4 files changed, 30 insertions, 2 deletions
diff --git a/clang-tools-extra/clangd/ClangdServer.cpp b/clang-tools-extra/clangd/ClangdServer.cpp
index cd1fb33efe6..8da5dec414f 100644
--- a/clang-tools-extra/clangd/ClangdServer.cpp
+++ b/clang-tools-extra/clangd/ClangdServer.cpp
@@ -482,8 +482,15 @@ void ClangdServer::onFileEvent(const DidChangeWatchedFilesParams &Params) {
 
 void ClangdServer::workspaceSymbols(
     StringRef Query, int Limit, Callback<std::vector<SymbolInformation>> CB) {
-  CB(clangd::getWorkspaceSymbols(Query, Limit, Index,
-                                 WorkspaceRoot.getValueOr("")));
+  std::string QueryCopy = Query;
+  WorkScheduler.run(
+      "getWorkspaceSymbols",
+      Bind(
+          [QueryCopy, Limit, this](decltype(CB) CB) {
+            CB(clangd::getWorkspaceSymbols(QueryCopy, Limit, Index,
+                                           WorkspaceRoot.getValueOr("")));
+          },
+          std::move(CB)));
 }
 
 void ClangdServer::documentSymbols(
diff --git a/clang-tools-extra/clangd/TUScheduler.cpp b/clang-tools-extra/clangd/TUScheduler.cpp
index 0c5c6fbdb69..63e9c019c5b 100644
--- a/clang-tools-extra/clangd/TUScheduler.cpp
+++ b/clang-tools-extra/clangd/TUScheduler.cpp
@@ -720,6 +720,12 @@ void TUScheduler::remove(PathRef File) {
          File);
 }
 
+void TUScheduler::run(StringRef Name, unique_function<void()> Action) {
+  if (!PreambleTasks)
+    return Action();
+  PreambleTasks->runAsync(Name, std::move(Action));
+}
+
 void TUScheduler::runWithAST(
     StringRef Name, PathRef File,
     unique_function<void(Expected<InputsAndAST>)> Action) {
diff --git a/clang-tools-extra/clangd/TUScheduler.h b/clang-tools-extra/clangd/TUScheduler.h
index bfe495e2d4a..da3d5253343 100644
--- a/clang-tools-extra/clangd/TUScheduler.h
+++ b/clang-tools-extra/clangd/TUScheduler.h
@@ -108,6 +108,9 @@ public:
   /// resources.
   void remove(PathRef File);
 
+  /// Schedule an async task with no dependencies.
+  void run(llvm::StringRef Name, llvm::unique_function<void()> Action);
+
   /// Schedule an async read of the AST. \p Action will be called when AST is
   /// ready. The AST passed to \p Action refers to the version of \p File
   /// tracked at the time of the call, even if new updates are received before
diff --git a/clang-tools-extra/unittests/clangd/TUSchedulerTests.cpp b/clang-tools-extra/unittests/clangd/TUSchedulerTests.cpp
index 936a790c884..125e6be4781 100644
--- a/clang-tools-extra/unittests/clangd/TUSchedulerTests.cpp
+++ b/clang-tools-extra/unittests/clangd/TUSchedulerTests.cpp
@@ -532,6 +532,18 @@ TEST_F(TUSchedulerTests, NoChangeDiags) {
   ASSERT_TRUE(S.blockUntilIdle(timeoutSeconds(10)));
 }
 
+TEST_F(TUSchedulerTests, Run) {
+  TUScheduler S(/*AsyncThreadsCount=*/getDefaultAsyncThreadsCount(),
+                /*StorePreambleInMemory=*/true, /*ASTCallbacks=*/nullptr,
+                /*UpdateDebounce=*/std::chrono::steady_clock::duration::zero(),
+                ASTRetentionPolicy());
+  std::atomic<int> Counter(0);
+  S.run("add 1", [&] { ++Counter; });
+  S.run("add 2", [&] { Counter += 2; });
+  ASSERT_TRUE(S.blockUntilIdle(timeoutSeconds(10)));
+  EXPECT_EQ(Counter.load(), 3);
+}
+
 } // namespace
 } // namespace clangd
 } // namespace clang