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 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 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 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 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 92 pipe_barrier_destroy_wait(struct pipe_barrier *p) 93 { 94 pipe_barrier_destroy_impl(p, 0); 95 } 96 97 static __inline void 98 pipe_barrier_destroy_ready(struct pipe_barrier *p) 99 { 100 pipe_barrier_destroy_impl(p, 1); 101 } 102 103 static __inline void 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