[Components] Suspicious self.release(RESTComponent)

[drew2a]

During the refactoring (#6335), we found few suspicious places that can indicate potential problems:

tribler/src/tribler-core/tribler_core/components/implementation/gigachannel.py

Line 59 in 2fa959e

await self.release(RESTComponent)

tribler/src/tribler-core/tribler_core/components/implementation/gigachannel_manager.py

Line 39 in 2fa959e

await self.release(RESTComponent)

tribler/src/tribler-core/tribler_core/components/implementation/ipv8.py

Line 132 in 2fa959e

await self.release(RESTComponent)

tribler/src/tribler-core/tribler_core/components/implementation/libtorrent.py

Line 57 in 2fa959e

await self.release(RESTComponent)

tribler/src/tribler-core/tribler_core/components/implementation/metadata_store.py

Line 63 in 2fa959e

await self.release(RESTComponent)

tribler/src/tribler-core/tribler_core/components/implementation/torrent_checker.py

Line 45 in 2fa959e

await self.release(RESTComponent)

Why they are suspicious? Because they call self.release(RESTComponent) manually, but this operation should be performed automatically during Session.shutdown():

class Session:
    async def shutdown(self):
        await gather(*[create_task(component.stop()) for component in self.components.values()])


class Component:
    async def stop(self):
        self.logger.info("Waiting for other components to release me")
        await self.unused.wait()
        self.logger.info("Component free, shutting down")
        await self.shutdown()
        self.stopped = True
        for dep in list(self.components_used_by_me):
            self._release_instance(dep)
        self.logger.info("Component free, shutting down")
    
    async def release_component(self, dependency: Type[T]):
        dep = dependency.instance()
        if dep:
            self._release_instance(dep)

    def _release_instance(self, dep: Component):
        assert dep in self.components_used_by_me
        self.components_used_by_me.discard(dep)
        dep.in_use_by.discard(self)
        if not dep.in_use_by:
            dep.unused.set()

[kozlovsky]

Fixed in #6381 (a5c774a)