41 lines
941 B
V
41 lines
941 B
V
// Copyright (c) 2019-2020 Alexander Medvednikov. All rights reserved.
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// Use of this source code is governed by an MIT license
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// that can be found in the LICENSE file.
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module sync
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// [init_with=new_waitgroup] // TODO: implement support for init_with struct attribute, and disallow WaitGroup{} from outside the sync.new_waitgroup() function.
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pub struct WaitGroup {
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mut:
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mu &Mutex = &Mutex(0)
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active int
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}
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pub fn new_waitgroup() &WaitGroup {
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return &WaitGroup{mu: sync.new_mutex() }
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}
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pub fn (wg mut WaitGroup) add(delta int) {
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wg.mu.lock()
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wg.active += delta
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wg.mu.unlock()
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if wg.active < 0 {
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panic('Negative number of jobs in waitgroup')
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}
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}
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pub fn (wg mut WaitGroup) done() {
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wg.add(-1)
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}
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pub fn (wg &WaitGroup) wait() {
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for wg.active > 0 {
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// Do not remove this, busy empty loops are optimized
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// with -prod by some compilers, see issue #2874
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$if windows {
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C.Sleep(1)
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} $else {
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C.usleep(1000)
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}
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}
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}
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