Line data    Source code

       1             : // Copyright 2020 The LevelDB-Go and Pebble Authors. All rights reserved. Use
       2             : // of this source code is governed by a BSD-style license that can be found in
       3             : // the LICENSE file.
       4             : 
       5             : //go:build invariants || race
       6             : // +build invariants race
       7             : 
       8             : package invariants
       9             : 
      10             : // Enabled is true if we were built with the "invariants" or "race" build tags.
      11             : const Enabled = true
      12             : 
      13             : // CloseChecker is used to check that objects are closed exactly once.
      14             : type CloseChecker struct {
      15             :         closed bool
      16             : }
      17             : 
      18             : // Close panics if called twice on the same object (if we were built with the
      19             : // "invariants" or "race" build tags).
      20           1 : func (d *CloseChecker) Close() {
      21           1 :         if d.closed {
      22           0 :                 // Note: to debug a double-close, you can add a stack field to CloseChecker
      23           0 :                 // and set it to string(debug.Stack()) in Close, then print that in this
      24           0 :                 // panic.
      25           0 :                 panic("double close")
      26             :         }
      27           1 :         d.closed = true
      28             : }
      29             : 
      30             : // AssertClosed panics in invariant builds if Close was not called.
      31           0 : func (d *CloseChecker) AssertClosed() {
      32           0 :         if !d.closed {
      33           0 :                 panic("not closed")
      34             :         }
      35             : }
      36             : 
      37             : // AssertNotClosed panics in invariant builds if Close was called.
      38           0 : func (d *CloseChecker) AssertNotClosed() {
      39           0 :         if d.closed {
      40           0 :                 panic("closed")
      41             :         }
      42             : }