| xf.li | bfc6e71 | 2025-02-07 01:54:34 -0800 | [diff] [blame^] | 1 | /* Copyright (C) 1996-2016 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | |
| 4 | The GNU C Library is free software; you can redistribute it and/or |
| 5 | modify it under the terms of the GNU Lesser General Public |
| 6 | License as published by the Free Software Foundation; either |
| 7 | version 2.1 of the License, or (at your option) any later version. |
| 8 | |
| 9 | The GNU C Library is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | Lesser General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU Lesser General Public |
| 15 | License along with the GNU C Library; if not, see |
| 16 | <http://www.gnu.org/licenses/>. */ |
| 17 | |
| 18 | #include <errno.h> |
| 19 | #include <hurd.h> |
| 20 | #include <hurd/signal.h> |
| 21 | #include <hurd/msg.h> |
| 22 | #include <hurd/sigpreempt.h> |
| 23 | #include <assert.h> |
| 24 | |
| 25 | /* Select any of pending signals from SET or wait for any to arrive. */ |
| 26 | int |
| 27 | __sigwait (const sigset_t *set, int *sig) |
| 28 | { |
| 29 | struct hurd_sigstate *ss; |
| 30 | sigset_t mask, ready; |
| 31 | int signo = 0; |
| 32 | struct hurd_signal_preemptor preemptor; |
| 33 | jmp_buf buf; |
| 34 | mach_port_t wait; |
| 35 | mach_msg_header_t msg; |
| 36 | |
| 37 | sighandler_t |
| 38 | preempt_fun (struct hurd_signal_preemptor *pe, |
| 39 | struct hurd_sigstate *ss, |
| 40 | int *sigp, |
| 41 | struct hurd_signal_detail *detail) |
| 42 | { |
| 43 | if (signo) |
| 44 | /* We've already been run; don't interfere. */ |
| 45 | return SIG_ERR; |
| 46 | |
| 47 | signo = *sigp; |
| 48 | |
| 49 | /* Make sure this is all kosher */ |
| 50 | assert (__sigismember (&mask, signo)); |
| 51 | |
| 52 | /* Make sure this signal is unblocked */ |
| 53 | __sigdelset (&ss->blocked, signo); |
| 54 | |
| 55 | return pe->handler; |
| 56 | } |
| 57 | |
| 58 | void |
| 59 | handler (int sig) |
| 60 | { |
| 61 | assert (sig == signo); |
| 62 | longjmp (buf, 1); |
| 63 | } |
| 64 | |
| 65 | wait = __mach_reply_port (); |
| 66 | |
| 67 | if (set != NULL) |
| 68 | /* Crash before locking */ |
| 69 | mask = *set; |
| 70 | else |
| 71 | __sigemptyset (&mask); |
| 72 | |
| 73 | ss = _hurd_self_sigstate (); |
| 74 | __spin_lock (&ss->lock); |
| 75 | |
| 76 | /* See if one of these signals is currently pending. */ |
| 77 | __sigandset (&ready, &ss->pending, &mask); |
| 78 | if (! __sigisemptyset (&ready)) |
| 79 | { |
| 80 | for (signo = 1; signo < NSIG; signo++) |
| 81 | if (__sigismember (&ready, signo)) |
| 82 | { |
| 83 | __sigdelset (&ready, signo); |
| 84 | goto all_done; |
| 85 | } |
| 86 | /* Huh? Where'd it go? */ |
| 87 | abort (); |
| 88 | } |
| 89 | |
| 90 | /* Wait for one of them to show up. */ |
| 91 | |
| 92 | if (!setjmp (buf)) |
| 93 | { |
| 94 | /* Make the preemptor */ |
| 95 | preemptor.signals = mask; |
| 96 | preemptor.first = 0; |
| 97 | preemptor.last = -1; |
| 98 | preemptor.preemptor = preempt_fun; |
| 99 | preemptor.handler = handler; |
| 100 | |
| 101 | /* Install this preemptor */ |
| 102 | preemptor.next = ss->preemptors; |
| 103 | ss->preemptors = &preemptor; |
| 104 | |
| 105 | __spin_unlock (&ss->lock); |
| 106 | |
| 107 | /* Wait. */ |
| 108 | __mach_msg (&msg, MACH_RCV_MSG, 0, sizeof (msg), wait, |
| 109 | MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL); |
| 110 | abort (); |
| 111 | } |
| 112 | else |
| 113 | { |
| 114 | assert (signo); |
| 115 | |
| 116 | __spin_lock (&ss->lock); |
| 117 | |
| 118 | /* Delete our preemptor. */ |
| 119 | assert (ss->preemptors == &preemptor); |
| 120 | ss->preemptors = preemptor.next; |
| 121 | } |
| 122 | |
| 123 | |
| 124 | all_done: |
| 125 | spin_unlock (&ss->lock); |
| 126 | |
| 127 | __mach_port_destroy (__mach_task_self (), wait); |
| 128 | *sig = signo; |
| 129 | return 0; |
| 130 | } |
| 131 | |
| 132 | libc_hidden_def (__sigwait) |
| 133 | weak_alias (__sigwait, sigwait) |