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
|
#include <time.h>
#include "pthread_impl.h"
struct ksigevent {
union sigval sigev_value;
int sigev_signo;
int sigev_notify;
int sigev_tid;
};
struct start_args {
pthread_barrier_t b;
struct sigevent *sev;
};
void __sigtimer_handler(pthread_t self)
{
int st;
void (*notify)(union sigval) = (void (*)(union sigval))self->start;
union sigval val = { .sival_ptr = self->start_arg };
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &st);
notify(val);
pthread_setcancelstate(st, 0);
}
static void cleanup(void *p)
{
pthread_t self = p;
__syscall(SYS_timer_delete, self->result);
}
static void *start(void *arg)
{
pthread_t self = __pthread_self();
struct start_args *args = arg;
/* Reuse no-longer-needed thread structure fields to avoid
* needing the timer address in the signal handler. */
self->start = (void *(*)(void *))args->sev->sigev_notify_function;
self->start_arg = args->sev->sigev_value.sival_ptr;
self->result = (void *)-1;
pthread_cleanup_push(cleanup, self);
pthread_barrier_wait(&args->b);
pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, 0);
/* Loop on async-signal-safe cancellation point */
for (;;) sleep(1000000000);
pthread_cleanup_pop(0);
return 0;
}
int timer_create(clockid_t clk, struct sigevent *evp, timer_t *res)
{
struct sigevent sev = {
.sigev_notify = SIGEV_SIGNAL,
.sigev_signo = SIGALRM
};
pthread_t td;
pthread_attr_t attr;
int r;
struct start_args args;
timer_t t;
struct ksigevent ksev;
int timerid;
if (evp) sev = *evp;
switch (sev.sigev_notify) {
case SIGEV_NONE:
case SIGEV_SIGNAL:
ksev.sigev_value = evp ? sev.sigev_value
: (union sigval){.sival_ptr=t};
ksev.sigev_signo = sev.sigev_signo;
ksev.sigev_notify = sev.sigev_notify;
ksev.sigev_tid = 0;
if (syscall(SYS_timer_create, clk, &ksev, &timerid) < 0)
return -1;
*res = (void *)(2*timerid+1);
break;
case SIGEV_THREAD:
if (sev.sigev_notify_attributes)
attr = *sev.sigev_notify_attributes;
else
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
pthread_barrier_init(&args.b, 0, 2);
args.sev = &sev;
r = pthread_create(&td, &attr, start, &args);
if (r) {
errno = r;
return -1;
}
ksev.sigev_value.sival_ptr = 0;
ksev.sigev_signo = SIGCANCEL;
ksev.sigev_notify = 4; /* SIGEV_THREAD_ID */
ksev.sigev_tid = td->tid;
r = syscall(SYS_timer_create, clk, &ksev, &timerid);
pthread_barrier_wait(&args.b);
if (r < 0) {
pthread_cancel(td);
return -1;
}
td->result = (void *)timerid;
*res = td;
break;
default:
errno = EINVAL;
return -1;
}
return 0;
}
|
