improve the TaskGroup API

the TaskGroup now holds an Executor instead of passing it when calling
its spawn method

also, define a global executor `Executor<'static>` and use static
lifetime instead of a lifetime placeholder

This improvement simplify the code for spawning a new task. There is no
need to pass the executor around.

1 files changed, 4 insertions, 1 deletions

diff --git a/p2p/src/protocol.rs b/p2p/src/protocol.rs
index 515efc6..770b695 100644
--- a/p2p/src/protocol.rs
+++ b/p2p/src/protocol.rs
@@ -87,8 +87,11 @@ impl EventValue for ProtocolEvent {
 ///     let peer_id = PeerID::random();
 ///     let config = Config::default();
 ///
+///     // Create a new Executor
+///     let ex = Arc::new(Executor::new());
+///
 ///     // Create a new Backend
-///     let backend = Backend::new(peer_id, config);
+///     let backend = Backend::new(peer_id, config, ex);
 ///
 ///     // Attach the NewProtocol
 ///     let c = move |peer| NewProtocol::new(peer);