f3245d63a0
The header file was introduced by fbcc3e5 ("qemu-thread: optimize QemuLockCnt
with futexes on Linux", 2017-01-16) without header guards. Add them.
Signed-off-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
42 lines
894 B
C
42 lines
894 B
C
/*
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* Wrappers around Linux futex syscall
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*
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* Copyright Red Hat, Inc. 2017
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*
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* Author:
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* Paolo Bonzini <pbonzini@redhat.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*
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*/
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#ifndef QEMU_FUTEX_H
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#define QEMU_FUTEX_H
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#include <sys/syscall.h>
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#include <linux/futex.h>
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#define qemu_futex(...) syscall(__NR_futex, __VA_ARGS__)
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static inline void qemu_futex_wake(void *f, int n)
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{
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qemu_futex(f, FUTEX_WAKE, n, NULL, NULL, 0);
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}
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static inline void qemu_futex_wait(void *f, unsigned val)
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{
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while (qemu_futex(f, FUTEX_WAIT, (int) val, NULL, NULL, 0)) {
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switch (errno) {
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case EWOULDBLOCK:
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return;
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case EINTR:
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break; /* get out of switch and retry */
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default:
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abort();
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}
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}
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}
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#endif /* QEMU_FUTEX_H */
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