ff5175ec76
The libc monitor facility enables the execution of monitor jobs by the main thread when the monitor pool was charged. In comparison to the current suspend/resume_all mechanism the main thread iterates over all job functions in contrast to waking up all threads to check their conditions by themselves. Threads are only woken up if the completion condition was met. This commit is the result of a collaboration with Christian Prochaska. Many thanks for your support, Christian. Fixes #3550
73 lines
1.8 KiB
C++
73 lines
1.8 KiB
C++
/*
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* \brief Libc-internal time utilities
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* \author Christian Helmuth
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* \date 2020-01-29
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*/
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/*
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* Copyright (C) 2020 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU Affero General Public License version 3.
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*/
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#ifndef _LIBC__INTERNAL__TIME_H_
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#define _LIBC__INTERNAL__TIME_H_
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/* libc includes */
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#include <time.h>
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/* libc-internal includes */
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#include <internal/types.h>
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namespace Libc {
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inline uint64_t calculate_relative_timeout_ms(timespec abs_now, timespec abs_timeout);
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}
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/**
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* Calculate relative timeout in milliseconds from 'abs_now' to 'abs_timeout'
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*
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* Returns 0 if timeout already expired.
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*/
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Libc::uint64_t Libc::calculate_relative_timeout_ms(timespec abs_now, timespec abs_timeout)
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{
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enum { S_IN_MS = 1000ULL, S_IN_NS = 1000 * 1000 * 1000ULL };
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if (abs_now.tv_nsec >= S_IN_NS) {
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abs_now.tv_sec += abs_now.tv_nsec / S_IN_NS;
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abs_now.tv_nsec = abs_now.tv_nsec % S_IN_NS;
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}
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if (abs_timeout.tv_nsec >= S_IN_NS) {
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abs_timeout.tv_sec += abs_timeout.tv_nsec / S_IN_NS;
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abs_timeout.tv_nsec = abs_timeout.tv_nsec % S_IN_NS;
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}
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/* check whether absolute timeout is in the past */
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if (abs_now.tv_sec > abs_timeout.tv_sec)
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return 0;
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uint64_t diff_ms = (abs_timeout.tv_sec - abs_now.tv_sec) * S_IN_MS;
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uint64_t diff_ns = 0;
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if (abs_timeout.tv_nsec >= abs_now.tv_nsec)
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diff_ns = abs_timeout.tv_nsec - abs_now.tv_nsec;
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else {
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/* check whether absolute timeout is in the past */
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if (diff_ms == 0)
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return 0;
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diff_ns = S_IN_NS - abs_now.tv_nsec + abs_timeout.tv_nsec;
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diff_ms -= S_IN_MS;
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}
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diff_ms += diff_ns / 1000 / 1000;
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/* if there is any diff then let the timeout be at least 1 MS */
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if (diff_ms == 0 && diff_ns != 0)
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return 1;
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return diff_ms;
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}
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#endif /* _LIBC__INTERNAL__TIME_H_ */
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