1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
#include <stdio.h>
#include <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <setjmp.h>
static volatile int run = 1;
static sem_t sem;
static sem_t sem_child;
static void
add (int n)
{
int i;
int arr[n];
for (i = 0; i < n; i++) {
arr[i]++;
}
memset (&arr[0], 0, n * sizeof(int));
}
static void *
high_load (void *unused)
{
while (run) {
add(10);
add(20);
}
return NULL;
}
static void *
do_signal (void *unused)
{
while (run) {
kill (getpid(), SIGUSR1);
while (sem_wait(&sem) < 0 && errno == EINTR);
}
return NULL;
}
static void *
do_fork (void *unused)
{
pid_t pid;
while (run) {
switch ((pid = fork())) {
case 0:
add(1000);
add(2000);
exit(0);
break;
case -1:
return NULL;
default:
while (sem_wait(&sem_child) < 0 && errno == EINTR);
wait(NULL);
break;
}
}
return NULL;
}
static void signal_handler(int sig)
{
add(10);
add(20);
sem_post (&sem);
}
static void child_handler(int sig)
{
add(10);
add(20);
sem_post (&sem_child);
}
int
main (void)
{
int i;
pthread_t id1, id2, id3;
struct sigaction act;
sigjmp_buf sj;
sigset_t m;
time_t end;
memset (&act, 0, sizeof (act));
act.sa_handler = signal_handler;
act.sa_flags = 0;
sigemptyset (&act.sa_mask);
sigaction (SIGUSR1, &act, NULL);
act.sa_handler = child_handler;
sigaction (SIGCHLD, &act, NULL);
printf ("start\n"); fflush(stdout);
sem_init (&sem, 0, 0);
sem_init (&sem_child, 0, 0);
pthread_create(&id1, NULL, high_load, NULL);
pthread_create(&id2, NULL, do_signal, NULL);
#if !defined(__APPLE__)
pthread_create(&id3, NULL, do_fork, NULL);
#endif
/* sleep does not work !!! */
end = time(NULL) + 2;
while (time(NULL) < end) ;
run = 0;
pthread_join(id1, NULL);
pthread_join(id2, NULL);
#if !defined(__APPLE__)
pthread_join(id3, NULL);
#endif
sem_destroy (&sem);
sem_destroy (&sem_child);
printf ("end\n"); fflush(stdout);
sigemptyset (&m);
sigprocmask (SIG_SETMASK, &m, NULL);
if (sigsetjmp (sj, 0) == 0)
{
sigaddset (&m, SIGUSR1);
sigprocmask (SIG_SETMASK, &m, NULL);
siglongjmp (sj, 1);
printf ("failed");
return 1;
}
sigprocmask (SIG_SETMASK, NULL, &m);
if (!sigismember (&m, SIGUSR1))
printf ("failed");
return 0;
}
|
