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4e56d89dcd
- Get ASAN working on Windows. - Deleting directories and then recreating them with the same name in a short period of time appears to be a no-no on Windows. - There's no reason to call FlushFileBuffers on close() for pipes, and it's harmful since it might block indefinitely for no good reason.
49 lines
2.5 KiB
C
49 lines
2.5 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=8 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/dce.h"
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#include "libc/nexgen32e/x86feature.h"
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#include "libc/rand/rand.h"
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#include "libc/rand/xorshift.h"
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hidden extern uint64_t g_rando64;
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/**
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* Returns nondeterministic random number.
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*
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* This function uses a good random source if it's available, which
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* takes ~400 cycles (~99ns). Otherwise it's seeded at program start
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* with the system provided random value and may perform a few
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* microseconds worth of system calls to get a good value.
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*
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* @see rngset()
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*/
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nodebuginfo uint64_t rand64(void) {
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uint64_t res;
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if (X86_HAVE(RDRND)) {
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res = rdrand();
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} else {
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if (IsWindows()) {
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res = winrandish();
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} else {
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devrand(&res, sizeof(res));
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}
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res ^= MarsagliaXorshift64(&g_rando64);
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}
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return res;
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}
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