1/* Copyright (C) 2003-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If
17 not, see <https://www.gnu.org/licenses/>. */
18
19#include <errno.h>
20#include <pthread.h>
21#include <signal.h>
22#include <stdlib.h>
23#include <string.h>
24#include <time.h>
25#include <sysdep.h>
26#include <internaltypes.h>
27#include <nptl/pthreadP.h>
28#include "kernel-posix-timers.h"
29#include "kernel-posix-cpu-timers.h"
30
31
32#ifdef timer_create_alias
33# define timer_create timer_create_alias
34#endif
35
36
37int
38timer_create (clockid_t clock_id, struct sigevent *evp, timer_t *timerid)
39{
40#undef timer_create
41 {
42 clockid_t syscall_clockid = (clock_id == CLOCK_PROCESS_CPUTIME_ID
43 ? MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED)
44 : clock_id == CLOCK_THREAD_CPUTIME_ID
45 ? MAKE_THREAD_CPUCLOCK (0, CPUCLOCK_SCHED)
46 : clock_id);
47
48 /* If the user wants notification via a thread we need to handle
49 this special. */
50 if (evp == NULL
51 || __builtin_expect (evp->sigev_notify != SIGEV_THREAD, 1))
52 {
53 struct sigevent local_evp;
54
55 if (evp == NULL)
56 {
57 /* The kernel has to pass up the timer ID which is a
58 userlevel object. Therefore we cannot leave it up to
59 the kernel to determine it. */
60 local_evp.sigev_notify = SIGEV_SIGNAL;
61 local_evp.sigev_signo = SIGALRM;
62 local_evp.sigev_value.sival_ptr = NULL;
63
64 evp = &local_evp;
65 }
66
67 kernel_timer_t ktimerid;
68 if (INLINE_SYSCALL_CALL (timer_create, syscall_clockid, evp,
69 &ktimerid) == -1)
70 return -1;
71
72 *timerid = kernel_timer_to_timerid (ktimerid);
73 }
74 else
75 {
76 /* Create the helper thread. */
77 pthread_once (&__helper_once, __start_helper_thread);
78 if (__helper_tid == 0)
79 {
80 /* No resources to start the helper thread. */
81 __set_errno (EAGAIN);
82 return -1;
83 }
84
85 struct timer *newp = malloc (sizeof (struct timer));
86 if (newp == NULL)
87 return -1;
88
89 /* Copy the thread parameters the user provided. */
90 newp->sival = evp->sigev_value;
91 newp->thrfunc = evp->sigev_notify_function;
92
93 /* We cannot simply copy the thread attributes since the
94 implementation might keep internal information for
95 each instance. */
96 pthread_attr_init (&newp->attr);
97 if (evp->sigev_notify_attributes != NULL)
98 {
99 struct pthread_attr *nattr;
100 struct pthread_attr *oattr;
101
102 nattr = (struct pthread_attr *) &newp->attr;
103 oattr = (struct pthread_attr *) evp->sigev_notify_attributes;
104
105 nattr->schedparam = oattr->schedparam;
106 nattr->schedpolicy = oattr->schedpolicy;
107 nattr->flags = oattr->flags;
108 nattr->guardsize = oattr->guardsize;
109 nattr->stackaddr = oattr->stackaddr;
110 nattr->stacksize = oattr->stacksize;
111 }
112
113 /* In any case set the detach flag. */
114 pthread_attr_setdetachstate (&newp->attr, PTHREAD_CREATE_DETACHED);
115
116 /* Create the event structure for the kernel timer. */
117 struct sigevent sev =
118 { .sigev_value.sival_ptr = newp,
119 .sigev_signo = SIGTIMER,
120 .sigev_notify = SIGEV_SIGNAL | SIGEV_THREAD_ID,
121 ._sigev_un = { ._pad = { [0] = __helper_tid } } };
122
123 /* Create the timer. */
124 int res;
125 res = INTERNAL_SYSCALL_CALL (timer_create, syscall_clockid, &sev,
126 &newp->ktimerid);
127 if (INTERNAL_SYSCALL_ERROR_P (res))
128 {
129 free (newp);
130 __set_errno (INTERNAL_SYSCALL_ERRNO (res));
131 return -1;
132 }
133
134 /* Add to the queue of active timers with thread delivery. */
135 pthread_mutex_lock (&__active_timer_sigev_thread_lock);
136 newp->next = __active_timer_sigev_thread;
137 __active_timer_sigev_thread = newp;
138 pthread_mutex_unlock (&__active_timer_sigev_thread_lock);
139
140 *timerid = timer_to_timerid (newp);
141 }
142 }
143
144 return 0;
145}
146