Line data    Source code

       1             : // Copyright 2024 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             : package invariants
       6             : 
       7             : import (
       8             :         "math/rand/v2"
       9             :         "runtime"
      10             : 
      11             :         "github.com/cockroachdb/pebble/internal/buildtags"
      12             : )
      13             : 
      14             : // Enabled is true if we were built with the "invariants" or "race" build tags.
      15             : //
      16             : // Enabled should be used to gate invariant checks that may be expensive. It
      17             : // should not be used to unconditionally alter a code path significantly (e.g.
      18             : // wrapping an iterator - see #3678); Sometimes() should be used instead so that
      19             : // the production code path gets test coverage as well.
      20             : const Enabled = buildtags.Race || buildtags.Invariants
      21             : 
      22             : // RaceEnabled is true if we were built with the "race" build tag.
      23             : const RaceEnabled = buildtags.Race
      24             : 
      25             : // Sometimes returns true percent% of the time if invariants are Enabled (i.e.
      26             : // we were built with the "invariants" or "race" build tags). Otherwise, always
      27             : // returns false.
      28           1 : func Sometimes(percent int) bool {
      29           1 :         return Enabled && rand.Uint32N(100) < uint32(percent)
      30           1 : }
      31             : 
      32             : // UseFinalizers is true if we want to use finalizers for assertions around
      33             : // object lifetime and cleanup. This happens when the invariants or tracing tags
      34             : // are set, but we exclude race builds because we historically ran into some
      35             : // finalizer-related race detector bugs.
      36             : const UseFinalizers = !buildtags.Race && (buildtags.Invariants || buildtags.Tracing)
      37             : 
      38             : // SetFinalizer is a wrapper around runtime.SetFinalizer that is a no-op under
      39             : // race builds or if neither the invariants nor tracing build tags are
      40             : // specified.
      41             : //
      42             : // We exclude race builds because we historically ran into some race detector
      43             : // bugs related to finalizers.
      44             : //
      45             : // This function is a no-op if UseFinalizers is false and it should inline to
      46             : // nothing.
      47           1 : func SetFinalizer(obj, finalizer interface{}) {
      48           1 :         if UseFinalizers {
      49           1 :                 runtime.SetFinalizer(obj, finalizer)
      50           1 :         }
      51             : }