52 lines
1.5 KiB
C
52 lines
1.5 KiB
C
/* Copyright (C) 1992-2015 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <errno.h>
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#include <unistd.h>
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#include <sys/resource.h>
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/* Increment the scheduling priority of the calling process by INCR.
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The superuser may use a negative INCR to decrement the priority. */
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int
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nice (int incr)
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{
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int save;
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int prio;
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int result;
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/* -1 is a valid priority, so we use errno to check for an error. */
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save = errno;
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__set_errno (0);
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prio = __getpriority (PRIO_PROCESS, 0);
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if (prio == -1)
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{
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if (errno != 0)
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return -1;
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}
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result = __setpriority (PRIO_PROCESS, 0, prio + incr);
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if (result == -1)
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{
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if (errno == EACCES)
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__set_errno (EPERM);
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return -1;
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}
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__set_errno (save);
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return __getpriority (PRIO_PROCESS, 0);
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}
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