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35 lines
1.2 KiB
Go
35 lines
1.2 KiB
Go
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/*
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Copyright 2019 The Kubernetes Authors.
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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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http://www.apache.org/licenses/LICENSE-2.0
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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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*/
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package promise
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// WriteOnce represents a variable that is initially not set and can
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// be set once and is readable. This is the common meaning for
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// "promise".
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type WriteOnce interface {
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// Get reads the current value of this variable. If this
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// variable is not set yet then this call blocks until this
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// variable gets a value.
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Get() interface{}
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// Set normally writes a value into this variable, unblocks every
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// goroutine waiting for this variable to have a value, and
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// returns true. In the unhappy case that this variable is
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// already set, this method returns false without modifying the
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// variable's value.
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Set(interface{}) bool
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}
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