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7822917fc2
You can now do things like implement mutexes using futexes in your redbean lua code. This provides the fastest possible inter-process communication for your production systems when SQLite alone as ipc or things like pipes aren't sufficient.
52 lines
3.1 KiB
C
52 lines
3.1 KiB
C
/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
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│vi: set et ft=c ts=8 tw=8 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/atomic.h"
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#include "libc/intrin/atomic.h"
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#include "libc/intrin/extend.internal.h"
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#include "libc/macros.internal.h"
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#include "libc/runtime/memtrack.internal.h"
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#include "libc/sysv/consts/map.h"
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#include "third_party/nsync/common.internal.h"
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#include "third_party/nsync/malloc.internal.h"
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// clang-format off
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static char *nsync_malloc_endptr_;
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static size_t nsync_malloc_total_;
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static atomic_char nsync_malloc_lock_;
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/* nsync_malloc_() is a malloc-like routine used by mutex and condition
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variable code to allocate waiter structs. This allows *NSYNC mutexes
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to be used by malloc(), by providing another, simpler allocator here.
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The intent is that the implicit NULL value here can be overridden by
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a client declaration that uses an initializer. */
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void *nsync_malloc_ (size_t size) {
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char *start;
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size_t offset;
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size = ROUNDUP (size, __BIGGEST_ALIGNMENT__);
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while (atomic_exchange (&nsync_malloc_lock_, 1)) nsync_yield_ ();
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offset = nsync_malloc_total_;
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nsync_malloc_total_ += size;
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start = (char *) kMemtrackNsyncStart;
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if (!nsync_malloc_endptr_) nsync_malloc_endptr_ = start;
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nsync_malloc_endptr_ =
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_extend (start, nsync_malloc_total_, nsync_malloc_endptr_,
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MAP_PRIVATE, kMemtrackNsyncStart + kMemtrackNsyncSize);
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atomic_store_explicit (&nsync_malloc_lock_, 0, memory_order_relaxed);
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return start + offset;
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}
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