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
|
#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;
};
static void dummy_1(pthread_t self)
{
}
weak_alias(dummy_1, __pthread_tsd_run_dtors);
static void cleanup_fromsig(void *p)
{
pthread_t self = __pthread_self();
__pthread_tsd_run_dtors(self);
self->cancel = 0;
self->cancelbuf = 0;
self->canceldisable = 0;
self->cancelasync = 0;
self->unblock_cancel = 0;
longjmp(p, 1);
}
static void timer_handler(int sig, siginfo_t *si, void *ctx)
{
pthread_t self = __pthread_self();
jmp_buf jb;
void (*notify)(union sigval) = (void (*)(union sigval))self->start;
union sigval val = { .sival_ptr = self->start_arg };
if (!setjmp(jb) && si->si_code == SI_TIMER) {
pthread_cleanup_push(cleanup_fromsig, jb);
notify(val);
pthread_cleanup_pop(1);
}
}
static void install_handler()
{
struct sigaction sa = {
.sa_sigaction = timer_handler,
.sa_flags = SA_SIGINFO | SA_RESTART
};
__libc_sigaction(SIGTIMER, &sa, 0);
__syscall(SYS_rt_sigprocmask, SIG_UNBLOCK,
SIGTIMER_SET, 0, __SYSCALL_SSLEN);
}
static void *start(void *arg)
{
pthread_t self = __pthread_self();
struct start_args *args = arg;
sigset_t set;
/* 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;
sigfillset(&set);
pthread_sigmask(SIG_BLOCK, &set, 0);
pthread_barrier_wait(&args->b);
__wait(&self->delete_timer, 0, 0, 1);
__syscall(SYS_timer_delete, self->result);
return 0;
}
int timer_create(clockid_t clk, struct sigevent *restrict evp, timer_t *restrict res)
{
static pthread_once_t once = PTHREAD_ONCE_INIT;
pthread_t td;
pthread_attr_t attr;
int r;
struct start_args args;
struct ksigevent ksev, *ksevp=0;
int timerid;
switch (evp ? evp->sigev_notify : SIGEV_SIGNAL) {
case SIGEV_NONE:
case SIGEV_SIGNAL:
if (evp) {
ksev.sigev_value = evp->sigev_value;
ksev.sigev_signo = evp->sigev_signo;
ksev.sigev_notify = evp->sigev_notify;
ksev.sigev_tid = 0;
ksevp = &ksev;
}
if (syscall(SYS_timer_create, clk, ksevp, &timerid) < 0)
return -1;
*res = (void *)timerid;
break;
case SIGEV_THREAD:
pthread_once(&once, install_handler);
if (evp->sigev_notify_attributes)
attr = *evp->sigev_notify_attributes;
else
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
pthread_barrier_init(&args.b, 0, 2);
args.sev = evp;
r = pthread_create(&td, &attr, start, &args);
if (r) {
errno = r;
return -1;
}
ksev.sigev_value.sival_ptr = 0;
ksev.sigev_signo = SIGTIMER;
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;
}
|
