1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2022 Jessica Clarke <jrtc27@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #define KILL_TIMEOUT 10
29
30 /*
31 * NB: Most of these do not need to be volatile, but a handful are used in
32 * signal handler contexts, so for simplicity we make them all volatile rather
33 * than duplicate the implementation.
34 */
35 struct pipe_barrier {
36 volatile int fds[2];
37 };
38
39 static __inline int
pipe_barrier_init(struct pipe_barrier * p)40 pipe_barrier_init(struct pipe_barrier *p)
41 {
42 int error, fds[2], i;
43
44 error = pipe(fds);
45 if (error != 0)
46 return (error);
47
48 for (i = 0; i < 2; ++i)
49 p->fds[i] = fds[i];
50
51 return (0);
52 }
53
54 static __inline void
pipe_barrier_wait(struct pipe_barrier * p)55 pipe_barrier_wait(struct pipe_barrier *p)
56 {
57 ssize_t ret;
58 char temp;
59 int fd;
60
61 fd = p->fds[0];
62 p->fds[0] = -1;
63 do {
64 ret = read(fd, &temp, 1);
65 } while (ret == -1 && errno == EINTR);
66 close(fd);
67 }
68
69 static __inline void
pipe_barrier_ready(struct pipe_barrier * p)70 pipe_barrier_ready(struct pipe_barrier *p)
71 {
72 int fd;
73
74 fd = p->fds[1];
75 p->fds[1] = -1;
76 close(fd);
77 }
78
79 static __inline void
pipe_barrier_destroy_impl(struct pipe_barrier * p,int i)80 pipe_barrier_destroy_impl(struct pipe_barrier *p, int i)
81 {
82 int fd;
83
84 fd = p->fds[i];
85 if (fd != -1) {
86 p->fds[i] = -1;
87 close(fd);
88 }
89 }
90
91 static __inline void
pipe_barrier_destroy_wait(struct pipe_barrier * p)92 pipe_barrier_destroy_wait(struct pipe_barrier *p)
93 {
94 pipe_barrier_destroy_impl(p, 0);
95 }
96
97 static __inline void
pipe_barrier_destroy_ready(struct pipe_barrier * p)98 pipe_barrier_destroy_ready(struct pipe_barrier *p)
99 {
100 pipe_barrier_destroy_impl(p, 1);
101 }
102
103 static __inline void
pipe_barrier_destroy(struct pipe_barrier * p)104 pipe_barrier_destroy(struct pipe_barrier *p)
105 {
106 pipe_barrier_destroy_wait(p);
107 pipe_barrier_destroy_ready(p);
108 }
109
110 void reproduce_signal_death(int sig);
111