ProtectedconstructorReadonlyShutdownOptional human-readable identifier surfaced in shutdown logs and used for
de-duplication when Register is called repeatedly with the same instance
but no name. Falls back to the constructor name.
StaticInstanceProcess-wide instance, resolved through the Global Object Store rather than a static field.
That distinction matters here specifically: this package is one of the ones that can be loaded twice in a process (a bundled connector copy alongside the standalone one). A static field would then give each copy its OWN registry and its OWN ticker, so samples registered through one would be absent from the other's report — a watchdog that silently under-reports what is in flight, which is worse than no watchdog, because the whole contract is that silence means the process is gone.
The report line, or null when nothing is in flight. Pure — this is what the ticker logs.
Overrides the defaults — the interval, and the clock/timer/log seams the tests drive.
Mirrors AgentRunWatchdog.Configure: a singleton cannot take constructor arguments,
because BaseSingleton returns the stored instance and would discard them.
Restarts the ticker when one is already running, so a changed interval takes effect at once.
Deregisters a sample. Stops the ticker once nothing is left in flight.
The Global Object Store is a place to store global objects that need to be shared across the application. Depending on the execution environment, this could be the window object in a browser, or the global object in a node environment, or something else in other contexts. The key here is that in some cases static variables are not truly shared because it is possible that a given class might have copies of its code in multiple paths in a deployed application. This approach ensures that no matter how many code copies might exist, there is only one instance of the object in question by using the Global Object Store.
Updates an in-flight sample. A key that has already ended is ignored.
Read-only view of what is in flight, for callers that want the numbers at the end.
Drops all in-flight state and stops the ticker. For tests, and for a clean shutdown.
IShutdownable: a diagnostic ticker must not keep firing while the process drains.
Registers a sample and returns the key used to update and end it.
OptionaldeadlineMs: numberEmits one report immediately. Exposed so the ticker and tests drive the same path.
Protected StaticgetReturns the singleton instance of the class. If the instance does not exist, it is created and stored in the Global Object Store. If className is provided it will be used as part of the key in the Global Object Store, otherwise the actual class name will be used. NOTE: the class name used by default is the lowest level of the object hierarchy, so if you have a class that extends another class, the lowest level class name will be used.
OptionalclassName: string
Implemented by long-lived singletons (engines, services) that own background work — timers, intervals, subscriptions, sockets, child processes — so a coordinated shutdown can release them. Without this contract,
SIGTERM/SIGINThandlers in the entry point have no way to reach into singleton state to clear timers, leaving the process unable to exit cleanly under load tests, CI runs, or graceful drains.Implementers register themselves with
ShutdownRegistry.Instance.Register(this)(typically in their constructor) and provide aShutdown()that releases the resource synchronously or returns a promise. The registry calls each implementer exactly once perShutdownAll()invocation.