gpui: Add Global marker trait (#7095)

This should prevent a class of bugs where one queries the wrong type of
global, which results in oddities at runtime.

Release Notes:

- N/A

---------

Co-authored-by: Marshall <marshall@zed.dev>
Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>

crates/client/Cargo.toml

@@ -18,6 +18,7 @@ collections = { path = "../collections" }
 db = { path = "../db" }
 gpui = { path = "../gpui" }
 util = { path = "../util" }
+release_channel = { path = "../release_channel" }
 rpc = { path = "../rpc" }
 text = { path = "../text" }
 settings = { path = "../settings" }

crates/client/src/client.rs

@@ -15,13 +15,14 @@ use futures::{
     TryFutureExt as _, TryStreamExt,
 };
 use gpui::{
-    actions, AnyModel, AnyWeakModel, AppContext, AsyncAppContext, Model, SemanticVersion, Task,
-    WeakModel,
+    actions, AnyModel, AnyWeakModel, AppContext, AsyncAppContext, Global, Model, SemanticVersion,
+    Task, WeakModel,
 };
 use lazy_static::lazy_static;
 use parking_lot::RwLock;
 use postage::watch;
 use rand::prelude::*;
+use release_channel::ReleaseChannel;
 use rpc::proto::{AnyTypedEnvelope, EntityMessage, EnvelopedMessage, PeerId, RequestMessage};
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
@@ -41,8 +42,7 @@ use std::{
 use telemetry::Telemetry;
 use thiserror::Error;
 use url::Url;
-use util::http::HttpClient;
-use util::{channel::ReleaseChannel, http::ZedHttpClient};
+use util::http::{HttpClient, ZedHttpClient};
 use util::{ResultExt, TryFutureExt};
 
 pub use rpc::*;
@@ -149,6 +149,10 @@ pub fn init(client: &Arc<Client>, cx: &mut AppContext) {
     });
 }
 
+struct GlobalClient(Arc<Client>);
+
+impl Global for GlobalClient {}
+
 pub struct Client {
     id: AtomicU64,
     peer: Arc<Peer>,
@@ -483,6 +487,13 @@ impl Client {
         self
     }
 
+    pub fn global(cx: &AppContext) -> Arc<Self> {
+        cx.global::<GlobalClient>().0.clone()
+    }
+    pub fn set_global(client: Arc<Client>, cx: &mut AppContext) {
+        cx.set_global(GlobalClient(client))
+    }
+
     pub fn user_id(&self) -> Option<u64> {
         self.state
             .read()
@@ -996,7 +1007,10 @@ impl Client {
         credentials: &Credentials,
         cx: &AsyncAppContext,
     ) -> Task<Result<Connection, EstablishConnectionError>> {
-        let release_channel = cx.try_read_global(|channel: &ReleaseChannel, _| *channel);
+        let release_channel = cx
+            .update(|cx| ReleaseChannel::try_global(cx))
+            .ok()
+            .flatten();
 
         let request = Request::builder()
             .header(

crates/client/src/telemetry.rs

@@ -5,6 +5,7 @@ use chrono::{DateTime, Utc};
 use futures::Future;
 use gpui::{AppContext, AppMetadata, BackgroundExecutor, Task};
 use parking_lot::Mutex;
+use release_channel::ReleaseChannel;
 use serde::Serialize;
 use settings::{Settings, SettingsStore};
 use std::{env, io::Write, mem, path::PathBuf, sync::Arc, time::Duration};
@@ -15,7 +16,7 @@ use tempfile::NamedTempFile;
 use util::http::{HttpClient, ZedHttpClient};
 #[cfg(not(debug_assertions))]
 use util::ResultExt;
-use util::{channel::ReleaseChannel, TryFutureExt};
+use util::TryFutureExt;
 
 use self::event_coalescer::EventCoalescer;
 
@@ -143,9 +144,8 @@ const FLUSH_INTERVAL: Duration = Duration::from_secs(60 * 5);
 
 impl Telemetry {
     pub fn new(client: Arc<ZedHttpClient>, cx: &mut AppContext) -> Arc<Self> {
-        let release_channel = cx
-            .try_global::<ReleaseChannel>()
-            .map(|release_channel| release_channel.display_name());
+        let release_channel =
+            ReleaseChannel::try_global(cx).map(|release_channel| release_channel.display_name());
 
         TelemetrySettings::register(cx);