3bfb6eeb14
Plus a little bit of cleanup of the sysconf() implementation... Change-Id: I017d50e537e4721c9a4c4a62e9dea771ee920fb8
347 lines
16 KiB
C++
347 lines
16 KiB
C++
/*
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* Copyright (C) 2008 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 <errno.h>
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#include <fcntl.h>
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#include <limits.h>
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#include <pthread.h>
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#include <stdio.h> // For FOPEN_MAX.
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#include <sys/auxv.h>
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#include <sys/param.h>
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#include <sys/resource.h>
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#include <sys/sysinfo.h>
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#include <time.h>
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#include <unistd.h>
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#include "platform/bionic/page.h"
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#include "private/bionic_tls.h"
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struct sysconf_cache {
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long size, assoc, linesize;
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static sysconf_cache from_size_and_geometry(int size_id, int geometry_id) {
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sysconf_cache result;
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result.size = getauxval(size_id);
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unsigned long geometry = getauxval(geometry_id);
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result.assoc = geometry >> 16;
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result.linesize = geometry & 0xffff;
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return result;
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}
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};
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struct sysconf_caches {
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sysconf_cache l1_i, l1_d, l2, l3, l4;
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};
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#if defined(__riscv)
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static sysconf_caches* __sysconf_caches() {
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static sysconf_caches cached = []{
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sysconf_caches info = {};
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// riscv64 kernels conveniently hand us all this information.
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info.l1_i = sysconf_cache::from_size_and_geometry(AT_L1I_CACHESIZE, AT_L1I_CACHEGEOMETRY);
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info.l1_d = sysconf_cache::from_size_and_geometry(AT_L1D_CACHESIZE, AT_L1D_CACHEGEOMETRY);
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info.l2 = sysconf_cache::from_size_and_geometry(AT_L2_CACHESIZE, AT_L2_CACHEGEOMETRY);
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info.l3 = sysconf_cache::from_size_and_geometry(AT_L3_CACHESIZE, AT_L3_CACHEGEOMETRY);
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return info;
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}();
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return &cached;
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}
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#elif defined(__aarch64__)
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static sysconf_caches* __sysconf_caches() {
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static sysconf_caches cached = []{
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sysconf_caches info = {};
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// arm64 is especially limited. We can infer the L1 line sizes, but that's it.
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uint64_t ctr_el0;
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__asm__ __volatile__("mrs %0, ctr_el0" : "=r"(ctr_el0));
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info.l1_i.linesize = 4 << (ctr_el0 & 0xf);
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info.l1_d.linesize = 4 << ((ctr_el0 >> 16) & 0xf);
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return info;
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}();
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return &cached;
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}
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#else
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static long __sysconf_fread_long(const char* path) {
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long result = 0;
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FILE* fp = fopen(path, "re");
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if (fp != nullptr) {
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fscanf(fp, "%ld", &result);
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fclose(fp);
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}
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return result;
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}
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static sysconf_caches* __sysconf_caches() {
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static sysconf_caches cached = []{
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sysconf_caches info = {};
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char path[64];
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for (int i = 0; i < 4; i++) {
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sysconf_cache c;
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snprintf(path, sizeof(path), "/sys/devices/system/cpu/cpu0/cache/index%d/size", i);
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c.size = __sysconf_fread_long(path) * 1024;
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if (c.size == 0) break;
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snprintf(path, sizeof(path), "/sys/devices/system/cpu/cpu0/cache/index%d/ways_of_associativity", i);
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c.assoc = __sysconf_fread_long(path);
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snprintf(path, sizeof(path), "/sys/devices/system/cpu/cpu0/cache/index%d/coherency_line_size", i);
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c.linesize = __sysconf_fread_long(path);
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snprintf(path, sizeof(path), "/sys/devices/system/cpu/cpu0/cache/index%d/level", i);
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int level = __sysconf_fread_long(path);
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if (level == 1) {
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snprintf(path, sizeof(path), "/sys/devices/system/cpu/cpu0/cache/index%d/type", i);
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FILE* fp = fopen(path, "re");
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char type = fgetc(fp);
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fclose(fp);
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if (type == 'D') {
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info.l1_d = c;
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} else if (type == 'I') {
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info.l1_i = c;
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}
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} else if (level == 2) {
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info.l2 = c;
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} else if (level == 3) {
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info.l3 = c;
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}
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}
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return info;
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}();
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return &cached;
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}
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#endif
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static long __sysconf_rlimit(int resource) {
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rlimit rl;
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getrlimit(resource, &rl);
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return rl.rlim_cur;
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}
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long sysconf(int name) {
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switch (name) {
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//
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// Things we actually have to calculate...
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//
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case _SC_ARG_MAX:
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// You might think that just returning a constant 128KiB (ARG_MAX) would
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// make sense, as this guy did:
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//
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// https://lkml.org/lkml/2017/11/15/813...
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//
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// I suspect a 128kB sysconf(_SC_ARG_MAX) is the sanest bet, simply
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// because of that "conservative is better than aggressive".
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//
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// Especially since _technically_ we're still limiting things to that
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// 128kB due to the single-string limit.
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//
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// Linus
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//
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// In practice that caused us trouble with toybox tests for xargs edge
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// cases. The tests assume that they can at least reach the kernel's
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// "minimum maximum" of 128KiB, but if we report 128KiB for _SC_ARG_MAX
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// and xargs starts subtracting the environment space and so on from that,
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// then xargs will think it's run out of space when given 128KiB of data,
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// which should always work. See this thread for more:
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//
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// http://lists.landley.net/pipermail/toybox-landley.net/2019-November/011229.html
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//
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// So let's resign ourselves to tracking what the kernel actually does.
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// Right now (2019, Linux 5.3) that amounts to:
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return MAX(MIN(__sysconf_rlimit(RLIMIT_STACK) / 4, 3 * _STK_LIM / 4), ARG_MAX);
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case _SC_AVPHYS_PAGES: return get_avphys_pages();
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case _SC_CHILD_MAX: return __sysconf_rlimit(RLIMIT_NPROC);
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case _SC_CLK_TCK:
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return static_cast<long>(getauxval(AT_CLKTCK));
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case _SC_NPROCESSORS_CONF: return get_nprocs_conf();
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case _SC_NPROCESSORS_ONLN: return get_nprocs();
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case _SC_OPEN_MAX: return __sysconf_rlimit(RLIMIT_NOFILE);
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case _SC_PAGESIZE:
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case _SC_PAGE_SIZE:
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// _SC_PAGESIZE and _SC_PAGE_SIZE are distinct, but return the same value.
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return getpagesize();
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case _SC_PHYS_PAGES: return get_phys_pages();
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//
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// Constants...
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//
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case _SC_BC_BASE_MAX: return _POSIX2_BC_BASE_MAX; // Minimum requirement.
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case _SC_BC_DIM_MAX: return _POSIX2_BC_DIM_MAX; // Minimum requirement.
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case _SC_BC_SCALE_MAX: return _POSIX2_BC_SCALE_MAX; // Minimum requirement.
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case _SC_BC_STRING_MAX: return _POSIX2_BC_STRING_MAX; // Minimum requirement.
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case _SC_COLL_WEIGHTS_MAX: return _POSIX2_COLL_WEIGHTS_MAX; // Minimum requirement.
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case _SC_EXPR_NEST_MAX: return _POSIX2_EXPR_NEST_MAX; // Minimum requirement.
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case _SC_LINE_MAX: return _POSIX2_LINE_MAX; // Minimum requirement.
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case _SC_NGROUPS_MAX:
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// Only root can read /proc/sys/kernel/ngroups_max on Android, and groups
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// are vestigial anyway, so the "maximum maximum" of NGROUPS_MAX is a good
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// enough answer for _SC_NGROUPS_MAX...
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return NGROUPS_MAX;
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case _SC_PASS_MAX: return PASS_MAX;
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case _SC_2_C_BIND: return _POSIX2_C_BIND;
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case _SC_2_C_DEV: return _POSIX2_C_DEV;
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case _SC_2_CHAR_TERM: return _POSIX2_CHAR_TERM;
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case _SC_2_FORT_DEV: return -1;
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case _SC_2_FORT_RUN: return -1;
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case _SC_2_LOCALEDEF: return _POSIX2_LOCALEDEF;
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case _SC_2_SW_DEV: return _POSIX2_SW_DEV;
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case _SC_2_UPE: return _POSIX2_UPE;
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case _SC_2_VERSION: return _POSIX2_VERSION;
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case _SC_JOB_CONTROL: return _POSIX_JOB_CONTROL;
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case _SC_SAVED_IDS: return _POSIX_SAVED_IDS;
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case _SC_VERSION: return _POSIX_VERSION;
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case _SC_RE_DUP_MAX: return _POSIX_RE_DUP_MAX; // Minimum requirement.
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case _SC_STREAM_MAX: return FOPEN_MAX;
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case _SC_TZNAME_MAX: return _POSIX_TZNAME_MAX; // Minimum requirement.
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case _SC_XOPEN_CRYPT: return _XOPEN_CRYPT;
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case _SC_XOPEN_ENH_I18N: return _XOPEN_ENH_I18N;
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case _SC_XOPEN_SHM: return _XOPEN_SHM;
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case _SC_XOPEN_VERSION: return _XOPEN_VERSION;
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case _SC_XOPEN_REALTIME: return _XOPEN_REALTIME;
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case _SC_XOPEN_REALTIME_THREADS: return _XOPEN_REALTIME_THREADS;
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case _SC_XOPEN_LEGACY: return _XOPEN_LEGACY;
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case _SC_ATEXIT_MAX: return LONG_MAX; // Unlimited.
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case _SC_IOV_MAX: return IOV_MAX;
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case _SC_XOPEN_UNIX: return _XOPEN_UNIX;
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case _SC_AIO_LISTIO_MAX: return _POSIX_AIO_LISTIO_MAX; // Minimum requirement.
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case _SC_AIO_MAX: return _POSIX_AIO_MAX; // Minimum requirement.
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case _SC_AIO_PRIO_DELTA_MAX:return 0; // Minimum requirement.
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case _SC_DELAYTIMER_MAX: return _POSIX_DELAYTIMER_MAX;
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case _SC_MQ_OPEN_MAX: return _POSIX_MQ_OPEN_MAX; // Minimum requirement.
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case _SC_MQ_PRIO_MAX: return _POSIX_MQ_PRIO_MAX; // Minimum requirement.
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case _SC_RTSIG_MAX: return RTSIG_MAX;
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case _SC_SEM_NSEMS_MAX: return _POSIX_SEM_NSEMS_MAX; // Minimum requirement.
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case _SC_SEM_VALUE_MAX: return SEM_VALUE_MAX;
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case _SC_SIGQUEUE_MAX: return _POSIX_SIGQUEUE_MAX; // Minimum requirement.
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case _SC_TIMER_MAX: return _POSIX_TIMER_MAX; // Minimum requirement.
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case _SC_ASYNCHRONOUS_IO: return _POSIX_ASYNCHRONOUS_IO;
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case _SC_FSYNC: return _POSIX_FSYNC;
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case _SC_MAPPED_FILES: return _POSIX_MAPPED_FILES;
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case _SC_MEMLOCK: return _POSIX_MEMLOCK;
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case _SC_MEMLOCK_RANGE: return _POSIX_MEMLOCK_RANGE;
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case _SC_MEMORY_PROTECTION: return _POSIX_MEMORY_PROTECTION;
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case _SC_MESSAGE_PASSING: return _POSIX_MESSAGE_PASSING;
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case _SC_PRIORITIZED_IO: return _POSIX_PRIORITIZED_IO;
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case _SC_PRIORITY_SCHEDULING: return _POSIX_PRIORITY_SCHEDULING;
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case _SC_REALTIME_SIGNALS: return _POSIX_REALTIME_SIGNALS;
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case _SC_SEMAPHORES: return _POSIX_SEMAPHORES;
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case _SC_SHARED_MEMORY_OBJECTS: return _POSIX_SHARED_MEMORY_OBJECTS;
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case _SC_SYNCHRONIZED_IO: return _POSIX_SYNCHRONIZED_IO;
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case _SC_TIMERS: return _POSIX_TIMERS;
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case _SC_GETGR_R_SIZE_MAX: return 1024;
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case _SC_GETPW_R_SIZE_MAX: return 1024;
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case _SC_LOGIN_NAME_MAX: return LOGIN_NAME_MAX;
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case _SC_THREAD_DESTRUCTOR_ITERATIONS: return PTHREAD_DESTRUCTOR_ITERATIONS;
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case _SC_THREAD_KEYS_MAX: return PTHREAD_KEYS_MAX;
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case _SC_THREAD_STACK_MIN: return PTHREAD_STACK_MIN;
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case _SC_THREAD_THREADS_MAX: return -1; // No specific limit.
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case _SC_TTY_NAME_MAX: return TTY_NAME_MAX;
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case _SC_THREADS: return _POSIX_THREADS;
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case _SC_THREAD_ATTR_STACKADDR: return _POSIX_THREAD_ATTR_STACKADDR;
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case _SC_THREAD_ATTR_STACKSIZE: return _POSIX_THREAD_ATTR_STACKSIZE;
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case _SC_THREAD_PRIORITY_SCHEDULING: return _POSIX_THREAD_PRIORITY_SCHEDULING;
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case _SC_THREAD_PRIO_INHERIT: return _POSIX_THREAD_PRIO_INHERIT;
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case _SC_THREAD_PRIO_PROTECT: return _POSIX_THREAD_PRIO_PROTECT;
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case _SC_THREAD_SAFE_FUNCTIONS: return _POSIX_THREAD_SAFE_FUNCTIONS;
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case _SC_MONOTONIC_CLOCK: return _POSIX_MONOTONIC_CLOCK;
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case _SC_2_PBS: return -1; // Obsolescent in POSIX.1-2008.
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case _SC_2_PBS_ACCOUNTING: return -1; // Obsolescent in POSIX.1-2008.
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case _SC_2_PBS_CHECKPOINT: return -1; // Obsolescent in POSIX.1-2008.
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case _SC_2_PBS_LOCATE: return -1; // Obsolescent in POSIX.1-2008.
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case _SC_2_PBS_MESSAGE: return -1; // Obsolescent in POSIX.1-2008.
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case _SC_2_PBS_TRACK: return -1; // Obsolescent in POSIX.1-2008.
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case _SC_ADVISORY_INFO: return _POSIX_ADVISORY_INFO;
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case _SC_BARRIERS: return _POSIX_BARRIERS;
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case _SC_CLOCK_SELECTION: return _POSIX_CLOCK_SELECTION;
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case _SC_CPUTIME: return _POSIX_CPUTIME;
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case _SC_HOST_NAME_MAX: return _POSIX_HOST_NAME_MAX; // Minimum requirement.
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case _SC_IPV6: return _POSIX_IPV6;
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case _SC_RAW_SOCKETS: return _POSIX_RAW_SOCKETS;
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case _SC_READER_WRITER_LOCKS: return _POSIX_READER_WRITER_LOCKS;
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case _SC_REGEXP: return _POSIX_REGEXP;
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case _SC_SHELL: return _POSIX_SHELL;
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case _SC_SPAWN: return _POSIX_SPAWN;
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case _SC_SPIN_LOCKS: return _POSIX_SPIN_LOCKS;
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case _SC_SPORADIC_SERVER: return _POSIX_SPORADIC_SERVER;
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case _SC_SS_REPL_MAX: return -1;
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case _SC_SYMLOOP_MAX: return _POSIX_SYMLOOP_MAX; // Minimum requirement.
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case _SC_THREAD_CPUTIME: return _POSIX_THREAD_CPUTIME;
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case _SC_THREAD_PROCESS_SHARED: return _POSIX_THREAD_PROCESS_SHARED;
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case _SC_THREAD_ROBUST_PRIO_INHERIT: return _POSIX_THREAD_ROBUST_PRIO_INHERIT;
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case _SC_THREAD_ROBUST_PRIO_PROTECT: return _POSIX_THREAD_ROBUST_PRIO_PROTECT;
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case _SC_THREAD_SPORADIC_SERVER: return _POSIX_THREAD_SPORADIC_SERVER;
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case _SC_TIMEOUTS: return _POSIX_TIMEOUTS;
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case _SC_TRACE: return -1;
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case _SC_TRACE_EVENT_FILTER: return -1;
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case _SC_TRACE_EVENT_NAME_MAX: return -1;
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case _SC_TRACE_INHERIT: return -1;
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case _SC_TRACE_LOG: return -1;
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case _SC_TRACE_NAME_MAX: return -1;
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case _SC_TRACE_SYS_MAX: return -1;
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case _SC_TRACE_USER_EVENT_MAX: return -1;
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case _SC_TYPED_MEMORY_OBJECTS: return _POSIX_TYPED_MEMORY_OBJECTS;
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case _SC_V7_ILP32_OFF32: return _POSIX_V7_ILP32_OFF32;
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case _SC_V7_ILP32_OFFBIG: return _POSIX_V7_ILP32_OFFBIG;
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case _SC_V7_LP64_OFF64: return _POSIX_V7_LP64_OFF64;
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case _SC_V7_LPBIG_OFFBIG: return _POSIX_V7_LPBIG_OFFBIG;
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case _SC_XOPEN_STREAMS: return -1;
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case _SC_XOPEN_UUCP: return -1;
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case _SC_LEVEL1_ICACHE_SIZE: return __sysconf_caches()->l1_i.size;
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case _SC_LEVEL1_ICACHE_ASSOC: return __sysconf_caches()->l1_i.assoc;
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case _SC_LEVEL1_ICACHE_LINESIZE: return __sysconf_caches()->l1_i.linesize;
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case _SC_LEVEL1_DCACHE_SIZE: return __sysconf_caches()->l1_d.size;
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case _SC_LEVEL1_DCACHE_ASSOC: return __sysconf_caches()->l1_d.assoc;
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case _SC_LEVEL1_DCACHE_LINESIZE: return __sysconf_caches()->l1_d.linesize;
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case _SC_LEVEL2_CACHE_SIZE: return __sysconf_caches()->l2.size;
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case _SC_LEVEL2_CACHE_ASSOC: return __sysconf_caches()->l2.assoc;
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case _SC_LEVEL2_CACHE_LINESIZE: return __sysconf_caches()->l2.linesize;
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case _SC_LEVEL3_CACHE_SIZE: return __sysconf_caches()->l3.size;
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case _SC_LEVEL3_CACHE_ASSOC: return __sysconf_caches()->l3.assoc;
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case _SC_LEVEL3_CACHE_LINESIZE: return __sysconf_caches()->l3.linesize;
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case _SC_LEVEL4_CACHE_SIZE: return __sysconf_caches()->l4.size;
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case _SC_LEVEL4_CACHE_ASSOC: return __sysconf_caches()->l4.assoc;
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case _SC_LEVEL4_CACHE_LINESIZE: return __sysconf_caches()->l4.linesize;
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default:
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errno = EINVAL;
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return -1;
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}
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}
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