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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
|
/* Copyright (C) 2003-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, see <https://www.gnu.org/licenses/>. */
#include <jmpbuf-unwind.h>
#include <kernel-posix-cpu-timers.h>
#include <kernel-posix-timers.h>
#include <ldsodefs.h>
#include <libc-internal.h>
#include <libc-lock.h>
#include <pthreadP.h>
#include <shlib-compat.h>
struct timer_helper_thread_args_t
{
/* The barrier is used to synchronize the arguments copy from timer_created
to the timer thread. */
pthread_barrier_t b;
struct sigevent *evp;
};
extern _Noreturn void __longjmp_cancel (__jmp_buf __env, int __val)
attribute_hidden;
struct cleanup_args_t
{
struct pthread_unwind_buf *cleanup_jmp_buf;
jmp_buf jb;
};
static void
timer_helper_thread_cleanup (void *arg)
{
struct pthread *self = THREAD_SELF;
/* Call destructors for the thread_local TLS variables. */
#ifndef SHARED
if (&__call_tls_dtors != NULL)
#endif
__call_tls_dtors ();
/* Run the destructor for the thread-local data. */
__nptl_deallocate_tsd ();
/* Clean up any state libc stored in thread-local variables. */
__libc_thread_freeres ();
/* Reset internal TCB state. */
struct cleanup_args_t *args = arg;
self->cleanup_jmp_buf = args->cleanup_jmp_buf;
self->cleanup_jmp_buf->priv.data.prev = NULL;
self->cleanup_jmp_buf->priv.data.cleanup = NULL;
self->cleanup_jmp_buf->priv.data.canceltype = 0;
self->cleanup = NULL;
self->exc = (struct _Unwind_Exception) { 0 };
self->cancelhandling = 0;
self->nextevent = NULL;
/* Re-initialize the TLS. */
_dl_allocate_tls_init (TLS_TPADJ (self), true);
internal_sigset_t ss;
internal_sigfillset (&ss);
internal_sigdelset (&ss, SIGSETXID);
internal_sigprocmask (SIG_SETMASK, &ss, NULL);
/* There is no need to perform any additional cleanup by the frames. */
struct __jmp_buf_tag *env = args->jb;
__longjmp (env[0].__jmpbuf, 1);
}
static void *
timer_helper_thread (void *arg)
{
struct pthread *self = THREAD_SELF;
struct timer_helper_thread_args_t *args = arg;
void (*thrfunc) (sigval_t) = args->evp->sigev_notify_function;
sigval_t sival = args->evp->sigev_value;
__pthread_barrier_wait (&args->b);
/* timer_create failed. */
if (self->timerid < 0)
return 0;
struct cleanup_args_t clargs = {
.cleanup_jmp_buf = self->cleanup_jmp_buf
};
while (1)
{
siginfo_t si;
while (__sigwaitinfo (&sigtimer_set, &si) < 0) {};
if (si.si_code == SI_TIMER && !setjmp (clargs.jb))
{
pthread_cleanup_push (timer_helper_thread_cleanup, &clargs);
thrfunc (sival);
pthread_cleanup_pop (0);
}
/* timer_delete will set the MSB and signal the thread. */
if (atomic_load_relaxed (&self->timerid) < 0)
break;
}
/* Clear the MSB bit set by timer_delete. */
INTERNAL_SYSCALL_CALL (timer_delete, self->timerid & INT_MAX);
return NULL;
}
static int
timer_create_sigev_thread (clockid_t syscall_clockid, struct sigevent *evp,
timer_t *timerid)
{
int ret = -1;
pthread_attr_t attr;
if (evp->sigev_notify_attributes != NULL)
__pthread_attr_copy (&attr, evp->sigev_notify_attributes);
else
__pthread_attr_init (&attr);
__pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
/* Block all signals in the helper thread but SIGSETXID. */
sigset_t ss;
__sigfillset (&ss);
__sigdelset (&ss, SIGSETXID);
ret = __pthread_attr_setsigmask_internal (&attr, &ss);
if (ret != 0)
goto out;
struct timer_helper_thread_args_t args;
__pthread_barrier_init (&args.b, NULL, 2);
args.evp = evp;
pthread_t th;
ret = __pthread_create (&th, &attr, timer_helper_thread, &args);
if (ret != 0)
{
__set_errno (ret);
goto out;
}
struct sigevent kevp = {
.sigev_value.sival_ptr = NULL,
.sigev_signo = SIGTIMER,
.sigev_notify = SIGEV_THREAD_ID,
._sigev_un = { ._pad = { [0] = ((struct pthread *)th)->tid } }
};
struct pthread *pthr = (struct pthread *)th;
kernel_timer_t ktimerid;
if (INLINE_SYSCALL_CALL (timer_create, syscall_clockid, &kevp, &ktimerid) < 0)
pthr->timerid = -1;
pthr->timerid = ktimerid;
/* Signal the thread to continue execution after it copies the arguments
or exit if the timer can not be created. */
__pthread_barrier_wait (&args.b);
if (timerid >= 0)
*timerid = pthread_to_timerid (th);
ret = 0;
out:
if (&attr != evp->sigev_notify_attributes)
__pthread_attr_destroy (&attr);
return ret;
}
int
___timer_create (clockid_t clock_id, struct sigevent *evp, timer_t *timerid)
{
clockid_t syscall_clockid = (clock_id == CLOCK_PROCESS_CPUTIME_ID
? PROCESS_CLOCK
: clock_id == CLOCK_THREAD_CPUTIME_ID
? THREAD_CLOCK
: clock_id);
switch (evp != NULL ? evp->sigev_notify : SIGEV_SIGNAL)
{
case SIGEV_NONE:
case SIGEV_SIGNAL:
case SIGEV_THREAD_ID:
{
struct sigevent kevp;
if (evp == NULL)
{
kevp.sigev_notify = SIGEV_SIGNAL;
kevp.sigev_signo = SIGALRM;
kevp.sigev_value.sival_ptr = NULL;
evp = &kevp;
}
kernel_timer_t ktimerid;
if (INLINE_SYSCALL_CALL (timer_create, syscall_clockid, evp,
&ktimerid) == -1)
return -1;
*timerid = kernel_timer_to_timerid (ktimerid);
}
break;
case SIGEV_THREAD:
if (timer_create_sigev_thread (syscall_clockid, evp, timerid) < 0)
return -1;
break;
default:
__set_errno (EINVAL);
return -1;
}
return 0;
}
versioned_symbol (libc, ___timer_create, timer_create, GLIBC_2_34);
libc_hidden_ver (___timer_create, __timer_create)
#if TIMER_T_WAS_INT_COMPAT
# if OTHER_SHLIB_COMPAT (librt, GLIBC_2_3_3, GLIBC_2_34)
compat_symbol (librt, ___timer_create, timer_create, GLIBC_2_3_3);
# endif
# if OTHER_SHLIB_COMPAT (librt, GLIBC_2_2, GLIBC_2_3_3)
timer_t __timer_compat_list[OLD_TIMER_MAX];
int
__timer_create_old (clockid_t clock_id, struct sigevent *evp, int *timerid)
{
timer_t newp;
int res = __timer_create (clock_id, evp, &newp);
if (res == 0)
{
int i;
for (i = 0; i < OLD_TIMER_MAX; ++i)
if (__timer_compat_list[i] == NULL
&& ! atomic_compare_and_exchange_bool_acq (&__timer_compat_list[i],
newp, NULL))
{
*timerid = i;
break;
}
if (__glibc_unlikely (i == OLD_TIMER_MAX))
{
/* No free slot. */
__timer_delete (newp);
__set_errno (EINVAL);
res = -1;
}
}
return res;
}
compat_symbol (librt, __timer_create_old, timer_create, GLIBC_2_2);
# endif /* OTHER_SHLIB_COMPAT */
#else /* !TIMER_T_WAS_INT_COMPAT */
# if OTHER_SHLIB_COMPAT (librt, GLIBC_2_2, GLIBC_2_34)
compat_symbol (librt, ___timer_create, timer_create, GLIBC_2_2);
# endif
#endif /* !TIMER_T_WAS_INT_COMPAT */
|
