mirror of
https://github.com/jart/cosmopolitan.git
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dd8c4dbd7d
There's now a much stronger level of assurance that signaling on Windows will be atomic, low-latency, low tail latency, and shall never deadlock.
83 lines
3.9 KiB
C
83 lines
3.9 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2023 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/internal.h"
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#include "libc/calls/sig.internal.h"
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#include "libc/calls/struct/sigset.h"
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#include "libc/calls/syscall_support-nt.internal.h"
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#include "libc/intrin/atomic.h"
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#include "libc/intrin/weaken.h"
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#include "libc/nt/enum/wait.h"
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#include "libc/nt/events.h"
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#include "libc/nt/runtime.h"
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#include "libc/nt/synchronization.h"
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#include "libc/sysv/consts/sicode.h"
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#include "libc/sysv/errfuns.h"
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#include "libc/thread/posixthread.internal.h"
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#ifdef __x86_64__
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// returns 0 on timeout or spurious wakeup
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// raises EINTR if a signal delivery interrupted wait operation
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// raises ECANCELED if this POSIX thread was canceled in masked mode
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textwindows static int _park_thread(uint32_t msdelay, sigset_t waitmask,
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bool restartable) {
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struct PosixThread *pt = _pthread_self();
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// perform the wait operation
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intptr_t sigev;
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if (!(sigev = CreateEvent(0, 0, 0, 0)))
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return __winerr();
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pt->pt_event = sigev;
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pt->pt_blkmask = waitmask;
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atomic_store_explicit(&pt->pt_blocker, PT_BLOCKER_EVENT,
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memory_order_release);
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//!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!//
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int sig = 0;
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uint32_t ws = 0;
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if (!_is_canceled() &&
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!(_weaken(__sig_get) && (sig = _weaken(__sig_get)(waitmask))))
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ws = WaitForSingleObject(sigev, msdelay);
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//!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!/!//
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atomic_store_explicit(&pt->pt_blocker, 0, memory_order_release);
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CloseHandle(sigev);
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// recursion is now safe
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if (ws == -1)
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return __winerr();
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int handler_was_called = 0;
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if (sig)
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handler_was_called = _weaken(__sig_relay)(sig, SI_KERNEL, waitmask);
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if (_check_cancel())
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return -1;
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if (handler_was_called & SIG_HANDLED_NO_RESTART)
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return eintr();
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if (handler_was_called & SIG_HANDLED_SA_RESTART)
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if (!restartable)
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return eintr();
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return 0;
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}
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textwindows int _park_norestart(uint32_t msdelay, sigset_t waitmask) {
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return _park_thread(msdelay, waitmask, false);
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}
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textwindows int _park_restartable(uint32_t msdelay, sigset_t waitmask) {
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return _park_thread(msdelay, waitmask, true);
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}
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#endif /* __x86_64__ */
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