CNA-BUG-266: GamerServicesDispatcher::Initialize re-initialises silently when gamer services are already initialised, where XNA 4.0 throws InvalidOperationException

CNA snapshot 009d40f5  ·  Known Issues › Current bugs  ·  source links pinned to 009d40f5

XNA 4.0's GamerServicesDispatcher.Initialize throws InvalidOperationException (GamerServicesAlreadyInitialized) when IsInitialized is true; CNA's Initialize follows FNA, frees the earlier stub gamers and installs four new ones, so a second call succeeds.

Identifier

CNA-BUG-266

Category

Bug

Subsystem

Networking & gamer services

Status

Open

Verified against

CNA 009d40f5 (009d40f5dd085c4e674d3479675fac84b12b3e0a)

Severity

Low (a triage suggestion, not a project priority)

Evidence basis

Source-verified: read at TARGET, not executed

Tests touching this area

Yes: see Current tests

Affected contract

Microsoft::Xna::Framework::GamerServices::GamerServicesDispatcher::Initialize(System::IServiceProvider&)

Expected behaviour

XNA 4.0 (read from the decompiled genuine Microsoft.Xna.Framework.GamerServices assembly) begins GamerServicesDispatcher.Initialize with if (IsInitialized) throw new InvalidOperationException(GamerServicesAlreadyInitialized), so initialising twice is a programming error that is reported. CNA's rule is that XNA 4.0 wins where FNA and XNA disagree.

Actual behaviour at TARGET

GamerServicesDispatcher::Initialize sets isInitialized_ without checking it, frees the previous call's stub gamers and installs four new ones; its comment records that a second call used to leak the first call's gamers and now frees them, so re-initialisation is treated as a supported path. A game that creates a GamerServicesComponent and also calls Initialize itself, or two components, therefore gets no exception where an XNA program would.

Source locations

• modules/gamer-services/src/Xna/GamerServicesDispatcher.cpp — Initialize: no already-initialised check; frees and rebuilds the stub gamers

Evidence

Read at 009d40f5 against the decompiled XNA 4.0 GamerServicesDispatcher.Initialize; nothing was executed. Noted by the D4 dismissal reviewer outside its candidates and re-verified by the orchestrator. CNA-BUG-166 covers what the re-initialisation deletes; this entry covers the missing exception.

Independent re-verification: XNA's GamerServicesComponent.Initialize calls GamerServicesDispatcher.Initialize unguarded, so two components throw in XNA too; the documented exception is InvalidOperationException (“the gamer services functionality is already initialized”).

Focused reproduction

No focused reproduction is known. Nothing has been invented here; the evidence above is what exists.

Current tests

One CNA test pins the opposite behaviour: GamerServicesDispatcherHangRegressionTest.SecondInitializeDoesNotLeakThePreviousFourGamers runs the dispatcher harness in --mode=initialize-leak-check, which calls Initialize a second time and requires it to succeed and free the four earlier gamers; no test asserts that a second call throws. A fix has to rewrite that test as well as add the check.

Regression test

Call GamerServicesDispatcher::Initialize twice and expect InvalidOperationException on the second call (and adjust the code that relies on re-initialisation).

Blast radius

XNA programs that initialise gamer services twice by mistake are not told; a program that relied on the exception to detect double initialisation behaves differently. Single initialisation, the normal case, is unaffected.

Workaround

Initialise gamer services exactly once (for example only through a GamerServicesComponent).