56 lines
1.4 KiB
Go
56 lines
1.4 KiB
Go
/*
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Timelinize
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Copyright (c) 2013 Matthew Holt
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU Affero General Public License as published
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by the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Affero General Public License for more details.
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You should have received a copy of the GNU Affero General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>.
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*/
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package timeline
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import "sync"
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// Modified from https://medium.com/@petrlozhkin/kmutex-lock-mutex-by-unique-id-408467659c24
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type mapMutex struct {
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cond *sync.Cond
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set map[any]struct{}
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}
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func newMapMutex() *mapMutex {
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return &mapMutex{
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cond: sync.NewCond(new(sync.Mutex)),
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set: make(map[any]struct{}),
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}
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}
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func (mmu *mapMutex) Lock(key any) {
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mmu.cond.L.Lock()
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defer mmu.cond.L.Unlock()
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for mmu.locked(key) {
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mmu.cond.Wait()
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}
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mmu.set[key] = struct{}{}
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}
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func (mmu *mapMutex) Unlock(key any) {
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mmu.cond.L.Lock()
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defer mmu.cond.L.Unlock()
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delete(mmu.set, key)
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mmu.cond.Broadcast()
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}
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func (mmu *mapMutex) locked(key any) (ok bool) {
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_, ok = mmu.set[key]
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return
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}
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