115 lines
3.1 KiB
C++
115 lines
3.1 KiB
C++
/*
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* Copyright (C) 2014-2016 Max Kellermann <max.kellermann@gmail.com>
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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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*
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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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*
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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 the
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* 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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* FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "Util.hxx"
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#include "system/Error.hxx"
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#ifdef __linux__
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#include <sched.h>
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#include <sys/syscall.h>
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#include <unistd.h>
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#elif defined(_WIN32)
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#include <windows.h>
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#endif
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#ifdef __linux__
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#ifndef ANDROID
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static int
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linux_ioprio_set(int which, int who, int ioprio) noexcept
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{
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return syscall(__NR_ioprio_set, which, who, ioprio);
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}
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static void
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ioprio_set_idle() noexcept
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{
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static constexpr int _IOPRIO_WHO_PROCESS = 1;
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static constexpr int _IOPRIO_CLASS_IDLE = 3;
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static constexpr int _IOPRIO_CLASS_SHIFT = 13;
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static constexpr int _IOPRIO_IDLE =
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(_IOPRIO_CLASS_IDLE << _IOPRIO_CLASS_SHIFT) | 7;
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linux_ioprio_set(_IOPRIO_WHO_PROCESS, 0, _IOPRIO_IDLE);
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}
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#endif /* !ANDROID */
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/**
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* Wrapper for the "sched_setscheduler" system call. We don't use the
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* one from the C library because Musl has an intentionally broken
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* implementation.
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*/
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static int
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linux_sched_setscheduler(pid_t pid, int sched,
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const struct sched_param *param) noexcept
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{
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return syscall(__NR_sched_setscheduler, pid, sched, param);
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}
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#endif
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void
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SetThreadIdlePriority() noexcept
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{
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#ifdef __linux__
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#ifdef SCHED_IDLE
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static struct sched_param sched_param;
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linux_sched_setscheduler(0, SCHED_IDLE, &sched_param);
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#endif
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#ifndef ANDROID
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/* this system call is forbidden via seccomp on Android 8 and
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leads to crash (SIGSYS) */
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ioprio_set_idle();
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#endif
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#elif defined(_WIN32)
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SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_IDLE);
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#endif
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}
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void
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SetThreadRealtime()
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{
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#ifdef __linux__
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struct sched_param sched_param;
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sched_param.sched_priority = 40;
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int policy = SCHED_FIFO;
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#ifdef SCHED_RESET_ON_FORK
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policy |= SCHED_RESET_ON_FORK;
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#endif
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if (linux_sched_setscheduler(0, policy, &sched_param) < 0)
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throw MakeErrno("sched_setscheduler failed");
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#endif // __linux__
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}
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