 if (report_finished) {
95 fprintf(stderr, "%s finished to sleep and/or burn\n", s->name);
96 fflush (stderr);
97 }
98 return NULL;
99 }
100
101 // wait till a thread signals it is ready
wait_ready(void)102 static void wait_ready(void)
103 {
104 int rc;
105 rc = pthread_mutex_lock(&ready_mutex);
106 if (rc != 0)
107 fprintf(stderr, "wait_ready lock error %d_n", rc);
108 while (! thread_ready && rc == 0) {
109 rc = pthread_cond_wait(&ready, &ready_mutex);
110 if (rc != 0)
111 fprintf(stderr, "wait_ready wait error %d_n", rc);
112 }
113 thread_ready = 0;
114 rc = pthread_mutex_unlock(&ready_mutex);
115 if (rc != 0)
116 fprintf(stderr, "wait_ready unlock error %d_n", rc);
117 }
118
119 // We will lock ourselves on one single cpu.
120 // This bypasses the unfairness of the Valgrind scheduler
121 // when a multi-cpu machine has enough cpu to run all the
122 // threads wanting to burn cpu.
setaffinity(void)123 static void setaffinity(void)
124 {
125 #ifdef VGO_linux
126 cpu_set_t single_cpu;
127 CPU_ZERO(&single_cpu);
128 CPU_SET(1, &single_cpu);
129 (void) sched_setaffinity(0, sizeof(single_cpu), &single_cpu);
130 #endif
131 // GDBTD: equivalent for Darwin ?
132 }
133
main(int argc,char * argv[])134 int main (int argc, char *argv[])
135 {
136 char *threads_spec;
137 pthread_t ebbr, egll, zzzz;
138 struct spec b, l, p, m;
139 char *some_mem __attribute__((unused)) = malloc(100);
140 if (argc > 5 && atoi(argv[5])) setaffinity();
141 setup_sigusr_handler();
142 if (argc > 1)
143 loops = atoi(argv[1]);
144
145 if (argc > 2)
146 sleepms = atoi(argv[2]);
147
148 if (argc > 3)
149 burn = atoll(argv[3]);
150
151 if (argc > 4)
152 threads_spec = argv[4];
153 else
154 threads_spec = "BSBSBSBS";
155
156 fprintf(stderr, "loops/sleep_ms/burn/threads_spec/affinity: %d %d %d %s %d\n",
157 loops, sleepms, burn, threads_spec, argc > 5 && atoi(argv[5]));
158 fflush(stderr);
159
160 b.name = "Brussels";
161 b.burn = *threads_spec++ == 'B';
162 b.sleep = *threads_spec++ == 'S';
163 b.t = -1;
164 if (b.burn || b.sleep) {
165 b.t = 1;
166 pthread_create(&ebbr, NULL, sleeper_or_burner, &b);
167 wait_ready();
168 }
169
170 l.name = "London";
171 l.burn = *threads_spec++ == 'B';
172 l.sleep = *threads_spec++ == 'S';
173 l.t = -1;
174 if (l.burn || l.sleep) {
175 l.t = 2;
176 pthread_create(&egll, NULL, sleeper_or_burner, &l);
177 wait_ready();
178 }
179
180 p.name = "Petaouchnok";
181 p.burn = *threads_spec++ == 'B';
182 p.sleep = *threads_spec++ == 'S';
183 p.t = -1;
184 if (p.burn || p.sleep) {
185 p.t = 3;
186 pthread_create(&zzzz, NULL, sleeper_or_burner, &p);
187 wait_ready();
188 }
189
190 m.name = "main";
191 m.burn = *threads_spec++ == 'B';
192 m.sleep = *threads_spec++ == 'S';
193 m.t = 0;
194 sleeper_or_burner(&m);
195
196 if (b.t != -1) pthread_join(ebbr, NULL);
197 if (l.t != -1) pthread_join(egll, NULL);
198 if (p.t != -1) pthread_join(zzzz, NULL);
199
200 return 0;
201 }
202
203 static int sigusr1_received = 0;
sigusr1_handler(int signr)204 static void sigusr1_handler(int signr)
205 {
206 sigusr1_received++;
207 }
setup_sigusr_handler(void)208 static void setup_sigusr_handler(void)
209 {
210 struct sigaction sa;
211 sa.sa_handler = sigusr1_handler;
212 sigemptyset(&sa.sa_mask);
213 sa.sa_flags = 0;
214
215 if (sigaction (SIGUSR1, &sa, NULL) != 0)
216 perror("sigaction SIGUSR1");
217
218 sa.sa_handler = SIG_IGN;
219 if (sigaction (SIGUSR2, &sa, NULL) != 0)
220 perror("sigaction SIGUSR2");
221 }
222
223