public async Task CollectDisposedSnapshots()
{
var d = new SnapDictionary <int, string>();
d.Test.CollectAuto = false;
// gen 1
d.Set(1, "one");
Assert.AreEqual(1, d.Test.GetValues(1).Length);
Assert.AreEqual(1, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
var s1 = d.CreateSnapshot();
Assert.AreEqual(1, d.Test.LiveGen);
Assert.IsFalse(d.Test.NextGen);
// gen 2
d.Set(1, "two");
Assert.AreEqual(2, d.Test.GetValues(1).Length);
Assert.AreEqual(2, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
var s2 = d.CreateSnapshot();
Assert.AreEqual(2, d.Test.LiveGen);
Assert.IsFalse(d.Test.NextGen);
// gen 3
d.Set(1, "three");
Assert.AreEqual(3, d.Test.GetValues(1).Length);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
var s3 = d.CreateSnapshot();
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsFalse(d.Test.NextGen);
Assert.AreEqual(3, d.SnapCount);
s1.Dispose();
await d.CollectAsync();
Assert.AreEqual(2, d.SnapCount);
Assert.AreEqual(2, d.Test.GetValues(1).Length);
s2.Dispose();
await d.CollectAsync();
Assert.AreEqual(1, d.SnapCount);
Assert.AreEqual(1, d.Test.GetValues(1).Length);
s3.Dispose();
await d.CollectAsync();
Assert.AreEqual(0, d.SnapCount);
Assert.AreEqual(1, d.Test.GetValues(1).Length);
}
public void WriteLocking2()
{
var d = new SnapDictionary <int, string>();
d.Test.CollectAuto = false;
// gen 1
d.Set(1, "one");
Assert.AreEqual(1, d.Test.GetValues(1).Length);
Assert.AreEqual(1, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
var s1 = d.CreateSnapshot();
Assert.AreEqual(1, s1.Gen);
Assert.AreEqual(1, d.Test.LiveGen);
Assert.IsFalse(d.Test.NextGen);
Assert.AreEqual("one", s1.Get(1));
// gen 2
Assert.AreEqual(1, d.Test.GetValues(1).Length);
d.Set(1, "uno");
Assert.AreEqual(2, d.Test.GetValues(1).Length);
Assert.AreEqual(2, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
var s2 = d.CreateSnapshot();
Assert.AreEqual(2, s2.Gen);
Assert.AreEqual(2, d.Test.LiveGen);
Assert.IsFalse(d.Test.NextGen);
Assert.AreEqual("uno", s2.Get(1));
var scopeProvider = GetScopeProvider();
using (d.GetScopedWriteLock(scopeProvider))
{
// gen 3
Assert.AreEqual(2, d.Test.GetValues(1).Length);
d.SetLocked(1, "ein");
Assert.AreEqual(3, d.Test.GetValues(1).Length);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
var s3 = d.CreateSnapshot();
Assert.AreEqual(2, s3.Gen);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen); // has NOT changed when (non) creating snapshot
Assert.AreEqual("uno", s3.Get(1));
}
var s4 = d.CreateSnapshot();
Assert.AreEqual(3, s4.Gen);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsFalse(d.Test.NextGen);
Assert.AreEqual("ein", s4.Get(1));
}
public async Task CollectNulls()
{
var d = new SnapDictionary <int, string>();
d.Test.CollectAuto = false;
// gen 1
d.Set(1, "one");
Assert.AreEqual(1, d.Test.GetValues(1).Length);
d.Set(1, "one");
Assert.AreEqual(1, d.Test.GetValues(1).Length);
d.Set(1, "uno");
Assert.AreEqual(1, d.Test.GetValues(1).Length);
Assert.AreEqual(1, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
var s1 = d.CreateSnapshot();
Assert.AreEqual(1, d.Test.LiveGen);
Assert.IsFalse(d.Test.NextGen);
// gen 2
Assert.AreEqual(1, d.Test.GetValues(1).Length);
d.Set(1, "one");
Assert.AreEqual(2, d.Test.GetValues(1).Length);
d.Set(1, "uno");
Assert.AreEqual(2, d.Test.GetValues(1).Length);
Assert.AreEqual(2, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
var s2 = d.CreateSnapshot();
Assert.AreEqual(2, d.Test.LiveGen);
Assert.IsFalse(d.Test.NextGen);
// gen 3
Assert.AreEqual(2, d.Test.GetValues(1).Length);
d.Set(1, "one");
Assert.AreEqual(3, d.Test.GetValues(1).Length);
d.Set(1, "uno");
Assert.AreEqual(3, d.Test.GetValues(1).Length);
d.Clear(1);
Assert.AreEqual(3, d.Test.GetValues(1).Length);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
var tv = d.Test.GetValues(1);
Assert.AreEqual(3, tv[0].Gen);
Assert.AreEqual(2, tv[1].Gen);
Assert.AreEqual(1, tv[2].Gen);
Assert.AreEqual(0, d.Test.FloorGen);
// nothing to collect
await d.CollectAsync();
GC.KeepAlive(s1);
GC.KeepAlive(s2);
Assert.AreEqual(0, d.Test.FloorGen);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
Assert.AreEqual(2, d.SnapCount);
Assert.AreEqual(3, d.Test.GetValues(1).Length);
// one snapshot to collect
s1 = null;
GC.Collect();
GC.KeepAlive(s2);
await d.CollectAsync();
Assert.AreEqual(1, d.Test.FloorGen);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
Assert.AreEqual(1, d.SnapCount);
Assert.AreEqual(2, d.Test.GetValues(1).Length);
// another snapshot to collect
s2 = null;
GC.Collect();
await d.CollectAsync();
Assert.AreEqual(2, d.Test.FloorGen);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
Assert.AreEqual(0, d.SnapCount);
// and everything is gone?
// no, cannot collect the live gen because we'd need to lock
Assert.AreEqual(1, d.Test.GetValues(1).Length);
d.CreateSnapshot();
GC.Collect();
await d.CollectAsync();
// poof, gone
Assert.AreEqual(0, d.Test.GetValues(1).Length);
}
[Retry(5)] // TODO make this test non-flaky.
public async Task EventuallyCollectNulls()
{
var d = new SnapDictionary <int, string>();
d.Test.CollectAuto = false;
Assert.AreEqual(0, d.Test.GetValues(1).Length);
// gen 1
d.Set(1, "one");
Assert.AreEqual(1, d.Test.GetValues(1).Length);
Assert.AreEqual(1, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
await d.CollectAsync();
var tv = d.Test.GetValues(1);
Assert.AreEqual(1, tv.Length);
Assert.AreEqual(1, tv[0].Gen);
var s = d.CreateSnapshot();
Assert.AreEqual("one", s.Get(1));
Assert.AreEqual(1, d.Test.LiveGen);
Assert.IsFalse(d.Test.NextGen);
Assert.AreEqual(1, d.Count);
Assert.AreEqual(1, d.SnapCount);
Assert.AreEqual(1, d.GenCount);
// gen 2
d.Clear(1);
tv = d.Test.GetValues(1);
Assert.AreEqual(2, tv.Length);
Assert.AreEqual(2, tv[0].Gen);
Assert.AreEqual(2, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
Assert.AreEqual(1, d.Count);
Assert.AreEqual(1, d.SnapCount);
Assert.AreEqual(1, d.GenCount);
// nothing to collect
await d.CollectAsync();
GC.KeepAlive(s);
Assert.AreEqual(2, d.Test.GetValues(1).Length);
Assert.AreEqual(1, d.Count);
Assert.AreEqual(1, d.SnapCount);
Assert.AreEqual(1, d.GenCount);
Assert.AreEqual(2, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
// collect snapshot
// don't collect liveGen+
s = null; // without being disposed
GC.Collect(); // should release the generation reference
await d.CollectAsync();
Assert.AreEqual(1, d.Test.GetValues(1).Length); // "one" value is gone
Assert.AreEqual(1, d.Count); // still have 1 item
Assert.AreEqual(0, d.SnapCount); // snapshot is gone
Assert.AreEqual(0, d.GenCount); // and generation has been dequeued
// liveGen/nextGen
s = d.CreateSnapshot();
s = null;
// collect liveGen
GC.Collect();
Assert.IsTrue(d.Test.GenObjs.TryPeek(out var genObj));
genObj = null;
// in Release mode, it works, but in Debug mode, the weak reference is still alive
// and for some reason we need to do this to ensure it is collected
#if DEBUG
await d.CollectAsync();
GC.Collect();
#endif
Assert.IsTrue(d.Test.GenObjs.TryPeek(out genObj));
Assert.IsFalse(genObj.WeakGenRef.IsAlive); // snapshot is gone, along with its reference
await d.CollectAsync();
Assert.AreEqual(0, d.Test.GetValues(1).Length); // null value is gone
Assert.AreEqual(0, d.Count); // item is gone
Assert.AreEqual(0, d.Test.GenObjs.Count);
Assert.AreEqual(0, d.SnapCount); // snapshot is gone
Assert.AreEqual(0, d.GenCount); // and generation has been dequeued
}
public void DontPanic()
{
var d = new SnapDictionary <int, string>();
d.Test.CollectAuto = false;
Assert.IsNull(d.Test.GenObj);
// gen 1
d.Set(1, "one");
Assert.IsTrue(d.Test.NextGen);
Assert.AreEqual(1, d.Test.LiveGen);
Assert.IsNull(d.Test.GenObj);
var s1 = d.CreateSnapshot();
Assert.IsFalse(d.Test.NextGen);
Assert.AreEqual(1, d.Test.LiveGen);
Assert.IsNotNull(d.Test.GenObj);
Assert.AreEqual(1, d.Test.GenObj.Gen);
Assert.AreEqual(1, s1.Gen);
Assert.AreEqual("one", s1.Get(1));
d.Set(1, "uno");
Assert.IsTrue(d.Test.NextGen);
Assert.AreEqual(2, d.Test.LiveGen);
Assert.IsNotNull(d.Test.GenObj);
Assert.AreEqual(1, d.Test.GenObj.Gen);
var scopeContext = new ScopeContext();
var scopeProvider = GetScopeProvider(scopeContext);
// scopeProvider.Context == scopeContext -> writer is scoped
// writer is scope contextual and scoped
// when disposed, nothing happens
// when the context exists, the writer is released
using (d.GetScopedWriteLock(scopeProvider))
{
d.SetLocked(1, "ein");
Assert.IsTrue(d.Test.NextGen);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsNotNull(d.Test.GenObj);
Assert.AreEqual(2, d.Test.GenObj.Gen);
}
// writer has not released
Assert.IsTrue(d.Test.IsLocked);
Assert.IsNotNull(d.Test.GenObj);
Assert.AreEqual(2, d.Test.GenObj.Gen);
// nothing changed
Assert.IsTrue(d.Test.NextGen);
Assert.AreEqual(3, d.Test.LiveGen);
// panic!
var s2 = d.CreateSnapshot();
Assert.IsTrue(d.Test.IsLocked);
Assert.IsNotNull(d.Test.GenObj);
Assert.AreEqual(2, d.Test.GenObj.Gen);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
// release writer
scopeContext.ScopeExit(true);
Assert.IsFalse(d.Test.IsLocked);
Assert.IsNotNull(d.Test.GenObj);
Assert.AreEqual(2, d.Test.GenObj.Gen);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
var s3 = d.CreateSnapshot();
Assert.IsFalse(d.Test.IsLocked);
Assert.IsNotNull(d.Test.GenObj);
Assert.AreEqual(3, d.Test.GenObj.Gen);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsFalse(d.Test.NextGen);
}
public void ScopeLocking2()
{
var d = new SnapDictionary <int, string>();
var t = d.Test;
t.CollectAuto = false;
// gen 1
d.Set(1, "one");
var s1 = d.CreateSnapshot();
Assert.AreEqual(1, s1.Gen);
Assert.AreEqual("one", s1.Get(1));
d.Set(1, "uno");
var s2 = d.CreateSnapshot();
Assert.AreEqual(2, s2.Gen);
Assert.AreEqual("uno", s2.Get(1));
Assert.AreEqual(2, t.LiveGen);
Assert.IsFalse(t.NextGen);
var scopeContext = new ScopeContext();
var scopeProvider = GetScopeProvider(scopeContext);
using (d.GetScopedWriteLock(scopeProvider))
{
// creating a snapshot in a write-lock does NOT return the "current" content
// it uses the previous snapshot, so new snapshot created only on release
d.SetLocked(1, "ein");
var s3 = d.CreateSnapshot();
Assert.AreEqual(2, s3.Gen);
Assert.AreEqual("uno", s3.Get(1));
// we made some changes, so a next gen is required
Assert.AreEqual(3, t.LiveGen);
Assert.IsTrue(t.NextGen);
Assert.IsTrue(t.IsLocked);
// but live snapshot contains changes
var ls = t.LiveSnapshot;
Assert.AreEqual("ein", ls.Get(1));
Assert.AreEqual(3, ls.Gen);
}
// nothing is committed until scope exits
Assert.AreEqual(3, t.LiveGen);
Assert.IsTrue(t.NextGen);
Assert.IsTrue(t.IsLocked);
// no changes until exit
var s4 = d.CreateSnapshot();
Assert.AreEqual(2, s4.Gen);
Assert.AreEqual("uno", s4.Get(1));
scopeContext.ScopeExit(false);
// now things have changed
Assert.AreEqual(2, t.LiveGen);
Assert.IsFalse(t.NextGen);
Assert.IsFalse(t.IsLocked);
// no changes since not completed
var s5 = d.CreateSnapshot();
Assert.AreEqual(2, s5.Gen);
Assert.AreEqual("uno", s5.Get(1));
}
internal Snapshot(SnapDictionary <TKey, TValue> store, long gen)
{
_store = store;
_gen = gen;
}
public TestHelper(SnapDictionary <TKey, TValue> dict) => _dict = dict;
public async Task CollectValues()
{
var d = new SnapDictionary <int, string>();
d.Test.CollectAuto = false;
// gen 1
d.Set(1, "one");
Assert.AreEqual(1, d.Test.GetValues(1).Length);
d.Set(1, "one");
Assert.AreEqual(1, d.Test.GetValues(1).Length);
d.Set(1, "uno");
Assert.AreEqual(1, d.Test.GetValues(1).Length);
Assert.AreEqual(1, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
SnapDictionary <int, string> .Snapshot s1 = d.CreateSnapshot();
Assert.AreEqual(1, d.Test.LiveGen);
Assert.IsFalse(d.Test.NextGen);
// gen 2
Assert.AreEqual(1, d.Test.GetValues(1).Length);
d.Set(1, "one");
Assert.AreEqual(2, d.Test.GetValues(1).Length);
d.Set(1, "uno");
Assert.AreEqual(2, d.Test.GetValues(1).Length);
Assert.AreEqual(2, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
SnapDictionary <int, string> .Snapshot s2 = d.CreateSnapshot();
Assert.AreEqual(2, d.Test.LiveGen);
Assert.IsFalse(d.Test.NextGen);
// gen 3
Assert.AreEqual(2, d.Test.GetValues(1).Length);
d.Set(1, "one");
Assert.AreEqual(3, d.Test.GetValues(1).Length);
d.Set(1, "uno");
Assert.AreEqual(3, d.Test.GetValues(1).Length);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
SnapDictionary <int, string> .TestHelper.GenVal[] tv = d.Test.GetValues(1);
Assert.AreEqual(3, tv[0].Gen);
Assert.AreEqual(2, tv[1].Gen);
Assert.AreEqual(1, tv[2].Gen);
Assert.AreEqual(0, d.Test.FloorGen);
// nothing to collect
await d.CollectAsync();
GC.KeepAlive(s1);
GC.KeepAlive(s2);
Assert.AreEqual(0, d.Test.FloorGen);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
Assert.AreEqual(2, d.SnapCount);
Assert.AreEqual(3, d.Test.GetValues(1).Length);
// one snapshot to collect
s1 = null;
GC.Collect();
GC.KeepAlive(s2);
await d.CollectAsync();
Assert.AreEqual(1, d.Test.FloorGen);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
Assert.AreEqual(1, d.SnapCount);
Assert.AreEqual(2, d.Test.GetValues(1).Length);
// another snapshot to collect
s2 = null;
GC.Collect();
await d.CollectAsync();
Assert.AreEqual(2, d.Test.FloorGen);
Assert.AreEqual(3, d.Test.LiveGen);
Assert.IsTrue(d.Test.NextGen);
Assert.AreEqual(0, d.SnapCount);
Assert.AreEqual(1, d.Test.GetValues(1).Length);
}
