mirror of https://github.com/minio/minio.git
87 lines
2.2 KiB
Go
87 lines
2.2 KiB
Go
// Copyright (c) 2015-2022 MinIO, Inc.
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//
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// This file is part of MinIO Object Storage stack
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//
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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 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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// 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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//
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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 <http://www.gnu.org/licenses/>.
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package cmd
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import (
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"context"
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"time"
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)
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var sharedLockTimeout = newDynamicTimeoutWithOpts(dynamicTimeoutOpts{
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timeout: 30 * time.Second,
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minimum: 10 * time.Second,
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retryInterval: time.Minute,
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})
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type sharedLock struct {
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lockContext chan LockContext
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}
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func (ld sharedLock) backgroundRoutine(ctx context.Context, objAPI ObjectLayer, lockName string) {
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for {
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locker := objAPI.NewNSLock(minioMetaBucket, lockName)
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lkctx, err := locker.GetLock(ctx, sharedLockTimeout)
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if err != nil {
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continue
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}
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for {
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select {
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case <-ctx.Done():
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return
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case <-lkctx.Context().Done():
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// The context of the lock is canceled, this can happen
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// if one lock lost quorum due to cluster instability
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// in that case, try to lock again.
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break
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case ld.lockContext <- lkctx:
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// Send the lock context to anyone asking for it
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}
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}
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}
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}
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func mergeContext(ctx1, ctx2 context.Context) (context.Context, context.CancelFunc) {
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ctx, cancel := context.WithCancel(context.Background())
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go func() {
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select {
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case <-ctx1.Done():
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case <-ctx2.Done():
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}
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cancel()
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}()
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return ctx, cancel
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}
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func (ld sharedLock) GetLock(ctx context.Context) (context.Context, context.CancelFunc) {
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select {
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case l := <-ld.lockContext:
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return mergeContext(l.Context(), ctx)
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}
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}
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func newSharedLock(ctx context.Context, objAPI ObjectLayer, lockName string) *sharedLock {
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l := &sharedLock{
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lockContext: make(chan LockContext),
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}
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go l.backgroundRoutine(ctx, objAPI, lockName)
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return l
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}
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