forked from Silverfish/proton-bridge
168 lines
3.4 KiB
Go
168 lines
3.4 KiB
Go
// Copyright (c) 2023 Proton AG
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//
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// This file is part of Proton Mail Bridge.
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//
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// Proton Mail Bridge is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// 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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//
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// Proton Mail Bridge 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 General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with Proton Mail Bridge. If not, see <https://www.gnu.org/licenses/>.
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package safe
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import (
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"sync"
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"sync/atomic"
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"golang.org/x/exp/slices"
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)
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var nextMutexID uint64 // nolint:gochecknoglobals
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// Mutex is a mutex that can be locked and unlocked.
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type Mutex interface {
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Lock()
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Unlock()
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getMutexID() uint64
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}
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// NewMutex returns a new mutex.
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func NewMutex() Mutex {
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return &mutex{
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mutexID: atomic.AddUint64(&nextMutexID, 1),
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}
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}
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type mutex struct {
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sync.Mutex
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mutexID uint64
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}
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func (m *mutex) getMutexID() uint64 {
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return m.mutexID
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}
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// RWMutex is a mutex that can be locked and unlocked for reading and writing.
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type RWMutex interface {
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Mutex
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RLock()
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RUnlock()
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}
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// NewRWMutex returns a new read-write mutex.
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func NewRWMutex() RWMutex {
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return &rwMutex{
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mutexID: atomic.AddUint64(&nextMutexID, 1),
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}
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}
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type rwMutex struct {
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sync.RWMutex
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mutexID uint64
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}
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func (m *rwMutex) getMutexID() uint64 {
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return m.mutexID
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}
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// Lock locks one or more mutexes for writing and calls the given function.
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// The mutexes are locked in a deterministic order to avoid deadlocks.
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func Lock(fn func(), m ...Mutex) {
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if len(m) == 0 {
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panic("no mutexes provided")
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}
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slices.SortFunc(m, func(a, b Mutex) bool {
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return a.getMutexID() < b.getMutexID()
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})
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for _, m := range m {
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m.Lock()
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defer m.Unlock()
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}
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fn()
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}
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// LockRet locks one or more mutexes for writing and calls the given function, returning a value.
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func LockRet[T any](fn func() T, m ...Mutex) T {
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var ret T
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Lock(func() {
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ret = fn()
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}, m...)
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return ret
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}
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// LockRetErr locks one or more mutexes for writing and calls the given function, returning a value and an error.
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func LockRetErr[T any](fn func() (T, error), m ...Mutex) (T, error) {
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var ret T
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err := LockRet(func() error {
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var err error
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ret, err = fn()
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return err
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}, m...)
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return ret, err
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}
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// RLock locks one or more mutexes for reading and calls the given function.
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// The mutexes are locked in a deterministic order to avoid deadlocks.
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func RLock(fn func(), m ...RWMutex) {
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if len(m) == 0 {
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panic("no mutexes provided")
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}
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slices.SortFunc(m, func(a, b RWMutex) bool {
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return a.getMutexID() < b.getMutexID()
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})
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for _, m := range m {
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m.RLock()
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defer m.RUnlock()
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}
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fn()
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}
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// RLockRet locks one or more mutexes for reading and calls the given function, returning a value.
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func RLockRet[T any](fn func() T, m ...RWMutex) T {
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var ret T
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RLock(func() {
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ret = fn()
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}, m...)
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return ret
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}
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// RLockRetErr locks one or more mutexes for reading and calls the given function, returning a value and an error.
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func RLockRetErr[T any](fn func() (T, error), m ...RWMutex) (T, error) {
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var err error
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ret := RLockRet(func() T {
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var ret T
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ret, err = fn()
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return ret
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}, m...)
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return ret, err
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}
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