56 lines
1.3 KiB
Go
56 lines
1.3 KiB
Go
// Copyright 2018 The gVisor Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package fs
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import (
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"fmt"
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"sync"
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)
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// DirentCacheLimiter acts as a global limit for all dirent caches in the
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// process.
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//
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// +stateify savable
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type DirentCacheLimiter struct {
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mu sync.Mutex `state:"nosave"`
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max uint64
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count uint64 `state:"zerovalue"`
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}
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// NewDirentCacheLimiter creates a new DirentCacheLimiter.
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func NewDirentCacheLimiter(max uint64) *DirentCacheLimiter {
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return &DirentCacheLimiter{max: max}
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}
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func (d *DirentCacheLimiter) tryInc() bool {
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d.mu.Lock()
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if d.count >= d.max {
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d.mu.Unlock()
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return false
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}
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d.count++
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d.mu.Unlock()
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return true
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}
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func (d *DirentCacheLimiter) dec() {
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d.mu.Lock()
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if d.count == 0 {
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panic(fmt.Sprintf("underflowing DirentCacheLimiter count: %+v", d))
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}
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d.count--
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d.mu.Unlock()
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}
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