mirror of
https://github.com/jart/cosmopolitan.git
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ec2cb88058
- Document more compiler flags - Expose new __print_maps() api - Better overflow checking in mmap() - Improve the shell example somewhat - Fix minor runtime bugs regarding stacks - Make kill() on fork()+execve()'d children work - Support CLONE_CHILD_CLEARTID for proper joining - Fix recent possible deadlock regression with --ftrace
56 lines
2.8 KiB
C
56 lines
2.8 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=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2022 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/calls/calls.h"
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#include "libc/intrin/kprintf.h"
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#include "libc/intrin/lockcmpxchgp.h"
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#include "libc/intrin/spinlock.h"
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#include "libc/nexgen32e/rdtsc.h"
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#include "libc/time/clockstonanos.internal.h"
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void _spinlock_debug_1(void *lockptr, const char *lockname, const char *file,
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int line, const char *func) {
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unsigned i;
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uint64_t ts1, ts2;
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int me, owner, *lock = lockptr;
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me = gettid();
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owner = 0;
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if (!_lockcmpxchgp(lock, &owner, me)) {
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if (owner == me) {
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kprintf("%s:%d: warning: possible re-entry on lock %s in %s()\n", file,
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line, lockname, func);
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}
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i = 0;
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ts1 = rdtsc();
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for (;;) {
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owner = 0;
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if (_lockcmpxchgp(lock, &owner, me)) break;
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ts2 = rdtsc();
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if (ClocksToNanos(ts1, ts2) > 1000000000ul) {
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ts1 = ts2;
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kprintf("%s:%d: warning: slow lock on %s in %s()\n", file, line,
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lockname, func);
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}
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if (++i & 7) {
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__builtin_ia32_pause();
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} else {
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sched_yield();
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}
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}
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}
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}
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