feat(sdk): Add Client::cross_proces_store_locks_holder_name().

This patch adds `ClientInner::cross_process_store_locks_holder_name` and
its public method `Client::cross_process_store_locks_holder_name`. This
patch also adds `ClientBuilder::cross_process_store_locks_holider_name`
to configure this value.

crates/matrix-sdk/src/client/builder/mod.rs

@@ -101,6 +101,7 @@ pub struct ClientBuilder {
     room_key_recipient_strategy: CollectStrategy,
     #[cfg(feature = "e2e-encryption")]
     decryption_trust_requirement: TrustRequirement,
+    cross_process_store_locks_holder_name: String,
 }
 
 impl ClientBuilder {
@@ -122,6 +123,7 @@ impl ClientBuilder {
             room_key_recipient_strategy: Default::default(),
             #[cfg(feature = "e2e-encryption")]
             decryption_trust_requirement: TrustRequirement::Untrusted,
+            cross_process_store_locks_holder_name: "main".to_owned(),
         }
     }
 
@@ -424,6 +426,20 @@ impl ClientBuilder {
         self
     }
 
+    /// Set the cross-process store locks holder name.
+    ///
+    /// The SDK provides cross-process store locks (see
+    /// [`matrix_sdk_common::store_locks::CrossProcessStoreLock`]). The
+    /// `holder_name` will be the value used for all cross-process store locks
+    /// used by the `Client` being built.
+    ///
+    /// If 2 concurrent `Client`s are running in 2 different process, this
+    /// method must be called with different `hold_name` values.
+    pub fn cross_process_store_locks_holder_name(mut self, holder_name: String) -> Self {
+        self.cross_process_store_locks_holder_name = holder_name;
+        self
+    }
+
     /// Create a [`Client`] with the options set on this builder.
     ///
     /// # Errors
@@ -529,6 +545,7 @@ impl ClientBuilder {
             send_queue,
             #[cfg(feature = "e2e-encryption")]
             self.encryption_settings,
+            self.cross_process_store_locks_holder_name,
         )
         .await;
 
@@ -1129,4 +1146,27 @@ pub(crate) mod tests {
             object
         })
     }
+
+    #[async_test]
+    async fn test_cross_process_lock_stores_holder_name() {
+        {
+            let homeserver = make_mock_homeserver().await;
+            let client =
+                ClientBuilder::new().homeserver_url(homeserver.uri()).build().await.unwrap();
+
+            assert_eq!(client.cross_process_lock_stores_holder_name(), "main");
+        }
+
+        {
+            let homeserver = make_mock_homeserver().await;
+            let client = ClientBuilder::new()
+                .homeserver_url(homeserver.uri())
+                .cross_process_store_locks_holder_name("foo".to_owned())
+                .build()
+                .await
+                .unwrap();
+
+            assert_eq!(client.cross_process_lock_stores_holder_name(), "foo");
+        }
+    }
 }

crates/matrix-sdk/src/client/mod.rs

@@ -274,6 +274,17 @@ pub(crate) struct ClientInner {
     /// deduplicate multiple calls to a method.
     pub(crate) locks: ClientLocks,
 
+    /// The cross-process store locks holder name.
+    ///
+    /// The SDK provides cross-process store locks (see
+    /// [`matrix_sdk_common::store_locks::CrossProcessStoreLock`]). The
+    /// `holder_name` is the value used for all cross-process store locks
+    /// used by this `Client`.
+    ///
+    /// If multiple `Client`s are running in different processes, this
+    /// value MUST be different for each `Client`.
+    cross_process_store_locks_holder_name: String,
+
     /// A mapping of the times at which the current user sent typing notices,
     /// keyed by room.
     pub(crate) typing_notice_times: StdRwLock<BTreeMap<OwnedRoomId, Instant>>,
@@ -340,6 +351,7 @@ impl ClientInner {
         event_cache: OnceCell<EventCache>,
         send_queue: Arc<SendQueueData>,
         #[cfg(feature = "e2e-encryption")] encryption_settings: EncryptionSettings,
+        cross_process_store_locks_holder_name: String,
     ) -> Arc<Self> {
         let client = Self {
             server,
@@ -350,6 +362,7 @@ impl ClientInner {
             http_client,
             base_client,
             locks: Default::default(),
+            cross_process_store_locks_holder_name,
             server_capabilities: RwLock::new(server_capabilities),
             typing_notice_times: Default::default(),
             event_handlers: Default::default(),
@@ -424,6 +437,16 @@ impl Client {
         &self.inner.locks
     }
 
+    /// The cross-process store locks holder name.
+    ///
+    /// The SDK provides cross-process store locks (see
+    /// [`matrix_sdk_common::store_locks::CrossProcessStoreLock`]). The
+    /// `holder_name` is the value used for all cross-process store locks
+    /// used by this `Client`.
+    pub fn cross_process_lock_stores_holder_name(&self) -> &str {
+        &self.inner.cross_process_store_locks_holder_name
+    }
+
     /// Change the homeserver URL used by this client.
     ///
     /// # Arguments
@@ -2217,6 +2240,7 @@ impl Client {
                 self.inner.send_queue_data.clone(),
                 #[cfg(feature = "e2e-encryption")]
                 self.inner.e2ee.encryption_settings,
+                self.inner.cross_process_store_locks_holder_name.clone(),
             )
             .await,
         };