57 lines
2.1 KiB
C++
57 lines
2.1 KiB
C++
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/*
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* Copyright (C) 2016 The Android Open Source Project
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <signal.h>
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#include <string.h>
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sighandler_t sigset(int sig, sighandler_t disp) {
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struct sigaction new_sa;
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if (disp != SIG_HOLD) {
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memset(&new_sa, 0, sizeof(new_sa));
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new_sa.sa_handler = disp;
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sigemptyset(&new_sa.sa_mask);
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}
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struct sigaction old_sa;
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if (sigaction(sig, disp == SIG_HOLD ? nullptr : &new_sa, &old_sa) == -1) {
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return SIG_ERR;
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}
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sigset_t new_proc_mask;
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sigemptyset(&new_proc_mask);
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sigaddset(&new_proc_mask, sig);
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sigset_t old_proc_mask;
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if (sigprocmask(disp == SIG_HOLD ? SIG_BLOCK : SIG_UNBLOCK,
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&new_proc_mask, &old_proc_mask) == -1) {
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return SIG_ERR;
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}
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return sigismember(&old_proc_mask, sig) ? SIG_HOLD : old_sa.sa_handler;
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}
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